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Sample records for ccr5-restricted hiv-1 envelope

  1. Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

    International Nuclear Information System (INIS)

    Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika

    2007-01-01

    HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1 IIIB infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent

  2. Asn 362 in gp120 contributes to enhanced fusogenicity by CCR5-restricted HIV-1 envelope glycoprotein variants from patients with AIDS

    Directory of Open Access Journals (Sweden)

    Wang Bin

    2007-12-01

    Full Text Available Abstract Background CCR5-restricted (R5 human immunodeficiency virus type 1 (HIV-1 variants cause CD4+ T-cell loss in the majority of individuals who progress to AIDS, but mechanisms underlying the pathogenicity of R5 strains are poorly understood. To better understand envelope glycoprotein (Env determinants contributing to pathogenicity of R5 viruses, we characterized 37 full-length R5 Envs from cross-sectional and longitudinal R5 viruses isolated from blood of patients with asymptomatic infection or AIDS, referred to as pre-AIDS (PA and AIDS (A R5 Envs, respectively. Results Compared to PA-R5 Envs, A-R5 Envs had enhanced fusogenicity in quantitative cell-cell fusion assays, and reduced sensitivity to inhibition by the fusion inhibitor T-20. Sequence analysis identified the presence of Asn 362 (N362, a potential N-linked glycosylation site immediately N-terminal to CD4-binding site (CD4bs residues in the C3 region of gp120, more frequently in A-R5 Envs than PA-R5 Envs. N362 was associated with enhanced fusogenicity, faster entry kinetics, and increased sensitivity of Env-pseudotyped reporter viruses to neutralization by the CD4bs-directed Env mAb IgG1b12. Mutagenesis studies showed N362 contributes to enhanced fusogenicity of most A-R5 Envs. Molecular models indicate N362 is located adjacent to the CD4 binding loop of gp120, and suggest N362 may enhance fusogenicity by promoting greater exposure of the CD4bs and/or stabilizing the CD4-bound Env structure. Conclusion Enhanced fusogenicity is a phenotype of the A-R5 Envs studied, which was associated with the presence of N362, enhanced HIV-1 entry kinetics and increased CD4bs exposure in gp120. N362 contributes to fusogenicity of R5 Envs in a strain dependent manner. Our studies suggest enhanced fusogenicity of A-R5 Envs may contribute to CD4+ T-cell loss in subjects who progress to AIDS whilst harbouring R5 HIV-1 variants. N362 may contribute to this effect in some individuals.

  3. Differential evolution of a CXCR4-using HIV-1 strain in CCR5wt/wt and CCR5∆32/∆32 hosts revealed by longitudinal deep sequencing and phylogenetic reconstruction.

    Science.gov (United States)

    Le, Anh Q; Taylor, Jeremy; Dong, Winnie; McCloskey, Rosemary; Woods, Conan; Danroth, Ryan; Hayashi, Kanna; Milloy, M-J; Poon, Art F Y; Brumme, Zabrina L

    2015-12-03

    Rare individuals homozygous for a naturally-occurring 32 base pair deletion in the CCR5 gene (CCR5∆32/∆32) are resistant to infection by CCR5-using ("R5") HIV-1 strains but remain susceptible to less common CXCR4-using ("X4") strains. The evolutionary dynamics of X4 infections however, remain incompletely understood. We identified two individuals, one CCR5wt/wt and one CCR5∆32/∆32, within the Vancouver Injection Drug Users Study who were infected with a genetically similar X4 HIV-1 strain. While early-stage plasma viral loads were comparable in the two individuals (~4.5-5 log10 HIV-1 RNA copies/ml), CD4 counts in the CCR5wt/wt individual reached a nadir of 250 cells/mm(3) in the CCR5∆32/∆32 individual. Ancestral phylogenetic reconstructions using longitudinal envelope-V3 deep sequences suggested that both individuals were infected by a single transmitted/founder (T/F) X4 virus that differed at only one V3 site (codon 24). While substantial within-host HIV-1 V3 diversification was observed in plasma and PBMC in both individuals, the CCR5wt/wt individual's HIV-1 population gradually reverted from 100% X4 to ~60% R5 over ~4 years whereas the CCR5∆32/∆32 individual's remained consistently X4. Our observations illuminate early dynamics of X4 HIV-1 infections and underscore the influence of CCR5 genotype on HIV-1 V3 evolution.

  4. CCR5 Signal Transduction in Macrophages by Human Immunodeficiency Virus and Simian Immunodeficiency Virus Envelopes

    OpenAIRE

    Arthos, James; Rubbert, Andrea; Rabin, Ronald L.; Cicala, Claudia; Machado, Elizabeth; Wildt, Kathryne; Hanbach, Meredith; Steenbeke, Tavis D.; Swofford, Ruth; Farber, Joshua M.; Fauci, Anthony S.

    2000-01-01

    The capacity of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) envelopes to transduce signals through chemokine coreceptors on macrophages was examined by measuring the ability of recombinant envelope proteins to mobilize intracellular calcium stores. Both HIV and SIV envelopes mobilized calcium via interactions with CCR5. The kinetics of these responses were similar to those observed when macrophages were treated with MIP-1β. Distinct differences in the capacity o...

  5. Involvement of both the V2 and V3 Regions of the CCR5-Tropic Human Immunodeficiency Virus Type 1 Envelope in Reduced Sensitivity to Macrophage Inflammatory Protein 1α

    Science.gov (United States)

    Maeda, Yosuke; Foda, Mohamed; Matsushita, Shuzo; Harada, Shinji

    2000-01-01

    To determine whether C-C chemokines play an important role in the phenotype switch of human immunodeficiency virus (HIV) from CCR5 to CXCR4 usage during the course of an infection in vivo, macrophage inflammatory protein (MIP)-1α-resistant variants were isolated from CCR5-tropic (R5) HIV-1 in vitro. The selected variants displayed reduced sensitivities to MIP-1α (fourfold) through CCR5-expressing CD4-HeLa/long terminal repeat–β-galactosidase (MAGI/CCR5) cells. The variants were also resistant to other natural ligands for CCR5, namely, MIP-1β (>4-fold) and RANTES (regulated upon activation, normal T-cell expressed and secreted) (6-fold). The env sequence analyses revealed that the variants had amino acid substitutions in V2 (valine 166 to methionine) and V3 (serine 303 to glycine), although the same V3 substitution appeared in virus passaged without MIP-1α. A single-round replication assay using a luciferase reporter HIV-1 strain pseudotyped with mutant envelopes confirmed that mutations in both V2 and V3 were necessary to confer the reduced sensitivity to MIP-1α, MIP-1β, and RANTES. However, the double mutant did not switch its chemokine receptor usage from CCR5 to CXCR4, indicating the altered recognition of CCR5 by this mutant. These results indicated that V2 combined with the V3 region of the CCR5-tropic HIV-1 envelope modulates the sensitivity of HIV-1 to C-C chemokines without altering the ability to use chemokine receptors. PMID:10644351

  6. Neutralizing antibody and anti-retroviral drug sensitivities of HIV-1 isolates resistant to small molecule CCR5 inhibitors

    International Nuclear Information System (INIS)

    Pugach, Pavel; Ketas, Thomas J.; Michael, Elizabeth; Moore, John P.

    2008-01-01

    The small molecule CCR5 inhibitors are a new class of drugs for treating infection by human immunodeficiency virus type 1 (HIV-1). They act by binding to the CCR5 co-receptor and preventing its use during HIV-1-cell fusion. Escape mutants can be raised against CCR5 inhibitors in vitro and will arise when these drugs are used clinically. Here, we have assessed the responses of CCR5 inhibitor-resistant viruses to other anti-retroviral drugs that act by different mechanisms, and their sensitivities to neutralizing antibodies (NAbs). The rationale for the latter study is that the resistance pathway for CCR5 inhibitors involves changes in the HIV-1 envelope glycoproteins (Env), which are also targets for NAbs. The escape mutants CC101.19 and D1/85.16 were selected for resistance to AD101 and vicriviroc (VVC), respectively, from the primary R5 HIV-1 isolate CC1/85. Each escape mutant was cross-resistant to other small molecule CCR5 inhibitors (aplaviroc, maraviroc, VVC, AD101 and CMPD 167), but sensitive to protein ligands of CCR5: the modified chemokine PSC-RANTES and the humanized MAb PRO-140. The resistant viruses also retained wild-type sensitivity to the nucleoside reverse transcriptase inhibitor (RTI) zidovudine, the non-nucleoside RTI nevirapine, the protease inhibitor atazanavir and other attachment and fusion inhibitors that act independently of CCR5 (BMS-806, PRO-542 and enfuvirtide). Of note is that the escape mutants were more sensitive than the parental CC1/85 isolate to a subset of neutralizing monoclonal antibodies and to some sera from HIV-1-infected people, implying that sequence changes in Env that confer resistance to CCR5 inhibitors can increase the accessibility of some NAb epitopes. The need to preserve NAb resistance may therefore be a constraint upon how escape from CCR5 inhibitors occurs in vivo

  7. Interaction of small molecule inhibitors of HIV-1 entry with CCR5

    International Nuclear Information System (INIS)

    Seibert, Christoph; Ying Weiwen; Gavrilov, Svetlana; Tsamis, Fotini; Kuhmann, Shawn E.; Palani, Anandan; Tagat, Jayaram R.; Clader, John W.; McCombie, Stuart W.; Baroudy, Bahige M.; Smith, Steven O.; Dragic, Tatjana; Moore, John P.; Sakmar, Thomas P.

    2006-01-01

    The CC-chemokine receptor 5 (CCR5) is the major coreceptor for macrophage-tropic (R5) HIV-1 strains. Several small molecule inhibitors of CCR5 that block chemokine binding and HIV-1 entry are being evaluated as drug candidates. Here we define how CCR5 antagonists TAK-779, AD101 (SCH-350581) and SCH-C (SCH-351125), which inhibit HIV-1 entry, interact with CCR5. Using a mutagenesis approach in combination with a viral entry assay to provide a direct functional read out, we tested predictions based on a homology model of CCR5 and analyzed the functions of more than 30 amino acid residues. We find that a key set of aromatic and aliphatic residues serves as a hydrophobic core for the ligand binding pocket, while E283 is critical for high affinity interaction, most likely by acting as the counterion for a positively charged nitrogen atom common to all three inhibitors. These results provide a structural basis for understanding how specific antagonists interact with CCR5, and may be useful for the rational design of new, improved CCR5 ligands

  8. HIV-1 entry inhibition by small-molecule CCR5 antagonists: A combined molecular modeling and mutant study using a high-throughput assay

    International Nuclear Information System (INIS)

    Labrecque, Jean; Metz, Markus; Lau, Gloria; Darkes, Marilyn C.; Wong, Rebecca S.Y.; Bogucki, David; Carpenter, Bryon; Chen Gang; Li Tongshuang; Nan, Susan; Schols, Dominique; Bridger, Gary J.; Fricker, Simon P.; Skerlj, Renato T.

    2011-01-01

    Based on the attrition rate of CCR5 small molecule antagonists in the clinic the discovery and development of next generation antagonists with an improved pharmacology and safety profile is necessary. Herein, we describe a combined molecular modeling, CCR5-mediated cell fusion, and receptor site-directed mutagenesis approach to study the molecular interactions of six structurally diverse compounds (aplaviroc, maraviroc, vicriviroc, TAK-779, SCH-C and a benzyloxycarbonyl-aminopiperidin-1-yl-butane derivative) with CCR5, a coreceptor for CCR5-tropic HIV-1 strains. This is the first study using an antifusogenic assay, a model of the interaction of the gp120 envelope protein with CCR5. This assay avoids the use of radioactivity and HIV infection assays, and can be used in a high throughput mode. The assay was validated by comparison with other established CCR5 assays. Given the hydrophobic nature of the binding pocket several binding models are suggested which could prove useful in the rational drug design of new lead compounds.

  9. Characterization of the virus-cell interactions by HIV-1 subtype C variants from an antiretroviral therapy-naïve subject with baseline resistance to the CCR5 inhibitor maraviroc

    DEFF Research Database (Denmark)

    Jakobsen, Martin Roelsgaard

    The CCR5 inhibitor maraviroc (MVC) exerts its antiviral activity by binding to- and altering the conformation of the CCR5 extracellular loops such that HIV-1 gp120 no longer recognizes CCR5. Viruses that have become resistant to MVC through long-term in vitro culture, or from treatment failure...... in vivo, can use the MVCbound form of CCR5 for HIV-1 entry via adaptive alterations in gp120. Partial baseline resistance to another CCR5 inhibitor through this mechanism, AD101, has been noted recently in one subject (1). Here, we identified and characterized envelope (Env) clones with baseline...

  10. IFITM Proteins Restrict HIV-1 Infection by Antagonizing the Envelope Glycoprotein

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    Jingyou Yu

    2015-10-01

    Full Text Available The interferon-induced transmembrane (IFITM proteins have been recently shown to restrict HIV-1 and other viruses. Here, we provide evidence that IFITM proteins, particularly IFITM2 and IFITM3, specifically antagonize the HIV-1 envelope glycoprotein (Env, thereby inhibiting viral infection. IFITM proteins interact with HIV-1 Env in viral producer cells, leading to impaired Env processing and virion incorporation. Notably, the level of IFITM incorporation into HIV-1 virions does not strictly correlate with the extent of inhibition. Prolonged passage of HIV-1 in IFITM-expressing T lymphocytes leads to emergence of Env mutants that overcome IFITM restriction. The ability of IFITMs to inhibit cell-to-cell infection can be extended to HIV-1 primary isolates, HIV-2 and SIVs; however, the extent of inhibition appears to be virus-strain dependent. Overall, our study uncovers a mechanism by which IFITM proteins specifically antagonize HIV-1 Env to restrict HIV-1 infection and provides insight into the specialized role of IFITMs in HIV infection.

  11. Oral CCR5 inhibitors: will they make it through?

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    Biswas, Priscilla; Nozza, Silvia; Scarlatti, Gabriella; Lazzarin, Adriano; Tambussi, Giuseppe

    2006-05-01

    The therapeutic armamentarium against HIV has recently gained a drug belonging to a novel class of antiretrovirals, the entry inhibitors. The last decade has driven an in-depth knowledge of the HIV entry process, unravelling the multiple engagements of the HIV envelope proteins with the cellular receptorial complex that is composed of a primary receptor (CD4) and a co-receptor (CCR5 or CXCR4). The vast majority of HIV-infected subjects exhibit biological viral variants that use CCR5 as a co-receptor. Individuals with a mutated CCR5 gene, both homo- and heterozygotes, appear to be healthy. For these and other reasons, CCR5 represents an appealing target for treatment intervention, although certain challenges can not be ignored. Promising small-molecule, orally bioavailable CCR5 antagonists are under development for the treatment of HIV-1 infection.

  12. Prognostic value of a CCR5 defective allele in pediatric HIV-1 infection.

    Science.gov (United States)

    Romiti, M L; Colognesi, C; Cancrini, C; Mas, A; Berrino, M; Salvatori, F; Orlandi, P; Jansson, M; Palomba, E; Plebani, A; Bertran, J M; Hernandez, M; de Martino, M; Amoroso, A; Tovo, P A; Rossi, P; Espanol, T; Scarlatti, G

    2000-01-01

    A deletion of 32 base pairs in the CCR5 gene (delta32 CCR5) has been linked to resistance to HIV-1 infection in exposed adults and to the delay of disease progression in infected adults. To determine the role of delta32 CCR5 in disease progression of HIV-1 infected children born to seropositive mothers, we studied a polymerase chain reaction in 301 HIV-1 infected, 262 HIV-1 exposed-uninfected and 47 HIV-1 unexposed-uninfected children of Spanish and Italian origin. Infected children were further divided into two groups according to their rate of HIV-1 disease progression: rapid progressors who developed severe clinical and/or immunological conditions within the second year of life, and delayed progressors with any other evolution of disease. Among the latter were the long-term, non-progressors (LTNP) who presented with mild or no symptoms of HIV-1 infection above 8 years of age. Viral phenotype was studied for 45 delayed progressors. No correlation was found between delta32 CCR5 and mother-to-child transmission of HIV-1. However, the frequency of the deletion was substantially higher in LTNP, compared with delayed (p = 0.019) and rapid progressors (p = 0.0003). In children carrying the delta32 CCRS mutation, the presence of MT-2 tropic virus isolate was associated with a severe immune suppression (p = 0.028); whereas, the presence of MT-2 negative viruses correlated with LTNP (p = 0.010). Given the rapidity and simplicity of the assay, the delta32 CCR5 mutation may be a useful predictive marker to identify children with delayed disease progression who, consequently, may not require immediate antiretroviral treatment.

  13. Targeting Spare CC Chemokine Receptor 5 (CCR5) as a Principle to Inhibit HIV-1 Entry*

    OpenAIRE

    Jin, Jun; Colin, Philippe; Staropoli, Isabelle; Lima-Fernandes, Evelyne; Ferret, Cécile; Demir, Arzu; Rogée, Sophie; Hartley, Oliver; Randriamampita, Clotilde; Scott, Mark G. H.; Marullo, Stefano; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando; Lagane, Bernard; Brelot, Anne

    2014-01-01

    International audience; : CCR5 binds the chemokines CCL3, CCL4, and CCL5 and is the major coreceptor for HIV-1 entry into target cells. Chemokines are supposed to form a natural barrier against human immunodeficiency virus, type 1 (HIV-1) infection. However, we showed that their antiviral activity is limited by CCR5 adopting low-chemokine affinity conformations at the cell surface. Here, we investigated whether a pool of CCR5 that is not stabilized by chemokines could represent a target for i...

  14. Haplotypes in CCR5-CCR2, CCL3 and CCL5 are associated with natural resistance to HIV-1 infection in a Colombian cohort.

    Science.gov (United States)

    Vega, Jorge A; Villegas-Ospina, Simón; Aguilar-Jiménez, Wbeimar; Rugeles, María T; Bedoya, Gabriel; Zapata, Wildeman

    2017-06-01

    Variants in genes encoding for HIV-1 co-receptors and their natural ligands have been individually associated to natural resistance to HIV-1 infection. However, the simultaneous presence of these variants has been poorly studied. To evaluate the association of single and multilocus haplotypes in genes coding for the viral co-receptors CCR5 and CCR2, and their ligands CCL3 and CCL5, with resistance or susceptibility to HIV-1 infection. Nine variants in CCR5-CCR2, two SNPs in CCL3 and two in CCL5 were genotyped by PCR-RFLP in 35 seropositive (cases) and 49 HIV-1-exposed seronegative Colombian individuals (controls). Haplotypes were inferred using the Arlequin software, and their frequency in individual or combined loci was compared between cases and controls by the chi-square test. A p' value ;0.05 after Bonferroni correction was considered significant. Homozygosis of the human haplogroup (HH) E was absent in controls and frequent in cases, showing a tendency to susceptibility. The haplotypes C-C and T-T in CCL3 were associated with susceptibility (p'=0.016) and resistance (p';0.0001) to HIV-1 infection, respectively. Finally, in multilocus analysis, the haplotype combinations formed by HHC in CCR5-CCR2, T-T in CCL3 and G-C in CCL5 were associated with resistance (p'=0.006). Our results suggest that specific combinations of variants in genes from the same signaling pathway can define an HIV-1 resistant phenotype. Despite our small sample size, our statistically significant associations suggest strong effects; however, these results should be further validated in larger cohorts.

  15. CCR5 Disruption in Induced Pluripotent Stem Cells Using CRISPR/Cas9 Provides Selective Resistance of Immune Cells to CCR5-tropic HIV-1 Virus.

    Science.gov (United States)

    Kang, HyunJun; Minder, Petra; Park, Mi Ae; Mesquitta, Walatta-Tseyon; Torbett, Bruce E; Slukvin, Igor I

    2015-12-15

    The chemokine (C-C motif) receptor 5 (CCR5) serves as an HIV-1 co-receptor and is essential for cell infection with CCR5-tropic viruses. Loss of functional receptor protects against HIV infection. Here, we report the successful targeting of CCR5 in GFP-marked human induced pluripotent stem cells (iPSCs) using CRISPR/Cas9 with single and dual guide RNAs (gRNAs). Following CRISPER/Cas9-mediated gene editing using a single gRNA, 12.5% of cell colonies demonstrated CCR5 editing, of which 22.2% showed biallelic editing as determined by a Surveyor nuclease assay and direct sequencing. The use of dual gRNAs significantly increased the efficacy of CCR5 editing to 27% with a biallelic gene alteration frequency of 41%. To ensure the homogeneity of gene editing within cells, we used single cell sorting to establish clonal iPSC lines. Single cell-derived iPSC lines with homozygous CCR5 mutations displayed the typical characteristics of pluripotent stem cells and differentiated efficiently into hematopoietic cells, including macrophages. Although macrophages from both wild-type and CCR5-edited iPSCs supported CXCR4-tropic virus replication, macrophages from CCR5-edited iPSCs were uniquely resistant to CCR5-tropic virus challenge. This study demonstrates the feasibility of applying iPSC technology for the study of the role of CCR5 in HIV infection in vitro, and generation of HIV-resistant cells for potential therapeutic applications.

  16. The Effects of the Recombinant CCR5 T4 Lysozyme Fusion Protein on HIV-1 Infection.

    Directory of Open Access Journals (Sweden)

    Qingwen Jin

    Full Text Available Insertion of T4 lysozyme (T4L into the GPCR successfully enhanced GPCR protein stability and solubilization. However, the biological functions of the recombinant GPCR protein have not been analyzed.We engineered the CCR5-T4L mutant and expressed and purified the soluble recombinant protein using an E.coli expression system. The antiviral effects of this recombinant protein in THP-1 cell lines, primary human macrophages, and PBMCs from different donors were investigated. We also explored the possible mechanisms underlying the observed antiviral effects.Our data showed the biphasic inhibitory and promotion effects of different concentrations of soluble recombinant CCR5-T4L protein on R5 tropic human immunodeficiency virus-1 (HIV-1 infection in THP-1 cell lines, human macrophages, and PBMCs from clinical isolates. We demonstrated that soluble recombinant CCR5-T4L acts as a HIV-1 co-receptor, interacts with wild type CCR5, down-regulates the surface CCR5 expression in human macrophages, and interacts with CCL5 to inhibit macrophage migration. Using binding assays, we further determined that recombinant CCR5-T4L and [125I]-CCL5 compete for the same binding site on wild type CCR5.Our results suggest that recombinant CCR5-T4L protein marginally promotes HIV-1 infection at low concentrations and markedly inhibits infection at higher concentrations. This recombinant protein may be helpful in the future development of anti-HIV-1 therapeutic agents.

  17. Antigen-driven C–C Chemokine-mediated HIV-1 Suppression by CD4+ T Cells from Exposed Uninfected Individuals Expressing the Wild-type CCR-5 Allele

    Science.gov (United States)

    Furci, Lucinda; Scarlatti, Gabriella; Burastero, Samuele; Tambussi, Giuseppe; Colognesi, Claudia; Quillent, Caroline; Longhi, Renato; Loverro, Patrizia; Borgonovo, Barbara; Gaffi, Davide; Carrow, Emily; Malnati, Mauro; Lusso, Paolo; Siccardi, Antonio G.; Lazzarin, Adriano; Beretta, Alberto

    1997-01-01

    Despite repeated exposure to HIV-1, certain individuals remain persistently uninfected. Such exposed uninfected (EU) people show evidence of HIV-1–specific T cell immunity and, in rare cases, selective resistance to infection by macrophage-tropic strains of HIV-1. The latter has been associated with a 32–base pair deletion in the C–C chemokine receptor gene CCR-5, the major coreceptor of macrophage-tropic strains of HIV-1. We have undertaken an analysis of the HIV-specific T cell responses in 12 EU individuals who were either homozygous for the wild-type CCR-5 allele or heterozygous for the deletion allele (CCR-5Δ32). We have found evidence of an oligoclonal T cell response mediated by helper T cells specific for a conserved region of the HIV-1 envelope. These cells produce very high levels of C–C chemokines when stimulated by the specific antigen and suppress selectively the replication of macrophage-tropic, but not T cell–tropic, strains of HIV-1. These chemokine-producing helper cells may be part of a protective immune response that could be potentially exploited for vaccine development. PMID:9236198

  18. CD4-binding site alterations in CCR5-using HIV-1 envelopes influencing gp120-CD4 interactions and fusogenicity

    International Nuclear Information System (INIS)

    Sterjovski, Jasminka; Churchill, Melissa J.; Roche, Michael; Ellett, Anne; Farrugia, William; Wesselingh, Steven L.; Cunningham, Anthony L.; Ramsland, Paul A.; Gorry, Paul R.

    2011-01-01

    CD4-binding site (CD4bs) alterations in gp120 contribute to different pathophysiological phenotypes of CCR5-using (R5) HIV-1 strains, but the potential structural basis is unknown. Here, we characterized functionally diverse R5 envelope (Env) clones (n = 16) to elucidate potential structural alterations within the gp120 CD4bs that influence Env function. Initially, we showed that the magnitude of gp120-CD4-binding correlates with increased fusogenicity and reduced CD4 dependence. Analysis of three-dimensional gp120 structural models revealed two CD4bs variants, D279 and N362, that were associated with reduced CD4 dependence. Further structural analysis showed that a wider aperture of the predicted CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop, was associated with amino acid alterations within V5 and correlated with increased gp120-CD4 binding and increased fusogenicity. Our results provide evidence that the gp120 V5 loop may alter CD4bs conformation and contribute to increased gp120-CD4 interactions and Env fusogenicity.

  19. Stable gene transfer of CCR5 and CXCR4 siRNAs by sleeping beauty transposon system to confer HIV-1 resistance

    Directory of Open Access Journals (Sweden)

    Akkina Ramesh

    2008-07-01

    Full Text Available Abstract Background Thus far gene therapy strategies for HIV/AIDS have used either conventional retroviral vectors or lentiviral vectors for gene transfer. Although highly efficient, their use poses a certain degree of risk in terms of viral mediated oncogenesis. Sleeping Beauty (SB transposon system offers a non-viral method of gene transfer to avoid this possible risk. With respect to conferring HIV resistance, stable knock down of HIV-1 coreceptors CCR5 and CXCR4 by the use of lentiviral vector delivered siRNAs has proved to be a promising strategy to protect cells from HIV-1 infection. In the current studies our aim is to evaluate the utility of SB system for stable gene transfer of CCR5 and CXCR4 siRNA genes to derive HIV resistant cells as a first step towards using this system for gene therapy. Results Two well characterized siRNAs against the HIV-1 coreceptors CCR5 and CXCR4 were chosen based on their previous efficacy for the SB transposon gene delivery. The siRNA transgenes were incorporated individually into a modified SB transfer plasmid containing a FACS sortable red fluorescence protein (RFP reporter and a drug selectable neomycin resistance gene. Gene transfer was achieved by co-delivery with a construct expressing a hyperactive transposase (HSB5 into the GHOST-R3/X4/R5 cell line, which expresses the major HIV receptor CD4 and and the co-receptors CCR5 and CXCR4. SB constructs expressing CCR5 or CXCR4 siRNAs were also transfected into MAGI-CCR5 or MAGI-CXCR4 cell lines, respectively. Near complete downregulation of CCR5 and CXCR4 surface expression was observed in transfected cells. During viral challenge with X4-tropic (NL4.3 or R5-tropic (BaL HIV-1 strains, the respective transposed cells showed marked viral resistance. Conclusion SB transposon system can be used to deliver siRNA genes for stable gene transfer. The siRNA genes against HIV-1 coreceptors CCR5 and CXCR4 are able to downregulate the respective cell surface proteins

  20. CCR5 antibodies HGS004 and HGS101 preferentially inhibit drug-bound CCR5 infection and restore drug sensitivity of Maraviroc-resistant HIV-1 in primary cells

    International Nuclear Information System (INIS)

    Latinovic, Olga; Reitz, Marvin; Le, Nhut M.; Foulke, James S.; Faetkenheuer, Gerd; Lehmann, Clara; Redfield, Robert R.; Heredia, Alonso

    2011-01-01

    R5 HIV-1 strains resistant to the CCR5 antagonist Maraviroc (MVC) can use drug-bound CCR5. We demonstrate that MVC-resistant HIV-1 exhibits delayed kinetics of coreceptor engagement and fusion during drug-bound versus free CCR5 infection of cell lines. Antibodies directed against the second extracellular loop (ECL2) of CCR5 had greater antiviral activity against MVC-bound compared to MVC-free CCR5 infection. However, in PBMCs, only ECL2 CCR5 antibodies HGS004 and HGS101, but not 2D7, inhibited infection by MVC resistant HIV-1 more potently with MVC-bound than with free CCR5. In addition, HGS004 and HGS101, but not 2D7, restored the antiviral activity of MVC against resistant virus in PBMCs. In flow cytometric studies, CCR5 binding by the HGS mAbs, but not by 2D7, was increased when PBMCs were treated with MVC, suggesting MVC increases exposure of the relevant epitope. Thus, HGS004 and HGS101 have antiviral mechanisms distinct from 2D7 and could help overcome MVC resistance.

  1. Elucidating a Key Anti-HIV-1 and Cancer-Associated Axis: The Structure of CCL5 (Rantes) in Complex with CCR5

    Science.gov (United States)

    Tamamis, Phanourios; Floudas, Christodoulos A.

    2014-06-01

    CCL5 (RANTES) is an inflammatory chemokine which binds to chemokine receptor CCR5 and induces signaling. The CCL5:CCR5 associated chemotactic signaling is of critical biological importance and is a potential HIV-1 therapeutic axis. Several studies provided growing evidence for the expression of CCL5 and CCR5 in non-hematological malignancies. Therefore, the delineation of the CCL5:CCR5 complex structure can pave the way for novel CCR5-targeted drugs. We employed a computational protocol which is primarily based on free energy calculations and molecular dynamics simulations, and report, what is to our knowledge, the first computationally derived CCL5:CCR5 complex structure which is in excellent agreement with experimental findings and clarifies the functional role of CCL5 and CCR5 residues which are associated with binding and signaling. A wealth of polar and non-polar interactions contributes to the tight CCL5:CCR5 binding. The structure of an HIV-1 gp120 V3 loop in complex with CCR5 has recently been derived through a similar computational protocol. A comparison between the CCL5 : CCR5 and the HIV-1 gp120 V3 loop : CCR5 complex structures depicts that both the chemokine and the virus primarily interact with the same CCR5 residues. The present work provides insights into the blocking mechanism of HIV-1 by CCL5.

  2. CCR5 Gene Disruption via Lentiviral Vectors Expressing Cas9 and Single Guided RNA Renders Cells Resistant to HIV-1 Infection

    Science.gov (United States)

    Liu, Jingjing; Zhang, Di; Kimata, Jason T.; Zhou, Paul

    2014-01-01

    CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN) or Transcription activator-like effector nuclease (TALEN). In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9) and single guided RNAs (sgRNAs). We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a single round transduction of lentiviral vectors expressing Cas9 and CCR5 sgRNAs into HIV-1 susceptible human CD4+ cells yields high frequencies of CCR5 gene disruption. CCR5 gene-disrupted cells are not only resistant to R5-tropic HIV-1, including transmitted/founder (T/F) HIV-1 isolates, but also have selective advantage over CCR5 gene-undisrupted cells during R5-tropic HIV-1 infection. Importantly, using T7 endonuclease I assay we did not detect genome mutations at potential off-target sites that are highly homologous to these CCR5 sgRNAs in stably transduced cells even at 84 days post transduction. Thus we conclude that silencing of CCR5 via Cas9 and CCR5-specific sgRNAs could be a viable alternative strategy for engineering resistance against HIV-1. PMID:25541967

  3. Peripheral Blood CCR4+CCR6+ and CXCR3+CCR6+ CD4+ T Cells Are Highly Permissive to HIV-1 Infection

    OpenAIRE

    Gosselin, Annie; Monteiro, Patricia; Chomont, Nicolas; Diaz-Griffero, Felipe; Said, Elias A.; Fonseca, Simone; Wacleche, Vanessa; El-Far, Mohamed; Boulassel, Mohamed-Rachid; Routy, Jean-Pierre; Sekaly, Rafick-Pierre; Ancuta, Petronela

    2009-01-01

    There is limited knowledge on the identity of primary CD4+ T cell subsets selectively targeted by HIV-1 in vivo. In this study, we established a link between HIV permissiveness, phenotype/homing potential, and lineage commitment in primary CD4+ T cells. CCR4+CCR6+, CCR4+CCR6−, CXCR3+CCR6+, and CXCR3+CCR6− T cells expressed cytokines and transcription factors specific for Th17, Th2, Th1Th17, and Th1 lineages, respectively. CCR4+CCR6+ and CXCR3+CCR6+ T cells expressed the HIV coreceptors CCR5 a...

  4. Biased small-molecule ligands for selective inhibition of HIV-1 cell entry via CCR5

    DEFF Research Database (Denmark)

    Berg, Christian; Spiess, Katja; von Lüttichau, Hans Rudolf

    2016-01-01

    Since the discovery of HIV's use of CCR5 as the primary coreceptor in fusion, the focus on developing small-molecule receptor antagonists for inhibition hereof has only resulted in one single drug, Maraviroc. We therefore investigated the possibility of using small-molecule CCR5 agonists as HIV-1...

  5. Bioinformatic analysis of neurotropic HIV envelope sequences identifies polymorphisms in the gp120 bridging sheet that increase macrophage-tropism through enhanced interactions with CCR5

    International Nuclear Information System (INIS)

    Mefford, Megan E.; Kunstman, Kevin; Wolinsky, Steven M.; Gabuzda, Dana

    2015-01-01

    Macrophages express low levels of the CD4 receptor compared to T-cells. Macrophage-tropic HIV strains replicating in brain of untreated patients with HIV-associated dementia (HAD) express Envs that are adapted to overcome this restriction through mechanisms that are poorly understood. Here, bioinformatic analysis of env sequence datasets together with functional studies identified polymorphisms in the β3 strand of the HIV gp120 bridging sheet that increase M-tropism. D197, which results in loss of an N-glycan located near the HIV Env trimer apex, was detected in brain in some HAD patients, while position 200 was estimated to be under positive selection. D197 and T/V200 increased fusion and infection of cells expressing low CD4 by enhancing gp120 binding to CCR5. These results identify polymorphisms in the HIV gp120 bridging sheet that overcome the restriction to macrophage infection imposed by low CD4 through enhanced gp120–CCR5 interactions, thereby promoting infection of brain and other macrophage-rich tissues. - Highlights: • We analyze HIV Env sequences and identify amino acids in beta 3 of the gp120 bridging sheet that enhance macrophage tropism. • These amino acids at positions 197 and 200 are present in brain of some patients with HIV-associated dementia. • D197 results in loss of a glycan near the HIV Env trimer apex, which may increase exposure of V3. • These variants may promote infection of macrophages in the brain by enhancing gp120–CCR5 interactions

  6. Bioinformatic analysis of neurotropic HIV envelope sequences identifies polymorphisms in the gp120 bridging sheet that increase macrophage-tropism through enhanced interactions with CCR5

    Energy Technology Data Exchange (ETDEWEB)

    Mefford, Megan E., E-mail: megan_mefford@hms.harvard.edu [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA (United States); Kunstman, Kevin, E-mail: kunstman@northwestern.edu [Northwestern University Medical School, Chicago, IL (United States); Wolinsky, Steven M., E-mail: s-wolinsky@northwestern.edu [Northwestern University Medical School, Chicago, IL (United States); Gabuzda, Dana, E-mail: dana_gabuzda@dfci.harvard.edu [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA (United States); Department of Neurology (Microbiology and Immunobiology), Harvard Medical School, Boston, MA (United States)

    2015-07-15

    Macrophages express low levels of the CD4 receptor compared to T-cells. Macrophage-tropic HIV strains replicating in brain of untreated patients with HIV-associated dementia (HAD) express Envs that are adapted to overcome this restriction through mechanisms that are poorly understood. Here, bioinformatic analysis of env sequence datasets together with functional studies identified polymorphisms in the β3 strand of the HIV gp120 bridging sheet that increase M-tropism. D197, which results in loss of an N-glycan located near the HIV Env trimer apex, was detected in brain in some HAD patients, while position 200 was estimated to be under positive selection. D197 and T/V200 increased fusion and infection of cells expressing low CD4 by enhancing gp120 binding to CCR5. These results identify polymorphisms in the HIV gp120 bridging sheet that overcome the restriction to macrophage infection imposed by low CD4 through enhanced gp120–CCR5 interactions, thereby promoting infection of brain and other macrophage-rich tissues. - Highlights: • We analyze HIV Env sequences and identify amino acids in beta 3 of the gp120 bridging sheet that enhance macrophage tropism. • These amino acids at positions 197 and 200 are present in brain of some patients with HIV-associated dementia. • D197 results in loss of a glycan near the HIV Env trimer apex, which may increase exposure of V3. • These variants may promote infection of macrophages in the brain by enhancing gp120–CCR5 interactions.

  7. CCR2, CCR5, and CXCL12 variation and HIV/AIDS in Papua New Guinea.

    Science.gov (United States)

    Mehlotra, Rajeev K; Hall, Noemi B; Bruse, Shannon E; John, Bangan; Zikursh, Melinda J Blood; Stein, Catherine M; Siba, Peter M; Zimmerman, Peter A

    2015-12-01

    Polymorphisms in chemokine receptors, serving as HIV co-receptors, and their ligands are among the well-known host genetic factors associated with susceptibility to HIV infection and/or disease progression. Papua New Guinea (PNG) has one of the highest adult HIV prevalences in the Asia-Pacific region. However, information regarding the distribution of polymorphisms in chemokine receptor (CCR5, CCR2) and chemokine (CXCL12) genes in PNG is very limited. In this study, we genotyped a total of nine CCR2-CCR5 polymorphisms, including CCR2 190G >A, CCR5 -2459G >A and Δ32, and CXCL12 801G >A in PNG (n=258), North America (n=184), and five countries in West Africa (n=178). Using this data, we determined previously characterized CCR5 haplotypes. In addition, based on the previously reported associations of CCR2 190, CCR5 -2459, CCR5 open reading frame, and CXCL12 801 genotypes with HIV acquisition and/or disease progression, we calculated composite full risk scores, considering both protective as well as susceptibility effects of the CXCL12 801 AA genotype. We observed a very high frequency of the CCR5 -2459A allele (0.98) in the PNG population, which together with the absence of Δ32 resulted in a very high frequency of the HHE haplotype (0.92). These frequencies were significantly higher than in any other population (all P-valuesnew insights regarding CCR5 variation in the PNG population, and suggest that the collective variation in CCR2, CCR5, and CXCL12 may increase the risk of HIV/AIDS in a large majority of Papua New Guineans. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Adverse effect of the CCR5 promoter -2459A allele on HIV-1 disease progression

    DEFF Research Database (Denmark)

    Knudsen, T B; Kristiansen, T B; Katzenstein, T L

    2001-01-01

    /G transition that has been discovered recently, have also been shown to influence HIV progression. Since genetic linkages make these polymorphisms interdependent variables, the aim of the present study was to isolate and evaluate the effect on HIV disease progression for each of these mutations independently......HIV positive individuals heterozygous for a 32 basepair deletion in the CCR5 encoding gene (CCR5 Delta32) have a reduced number of CCR5 receptors on the cell surface and a slower progression towards AIDS and death. Other human polymorphisms, such as the CCR2 64I and the CCR5 promoter -2459 A...

  9. Chemokine Receptor CCR5 Antagonist Maraviroc: Medicinal Chemistry and Clinical Applications

    Science.gov (United States)

    Xu, Guoyan G.; Guo, Jia; Wu, Yuntao

    2015-01-01

    The human immunodeficiency virus (HIV) causes acquired immumodeficiency syndrome (AIDS), one of the worst global pandemic. The virus infects human CD4 T cells and macrophages, and causes CD4 depletion. HIV enters target cells through the binding of the viral envelope glycoprotein to CD4 and the chemokine coreceptor, CXCR4 or CCR5. In particular, the CCR5-utilizing viruses predominate in the blood during the disease course. CCR5 is expressed on the surface of various immune cells including macrophages, monocytes, microglia, dendric cells, and active memory CD4 T cells. In the human population, the CCR5 genomic mutation, CCR5Δ32, is associated with relative resistance to HIV. These findings paved the way for the discovery and development of CCR5 inhibitors to block HIV transmission and replication. Maraviroc, discovered as a CCR5 antagonist, is the only CCR5 inhibitor that has been approved by both US FDA and the European Medicines Agency (EMA) for treating HIV/AIDS patients. In this review, we summarize the medicinal chemistry and clinical studies of Maraviroc. PMID:25159165

  10. Cryptic nature of a conserved, CD4-inducible V3 loop neutralization epitope in the native envelope glycoprotein oligomer of CCR5-restricted, but not CXCR4-using, primary human immunodeficiency virus type 1 strains.

    Science.gov (United States)

    Lusso, Paolo; Earl, Patricia L; Sironi, Francesca; Santoro, Fabio; Ripamonti, Chiara; Scarlatti, Gabriella; Longhi, Renato; Berger, Edward A; Burastero, Samuele E

    2005-06-01

    The external subunit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env), gp120, contains conserved regions that mediate sequential interactions with two cellular receptor molecules, CD4 and a chemokine receptor, most commonly CCR5 or CXCR4. However, antibody accessibility to such regions is hindered by diverse protective mechanisms, including shielding by variable loops, conformational flexibility and extensive glycosylation. For the conserved neutralization epitopes hitherto described, antibody accessibility is reportedly unrelated to the viral coreceptor usage phenotype. Here, we characterize a novel, conserved gp120 neutralization epitope, recognized by a murine monoclonal antibody (MAb), D19, which is differentially accessible in the native HIV-1 Env according to its coreceptor specificity. The D19 epitope is contained within the third variable (V3) domain of gp120 and is distinct from those recognized by other V3-specific MAbs. To study the reactivity of MAb D19 with the native oligomeric Env, we generated a panel of PM1 cells persistently infected with diverse primary HIV-1 strains. The D19 epitope was conserved in the majority (23/29; 79.3%) of the subtype-B strains tested, as well as in selected strains from other genetic subtypes. Strikingly, in CCR5-restricted (R5) isolates, the D19 epitope was invariably cryptic, although it could be exposed by addition of soluble CD4 (sCD4); epitope masking was dependent on the native oligomeric structure of Env, since it was not observed with the corresponding monomeric gp120 molecules. By contrast, in CXCR4-using strains (X4 and R5X4), the epitope was constitutively accessible. In accordance with these results, R5 isolates were resistant to neutralization by MAb D19, becoming sensitive only upon addition of sCD4, whereas CXCR4-using isolates were neutralized regardless of the presence of sCD4. Other V3 epitopes examined did not display a similar divergence in accessibility based on

  11. Role of HIV-2 envelope in Lv2-mediated restriction

    International Nuclear Information System (INIS)

    Reuter, Sandra; Kaumanns, Patrick; Buschhorn, Sabine B.; Dittmar, Matthias T.

    2005-01-01

    We have characterized envelope protein pseudotyped HIV-2 particles derived from two HIV-2 isolates termed prCBL23 and CBL23 in order to define the role of the envelope protein for the Lv2-mediated restriction to infection. Previously, it has been described that the primary isolate prCBL23 is restricted to infection of several human cell types, whereas the T cell line adapted isolate CBL23 is not restricted in these cell types. Molecular cloning of the two isolates revealed that the env and the gag gene are responsible for the observed phenotype and that this restriction is mediated by Lv2, which is distinct from Ref1/Lv1 (Schmitz, C., Marchant, D., Neil, S.J., Aubin, K., Reuter, S., Dittmar, M.T., McKnight, A., Kizhatil, K., Albritton, L.M., 2004. Lv2, a novel postentry restriction, is mediated by both capsid and envelope. J. Virol. 78 (4), 2006-2016). We generated pseudotyped viruses consisting of HIV-2 (ROD-AΔenv-GFP, ROD-AΔenv-RFP, or ROD-AΔenv-REN) and the prCBL23 or CBL23 envelope proteins as well as chimeric proteins between these envelopes. We demonstrate that a single amino acid exchange at position 74 in the surface unit of CBL23-Env confers restriction to infection. This single point mutation causes tighter CD4 binding, resulting in a less efficient fusion into the cytosol of the restricted cell line. Prevention of endosome formation and prevention of endosome acidification enhance infectivity of the restricted particles for GHOST/X4 cells indicating a degradative lysosomal pathway as a cause for the reduced cytosolic entry. The described restriction to infection of the primary isolate prCBL23 is therefore largely caused by an entry defect. A remaining restriction to infection (19-fold) is preserved when endosomal acidification is prevented. This restriction to infection is also dependent on the presence of the point mutation at position 74 (G74E)

  12. CCL3L1-CCR5 genotype improves the assessment of AIDS Risk in HIV-1-infected individuals.

    Science.gov (United States)

    Kulkarni, Hemant; Agan, Brian K; Marconi, Vincent C; O'Connell, Robert J; Camargo, Jose F; He, Weijing; Delmar, Judith; Phelps, Kenneth R; Crawford, George; Clark, Robert A; Dolan, Matthew J; Ahuja, Sunil K

    2008-09-08

    Whether vexing clinical decision-making dilemmas can be partly addressed by recent advances in genomics is unclear. For example, when to initiate highly active antiretroviral therapy (HAART) during HIV-1 infection remains a clinical dilemma. This decision relies heavily on assessing AIDS risk based on the CD4+ T cell count and plasma viral load. However, the trajectories of these two laboratory markers are influenced, in part, by polymorphisms in CCR5, the major HIV coreceptor, and the gene copy number of CCL3L1, a potent CCR5 ligand and HIV-suppressive chemokine. Therefore, we determined whether accounting for both genetic and laboratory markers provided an improved means of assessing AIDS risk. In a prospective, single-site, ethnically-mixed cohort of 1,132 HIV-positive subjects, we determined the AIDS risk conveyed by the laboratory and genetic markers separately and in combination. Subjects were assigned to a low, moderate or high genetic risk group (GRG) based on variations in CCL3L1 and CCR5. The predictive value of the CCL3L1-CCR5 GRGs, as estimated by likelihood ratios, was equivalent to that of the laboratory markers. GRG status also predicted AIDS development when the laboratory markers conveyed a contrary risk. Additionally, in two separate and large groups of HIV+ subjects from a natural history cohort, the results from additive risk-scoring systems and classification and regression tree (CART) analysis revealed that the laboratory and CCL3L1-CCR5 genetic markers together provided more prognostic information than either marker alone. Furthermore, GRGs independently predicted the time interval from seroconversion to CD4+ cell count thresholds used to guide HAART initiation. The combination of the laboratory and genetic markers captures a broader spectrum of AIDS risk than either marker alone. By tracking a unique aspect of AIDS risk distinct from that captured by the laboratory parameters, CCL3L1-CCR5 genotypes may have utility in HIV clinical management

  13. Chemokine (C-C motif) receptor 5-using envelopes predominate in dual/mixed-tropic HIV from the plasma of drug-naive individuals.

    Science.gov (United States)

    Irlbeck, David M; Amrine-Madsen, Heather; Kitrinos, Kathryn M; Labranche, Celia C; Demarest, James F

    2008-07-31

    HIV-1 utilizes CD4 and either chemokine (C-C motif) receptor 5 (CCR5) or chemokine (C-X-C motif) receptor 4 (CXCR4) to gain entry into host cells. Small molecule CCR5 antagonists are currently being developed for the treatment of HIV-1 infection. Because HIV-1 may also use CXCR4 for entry, the use of CCR5 entry inhibitors is controversial for patients harboring CCR5-using and CXCR4-using (dual/mixed-tropic) viruses. The goal of the present study was to determine the proportion of CCR5-tropic and CXCR4-tropic viruses in dual/mixed-tropic virus isolates from drug-naïve patients and the phenotypic and genotypic relationships of viruses that use CCR5 or CXCR4 or both. Fourteen antiretroviral-naive HIV-1-infected patients were identified as having population coreceptor tropism readout of dual/mixed-tropic viruses. Intrapatient comparisons of coreceptor tropism and genotype of env clones were conducted on plasma virus from each patient. Population HIV-1 envelope tropism and susceptibility to the CCR5 entry inhibitor, aplaviroc, were performed using the Monogram Biosciences Trofile Assay. Twelve env clones from each patient were analyzed for coreceptor tropism, aplaviroc sensitivity, genotype, and intrapatient phylogenetic relationships. Viral populations from antiretroviral-naive patients with dual/mixed-tropic virus are composed primarily of CCR5-tropic env clones mixed with those that use both coreceptors (R5X4-tropic) and, occasionally, CXCR4-tropic env clones. Interestingly, the efficiency of CXCR4 use by R5X4-tropic env clones varied with their genetic relationships to CCR5-tropic env clones from the same patient. These data show that the majority of viruses in these dual/mixed-tropic populations use CCR5 and suggest that antiretroviral-naive patients may benefit from combination therapy that includes CCR5 entry inhibitors.

  14. Partial protective effect of CCR5-Delta 32 heterozygosity in a cohort of heterosexual Italian HIV-1 exposed uninfected individuals

    Directory of Open Access Journals (Sweden)

    Cauda Roberto

    2006-09-01

    Full Text Available Abstract Despite multiple sexual exposure to HIV-1 virus, some individuals remain HIV-1 seronegative (exposed seronegative, ESN. The mechanisms underlying this resistance remain still unclear, although a multifactorial pathogenesis can be hypothesised. Although several genetic factors have been related to HIV-1 resistance, the homozigosity for a mutation in CCR5 gene (the 32 bp deletion, i.e. CCR5-Delta32 allele is presently considered the most relevant one. In the present study we analysed the genotype at CCR5 locus of 30 Italian ESN individuals (case group who referred multiple unprotected heterosexual intercourse with HIV-1 seropositive partner(s, for at least two years. One hundred and twenty HIV-1 infected patients and 120 individuals representative of the general population were included as control groups. Twenty percent of ESN individuals had heterozygous CCR5-Delta 32 genotype, compared to 7.5% of HIV-1 seropositive and 10% of individuals from the general population, respectively. None of the analysed individuals had CCR5-Delta 32 homozygous genotype. Sequence analysis of the entire open reading frame of CCR5 was performed in all ESN subjects and no polymorphisms or mutations were identified. Moreover, we determined the distribution of C77G variant in CD45 gene, which has been previously related to HIV-1 infection susceptibility. The frequency of the C77G variant showed no significant difference between ESN subjects and the two control groups. In conclusion, our data show a significantly higher frequency of CCR5-Delta 32 heterozygous genotype (p = 0.04 among the Italian heterosexual ESN individuals compared to HIV-1 seropositive patients, suggesting a partial protective role of CCR5-Delta 32 heterozygosity in this cohort.

  15. Medicinal chemistry of small molecule CCR5 antagonists for blocking HIV-1 entry: a review of structural evolution.

    Science.gov (United States)

    Tian, Ye; Zhang, Dujuan; Zhan, Peng; Liu, Xinyong

    2014-01-01

    CCR5, a member of G protein-coupled receptors superfamily, plays an important role in the HIV-1 entry process. Antagonism of this receptor finally leads to the inhibition of R5 strains of HIV entry into the human cells. The identification of CCR5 antagonists as antiviral agents will provide more option for HAART. Now, more than a decade after the first small molecule CCR5 inhibitor was discovered, great achievements have been made. In this article, we will give a brief introduction of several series of small molecule CCR5 antagonists, focused on their appealing structure evolution, essential SAR information and thereof the enlightenment of strategies on CCR5 inhibitors design.

  16. HIV-1 and SIV Predominantly Use CCR5 Expressed on a Precursor Population to Establish Infection in T Follicular Helper Cells

    Directory of Open Access Journals (Sweden)

    John Zaunders

    2017-04-01

    Full Text Available BackgroundT follicular helper (Tfh cells are increasingly recognized as a major reservoir of HIV infection that will likely need to be addressed in approaches to curing HIV. However, Tfh express minimal CCR5, the major coreceptor for HIV-1, and the mechanism by which they are infected is unclear. We have previously shown that macaque Tfh lack CCR5, but are infected in vivo with CCR5-using SIV at levels comparable to other memory CD4+ T cells. Similarly, human splenic Tfh cells are highly infected with HIV-1 DNA. Therefore, we set out to examine the mechanism of infection of Tfh cells.MethodologyTfh and other CD4+ T cell subsets from macaque lymph nodes and spleens, splenic Tfh from HIV+ subjects, and tonsillar Tfh from HIV-uninfected subjects were isolated by cell sorting prior to cell surface and molecular characterization. HIV proviral gp120 sequences were submitted to genotypic and phenotypic tropism assays. Entry of CCR5- and CXCR4-using viruses into Tfh from uninfected tonsillar tissue was measured using a fusion assay.ResultsPhylogenetic analysis, genotypic, and phenotypic analysis showed that splenic Tfh cells from chronic HIV+ subjects were predominantly infected with CCR5-using viruses. In macaques, purified CCR5+PD-1intermediate(int+ memory CD4+ T cells were shown to include pre-Tfh cells capable of differentiating in vitro to Tfh by upregulation of PD-1 and Bcl6, confirmed by qRT-PCR and single-cell multiplex PCR. Infected PD-1int cells survive, carry SIV provirus, and differentiate into PD-1hi Tfh after T cell receptor stimulation, suggesting a pathway for SIV infection of Tfh. In addition, a small subset of macaque and human PD-1hi Tfh can express low levels of CCR5, which makes them susceptible to infection. Fusion assays demonstrated CCR5-using HIV-1 entry into CCR5+ Tfh and pre-Tfh cells from human tonsils.ConclusionThe major route of infection of Tfh in macaques and humans appears to be via a CCR5-expressing pre-Tfh population

  17. An anti-CCR5 monoclonal antibody and small molecule CCR5 antagonists synergize by inhibiting different stages of human immunodeficiency virus type 1 entry

    International Nuclear Information System (INIS)

    Safarian, Diana; Carnec, Xavier; Tsamis, Fotini; Kajumo, Francis; Dragic, Tatjana

    2006-01-01

    HIV-1 coreceptors are attractive targets for novel antivirals. Here, inhibition of entry by two classes of CCR5 antagonists was investigated. We confirmed previous findings that HIV-1 isolates vary greatly in their sensitivity to small molecule inhibitors of CCR5-mediated entry, SCH-C and TAK-779. In contrast, an anti-CCR5 monoclonal antibody (PA14) similarly inhibited entry of diverse viral isolates. Sensitivity to small molecules was V3 loop-dependent and inversely proportional to the level of gp120 binding to CCR5. Moreover, combinations of the MAb and small molecules were highly synergistic in blocking HIV-1 entry, suggesting different mechanisms of action. This was confirmed by time course of inhibition experiments wherein the PA14 MAb and small molecules were shown to inhibit temporally distinct stages of CCR5 usage. We propose that small molecules inhibit V3 binding to the second extracellular loop of CCR5, whereas PA14 preferentially inhibits subsequent events such as CCR5 recruitment into the fusion complex or conformational changes in the gp120-CCR5 complex that trigger fusion. Importantly, our findings suggest that combinations of CCR5 inhibitors with different mechanisms of action will be central to controlling HIV-1 infection and slowing the emergence of resistant strains

  18. HIV-1 tropism for the central nervous system: Brain-derived envelope glycoproteins with lower CD4 dependence and reduced sensitivity to a fusion inhibitor

    International Nuclear Information System (INIS)

    Martin-Garcia, Julio; Cao, Wei; Varela-Rohena, Angel; Plassmeyer, Matthew L.; Gonzalez-Scarano, Francisco

    2006-01-01

    We previously described envelope glycoproteins of an HIV-1 isolate adapted in vitro for growth in microglia that acquired a highly fusogenic phenotype and lower CD4 dependence, as well as resistance to inhibition by anti-CD4 antibodies. Here, we investigated whether similar phenotypic changes are present in vivo. Envelope clones from the brain and spleen of an HIV-1-infected individual with neurological disease were amplified, cloned, and sequenced. Phylogenetic analysis demonstrated clustering of sequences according to the tissue of origin, as expected. Functional clones were then used in cell-to-cell fusion assays to test for CD4 and co-receptor utilization and for sensitivity to various antibodies and inhibitors. Both brain- and spleen-derived envelope clones mediated fusion in cells expressing both CD4 and CCR5 and brain envelopes also used CCR3 as co-receptor. We found that the brain envelopes had a lower CD4 dependence, since they efficiently mediated fusion in the presence of low levels of CD4 on the target cell membrane, and they were significantly more resistant to blocking by anti-CD4 antibodies than the spleen-derived envelopes. In contrast, we observed no difference in sensitivity to the CCR5 antagonist TAK-779. However, brain-derived envelopes were significantly more resistant than those from spleen to the fusion inhibitor T-1249 and concurrently showed slightly greater fusogenicity. Our results suggest an increased affinity for CD4 of brain-derived envelopes that may have originated from in vivo adaptation to replication in microglial cells. Interestingly, we note the presence of envelopes more resistant to a fusion inhibitor in the brain of an untreated, HIV-1-infected individual

  19. Effects of sequence changes in the HIV-1 gp41 fusion peptide on CCR5 inhibitor resistance

    International Nuclear Information System (INIS)

    Anastassopoulou, Cleo G.; Ketas, Thomas J.; Sanders, Rogier W.; Johan Klasse, Per; Moore, John P.

    2012-01-01

    A rare pathway of HIV-1 resistance to small molecule CCR5 inhibitors such as Vicriviroc (VCV) involves changes solely in the gp41 fusion peptide (FP). Here, we show that the G516V change is critical to VCV resistance in PBMC and TZM-bl cells, although it must be accompanied by either M518V or F519I to have a substantial impact. Modeling VCV inhibition data from the two cell types indicated that G516V allows both double mutants to use VCV-CCR5 complexes for entry. The model further identified F519I as an independent determinant of preference for the unoccupied, high-VCV affinity form of CCR5. From inhibitor-free reversion cultures, we also identified a substitution in the inner domain of gp120, T244A, which appears to counter the resistance phenotype created by the FP substitutions. Examining the interplay of these changes will enhance our understanding of Env complex interactions that influence both HIV-1 entry and resistance to CCR5 inhibitors.

  20. Maraviroc (UK-427,857), a potent, orally bioavailable, and selective small-molecule inhibitor of chemokine receptor CCR5 with broad-spectrum anti-human immunodeficiency virus type 1 activity.

    Science.gov (United States)

    Dorr, Patrick; Westby, Mike; Dobbs, Susan; Griffin, Paul; Irvine, Becky; Macartney, Malcolm; Mori, Julie; Rickett, Graham; Smith-Burchnell, Caroline; Napier, Carolyn; Webster, Rob; Armour, Duncan; Price, David; Stammen, Blanda; Wood, Anthony; Perros, Manos

    2005-11-01

    Maraviroc (UK-427,857) is a selective CCR5 antagonist with potent anti-human immunodeficiency virus type 1 (HIV-1) activity and favorable pharmacological properties. Maraviroc is the product of a medicinal chemistry effort initiated following identification of an imidazopyridine CCR5 ligand from a high-throughput screen of the Pfizer compound file. Maraviroc demonstrated potent antiviral activity against all CCR5-tropic HIV-1 viruses tested, including 43 primary isolates from various clades and diverse geographic origin (geometric mean 90% inhibitory concentration of 2.0 nM). Maraviroc was active against 200 clinically derived HIV-1 envelope-recombinant pseudoviruses, 100 of which were derived from viruses resistant to existing drug classes. There was little difference in the sensitivity of the 200 viruses to maraviroc, as illustrated by the biological cutoff in this assay (= geometric mean plus two standard deviations [SD] of 1.7-fold). The mechanism of action of maraviroc was established using cell-based assays, where it blocked binding of viral envelope, gp120, to CCR5 to prevent the membrane fusion events necessary for viral entry. Maraviroc did not affect CCR5 cell surface levels or associated intracellular signaling, confirming it as a functional antagonist of CCR5. Maraviroc has no detectable in vitro cytotoxicity and is highly selective for CCR5, as confirmed against a wide range of receptors and enzymes, including the hERG ion channel (50% inhibitory concentration, >10 microM), indicating potential for an excellent clinical safety profile. Studies in preclinical in vitro and in vivo models predicted maraviroc to have human pharmacokinetics consistent with once- or twice-daily dosing following oral administration. Clinical trials are ongoing to further investigate the potential of using maraviroc for the treatment of HIV-1 infection and AIDS.

  1. CCL3L1-CCR5 genotype influences durability of immune recovery during antiretroviral therapy of HIV-1–infected individuals

    Science.gov (United States)

    Ahuja, Sunil K; Kulkarni, Hemant; Catano, Gabriel; Agan, Brian K; Camargo, Jose F; He, Weijing; O'Connell, Robert J; Marconi, Vincent C; Delmar, Judith; Eron, Joseph; Clark, Robert A; Frost, Simon; Martin, Jeffrey; Ahuja, Seema S; Deeks, Steven G; Little, Susan; Richman, Douglas; Hecht, Frederick M; Dolan, Matthew J

    2008-01-01

    The basis for the extensive variability seen in the reconstitution of CD4+ T cell counts in HIV-infected individuals receiving highly active antiretroviral therapy (HAART) is not fully known. Here, we show that variations in CCL3L1 gene dose and CCR5 genotype, but not major histocompatibility complex HLA alleles, influence immune reconstitution, especially when HAART is initiated at <350 CD4+ T cells/mm3. The CCL3L1-CCR5 genotypes favoring CD4+ T cell recovery are similar to those that blunted CD4+ T cell depletion during the time before HAART became available (pre-HAART era), suggesting that a common CCL3L1-CCR5 genetic pathway regulates the balance between pathogenic and reparative processes from early in the disease course. Hence, CCL3L1-CCR5 variations influence HIV pathogenesis even in the presence of HAART and, therefore, may prospectively identify subjects in whom earlier initiation of therapy is more likely to mitigate immunologic failure despite viral suppression by HAART. Furthermore, as reconstitution of CD4+ cells during HAART is more sensitive to CCL3L1 dose than to CCR5 genotypes, CCL3L1 analogs might be efficacious in supporting immunological reconstitution. PMID:18376407

  2. HIV-1 resistance conferred by siRNA cosuppression of CXCR4 and CCR5 coreceptors by a bispecific lentiviral vector

    Directory of Open Access Journals (Sweden)

    Akkina Ramesh

    2005-01-01

    Full Text Available Abstract Background RNA interference (RNAi mediated by small interfering RNAs (siRNAs has proved to be a highly effective gene silencing mechanism with great potential for HIV/AIDS gene therapy. Previous work with siRNAs against cellular coreceptors CXCR4 and CCR5 had shown that down regulation of these surface molecules could prevent HIV-1 entry and confer viral resistance. Since monospecific siRNAs targeting individual coreceptors are inadequate in protecting against both T cell tropic (X4 and monocyte tropic (R5 viral strains simultaneously, bispecific constructs with dual specificity are required. For effective long range therapy, the bispecific constructs need to be stably transduced into HIV-1 target cells via integrating viral vectors. Results To achieve this goal, lentiviral vectors incorporating both CXCR4 and CCR5 siRNAs of short hairpin design were constructed. The CXCR4 siRNA was driven by a U6 promoter whereas the CCR5 siRNA was driven by an H1 promoter. A CMV promoter driven EGFP reporter gene is also incorporated in the bispecific construct. High efficiency transduction into coreceptor expressing Magi and Ghost cell lines with a concomitant down regulation of respective coreceptors was achieved with lentiviral vectors. When the siRNA expressing transduced cells were challenged with X4 and R5 tropic HIV-1, they demonstrated marked viral resistance. HIV-1 resistance was also observed in bispecific lentiviral vector transduced primary PBMCs. Conclusions Both CXCR4 and CCR5 coreceptors could be simultaneously targeted for down regulation by a single combinatorial lentiviral vector incorporating respective anti-coreceptor siRNAs. Stable down regulation of both the coreceptors protects cells against infection by both X4 and R5 tropic HIV-1. Stable down regulation of cellular molecules that aid in HIV-1 infection will be an effective strategy for long range HIV gene therapy.

  3. Influence of the CCR2-V64I Polymorphism on Human Immunodeficiency Virus Type 1 Coreceptor Activity and on Chemokine Receptor Function of CCR2b, CCR3, CCR5, and CXCR4

    OpenAIRE

    Lee, Benhur; Doranz, Benjamin J.; Rana, Shalini; Yi, Yanji; Mellado, Mario; Frade, Jose M. R.; Martinez-A., Carlos; O’Brien, Stephen J.; Dean, Michael; Collman, Ronald G.; Doms, Robert W.

    1998-01-01

    The chemokine receptors CCR5 and CXCR4 are used by human immunodeficiency virus type 1 (HIV-1) in conjunction with CD4 to infect cells. In addition, some virus strains can use alternative chemokine receptors, including CCR2b and CCR3, for infection. A polymorphism in CCR2 (CCR2-V64I) is associated with a 2- to 4-year delay in the progression to AIDS. To investigate the mechanism of this protective effect, we studied the expression of CCR2b and CCR2b-V64I, their chemokine and HIV-1 coreceptor ...

  4. Molecular anatomy of CCR5 engagement by physiologic and viral chemokines and HIV-1 envelope glycoproteins: differences in primary structural requirements for RANTES, MIP-1 alpha, and vMIP-II Binding.

    Science.gov (United States)

    Navenot, J M; Wang, Z X; Trent, J O; Murray, J L; Hu, Q X; DeLeeuw, L; Moore, P S; Chang, Y; Peiper, S C

    2001-11-09

    Molecular analysis of CCR5, the cardinal coreceptor for HIV-1 infection, has implicated the N-terminal extracellular domain (N-ter) and regions vicinal to the second extracellular loop (ECL2) in this activity. It was shown that residues in the N-ter are necessary for binding of the physiologic ligands, RANTES (CCL5) and MIP-1 alpha (CCL3). vMIP-II, encoded by the Kaposi's sarcoma-associated herpesvirus, is a high affinity CCR5 antagonist, but lacks efficacy as a coreceptor inhibitor. Therefore, we compared the mechanism for engagement by vMIP-II of CCR5 to its interaction with physiologic ligands. RANTES, MIP-1 alpha, and vMIP-II bound CCR5 at high affinity, but demonstrated partial cross-competition. Characterization of 15 CCR5 alanine scanning mutants of charged extracellular amino acids revealed that alteration of acidic residues in the distal N-ter abrogated binding of RANTES, MIP-1 alpha, and vMIP-II. Whereas mutation of residues in ECL2 of CCR5 dramatically reduced the binding of RANTES and MIP-1 alpha and their ability to induce signaling, interaction with vMIP-II was not altered by any mutation in the exoloops of the receptor. Paradoxically, monoclonal antibodies to N-ter epitopes did not block chemokine binding, but those mapped to ECL2 were effective inhibitors. A CCR5 chimera with the distal N-ter residues of CXCR2 bound MIP-1 alpha and vMIP-II with an affinity similar to that of the wild-type receptor. Engagement of CCR5 by vMIP-II, but not RANTES or MIP-1 alpha blocked the binding of monoclonal antibodies to the receptor, providing additional evidence for a distinct mechanism for viral chemokine binding. Analysis of the coreceptor activity of randomly generated mouse-human CCR5 chimeras implicated residues in ECL2 between H173 and V197 in this function. RANTES, but not vMIP-II blocked CCR5 M-tropic coreceptor activity in the fusion assay. The insensitivity of vMIP-II binding to mutations in ECL2 provides a potential rationale to its inefficiency as an

  5. Effects of CCR5-delta32 and CCR2-64I alleles on disease progression of perinatally HIV-1-infected children: an international meta-analysis.

    Science.gov (United States)

    Ioannidis, John P A; Contopoulos-Ioannidis, Despina G; Rosenberg, Philip S; Goedert, James J; De Rossi, Anita; Espanol, Teresa; Frenkel, Lisa; Mayaux, Marie-Jeanne; Newell, Marie-Louise; Pahwa, Savita G; Rousseau, Christine; Scarlatti, Gabriella; Sei, Shizuko; Sen, Luisa; O'Brien, Thomas R

    2003-07-25

    Among perinatally infected children, the effects of certain alleles of the CCR5 and CCR2 genes on the rate of disease progression remain unclear. We addressed the effects of CCR5-delta32 and CCR2-64I in an international meta-analysis. Genotype data were contributed from 10 studies with 1317 HIV-1-infected children (7263 person-years of follow-up). Time-to-event analyses were performed stratified by study and racial group. Endpoints included progression to clinical AIDS, death, and death after the diagnosis of clinical AIDS. The time-dependence of the genetic effects was specifically investigated. There was large heterogeneity in the observed rates of disease progression between different cohorts. For progression to clinical AIDS, both CCR5-delta32 and CCR2-64I showed overall non-significant trends for protection [hazard ratios 0.84, 95% confidence interval (CI) 0.58-1.23; and 0.87, 95% CI 0.67-1.14, respectively]. However, analyses of survival showed statistically significant time-dependence. No deaths occurred among CCR5-delta32 carriers in the first 3 years of life, whereas there was no protective effect (hazard ratio 0.95; 95% CI 0.43-2.10) in later years (P=0.01 for the time-dependent model). For CCR2-64I, the hazard ratio for death was 0.69 (95% CI 0.39-1.21) in the first 6 years of life and 2.56 (95% CI 1.26-5.20) in subsequent years (P<0.01 for the time-dependent model). CCR5-delta32 and CCR2-64I offered no clear protection after clinical AIDS had developed. The CCR5-delta32 and CCR2-64I alleles are associated with a decreased risk of death among perinatally infected children, but only for the first years of life.

  6. The CCL3L1-CCR5 genotype influences the development of AIDS, but not HIV susceptibility or the response to HAART

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Tanmoy [Los Alamos National Laboratory; Stanton, Jennifer [NORTHWESTERN UNIV; Kim, Eun - Young [NORTHWESTERN UNIV; Kunstman, Kevin [NORTHWESTERN UNIV; Phair, John [NORTHWESTERN UNIV; Jacobson, Lisa P [JOHNS HOPKINS UNIV; Wolinsky, Steven M [NORTHWESTERN UNIV

    2008-01-01

    A selective advantage against infectious diseases such as HIV/AIDS is associated with differences in the genes relevant to immunity and virus replication. The CC chemokine receptor 5 (CCR5), the principal coreceptor for HIV, and its chemokine ligands, including CCL3L1, influences the CD4+ target cells susceptibility to infection. The CCL3L1 gene is in a region of segmental duplication on the q-arm of human chromosome 17. Increased numbers of CCL3L1 gene copies that affect the gene expression phenotype might have substantial protective effects. Here we show that the population-specific CCL3L1 gene copy number and the CCR5 {Delta}32 protein-inactivating deletion that categorizes the CCL3L1-CCR5 genotype do not influence HIV/AIDS susceptibility or the robustness of immune recovery after the initiation of highly active antiretroviral therapy (HAART).

  7. Flexible use of CCR5 in the absence of CXCR4 use explains the immune deficiency in HIV-1 infected children.

    Science.gov (United States)

    Cavarelli, Mariangela; Karlsson, Ingrid; Ripamonti, Chiara; Plebani, Anna; Fenyo, Eva Maria; Scarlatti, Gabriella

    2010-10-23

    CCR5-using HIV-1 (R5 viruses) are usually isolated during acute infection from both adults and children. We have recently demonstrated that R5 viruses with a flexible use of CCR5 (called R5broad) can be detected in children close to birth and are predictive of a fast immunological failure. The aim of the present work was to investigate viral phenotype variation during disease progression in HIV-1 infected children, six slow and eight fast progressors. A total of 74 viral isolates obtained sequentially from 14 HIV-1 infected children were tested for their ability to infect U87.CD4 cells expressing a set of six different CCR5/CXCR4 chimeric receptors or wild-type coreceptors. The sensitivity of 35 R5 viruses to inhibition with the CC-chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) was evaluated in a peripheral blood mononuclear cells based assay. Viral evolution to R5broad or to R5X4 phenotype occurred with one exception, in all children, although at a different time point according to rate of disease progression. Immune deficiency in the children was significantly associated with the appearance of R5broad phenotype or R5X4 viruses. Analysis of the sensitivity to inhibition by RANTES revealed a significant correlation between the R5broad phenotype and an augmented resistance to this CC-chemokine. We demonstrate that the viral evolution to a more flexible CCR5-use is sufficient to explain the immunological failure in the absence of CXCR4 usage. These results warrant detailed analysis of the R5 phenotype in forthcoming clinical studies introducing CCR5 inhibitors for the treatment of pediatric HIV-1 infection.

  8. CCR5 Targeted Cell Therapy for HIV and Prevention of Viral Escape

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    Gero Hütter

    2015-07-01

    Full Text Available Allogeneic transplantation with CCR5-delta 32 (CCR5-d32 homozygous stem cells in an HIV infected individual in 2008, led to a sustained virus control and probably eradication of HIV. Since then there has been a high degree of interest to translate this approach to a wider population. There are two cellular ways to do this. The first one is to use a CCR5 negative cell source e.g., hematopoietic stem cells (HSC to copy the initial finding. However, a recent case of a second allogeneic transplantation with CCR5-d32 homozygous stem cells suffered from viral escape of CXCR4 quasi-species. The second way is to knock down CCR5 expression by gene therapy. Currently, there are five promising techniques, three of which are presently being tested clinically. These techniques include zinc finger nucleases (ZFN, clustered regularly interspaced palindromic repeats/CRISPR-associated protein 9 nuclease (CRISPR/Cas9, transcription activator-like effectors nuclease (TALEN, short hairpin RNA (shRNA, and a ribozyme. While there are multiple gene therapy strategies being tested, in this review we reflect on our current knowledge of inhibition of CCR5 specifically and whether this approach allows for consequent viral escape.

  9. CD4 is expressed on a heterogeneous subset of hematopoietic progenitors, which persistently harbor CXCR4 and CCR5-tropic HIV proviral genomes in vivo.

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    Nadia T Sebastian

    2017-07-01

    Full Text Available Latent HIV infection of long-lived cells is a barrier to viral clearance. Hematopoietic stem and progenitor cells are a heterogeneous population of cells, some of which are long-lived. CXCR4-tropic HIVs infect a broad range of HSPC subtypes, including hematopoietic stem cells, which are multi-potent and long-lived. However, CCR5-tropic HIV infection is limited to more differentiated progenitor cells with life spans that are less well understood. Consistent with emerging data that restricted progenitor cells can be long-lived, we detected persistent HIV in restricted HSPC populations from optimally treated people. Further, genotypic and phenotypic analysis of amplified env alleles from donor samples indicated that both CXCR4- and CCR5-tropic viruses persisted in HSPCs. RNA profiling confirmed expression of HIV receptor RNA in a pattern that was consistent with in vitro and in vivo results. In addition, we characterized a CD4high HSPC sub-population that was preferentially targeted by a variety of CXCR4- and CCR5-tropic HIVs in vitro. Finally, we present strong evidence that HIV proviral genomes of both tropisms can be transmitted to CD4-negative daughter cells of multiple lineages in vivo. In some cases, the transmitted proviral genomes contained signature deletions that inactivated the virus, eliminating the possibility that coincidental infection explains the results. These data support a model in which both stem and non-stem cell progenitors serve as persistent reservoirs for CXCR4- and CCR5-tropic HIV proviral genomes that can be passed to daughter cells.

  10. CD4 is expressed on a heterogeneous subset of hematopoietic progenitors, which persistently harbor CXCR4 and CCR5-tropic HIV proviral genomes in vivo.

    Science.gov (United States)

    Sebastian, Nadia T; Zaikos, Thomas D; Terry, Valeri; Taschuk, Frances; McNamara, Lucy A; Onafuwa-Nuga, Adewunmi; Yucha, Ryan; Signer, Robert A J; Riddell, James; Bixby, Dale; Markowitz, Norman; Morrison, Sean J; Collins, Kathleen L

    2017-07-01

    Latent HIV infection of long-lived cells is a barrier to viral clearance. Hematopoietic stem and progenitor cells are a heterogeneous population of cells, some of which are long-lived. CXCR4-tropic HIVs infect a broad range of HSPC subtypes, including hematopoietic stem cells, which are multi-potent and long-lived. However, CCR5-tropic HIV infection is limited to more differentiated progenitor cells with life spans that are less well understood. Consistent with emerging data that restricted progenitor cells can be long-lived, we detected persistent HIV in restricted HSPC populations from optimally treated people. Further, genotypic and phenotypic analysis of amplified env alleles from donor samples indicated that both CXCR4- and CCR5-tropic viruses persisted in HSPCs. RNA profiling confirmed expression of HIV receptor RNA in a pattern that was consistent with in vitro and in vivo results. In addition, we characterized a CD4high HSPC sub-population that was preferentially targeted by a variety of CXCR4- and CCR5-tropic HIVs in vitro. Finally, we present strong evidence that HIV proviral genomes of both tropisms can be transmitted to CD4-negative daughter cells of multiple lineages in vivo. In some cases, the transmitted proviral genomes contained signature deletions that inactivated the virus, eliminating the possibility that coincidental infection explains the results. These data support a model in which both stem and non-stem cell progenitors serve as persistent reservoirs for CXCR4- and CCR5-tropic HIV proviral genomes that can be passed to daughter cells.

  11. Impact of CCR5 Delta32/+ deletion on herpes zoster among HIV-1-infected homosexual men

    NARCIS (Netherlands)

    Krol, Anneke; Lensen, Ruud; Veenstra, Jan; Prins, Maria; Schuitemaker, Hanneke; Coutinho, Roel A.

    2006-01-01

    The association between the presence of CCR5 Delta32 heterozygosity and incidence of clinical herpes zoster was studied among 296 homosexual men from the Amsterdam cohort study (ACS) infected with human immunodeficiency virus type I (HIV-1) with an estimated date of seroconversion. Of them 63 were

  12. Elite suppressor-derived HIV-1 envelope glycoproteins exhibit reduced entry efficiency and kinetics.

    Directory of Open Access Journals (Sweden)

    Kara G Lassen

    2009-04-01

    Full Text Available Elite suppressors (ES are a rare subset of HIV-1-infected individuals who are able to maintain HIV-1 viral loads below the limit of detection by ultra-sensitive clinical assays in the absence of antiretroviral therapy. Mechanism(s responsible for this elite control are poorly understood but likely involve both host and viral factors. This study assesses ES plasma-derived envelope glycoprotein (env fitness as a function of entry efficiency as a possible contributor to viral suppression. Fitness of virus entry was first evaluated using a novel inducible cell line with controlled surface expression levels of CD4 (receptor and CCR5 (co-receptor. In the context of physiologic CCR5 and CD4 surface densities, ES envs exhibited significantly decreased entry efficiency relative to chronically infected viremic progressors. ES envs also demonstrated slow entry kinetics indicating the presence of virus with reduced entry fitness. Overall, ES env clones were less efficient at mediating entry than chronic progressor envs. Interestingly, acute infection envs exhibited an intermediate phenotypic pattern not distinctly different from ES or chronic progressor envs. These results imply that lower env fitness may be established early and may directly contribute to viral suppression in ES individuals.

  13. HIV-1 with multiple CCR5/CXCR4 chimeric receptor use is predictive of immunological failure in infected children.

    Science.gov (United States)

    Cavarelli, Mariangela; Karlsson, Ingrid; Zanchetta, Marisa; Antonsson, Liselotte; Plebani, Anna; Giaquinto, Carlo; Fenyö, Eva Maria; De Rossi, Anita; Scarlatti, Gabriella

    2008-09-29

    HIV-1 R5 viruses are characterized by a large phenotypic variation, that is reflected by the mode of coreceptor use. The ability of R5 HIV-1 to infect target cells expressing chimeric receptors between CCR5 and CXCR4 (R5(broad) viruses), was shown to correlate with disease stage in HIV-1 infected adults. Here, we ask the question whether phenotypic variation of R5 viruses could play a role also in mother-to-child transmission (MTCT) of HIV-1 and pediatric disease progression. Viral isolates obtained from a total of 59 HIV-1 seropositive women (24 transmitting and 35 non transmitting) and 28 infected newborn children, were used to infect U87.CD4 cells expressing wild type or six different CCR5/CXCR4 chimeric receptors. HIV-1 isolates obtained from newborn infants had predominantly R5(narrow) phenotype (n = 20), but R5(broad) and R5X4 viruses were also found in seven and one case, respectively. The presence of R5(broad) and R5X4 phenotypes correlated significantly with a severe decline of the CD4+ T cells (CDC stage 3) or death within 2 years of age. Forty-three percent of the maternal R5 isolates displayed an R5(broad) phenotype, however, the presence of the R5(broad) virus was not predictive for MTCT of HIV-1. Of interest, while only 1 of 5 mothers with an R5X4 virus transmitted the dualtropic virus, 5 of 6 mothers carrying R5(broad) viruses transmitted viruses with a similar broad chimeric coreceptor usage. Thus, the maternal R5(broad) phenotype was largely preserved during transmission and could be predictive of the phenotype of the newborn's viral variant. Our results show that R5(broad) viruses are not hampered in transmission. When transmitted, immunological failure occurs earlier than in children infected with HIV-1 of R5(narrow) phenotype. We believe that this finding is of utmost relevance for therapeutic interventions in pediatric HIV-1 infection.

  14. CCL5, CCR1 and CCR5 in murine glioblastoma: immune cell infiltration and survival rates are not dependent on individual expression of either CCR1 or CCR5

    OpenAIRE

    Pham, Kien; Luo, Defang; Liu, Che; Harrison, Jeffrey K.

    2012-01-01

    Glioblastoma multiforme (GBM) is the most malignant brain tumor. Microglia/macrophages are found within human GBM where they likely promote tumor progression. We report that CCL5, CCR1, and CCR5 are expressed in glioblastoma. Individual deletion of CCR1 or CCR5 had little to no effect on survival of tumor bearing mice, or numbers of glioblastoma-infiltrated microglia/macrophages or lymphocytes. CCL5 promoted in vitro migration of wild type, CCR1- or CCR5-deficient microglia/macrophages that w...

  15. R5 HIV-1 envelope attracts dendritic cells to cross the human intestinal epithelium and sample luminal virions via engagement of the CCR5.

    Science.gov (United States)

    Cavarelli, Mariangela; Foglieni, Chiara; Rescigno, Maria; Scarlatti, Gabriella

    2013-05-01

    The gastrointestinal tract is a principal route of entry and site of persistence of human immunodeficiency virus type 1 (HIV-1). The intestinal mucosa, being rich of cells that are the main target of the virus, represents a primary site of viral replication and CD4(+) T-cell depletion. Here, we show both in vitro and ex vivo that HIV-1 of R5 but not X4 phenotype is capable of selectively triggering dendritic cells (DCs) to migrate within 30 min between intestinal epithelial cells to sample virions and transfer infection to target cells. The engagement of the chemokine receptor 5 on DCs and the viral envelope, regardless of the genetic subtype, drive DC migration. Viruses penetrating through transient opening of the tight junctions likely create a paracellular gradient to attract DCs. The formation of junctions with epithelial cells may initiate a haptotactic process of DCs and at the same time favour cell-to-cell viral transmission. Our findings indicate that HIV-1 translocation across the intestinal mucosa occurs through the selective engagement of DCs by R5 viruses, and may guide the design of new prevention strategies. Copyright © 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.

  16. CD4-independent use of the CCR5 receptor by sequential primary SIVsm isolates

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    Thorstensson Rigmor

    2007-07-01

    Full Text Available Abstract Background CD4-independence has been taken as a sign of a more open envelope structure that is more accessible to neutralizing antibodies and may confer altered cell tropism. In the present study, we analyzed SIVsm isolates for CD4-independent use of CCR5, mode of CCR5-use and macrophage tropism. The isolates have been collected sequentially from 13 experimentally infected cynomolgus macaques and have previously been shown to use CCR5 together with CD4. Furthermore, viruses obtained early after infection were neutralization sensitive, while neutralization resistance appeared already three months after infection in monkeys with progressive immunodeficiency. Results Depending whether isolated early or late in infection, two phenotypes of CD4-independent use of CCR5 could be observed. The inoculum virus (SIVsm isolate SMM-3 and reisolates obtained early in infection often showed a pronounced CD4-independence since virus production and/or syncytia induction could be detected directly in NP-2 cells expressing CCR5 but not CD4 (CD4-independent-HIGH. Conversely, late isolates were often more CD4-dependent in that productive infection in NP-2/CCR5 cells was in most cases weak and was revealed only after cocultivation of infected NP-2/CCR5 cells with peripheral blood mononuclear cells (CD4-independent-LOW. Considering neutralization sensitivity of these isolates, newly infected macaques often harbored virus populations with a CD4-independent-HIGH and neutralization sensitive phenotype that changed to a CD4-independent-LOW and neutralization resistant virus population in the course of infection. Phenotype changes occurred faster in progressor than long-term non-progressor macaques. The phenotypes were not reflected by macrophage tropism, since all isolates replicated efficiently in macrophages. Infection of cells expressing CCR5/CXCR4 chimeric receptors revealed that SIVsm used the CCR5 receptor in a different mode than HIV-1. Conclusion Our

  17. Infection of human and non-human cells by a highly fusogenic primary CD4-independent HIV-1 isolate with a truncated envelope cytoplasmic tail

    International Nuclear Information System (INIS)

    Saha, Kunal; Yan Hui; Nelson, Julie A.E.; Zerhouni-Layachi, Bouchra

    2005-01-01

    Truncation of the envelope cytoplasmic tail has enabled FIV, SIV, and some laboratory HIV-1 strains to acquire broader cellular tropism and enhanced fusogenicity. Here we have characterized a primary CD4-independent HIV-1 isolate (92UG046-T8) with a truncated cytoplasmic tail that was able to infect and induce syncytia in primary lymphocytes from human, chimpanzee, and monkey, as well as CD4-negative cell lines from human and monkey. Increased syncytia were also noticeable with 293 cells expressing the cloned envelope from the 92UG046-T8 isolate suggesting envelope-mediated cellular fusion. Except pooled serum from HIV-1-infected individuals, monoclonal anti-envelope antibodies or antibodies/antagonists against CD4, CXCR4, and CCR5 were not able to prevent infection by the 92UG046-T8 isolate. This is the first report showing a primary HIV-1 variant with truncated cytoplasmic tail which is highly fusogenic and can infect a broad range of cells from human and non-human origins. In vivo evolution of similar HIV-1 mutants may have important implications in AIDS pathogenesis

  18. HIV-1 with multiple CCR5/CXCR4 chimeric receptor use is predictive of immunological failure in infected children.

    Directory of Open Access Journals (Sweden)

    Mariangela Cavarelli

    Full Text Available BACKGROUND: HIV-1 R5 viruses are characterized by a large phenotypic variation, that is reflected by the mode of coreceptor use. The ability of R5 HIV-1 to infect target cells expressing chimeric receptors between CCR5 and CXCR4 (R5(broad viruses, was shown to correlate with disease stage in HIV-1 infected adults. Here, we ask the question whether phenotypic variation of R5 viruses could play a role also in mother-to-child transmission (MTCT of HIV-1 and pediatric disease progression. METHODOLOGY/PRINCIPAL FINDINGS: Viral isolates obtained from a total of 59 HIV-1 seropositive women (24 transmitting and 35 non transmitting and 28 infected newborn children, were used to infect U87.CD4 cells expressing wild type or six different CCR5/CXCR4 chimeric receptors. HIV-1 isolates obtained from newborn infants had predominantly R5(narrow phenotype (n = 20, but R5(broad and R5X4 viruses were also found in seven and one case, respectively. The presence of R5(broad and R5X4 phenotypes correlated significantly with a severe decline of the CD4+ T cells (CDC stage 3 or death within 2 years of age. Forty-three percent of the maternal R5 isolates displayed an R5(broad phenotype, however, the presence of the R5(broad virus was not predictive for MTCT of HIV-1. Of interest, while only 1 of 5 mothers with an R5X4 virus transmitted the dualtropic virus, 5 of 6 mothers carrying R5(broad viruses transmitted viruses with a similar broad chimeric coreceptor usage. Thus, the maternal R5(broad phenotype was largely preserved during transmission and could be predictive of the phenotype of the newborn's viral variant. CONCLUSIONS/SIGNIFICANCE: Our results show that R5(broad viruses are not hampered in transmission. When transmitted, immunological failure occurs earlier than in children infected with HIV-1 of R5(narrow phenotype. We believe that this finding is of utmost relevance for therapeutic interventions in pediatric HIV-1 infection.

  19. SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo.

    Science.gov (United States)

    Strizki, J M; Xu, S; Wagner, N E; Wojcik, L; Liu, J; Hou, Y; Endres, M; Palani, A; Shapiro, S; Clader, J W; Greenlee, W J; Tagat, J R; McCombie, S; Cox, K; Fawzi, A B; Chou, C C; Pugliese-Sivo, C; Davies, L; Moreno, M E; Ho, D D; Trkola, A; Stoddart, C A; Moore, J P; Reyes, G R; Baroudy, B M

    2001-10-23

    We describe here the identification and properties of SCH-C (SCH 351125), a small molecule inhibitor of HIV-1 entry via the CCR5 coreceptor. SCH-C, an oxime-piperidine compound, is a specific CCR5 antagonist as determined in multiple receptor binding and signal transduction assays. This compound specifically inhibits HIV-1 infection mediated by CCR5 in U-87 astroglioma cells but has no effect on infection of CXCR4-expressing cells. SCH-C has broad and potent antiviral activity in vitro against primary HIV-1 isolates that use CCR5 as their entry coreceptor, with mean 50% inhibitory concentrations ranging between 0.4 and 9 nM. Moreover, SCH-C strongly inhibits the replication of an R5-using HIV-1 isolate in SCID-hu Thy/Liv mice. SCH-C has a favorable pharmacokinetic profile in rodents and primates with an oral bioavailability of 50-60% and a serum half-life of 5-6 h. On the basis of its novel mechanism of action, potent antiviral activity, and in vivo pharmacokinetic profile, SCH-C is a promising new candidate for therapeutic intervention of HIV infection.

  20. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  1. Priming B cell-mediated anti-HIV envelope responses by vaccination allows for the long-term control of infection in macaques exposed to a R5-tropic SHIV

    International Nuclear Information System (INIS)

    Buckner, Clarisa; Gines, Leoned G.; Saunders, Cheryl J.; Vojtech, Lucia; Srivastava, Indresh; Gettie, Agegnehu; Bohm, Rudolph; Blanchard, James; Barnett, Susan W.; Safrit, Jeffrey T.; Stamatatos, Leonidas

    2004-01-01

    The potential of vaccine-elicited anti-HIV envelope antibodies to control HIV-infection was evaluated by immunizing macaques with the HIV envelope protein and transiently depleting them of their CD8+ cells before intravenous challenge with the pathogenic CCR5-tropic SIV/HIV chimeric virus, SHIV SF162P4 . Although sterilizing immunity was not achieved, all vaccinated animals effectively controlled infection and remained free of disease for the duration of observation (over 3 years). In contrast, during the same period, the control animals progressed to disease. Both the vaccinees and the controls developed robust cell-mediated antiviral and neutralizing antibody responses following infection. A comparative analysis of these responses suggests that the more effective long-term control of infection by the vaccinated animals is due to the more rapid development of anti-HIV envelope antibodies. These studies suggest that priming by vaccination of B cell anti-HIV envelope responses maybe crucial for the long-term control of HIV infection

  2. Preclinical safety and efficacy of an anti–HIV-1 lentiviral vector containing a short hairpin RNA to CCR5 and the C46 fusion inhibitor

    Directory of Open Access Journals (Sweden)

    Orit Wolstein

    2014-01-01

    Full Text Available Gene transfer has therapeutic potential for treating HIV-1 infection by generating cells that are resistant to the virus. We have engineered a novel self-inactivating lentiviral vector, LVsh5/C46, using two viral-entry inhibitors to block early steps of HIV-1 cycle. The LVsh5/C46 vector encodes a short hairpin RNA (shRNA for downregulation of CCR5, in combination with the HIV-1 fusion inhibitor, C46. We demonstrate here the effective delivery of LVsh5/C46 to human T cell lines, peripheral blood mononuclear cells, primary CD4+ T lymphocytes, and CD34+ hematopoietic stem/progenitor cells (HSPC. CCR5-targeted shRNA (sh5 and C46 peptide were stably expressed in the target cells and were able to effectively protect gene-modified cells against infection with CCR5- and CXCR4-tropic strains of HIV-1. LVsh5/C46 treatment was nontoxic as assessed by cell growth and viability, was noninflammatory, and had no adverse effect on HSPC differentiation. LVsh5/C46 could be produced at a scale sufficient for clinical development and resulted in active viral particles with very low mutagenic potential and the absence of replication-competent lentivirus. Based on these in vitro results, plus additional in vivo safety and efficacy data, LVsh5/C46 is now being tested in a phase 1/2 clinical trial for the treatment of HIV-1 disease.

  3. Frequencies of CCR5-D32, CCR2-64I and SDF1-3’A mutations in Human Immunodeficiency Virus (HIV seropositive subjects and seronegative individuals from the state of Pará in Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Fernanda Andreza de Pinho Lott Carvalhaes

    2005-12-01

    Full Text Available The distribution of genetic polymorphisms of chemokine receptors CCR5-delta32, CCR2-64I and chemokine (SDF1-3’A mutations were studied in 110 Human Immunodeficiency Virus type 1 (HIV-1 seropositive individuals (seropositive group and 139 seronegative individuals (seronegative group from the population of the northern Brazilian city of Belém which is the capital of the state of Pará in the Brazilian Amazon. The CCR5-delta32 mutation was found in the two groups at similar frequencies, i.e. 2.2% for the seronegative group and 2.7% for the seropositive group. The frequencies of the SDF1-3’A mutation were 21.0% for the seronegative group and 15.4% for the seropositive group, and the CCR2-64I allele was found at frequencies of 12.5% for the seronegative group and 5.4% for the seropositive group. Genotype distributions were consistent with Hardy-Weinberg expectations in both groups, suggesting that none of the three mutations has a detectable selective effect. Difference in the allelic and genotypic frequencies was statistically significant for the CCR2 locus, the frequency in the seronegative group being twice that found in the seropositive group. This finding may indicate a protective effect of the CCR2-64I mutation in relation to HIV transmission. However, considering that the CCR2-64I mutation has been more strongly associated with a decreased risk for progression for AIDS than to the resistance to the HIV infection, this could reflect an aspect of population structure or a Type I error.

  4. In vivo evolution of HIV-1 co-receptor usage and sensitivity to chemokine-mediated suppression.

    Science.gov (United States)

    Scarlatti, G; Tresoldi, E; Björndal, A; Fredriksson, R; Colognesi, C; Deng, H K; Malnati, M S; Plebani, A; Siccardi, A G; Littman, D R; Fenyö, E M; Lusso, P

    1997-11-01

    Following the identification of the C-C chemokines RANTES, MIP-1alpha and MIP-1beta as major human immunodeficiency virus (HIV)-suppressive factors produced by CD8+ T cells, several chemokine receptors were found to serve as membrane co-receptors for primate immunodeficiency lentiretroviruses. The two most widely used co-receptors thus far recognized, CCR5 and CXCR4, are expressed by both activated T lymphocytes and mononuclear phagocytes. CCR5, a specific RANTES, MIP-1alpha and MIP-1 receptor, is used preferentially by non-MT2-tropic HIV-1 and HIV-2 strains and by simian immunodeficiency virus (SIV), whereas CXCR4, a receptor for the C-X-C chemokine SDF-1, is used by MT2-tropic HIV-1 and HIV-2, but not by SIV. Other receptors with a more restricted cellular distribution, such as CCR2b, CCR3 and STRL33, can also function as co-receptors for selected viral isolates. The third variable region (V3) of the gp120 envelope glycoprotein of HIV-1 has been fingered as a critical determinant of the co-receptor choice. Here, we document a consistent pattern of evolution of viral co-receptor usage and sensitivity to chemokine-mediated suppression in a longitudinal follow-up of children with progressive HIV-1 infection. Viral isolates obtained during the asymptomatic stages generally used only CCR5 as a co-receptor and were inhibited by RANTES, MIP-1alpha and MIP-1beta, but not by SDF-1. By contrast, the majority of the isolates derived after the progression of the disease were resistant to C-C chemokines, having acquired the ability to use CXCR4 and, in some cases, CCR3, while gradually losing CCR5 usage. Surprisingly, most of these isolates were also insensitive to SDF-1, even when used in combination with RANTES. An early acquisition of CXCR4 usage predicted a poor prognosis. In children who progressed to AIDS without a shift to CXCR4 usage, all the sequential isolates were CCR5-dependent but showed a reduced sensitivity to C-C chemokines. Discrete changes in the V3 domain

  5. CCR2-64I polymorphism is not associated with altered CCR5 expression or coreceptor function.

    Science.gov (United States)

    Mariani, R; Wong, S; Mulder, L C; Wilkinson, D A; Reinhart, A L; LaRosa, G; Nibbs, R; O'Brien, T R; Michael, N L; Connor, R I; Macdonald, M; Busch, M; Koup, R A; Landau, N R

    1999-03-01

    A polymorphism in the gene encoding CCR2 is associated with a delay in progression to AIDS in human immunodeficiency virus (HIV)-infected individuals. The polymorphism, CCR2-64I, changes valine 64 of CCR2 to isoleucine. However, it is not clear whether the effect on AIDS progression results from the amino acid change or whether the polymorphism marks a genetically linked, yet unidentified mutation that mediates the effect. Because the gene encoding CCR5, the major coreceptor for HIV type 1 primary isolates, lies 15 kb 3' to CCR2, linked mutations in the CCR5 promoter or other regulatory sequences could explain the association of CCR2-64I with slowed AIDS pathogenesis. Here, we show that CCR2-64I is efficiently expressed on the cell surface but does not have dominant negative activity on CCR5 coreceptor function. A panel of peripheral blood mononuclear cells (PBMC) from uninfected donors representing the various CCR5/CCR2 genotypes was assembled. Activated primary CD4(+) T cells of CCR2 64I/64I donors expressed cell surface CCR5 at levels comparable to those of CCR2 +/+ donors. A slight reduction in CCR5 expression was noted, although this was not statistically significant. CCR5 and CCR2 mRNA levels were nearly identical for each of the donor PBMC, regardless of genotype. Cell surface CCR5 and CCR2 levels were more variable than mRNA transcript levels, suggesting that an alternative mechanism may influence CCR5 cell surface levels. CCR2-64I is linked to the CCR5 promoter polymorphisms 208G, 303A, 627C, and 676A; however, in transfected promoter reporter constructs, these did not affect transcriptional activity. Taken together, these findings suggest that CCR2-64I does not act by influencing CCR5 transcription or mRNA levels.

  6. HIV restriction by APOBEC3 in humanized mice.

    Directory of Open Access Journals (Sweden)

    John F Krisko

    2013-03-01

    Full Text Available Innate immune restriction factors represent important specialized barriers to zoonotic transmission of viruses. Significant consideration has been given to their possible use for therapeutic benefit. The apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3 family of cytidine deaminases are potent immune defense molecules capable of efficiently restricting endogenous retroelements as well as a broad range of viruses including Human Immunodeficiency virus (HIV, Hepatitis B virus (HBV, Human Papilloma virus (HPV, and Human T Cell Leukemia virus (HTLV. The best characterized members of this family are APOBEC3G (A3G and APOBEC3F (A3F and their restriction of HIV. HIV has evolved to counteract these powerful restriction factors by encoding an accessory gene designated viral infectivity factor (vif. Here we demonstrate that APOBEC3 efficiently restricts CCR5-tropic HIV in the absence of Vif. However, our results also show that CXCR4-tropic HIV can escape from APOBEC3 restriction and replicate in vivo independent of Vif. Molecular analysis identified thymocytes as cells with reduced A3G and A3F expression. Direct injection of vif-defective HIV into the thymus resulted in viral replication and dissemination detected by plasma viral load analysis; however, vif-defective viruses remained sensitive to APOBEC3 restriction as extensive G to A mutation was observed in proviral DNA recovered from other organs. Remarkably, HIV replication persisted despite the inability of HIV to develop resistance to APOBEC3 in the absence of Vif. Our results provide novel insight into a highly specific subset of cells that potentially circumvent the action of APOBEC3; however our results also demonstrate the massive inactivation of CCR5-tropic HIV in the absence of Vif.

  7. Transmitted/founder and chronic subtype C HIV-1 use CD4 and CCR5 receptors with equal efficiency and are not inhibited by blocking the integrin α4β7.

    Directory of Open Access Journals (Sweden)

    Nicholas F Parrish

    Full Text Available Sexual transmission of human immunodeficiency virus type 1 (HIV-1 most often results from productive infection by a single transmitted/founder (T/F virus, indicating a stringent mucosal bottleneck. Understanding the viral traits that overcome this bottleneck could have important implications for HIV-1 vaccine design and other prevention strategies. Most T/F viruses use CCR5 to infect target cells and some encode envelope glycoproteins (Envs that contain fewer potential N-linked glycosylation sites and shorter V1/V2 variable loops than Envs from chronic viruses. Moreover, it has been reported that the gp120 subunits of certain transmitted Envs bind to the gut-homing integrin α4β7, possibly enhancing virus entry and cell-to-cell spread. Here we sought to determine whether subtype C T/F viruses, which are responsible for the majority of new HIV-1 infections worldwide, share biological properties that increase their transmission fitness, including preferential α4β7 engagement. Using single genome amplification, we generated panels of both T/F (n = 20 and chronic (n = 20 Env constructs as well as full-length T/F (n = 6 and chronic (n = 4 infectious molecular clones (IMCs. We found that T/F and chronic control Envs were indistinguishable in the efficiency with which they used CD4 and CCR5. Both groups of Envs also exhibited the same CD4+ T cell subset tropism and showed similar sensitivity to neutralization by CD4 binding site (CD4bs antibodies. Finally, saturating concentrations of anti-α4β7 antibodies failed to inhibit infection and replication of T/F as well as chronic control viruses, although the growth of the tissue culture-adapted strain SF162 was modestly impaired. These results indicate that the population bottleneck associated with mucosal HIV-1 acquisition is not due to the selection of T/F viruses that use α4β7, CD4 or CCR5 more efficiently.

  8. Variation in HIV-1 R5 macrophage-tropism correlates with sensitivity to reagents that block envelope: CD4 interactions but not with sensitivity to other entry inhibitors

    Directory of Open Access Journals (Sweden)

    Simmonds Peter

    2008-01-01

    Full Text Available Abstract Background HIV-1 R5 viruses cause most of the AIDS cases worldwide and are preferentially transmitted compared to CXCR4-using viruses. Furthermore, R5 viruses vary extensively in capacity to infect macrophages and highly macrophage-tropic variants are frequently identified in the brains of patients with dementia. Here, we investigated the sensitivity of R5 envelopes to a range of inhibitors and antibodies that block HIV entry. We studied a large panel of R5 envelopes, derived by PCR amplification without culture from brain, lymph node, blood and semen. These R5 envelopes conferred a wide range of macrophage tropism and included highly macrophage-tropic variants from brain and non-macrophage-tropic variants from lymph node. Results R5 macrophage-tropism correlated with sensitivity to inhibition by reagents that inhibited gp120:CD4 interactions. Thus, increasing macrophage-tropism was associated with increased sensitivity to soluble CD4 and to IgG-CD4 (PRO 542, but with increased resistance to the anti-CD4 monoclonal antibody (mab, Q4120. These observations were highly significant and are consistent with an increased affinity of envelope for CD4 for macrophage-tropic envelopes. No overall correlations were noted between R5 macrophage-tropism and sensitivity to CCR5 antagonists or to gp41 specific reagents. Intriguingly, there was a relationship between increasing macrophage-tropism and increased sensitivity to the CD4 binding site mab, b12, but decreased sensitivity to 2G12, a mab that binds a glycan complex on gp120. Conclusion Variation in R5 macrophage-tropism is caused by envelope variation that predominantly influences sensitivity to reagents that block gp120:CD4 interactions. Such variation has important implications for therapy using viral entry inhibitors and for the design of envelope antigens for vaccines.

  9. HIV-1 tropism testing and clinical management of CCR5 antagonists: Quebec review and recommendations.

    Science.gov (United States)

    Tremblay, Cécile; Hardy, Isabelle; Lalonde, Richard; Trottier, Benoit; Tsarevsky, Irina; Vézina, Louis-Philippe; Roger, Michel; Wainberg, Mark; Baril, Jean-Guy

    2013-01-01

    HIV-1 tropism assays play a crucial role in determining the response to CCR5 receptor antagonists. Initially, phenotypic tests were used, but limited access to these tests prompted the development of alternative strategies. Recently, genotyping tropism has been validated using a Canadian technology in clinical trials investigating the use of maraviroc in both experienced and treatment-naive patients. The present guidelines review the evidence supporting the use of genotypic assays and provide recommendations regarding tropism testing in daily clinical management.

  10. Nanoparticles containing siRNA to silence CD4 and CCR5 reduce expression of these receptors and inhibit HIV-1 infection in human female reproductive tract tissue explants

    Directory of Open Access Journals (Sweden)

    Susan K. Eszterhas

    2011-09-01

    Full Text Available Human Immunodeficiency Virus-type 1 (HIV- 1 binds to CD4 and CCR5 receptors on target cells in the human female reproductive tract. We sought to determine whether reducing levels of messenger RNA (mRNA transcripts that encode these receptors in female reproductive tract cells could protect mucosal tissue explants from HIV- 1 infection. Explants prepared from the endometrium, endocervix, and ectocervix of hysterectomy tissues from HIV-1 sero-negative women were exposed to nanoparticles containing CD4- and CCR5-specific short-interfering RNA (siRNA sequences. Explants were then exposed two days later to HIV-1, and HIV-1 reverse transcripts were measured five days post-infection. Explants treated with nanoparticles containing CD4- and CCR5-specific siRNA showed reduced levels of CD4 and CCR5 transcripts, and significantly lower levels of HIV-1 reverse transcripts compared to those treated with an irrelevant siRNA. In female reproductive tract explants and in peripheral blood cell cultures, siRNA transfection induced the secretion of IFN-alpha (IFN-α, a potent antiviral cytokine. In female mice, murine-specific Cd4-siRNA nanoparticles instilled within the uterus significantly reduced murine Cd4 transcripts by day 3. Our findings demonstrate that siRNA nanoparticles reduce expression of HIV-1 infectivity receptors in human female reproductive tract tissues and also inhibit HIV-1 infection. Murine studies demonstrate that nanoparticles can penetrate the reproductive tract tissues in vivo and silence gene expression. The induction of IFN-α after siRNA transfection can potentially contribute to the antiviral effect. These findings support the therapeutic development of nanoparticles to deliver siRNA molecules to silence host cell receptors in the female reproductive tract as a novel microbicide to inhibit mucosal HIV-1 transmission.

  11. HIV-1 envelope glycoprotein

    Science.gov (United States)

    Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

    2017-08-22

    The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

  12. HIV-1 Tropism Testing and Clinical Management of CCR5 Antagonists: Quebec Review and Recommendations

    Directory of Open Access Journals (Sweden)

    Cécile Tremblay

    2013-01-01

    Full Text Available HIV-1 tropism assays play a crucial role in determining the response to CCR5 receptor antagonists. Initially, phenotypic tests were used, but limited access to these tests prompted the development of alternative strategies. Recently, genotyping tropism has been validated using a Canadian technology in clinical trials investigating the use of maraviroc in both experienced and treatment-naive patients. The present guidelines review the evidence supporting the use of genotypic assays and provide recommendations regarding tropism testing in daily clinical management.

  13. Biological characterization of HIV type 1 envelope V3 regions from mothers and infants associated with perinatal transmission.

    Science.gov (United States)

    Matala, E; Hahn, T; Yedavalli, V R; Ahmad, N

    2001-12-10

    Our previous study has shown that the human immunodeficiency virus type 1 (HIV-1) envelope V3 region minor genotypes of infected mothers were transmitted to their infants and predominated initially as a homogeneous virus population in the infants (Ahmad N, Baroudy BM, Baker RC, et al.: J Virol 1995;69:1001-1012). Here we have characterized the biological properties, including cellular tropism, replication efficiency, cytopathic effects, and coreceptor utilization, of these V3 region isolates from mothers and infants. Nineteen V3 region sequences from three mother-infant pairs, including the minor variants of mothers and the major variants of infants as characterized in our previous study, were reciprocally inserted into an HIV-1 infectious molecular clone, pNL4-3, and chimeric viruses were generated by DNA transfections into HeLa cells. Equal amounts of chimeric viruses were then used to infect T lymphocyte cell lines (A3.01 and MT-2), primary blood lymphocytes (PBLs), primary monocyte-derived macrophages (MDMs), and coreceptor cell lines. We found that the V3 region chimeras failed to replicate in T lymphocyte cell lines but replicated in MDMs and PBLs, albeit at reduced levels compared with R5 laboratory HIV-1 strains. In addition, the V3 region chimeras were able to infect the HOS-CD4(+)CCR5(+) cell line, suggesting CCR5 coreceptor utilization. Moreover, the V3 region chimeras were unable to induce syncytia in MT-2 cells, indicative of non-syncytium-inducing (NSI) phenotypes. In conclusion, the HIV-1 minor genotypes of infected mothers with macrophage-tropic and NSI or R5 phenotypes are transmitted to their infants and are initially maintained with the same properties.

  14. Memory CD4(+)CCR5(+) T cells are abundantly present in the gut of newborn infants to facilitate mother-to-child transmission of HIV-1

    NARCIS (Netherlands)

    Bunders, Madeleine J.; van der Loos, Chris M.; Klarenbeek, Paul L.; van Hamme, John L.; Boer, Kees; Wilde, Jim C. H.; de Vries, Niek; van Lier, Rene A. W.; Kootstra, Neeltje; Pals, Steven T.; Kuijpers, Taco W.

    2012-01-01

    Despite potential clinical importance, target cells for mother-to-child transmission of HIV-1 have not yet been identified. Cord blood-derived CD4(+) T cells are largely naive and do not express CCR5, the mandatory coreceptor for transmitted HIV-1 R5 strains in infants. In the present study, we

  15. [Single nucleotide polymorphisms of HIV coreceptor CCR5 gene in Chinese Yi ethnic group and its association with HIV infection].

    Science.gov (United States)

    Ma, Li-ying; Hong, Kun-xue; Lu, Xiao-zhi; Qin, Guang-ming; Chen, Jian-ping; Chen, Kang-lin; Ruan, Yu-hua; Xing, Hui; Zhu, Jia-hong; Shao, Yi-ming

    2005-11-30

    To investigate the single nucleotide polymorphism (SNP) of HIV-1 coreceptor CCR5 gene in Chinese Yi ethnic group and the association between these SNPs and HIV/AIDS. Peripheral blood samples of 102 HIV negative persons of Chinese Yi nationality, 87 males amd 15 females, aged 23 (12-37), and 68 HIV carriers, 61 males and 7 females, aged 27 (17-51). The regulatory and structural regions of the HIV coreceptor CCR5 gene were amplified from the genomic DNA by nested PCR, each of the two regions was divided into three gene fragments which were overlapped. High throughput DHPLC was used for screening of unknown mutations in each gene fragment. The PCR products showing different peak traces from wild types in DHPLC were sequenced by forward and reverse primers respectively. The sequences were analyzed with the help of Sequence Navigator software to search for SNP loci. Statistical analysis by SPSS and PPAP softwares were made to study the association between these SNPs and HIV infection. Five SNPs (A77G, G316A, T532C, C921T, and G668A) and a AGA deletion of the 686-688 nucleotides were discovered in the coding region of this gene in Chinese Yi ethnic group. C921T mutation was a nonsense mutation, and the other SNPs (A77G, G316A, T532C, and G668A) are sense mutation, with the amino acid changes of K26R, G106R, C178R, and R223Q. Only the frequency of R223Q allelic gene was high (0.08) but those of the others were low (less than 0.01). There was no significant difference in the allele frequency between the HIV negative and HIV positive groups (all P > 0.05). Five SNP loci (T58934G, G59029A, T59353C, G59402A, and C59653T) were found in the regulatory region of CCR5 gene with high allelic frequencies of 0.1912-0.2941. Between the HIV negative and HIV positive groups, there were no differences in the SNP loc (all P > 0.05). Statistical analysis of the association between the linkage of mutation loci with HIV infection suggested a significant difference in the haplotype frequency

  16. Autologous Hematopoietic Stem Cells transplantation and genetic modification of CCR5 m303/m303 mutant patient for HIV/AIDS.

    Science.gov (United States)

    Esmaeilzadeh, Abdolreza; Farshbaf, Alieh; Erfanmanesh, Maryam

    2015-03-01

    HIV and AIDS is one of the biggest challenges all over the world. There are an approximately 34 million people living with the virus, and a large number of them become infected each year. Although there are some antiviral drugs for HIV viral load reduction, they are not sufficient. There is no cure for AIDS. Nowadays natural resistance or immunity has absorbed attentions. Because in some HIV positive patients progression trend is slow or even they indicate resistance to AIDS. One of the most interesting approaches in this category is CCR5 gene. CCR5 is a main cc-chemokine co-receptor that facilitates HIV-1 entry to macrophage and CD4(+) T cells. To now, many polymorphisms have been known by CCR5 gene that produces a truncated protein with no function. So, HIV-1 could not entry to immune-cells and the body resistant to HIV/AIDS. Δ32/Δ32 and m303/m303 homozygotes are example of mutations that could create this resistance mechanism. There is a new treatment, such as Hematopoietic Stem Cell transplantation (HSCT) in Berlin and Boston patients for Δ32/Δ32 mutation. It could eliminate co-receptor antagonist and highly-active-anti retroviral therapy (HAART) drugs problems such as toxicity, low safety and side-effects. Now there, the aim of this hypothesis will be evaluation of a new mutation CCR5 m303/m303 as autologous HSCT. This novel hypothesis indicates that autologous HSCT for m303/m303 could be effective treatment for anyone HIV/AIDS affected patient worldwide. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Solution Structure of LC4 Transmembrane Segment of CCR5

    OpenAIRE

    Miyamoto, Kazuhide; Togiya, Kayo

    2011-01-01

    CC-chemokine receptor 5 (CCR5) is a specific co-receptor allowing the entry of human immunodeficiency virus type 1 (HIV-1). The LC4 region in CCR5 is required for HIV-1 entry into the cells. In this study, the solution structure of LC4 in SDS micelles was elucidated by using standard 1H two-dimensional NMR spectroscopy, circular dichroism, and fluorescdence quenching. The LC4 structure adopts two helical structures, whereas the C-terminal part remains unstructured. The positions in which LC4 ...

  18. CCR5 is a suppressor for cortical plasticity and hippocampal learning and memory.

    Science.gov (United States)

    Zhou, Miou; Greenhill, Stuart; Huang, Shan; Silva, Tawnie K; Sano, Yoshitake; Wu, Shumin; Cai, Ying; Nagaoka, Yoshiko; Sehgal, Megha; Cai, Denise J; Lee, Yong-Seok; Fox, Kevin; Silva, Alcino J

    2016-12-20

    Although the role of CCR5 in immunity and in HIV infection has been studied widely, its role in neuronal plasticity, learning and memory is not understood. Here, we report that decreasing the function of CCR5 increases MAPK/CREB signaling, long-term potentiation (LTP), and hippocampus-dependent memory in mice, while neuronal CCR5 overexpression caused memory deficits. Decreasing CCR5 function in mouse barrel cortex also resulted in enhanced spike timing dependent plasticity and consequently, dramatically accelerated experience-dependent plasticity. These results suggest that CCR5 is a powerful suppressor for plasticity and memory, and CCR5 over-activation by viral proteins may contribute to HIV-associated cognitive deficits. Consistent with this hypothesis, the HIV V3 peptide caused LTP, signaling and memory deficits that were prevented by Ccr5 knockout or knockdown. Overall, our results demonstrate that CCR5 plays an important role in neuroplasticity, learning and memory, and indicate that CCR5 has a role in the cognitive deficits caused by HIV.

  19. Inhibition of human immunodeficiency virus replication by a dual CCR5/CXCR4 antagonist

    DEFF Research Database (Denmark)

    Princen, Katrien; Hatse, Sigrid; Vermeire, Kurt

    2004-01-01

    Here we report that the N-pyridinylmethyl cyclam analog AMD3451 has antiviral activity against a wide variety of R5, R5/X4, and X4 strains of human immunodeficiency virus type 1 (HIV-1) and HIV-2 (50% inhibitory concentration [IC(50)] ranging from 1.2 to 26.5 microM) in various T-cell lines, CCR5...... at the virus entry stage. AMD3451 dose-dependently inhibited the intracellular Ca(2+) signaling induced by the CXCR4 ligand CXCL12 in T-lymphocytic cells and in CXCR4-transfected cells, as well as the Ca(2+) flux induced by the CCR5 ligands CCL5, CCL3, and CCL4 in CCR5-transfected cells. The compound did...... not interfere with chemokine-induced Ca(2+) signaling through CCR1, CCR2, CCR3, CCR4, CCR6, CCR9, or CXCR3 and did not induce intracellular Ca(2+) signaling by itself at concentrations up to 400 microM. In freshly isolated monocytes, AMD3451 inhibited the Ca(2+) flux induced by CXCL12 and CCL4...

  20. Solution structure of LC4 transmembrane segment of CCR5.

    Directory of Open Access Journals (Sweden)

    Kazuhide Miyamoto

    Full Text Available CC-chemokine receptor 5 (CCR5 is a specific co-receptor allowing the entry of human immunodeficiency virus type 1 (HIV-1. The LC4 region in CCR5 is required for HIV-1 entry into the cells. In this study, the solution structure of LC4 in SDS micelles was elucidated by using standard 1H two-dimensional NMR spectroscopy, circular dichroism, and fluorescence quenching. The LC4 structure adopts two helical structures, whereas the C-terminal part remains unstructured. The positions in which LC4 binds to the HIV-1 inhibitory peptide LC5 were determined by docking calculations in addition to NMR data. The poses showed the importance of the hydrophobic interface of the assembled structures. The solution structure of LC4 elucidated in the present work provides a structural basis for further studies on the HIV-1 inhibitory function of the LC4 region.

  1. Solution structure of LC4 transmembrane segment of CCR5.

    Science.gov (United States)

    Miyamoto, Kazuhide; Togiya, Kayo

    2011-01-01

    CC-chemokine receptor 5 (CCR5) is a specific co-receptor allowing the entry of human immunodeficiency virus type 1 (HIV-1). The LC4 region in CCR5 is required for HIV-1 entry into the cells. In this study, the solution structure of LC4 in SDS micelles was elucidated by using standard 1H two-dimensional NMR spectroscopy, circular dichroism, and fluorescence quenching. The LC4 structure adopts two helical structures, whereas the C-terminal part remains unstructured. The positions in which LC4 binds to the HIV-1 inhibitory peptide LC5 were determined by docking calculations in addition to NMR data. The poses showed the importance of the hydrophobic interface of the assembled structures. The solution structure of LC4 elucidated in the present work provides a structural basis for further studies on the HIV-1 inhibitory function of the LC4 region.

  2. Seamless modification of wild-type induced pluripotent stem cells to the natural CCR5Δ32 mutation confers resistance to HIV infection.

    Science.gov (United States)

    Ye, Lin; Wang, Jiaming; Beyer, Ashley I; Teque, Fernando; Cradick, Thomas J; Qi, Zhongxia; Chang, Judy C; Bao, Gang; Muench, Marcus O; Yu, Jingwei; Levy, Jay A; Kan, Yuet Wai

    2014-07-01

    Individuals homozygous for the C-C chemokine receptor type 5 gene with 32-bp deletions (CCR5Δ32) are resistant to HIV-1 infection. In this study, we generated induced pluripotent stem cells (iPSCs) homozygous for the naturally occurring CCR5Δ32 mutation through genome editing of wild-type iPSCs using a combination of transcription activator-like effector nucleases (TALENs) or RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 together with the piggyBac technology. Remarkably, TALENs or CRISPR-Cas9-mediated double-strand DNA breaks resulted in up to 100% targeting of the colonies on one allele of which biallelic targeting occurred at an average of 14% with TALENs and 33% with CRISPR. Excision of the piggyBac using transposase seamlessly reproduced exactly the naturally occurring CCR5Δ32 mutation without detectable exogenous sequences. We differentiated these modified iPSCs into monocytes/macrophages and demonstrated their resistance to HIV-1 challenge. We propose that this strategy may provide an approach toward a functional cure of HIV-1 infection.

  3. The Isolation of Novel Phage Display-Derived Human Recombinant Antibodies Against CCR5, the Major Co-Receptor of HIV

    Science.gov (United States)

    Shimoni, Moria; Herschhorn, Alon; Britan-Rosich, Yelena; Kotler, Moshe; Benhar, Itai

    2013-01-01

    Abstract Selecting for antibodies against specific cell-surface proteins is a difficult task due to many unrelated proteins that are expressed on the cell surface. Here, we describe a method to screen antibody-presenting phage libraries against native cell-surface proteins. We applied this method to isolate antibodies that selectively recognize CCR5, which is the major co-receptor for HIV entry (consequently, playing a pivotal role in HIV transmission and pathogenesis). We employed a phage screening strategy by using cells that co-express GFP and CCR5, along with an excess of control cells that do not express these proteins (and are otherwise identical to the CCR5-expressing cells). These control cells are intended to remove most of the phages that bind the cells nonspecifically; thus leading to an enrichment of the phages presenting anti-CCR5-specific antibodies. Subsequently, the CCR5-presenting cells were quantitatively sorted by flow cytometry, and the bound phages were eluted, amplified, and used for further successive selection rounds. Several different clones of human single-chain Fv antibodies that interact with CCR5-expressing cells were identified. The most specific monoclonal antibody was converted to a full-length IgG and bound the second extracellular loop of CCR5. The experimental approach presented herein for screening for CCR5-specific antibodies can be applicable to screen antibody-presenting phage libraries against any cell-surface expressed protein of interest. PMID:23941674

  4. More about the Viking hypothesis of origin of the delta32 mutation in the CCR5 gene conferring resistance to HIV-1 infection.

    Science.gov (United States)

    Lucotte, Gérard; Dieterlen, Florent

    2003-11-01

    The chemokine receptor CCR5 constitutes the major coreceptor for the HIV-1, because a mutant allele of the CCR5 gene named delta32 was shown to provide to homozygotes a strong resistance against infection. In the present study the frequency of the delta32 allele was collected in 36 European populations and in Cyprus, and the highest allele frequencies were found in Nordic countries. We constructed an allele map of delta32 frequencies in Europe; the map is in accordance to the Vikings hypothesis of the origin of the mutation and his dissemination during the eighth to the tenth centuries.

  5. Impact of CCR5delta32 Host Genetic Background and Disease Progression on HIV-1 Intrahost Evolutionary Processes: Efficient Hypothesis Testing through Hierarchical Phylogenetic Models

    NARCIS (Netherlands)

    Edo-Matas, Diana; Lemey, Philippe; Tom, Jennifer A.; Serna-Bolea, Cèlia; van den Blink, Agnes E.; van 't Wout, Angélique B.; Schuitemaker, Hanneke; Suchard, Marc A.

    2011-01-01

    The interplay between C-C chemokine receptor type 5 (CCR5) host genetic background, disease progression, and intrahost HIV-1 evolutionary dynamics remains unclear because differences in viral evolution between hosts limit the ability to draw conclusions across hosts stratified into clinically

  6. Novel host restriction factors implicated in HIV-1 replication.

    Science.gov (United States)

    Ghimire, Dibya; Rai, Madhu; Gaur, Ritu

    2018-04-01

    Human immunodeficiency virus-1 (HIV-1) is known to interact with multiple host cellular proteins during its replication in the target cell. While many of these host cellular proteins facilitate viral replication, a number of them are reported to inhibit HIV-1 replication at various stages of its life cycle. These host cellular proteins, which are known as restriction factors, constitute an integral part of the host's first line of defence against the viral pathogen. Since the discovery of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G) as an HIV-1 restriction factor, several human proteins have been identified that exhibit anti-HIV-1 restriction. While each restriction factor employs a distinct mechanism of inhibition, the HIV-1 virus has equally evolved complex counter strategies to neutralize their inhibitory effect. APOBEC3G, tetherin, sterile alpha motif and histidine-aspartate domain 1 (SAMHD1), and trim-5α are some of the best known HIV-1 restriction factors that have been studied in great detail. Recently, six novel restriction factors were discovered that exhibit significant antiviral activity: endoplasmic reticulum α1,2-mannosidase I (ERManI), translocator protein (TSPO), guanylate-binding protein 5 (GBP5), serine incorporator (SERINC3/5) and zinc-finger antiviral protein (ZAP). The focus of this review is to discuss the antiviral mechanism of action of these six restriction factors and provide insights into the probable counter-evasion strategies employed by the HIV-1 virus. The recent discovery of new restriction factors substantiates the complex host-pathogen interactions occurring during HIV-1 pathogenesis and makes it imperative that further investigations are conducted to elucidate the molecular basis of HIV-1 replication.

  7. HIV-infected individuals with the CCR delta32/CCR5 genotype have lower HIV RNA levels and higher CD4 cell counts in the early years of the infection than do patients with the wild type. Copenhagen AIDS Cohort Study Group

    DEFF Research Database (Denmark)

    Katzenstein, T L; Eugen-Olsen, J; Hofmann, B

    1997-01-01

    The relations among serum HIV RNA levels, CD4 cell counts, presence of the mutant CCR5-allele in heterozygous form, and clinical outcome was analyzed in 96 patients from the Copenhagen AIDS Cohort. In the early years of the infection, patients with the CCR5 delta32/CCR5 genotype had significantly...

  8. The geographic spread of the CCR5 Delta32 HIV-resistance allele.

    Directory of Open Access Journals (Sweden)

    John Novembre

    2005-11-01

    Full Text Available The Delta32 mutation at the CCR5 locus is a well-studied example of natural selection acting in humans. The mutation is found principally in Europe and western Asia, with higher frequencies generally in the north. Homozygous carriers of the Delta32 mutation are resistant to HIV-1 infection because the mutation prevents functional expression of the CCR5 chemokine receptor normally used by HIV-1 to enter CD4+ T cells. HIV has emerged only recently, but population genetic data strongly suggest Delta32 has been under intense selection for much of its evolutionary history. To understand how selection and dispersal have interacted during the history of the Delta32 allele, we implemented a spatially explicit model of the spread of Delta32. The model includes the effects of sampling, which we show can give rise to local peaks in observed allele frequencies. In addition, we show that with modest gradients in selection intensity, the origin of the Delta32 allele may be relatively far from the current areas of highest allele frequency. The geographic distribution of the Delta32 allele is consistent with previous reports of a strong selective advantage (>10% for Delta32 carriers and of dispersal over relatively long distances (>100 km/generation. When selection is assumed to be uniform across Europe and western Asia, we find support for a northern European origin and long-range dispersal consistent with the Viking-mediated dispersal of Delta32 proposed by G. Lucotte and G. Mercier. However, when we allow for gradients in selection intensity, we estimate the origin to be outside of northern Europe and selection intensities to be strongest in the northwest. Our results describe the evolutionary history of the Delta32 allele and establish a general methodology for studying the geographic distribution of selected alleles.

  9. Proteasome-independent degradation of HIV-1 in naturally non-permissive human placental trophoblast cells

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    Barré-Sinoussi Françoise

    2009-05-01

    Full Text Available Abstract Background The human placenta-derived cell line BeWo has been demonstrated to be restrictive to cell-free HIV-1 infection. BeWo cells are however permissive to infection by VSV-G pseudotyped HIV-1, which enters cells by a receptor-independent mechanism, and to infection by HIV-1 via a cell-to-cell route. Results Here we analysed viral entry in wild type BeWo (CCR5+, CXCR4+ and BeWo-CD4+ (CD4+, CCR5+, CXCR4+ cells. We report that HIV-1 internalisation is not restricted in either cell line. Levels of internalised p24 antigen between VSV-G HIV-1 pseudotypes and R5 or X4 virions were comparable. We next analysed the fate of internalised virions; X4 and R5 HIV-1 virions were less stable over time in BeWo cells than VSV-G HIV-1 pseudotypes. We then investigated the role of the proteasome in restricting cell-free HIV-1 infection in BeWo cells using proteasome inhibitors. We observed an increase in the levels of VSV-G pseudotyped HIV-1 infection in proteasome-inhibitor treated cells, but the infection by R5-Env or X4-Env pseudotyped virions remains restricted. Conclusion Collectively these results suggest that cell-free HIV-1 infection encounters a surface block leading to a non-productive entry route, which either actively targets incoming virions for non-proteasomal degradation, and impedes their release into the cytoplasm, or causes the inactivation of mechanisms essential for viral replication.

  10. Limited protective effect of the CCR5Delta32/CCR5Delta32 genotype on human immunodeficiency virus infection incidence in a cohort of patients with hemophilia and selection for genotypic X4 virus

    DEFF Research Database (Denmark)

    Iversen, Astrid K N; Christiansen, Claus Bohn; Attermann, Jørn

    2003-01-01

    The relationship among CCR5 genotype, cytomegalovirus infection, and disease progression and death was studied among 159 human immunodeficiency virus (HIV)-infected patients with hemophilia. One patient (0.6%) had the CCR5Delta32/CCR5Delta32 genotype (which occurs in approximately 2% of the Scand......The relationship among CCR5 genotype, cytomegalovirus infection, and disease progression and death was studied among 159 human immunodeficiency virus (HIV)-infected patients with hemophilia. One patient (0.6%) had the CCR5Delta32/CCR5Delta32 genotype (which occurs in approximately 2...

  11. Maraviroc (UK-427,857), a Potent, Orally Bioavailable, and Selective Small-Molecule Inhibitor of Chemokine Receptor CCR5 with Broad-Spectrum Anti-Human Immunodeficiency Virus Type 1 Activity

    OpenAIRE

    Dorr, Patrick; Westby, Mike; Dobbs, Susan; Griffin, Paul; Irvine, Becky; Macartney, Malcolm; Mori, Julie; Rickett, Graham; Smith-Burchnell, Caroline; Napier, Carolyn; Webster, Rob; Armour, Duncan; Price, David; Stammen, Blanda; Wood, Anthony

    2005-01-01

    Maraviroc (UK-427,857) is a selective CCR5 antagonist with potent anti-human immunodeficiency virus type 1 (HIV-1) activity and favorable pharmacological properties. Maraviroc is the product of a medicinal chemistry effort initiated following identification of an imidazopyridine CCR5 ligand from a high-throughput screen of the Pfizer compound file. Maraviroc demonstrated potent antiviral activity against all CCR5-tropic HIV-1 viruses tested, including 43 primary isolates from various clades a...

  12. μ-opioid modulation of HIV-1 coreceptor expressionand HIV-1 replication

    International Nuclear Information System (INIS)

    Steele, Amber D.; Henderson, Earl E.; Rogers, Thomas J.

    2003-01-01

    A substantial proportion of HIV-1-infected individuals are intravenous drug users (IVDUs) who abuse opiates. Opioids induce a number of immunomodulatory effects that may directly influence HIV-1 disease progression. In the present report, we have investigated the effect of opioids on the expression of the major HIV-1 coreceptors CXCR4 and CCR5. For these studies we have focused on opiates which are ligands for the μ-opioid receptor. Our results show that DAMGO, a selective μ-opioid agonist, increases CXCR4 and CCR5 expression in both CD3 + lymphoblasts and CD14 + monocytes three- to fivefold. Furthermore, DAMGO-induced elevation of HIV-1 coreceptor expression translates into enhanced replication of both X4 and R5 viral strains of HIV-1. We have confirmed the role of the μ-opioid receptor based on the ability of a μ-opioid receptor-selective antagonist to block the effects of DAMGO. We have also found that morphine enhances CXCR4 and CCR5 expression and subsequently increases both X4 and R5 HIV-1 infection. We suggest that the capacity of μ-opioids to increase HIV-1 coreceptor expression and replication may promote viral binding, trafficking of HIV-1-infected cells, and enhanced disease progression

  13. HIV-1 gp41 Fusion Intermediate: A Target for HIV Therapeutics

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    Chungen Pan

    2010-02-01

    Full Text Available Human immunodeficiency virus (HIV-1 infection is initiated by the binding of gp120 envelope glyco-protein to its cell receptor (CD4 and a coreceptor (CXCR4 or CCR5, followed by a series of conformational changes in the gp41 transmembrane subunit. These changes include insertion of fusion peptide into the target cell membrane and association of C-heptad repeat (CHR peptide with the N-heptad repeat (NHR trimer, a pre-hairpin fusion intermediate. A stable six-helix bundle core is then formed, bringing the viral envelope and target cell membrane into close proximity for fusion. Peptides derived from the CHR region, such as T20 and C34, inhibit HIV-1 fusion by interacting with the gp41 fusion intermediate. A number of anti-HIV-1 peptides and small molecule compounds targeting the gp41 NHR-trimer have been identified. By combining HIV fusion/entry inhibitors targeting different sites in the gp41 fusion intermediate, a potent synergistic effect takes place, resulting in a potential new therapeutic strategy for the HIV infection/AIDS. Here, we present an overview of the current development of anti-HIV drugs, particularly those targeting the gp41 fusion intermediate.

  14. Specific interaction of CXCR4 with CD4 and CD8α: Functional analysis of the CD4/CXCR4 interaction in the context of HIV-1 envelope glycoprotein-mediated membrane fusion

    International Nuclear Information System (INIS)

    Basmaciogullari, Stephane; Pacheco, Beatriz; Bour, Stephan; Sodroski, Joseph

    2006-01-01

    We investigated possible interactions between HIV-1 receptor (CD4) and the main coreceptors CXCR4 and CCR5. We found that CD4 and CXCR4 coexpressed in 293T cells form a complex that can be immunoprecipitated with antibodies directed against the extracellular domain of either protein. Mutagenesis revealed that the CD4/CXCR4 interaction maps to two previously uncharacterized basic motifs in the cytoplasmic domain of CD4. HIV-1 envelope glycoprotein-mediated membrane fusion was found to be independent of the ability of CD4 and CXCR4 to interact, whether fusion was studied in a virus-cell or a cell-cell model. However, this interaction might explain the adaptation of HIV-1 to CXCR4 as an alternative to CCR5. We found that CXCR4 also interacts with the cytoplasmic domain of CD8α in a way that is similar to the CD4/CXCR4 interaction. The CD4/CXCR4 and CD8α/CXCR4 interactions may thus be involved in cellular signaling pathways shared by the CD4 and CD8α molecules

  15. The Role of Natural Antibodies to CC Chemokine Receptor 5 in HIV Infection

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    Assunta Venuti

    2017-10-01

    Full Text Available The CC chemokine receptor 5 (CCR5 is responsible for immune and inflammatory responses by mediation of chemotactic activity in leukocytes, although it is expressed on different cell types. It has been shown to act as co-receptor for the human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIV. Natural reactive antibodies (Abs recognizing first loop (ECL1 of CCR5 have been detected in several pools of immunoglobulins from healthy donors and from several cohorts of either HIV-exposed but uninfected subjects (ESN or HIV-infected individuals who control disease progression (LTNP as well. The reason of development of anti-CCR5 Abs in the absence of autoimmune disease is still unknown; however, the presence of these Abs specific for CCR5 or for other immune receptors and mediators probably is related to homeostasis maintenance. The majority of anti-CCR5 Abs is directed to HIV binding site (N-terminus and ECL2 of the receptor. Conversely, it is well known that ECL1 of CCR5 does not bind HIV; thus, the anti-CCR5 Abs directed to ECL1 elicit a long-lasting internalization of CCR5 but not interfere with HIV binding directly; these Abs block HIV infection in either epithelial cells or CD4+ T lymphocytes and the mechanism differs from those ones described for all other CCR5-specific ligands. The Ab-mediated CCR5 internalization allows the formation of a stable signalosome by interaction of CCR5, β-arrestin2 and ERK1 proteins. The signalosome degradation and the subsequent de novo proteins synthesis determine the CCR5 reappearance on the cell membrane with a very long-lasting kinetics (8 days. The use of monoclonal Abs to CCR5 with particular characteristics and mode of action may represent a novel mode to fight viral infection in either vaccinal or therapeutic strategies.

  16. Frequency of CCR5 Delta-32 Mutation in Human Immunodeficiency Virus (HIV-seropositive and HIV-exposed Seronegative Individuals and in General Population of Medellin, Colombia

    Directory of Open Access Journals (Sweden)

    Francisco J Díaz

    2000-04-01

    Full Text Available Repeated exposure to human immunodeficiency virus (HIV does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR: 29 HIV seropositive (SP, 39 exposed seronegative (ESN and 150 individuals as a general population sample (GPS. The frequency of the Delta-32 mutant allele was 3.8% for ESN, 2.7% for GPS and 1.7% for SP. Only one homozygous mutant genotype (Delta-32/Delta-32 was found among the ESN (2.6%. The heterozygous genotype (ccr5/Delta-32 was found in eight GPS (5.3%, in one SP (3.4% and in one ESN (2.6%. The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32. Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.

  17. Short Communication: Evolution of HIV-1 Coreceptor Usage and Coreceptor Switching During Pregnancy

    OpenAIRE

    Ransy, Doris G.; Motorina, Alena; Merindol, Natacha; Akouamba, Bertine S.; Samson, Johanne; Lie, Yolanda; Napolitano, Laura A.; Lapointe, Normand; Boucher, Marc; Soudeyns, Hugo

    2014-01-01

    Coreceptor switch from CCR5 to CXCR4 is associated with HIV disease progression. To document the evolution of coreceptor tropism during pregnancy, a longitudinal study of envelope gene sequences was performed in a group of pregnant women infected with HIV-1 of clade B (n=10) or non-B (n=9). Polymerase chain reaction (PCR) amplification of the V1-V3 region was performed on plasma viral RNA, followed by cloning and sequencing. Using geno2pheno and PSSMX4R5, the presence of X4 variants was predi...

  18. Polymorphisms of CCL3L1/CCR5 genes and recurrence of hepatitis B in liver transplant recipients.

    Science.gov (United States)

    Li, Hong; Xie, Hai-Yang; Zhou, Lin; Wang, Wei-Lin; Liang, Ting-Bo; Zhang, Min; Zheng, Shu-Sen

    2011-12-01

    The genetic diversity of chemokines and chemokine receptors has been associated with the outcome of hepatitis B virus infection. The aim of this study was to evaluate whether the copy number variation in the CCL3L1 gene and the polymorphisms of CCR5Δ32 and CCR5-2459A→G (rs1799987) are associated with recurrent hepatitis B in liver transplantation for hepatitis B virus infection-related end-stage liver disease. A total of 185 transplant recipients were enrolled in this study. The genomic DNA was extracted from whole blood, the copy number of the CCL3L1 gene was determined by a quantitative real-time PCR based assay, CCR5Δ32 was detected by a sizing PCR method, and a single-nucleotide polymorphism in CCR5-2459 was detected by restriction fragment length polymorphism PCR. No CCR5Δ32 mutation was detected in any of the individuals from China. Neither copy number variation nor polymorphism in CCR5-2459 was associated with post-transplant re-infection with hepatitis B virus. However, patients with fewer copies (CCR5 genes might be more likely to have recurrence of hepatitis B after transplantation.

  19. Why CCR2 and CCR5 blockade failed and why CCR1 blockade might still be effective in the treatment of rheumatoid arthritis

    OpenAIRE

    Lebre, M.C.; Vergunst, C.E.; Choi, I.Y.K.; Aarrass, S.; Oliveira, A.S.F.; Wyant, T.; Horuk, R.; Reedquist, K.A.; Tak, P.P.

    2011-01-01

    BACKGROUND: The aim of this study was to provide more insight into the question as to why blockade of CCR1, CCR2, and CCR5 may have failed in clinical trials in rheumatoid arthritis (RA) patients, using an in vitro monocyte migration system model. METHODOLOGY/PRINCIPAL FINDINGS: Monocytes from healthy donors (HD; n = 8) or from RA patients (for CCR2 and CCR5 antibody n = 8; for CCR1 blockade n = 13) were isolated from peripheral blood and pre-incubated with different concentrations of either ...

  20. The discovery of tropane-derived CCR5 receptor antagonists.

    Science.gov (United States)

    Armour, Duncan R; de Groot, Marcel J; Price, David A; Stammen, Blanda L C; Wood, Anthony; Perros, Manos; Burt, Catherine

    2006-04-01

    The development of compound 1, a piperidine-based CCR5 receptor antagonist with Type I CYP2D6 inhibition, into the tropane-derived analogue 5, is described. This compound, which is devoid of CYP2D6 liabilities, is a highly potent ligand for the CCR5 receptor and has broad-spectrum activity against a range of clinically relevant HIV isolates. The identification of human ether a-go-go-related gene channel inhibition within this series is described and the potential for QTc interval prolongation discussed. Furthermore, structure activity relationship (SAR) around the piperidine moiety is also described.

  1. Analysis of the CCR5 gene coding region diversity in five South American populations reveals two new non-synonymous alleles in Amerindians and high CCR5*D32 frequency in Euro-Brazilians

    Directory of Open Access Journals (Sweden)

    Angelica B.W. Boldt

    2009-01-01

    Full Text Available The CC chemokine receptor 5 (CCR5 molecule is an important co-receptor for HIV. The effect of the CCR5*D32 allele in susceptibility to HIV infection and AIDS disease is well known. Other alleles than CCR5*D32 have not been analysed before, neither in Amerindians nor in the majority of the populations all over the world. We investigated the distribution of the CCR5 coding region alleles in South Brazil and noticed a high CCR5*D32 frequency in the Euro-Brazilian population of the Paraná State (9.3%, which is the highest thus far reported for Latin America. The D32 frequency is even higher among the Euro-Brazilian Mennonites (14.2%. This allele is uncommon in Afro-Brazilians (2.0%, rare in the Guarani Amerindians (0.4% and absent in the Kaingang Amerindians and the Oriental-Brazilians. R223Q is common in the Oriental-Brazilians (7.7% and R60S in the Afro-Brazilians (5.0%. A29S and L55Q present an impaired response to b-chemokines and occurred in Afro- and Euro-Brazilians with cumulative frequencies of 4.4% and 2.7%, respectively. Two new non-synonymous alleles were found in Amerindians: C323F (g.3729G > T in Guarani (1.4% and Y68C (g.2964A > G in Kaingang (10.3%. The functional characteristics of these alleles should be defined and considered in epidemiological investigations about HIV-1 infection and AIDS incidence in Amerindian populations.

  2. Rational design of micro-RNA-like bifunctional siRNAs targeting HIV and the HIV coreceptor CCR5.

    Science.gov (United States)

    Ehsani, Ali; Saetrom, Pål; Zhang, Jane; Alluin, Jessica; Li, Haitang; Snøve, Ola; Aagaard, Lars; Rossi, John J

    2010-04-01

    Small-interfering RNAs (siRNAs) and micro-RNAs (miRNAs) are distinguished by their modes of action. SiRNAs serve as guides for sequence-specific cleavage of complementary mRNAs and the targets can be in coding or noncoding regions of the target transcripts. MiRNAs inhibit translation via partially complementary base-pairing to 3' untranslated regions (UTRs) and are generally ineffective when targeting coding regions of a transcript. In this study, we deliberately designed siRNAs that simultaneously direct cleavage and translational suppression of HIV RNAs, or cleavage of the mRNA encoding the HIV coreceptor CCR5 and suppression of translation of HIV. These bifunctional siRNAs trigger inhibition of HIV infection and replication in cell culture. The design principles have wide applications throughout the genome, as about 90% of genes harbor sites that make the design of bifunctional siRNAs possible.

  3. The case for selection at CCR5-Delta32.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Delta32 allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested that CCR5-Delta32 arose within the past 1,000 y and rose to its present high frequency (5%-14% in Europe as a result of strong positive selection, perhaps by such selective agents as the bubonic plague or smallpox during the Middle Ages. This hypothesis was based on several lines of evidence, including the absence of the allele outside of Europe and long-range linkage disequilibrium at the locus. We reevaluated this evidence with the benefit of much denser genetic maps and extensive control data. We find that the pattern of genetic variation at CCR5-Delta32 does not stand out as exceptional relative to other loci across the genome. Moreover using newer genetic maps, we estimated that the CCR5-Delta32 allele is likely to have arisen more than 5,000 y ago. While such results can not rule out the possibility that some selection may have occurred at C-C chemokine receptor 5 (CCR5, they imply that the pattern of genetic variation seen atCCR5-Delta32 is consistent with neutral evolution. More broadly, the results have general implications for the design of future studies to detect the signs of positive selection in the human genome.

  4. The case for selection at CCR5-Delta32.

    Directory of Open Access Journals (Sweden)

    Pardis C Sabeti

    2005-11-01

    Full Text Available The C-C chemokine receptor 5, 32 base-pair deletion (CCR5-Delta32 allele confers strong resistance to infection by the AIDS virus HIV. Previous studies have suggested that CCR5-Delta32 arose within the past 1,000 y and rose to its present high frequency (5%-14% in Europe as a result of strong positive selection, perhaps by such selective agents as the bubonic plague or smallpox during the Middle Ages. This hypothesis was based on several lines of evidence, including the absence of the allele outside of Europe and long-range linkage disequilibrium at the locus. We reevaluated this evidence with the benefit of much denser genetic maps and extensive control data. We find that the pattern of genetic variation at CCR5-Delta32 does not stand out as exceptional relative to other loci across the genome. Moreover using newer genetic maps, we estimated that the CCR5-Delta32 allele is likely to have arisen more than 5,000 y ago. While such results can not rule out the possibility that some selection may have occurred at C-C chemokine receptor 5 (CCR5, they imply that the pattern of genetic variation seen at CCR5-Delta32 is consistent with neutral evolution. More broadly, the results have general implications for the design of future studies to detect the signs of positive selection in the human genome.

  5. Extracellular Disulfide Bridges Serve Different Purposes in Two Homologous Chemokine Receptors, CCR1 and CCR5

    DEFF Research Database (Denmark)

    Rummel, Pia Cwarzko; Thiele, Stefanie; Hansen, Laerke Smidt

    2013-01-01

    interact with residues in the main binding crevice, we show that the 7TM-conserved bridge is essential for all types of ligand-mediated activation, whereas the chemokine-conserved bridge is dispensable for small-molecule activation in CCR1. However, in striking contrast to previous studies in other...... chemokine receptors, high affinity CCL3 chemokine binding was maintained in the absence of either bridge. In CCR5, the closest homolog to CCR1, a completely different dependency was observed as neither chemokine activation nor binding was retained in the absence of either bridge. In contrast, both bridges...... where dispensable for small-molecule activation. This indicates that CCR5 activity is independent of extracellular regions, whereas in CCR1, preserved folding of ECL2 is necessary for activation. These results indicate that conserved structural features in a receptor subgroup, does not necessarily...

  6. A Simplified Technique for Evaluating Human "CCR5" Genetic Polymorphism

    Science.gov (United States)

    Falteisek, Lukáš; Cerný, Jan; Janštová, Vanda

    2013-01-01

    To involve students in thinking about the problem of AIDS (which is important in the view of nondecreasing infection rates), we established a practical lab using a simplified adaptation of Thomas's (2004) method to determine the polymorphism of HIV co-receptor CCR5 from students' own epithelial cells. CCR5 is a receptor involved in inflammatory…

  7. Human cellular restriction factors that target HIV-1 replication

    Directory of Open Access Journals (Sweden)

    Jeang Kuan-Teh

    2009-09-01

    Full Text Available Abstract Recent findings have highlighted roles played by innate cellular factors in restricting intracellular viral replication. In this review, we discuss in brief the activities of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G, bone marrow stromal cell antigen 2 (BST-2, cyclophilin A, tripartite motif protein 5 alpha (Trim5α, and cellular microRNAs as examples of host restriction factors that target HIV-1. We point to countermeasures encoded by HIV-1 for moderating the potency of these cellular restriction functions.

  8. Frequency of CCR5Δ32 allele in healthy Bosniak population.

    Directory of Open Access Journals (Sweden)

    Grażyna Adler

    2014-08-01

    Full Text Available Recent evidence has demonstrated the role of CCR5Δ32 in a variety of human diseases: from infectious and inflammatory diseases to cancer. Several studies have confirmed that genetic variants in chemokine receptor CCR5 gene are correlated with susceptibility and resistance to HIV infection. A 32-nucleotide deletion within the CCR5 reading frame is associated with decreased susceptibility to HIV acquisition and a slower progression to AIDS. Mean frequency of CCR5Δ32 allele in Europe is approximately 10%. The highest allele frequency is observed among Nordic populations (about 12% and lower in the regions of Southeast Mediterranean (about 5%. Although the frequency of CCR5Δ32 was determined in numerous European populations, there is a lack of studies on this variant in the Bosnia and Hercegovina population. Therefore, the aim of our study was to assess the frequency of CCR5Δ32 allele in the cohort of Bosniaks and compare the results with European reports. CCR5Δ32 was detected by sequence-specific PCR in a sample of 100 healthy subjects from Bosnia and Herzegovina (DNA collected 2011-2013.  Mean age of the cohort being 58.8 (±10.7 years, with 82% of women. We identified 17 heterozygotes and one mutant homozygote in study group, with mean ∆32 allele frequency of 9.5%. CCR5∆32 allele frequency among Bosniaks is comparable to that found in Caucasian populations and follows the pattern of the north-southern gradient observed for Europe. Further studies on larger cohorts with adequate female-to-male ratio are necessary. 

  9. HIV-1 neutralizing antibodies induced by native-like envelope trimers

    NARCIS (Netherlands)

    Sanders, Rogier W.; van Gils, Marit J.; Derking, Ronald; Sok, Devin; Ketas, Thomas J.; Burger, Judith A.; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J.; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J.; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C.; Julien, Jean-Philippe; Rakasz, Eva G.; Seaman, Michael S.; Guttman, Miklos; Lee, Kelly K.; Klasse, Per Johan; Labranche, Celia; Schief, William R.; Wilson, Ian A.; Overbaugh, Julie; Burton, Dennis R.; Ward, Andrew B.; Montefiori, David C.; Dean, Hansi; Moore, John P.

    2015-01-01

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505

  10. Identification of dual-tropic HIV-1 using evolved neural networks.

    Science.gov (United States)

    Fogel, Gary B; Lamers, Susanna L; Liu, Enoch S; Salemi, Marco; McGrath, Michael S

    2015-11-01

    Blocking the binding of the envelope HIV-1 protein to immune cells is a popular concept for development of anti-HIV therapeutics. R5 HIV-1 binds CCR5, X4 HIV-1 binds CXCR4, and dual-tropic HIV-1 can bind either coreceptor for cellular entry. R5 viruses are associated with early infection and over time can evolve to X4 viruses that are associated with immune failure. Dual-tropic HIV-1 is less studied; however, it represents functional antigenic intermediates during the transition of R5 to X4 viruses. Viral tropism is linked partly to the HIV-1 envelope V3 domain, where the amino acid sequence helps dictate the receptor a particular virus will target; however, using V3 sequence information to identify dual-tropic HIV-1 isolates has remained difficult. Our goal in this study was to elucidate features of dual-tropic HIV-1 isolates that assist in the biological understanding of dual-tropism and develop an approach for their detection. Over 1559 HIV-1 subtype B sequences with known tropisms were analyzed. Each sequence was represented by 73 structural, biochemical and regional features. These features were provided to an evolved neural network classifier and evaluated using balanced and unbalanced data sets. The study resolved R5X4 viruses from R5 with an accuracy of 81.8% and from X4 with an accuracy of 78.8%. The approach also identified a set of V3 features (hydrophobicity, structural and polarity) that are associated with tropism transitions. The ability to distinguish R5X4 isolates will improve computational tropism decisions for R5 vs. X4 and assist in HIV-1 research and drug development efforts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. The frequency of CCR5 promoter polymorphisms and CCR5 32 mutation in Iranian populations

    Directory of Open Access Journals (Sweden)

    Mohammad Zare-Bidaki

    2015-04-01

    Full Text Available Evidence showed that chemokines serve as pro-migratory factors for immune cells. CCL3, CCL4 and CCL5, as the main CC  chemokines subfamily members, activate immune cells through binding to CC chemokine receptor 5 or CCR5. Macrophages, NK cells and T lymphocytes express CCR5 and thus, affected CCR5 expression or functions could be associated with altered immune responses. Deletion of 32 base pairs (D 32 in the exon 1 of the CCR5 gene, which is known as CCR5 D 32 mutation causes down regulation and malfunction of the molecule. Furthermore, it has been evidenced that three polymorphisms in the promoter region of CCR5 modulate its expression. Altered CCR5 expression in microbial infection and immune related diseases have been reported by several researchers but the role of CCR5 promoter polymorphisms and CCR5 D 32 mutation in Iranian patients suffering from these diseases are controversial. Due to the fact that Iranian people have different genetic backgrounds compared to other ethnics, hence, CCR5 promoter polymorphisms and CCR5 D 32 mutation association with the diseases may be different in Iranian patients. Therefore, this review addresses the most recent information regarding the prevalence as well as association of the mutation and polymorphisms in Iranian patients with microbial infection and immune related diseases as along with normal population.

  12. The chemokine receptor CCR5 in the central nervous system.

    Science.gov (United States)

    Sorce, Silvia; Myburgh, Renier; Krause, Karl-Heinz

    2011-02-01

    The expression and the role of the chemokine receptor CCR5 have been mainly studied in the context of HIV infection. However, this protein is also expressed in the brain, where it can be crucial in determining the outcome in response to different insults. CCR5 expression can be deleterious or protective in controlling the progression of certain infections in the CNS, but it is also emerging that it could play a role in non-infectious diseases. In particular, it appears that, in addition to modulating immune responses, CCR5 can influence neuronal survival. Here, we summarize the present knowledge about the expression of CCR5 in the brain and highlight recent findings suggesting its possible involvement in neuroprotective mechanisms. Copyright © 2011. Published by Elsevier Ltd.

  13. Genetic Polymorphism at CCL5 Is Associated With Protection in Chagas' Heart Disease: Antagonistic Participation of CCR1+ and CCR5+ Cells in Chronic Chagasic Cardiomyopathy.

    Science.gov (United States)

    Batista, Angelica Martins; Alvarado-Arnez, Lucia Elena; Alves, Silvia Marinho; Melo, Gloria; Pereira, Isabela Resende; Ruivo, Leonardo Alexandre de Souza; da Silva, Andrea Alice; Gibaldi, Daniel; da Silva, Thayse do E S Protásio; de Lorena, Virginia Maria Barros; de Melo, Adriene Siqueira; de Araújo Soares, Ana Karine; Barros, Michelle da Silva; Costa, Vláudia Maria Assis; Cardoso, Cynthia C; Pacheco, Antonio G; Carrazzone, Cristina; Oliveira, Wilson; Moraes, Milton Ozório; Lannes-Vieira, Joseli

    2018-01-01

    Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by Trypanosoma cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation mainly composed of CD8 + and CD4 + T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611) and CCL5 (rs2107538, rs2280788) and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672) and CCR5 (rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n  = 110) or cardiopathic (mild, B1, n  = 163; severe, C, n  = 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5 -403 (rs2107538) CT heterozygotes (OR = 0.5, P -value = 0.04) and T carriers (OR = 0.5, P -value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5-CCR5/CCR1 axis in CCC, mice were infected with the Colombian T. cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1 + CD8 + T cells and CD14 + macrophages were decreased, while frequencies of CCR5 + cells were increased. Importantly, CCR1 + CD14 + macrophages were mainly IL-10 + , while CCR5 + cells were mostly TNF + . CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met

  14. Genetic Polymorphism at CCL5 Is Associated With Protection in Chagas’ Heart Disease: Antagonistic Participation of CCR1+ and CCR5+ Cells in Chronic Chagasic Cardiomyopathy

    Science.gov (United States)

    Batista, Angelica Martins; Alvarado-Arnez, Lucia Elena; Alves, Silvia Marinho; Melo, Gloria; Pereira, Isabela Resende; Ruivo, Leonardo Alexandre de Souza; da Silva, Andrea Alice; Gibaldi, Daniel; da Silva, Thayse do E. S. Protásio; de Lorena, Virginia Maria Barros; de Melo, Adriene Siqueira; de Araújo Soares, Ana Karine; Barros, Michelle da Silva; Costa, Vláudia Maria Assis; Cardoso, Cynthia C.; Pacheco, Antonio G.; Carrazzone, Cristina; Oliveira, Wilson; Moraes, Milton Ozório; Lannes-Vieira, Joseli

    2018-01-01

    Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by Trypanosoma cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation mainly composed of CD8+ and CD4+ T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611) and CCL5 (rs2107538, rs2280788) and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672) and CCR5 (rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n = 110) or cardiopathic (mild, B1, n = 163; severe, C, n = 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5 −403 (rs2107538) CT heterozygotes (OR = 0.5, P-value = 0.04) and T carriers (OR = 0.5, P-value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5CCR5/CCR1 axis in CCC, mice were infected with the Colombian T. cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1+ CD8+ T cells and CD14+ macrophages were decreased, while frequencies of CCR5+ cells were increased. Importantly, CCR1+CD14+ macrophages were mainly IL-10+, while CCR5+ cells were mostly TNF+. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy) in

  15. Genetic Polymorphism at CCL5 Is Associated With Protection in Chagas’ Heart Disease: Antagonistic Participation of CCR1+ and CCR5+ Cells in Chronic Chagasic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Angelica Martins Batista

    2018-04-01

    Full Text Available Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD, a disease caused by Trypanosoma cruzi infection. A hallmark of chronic chagasic cardiomyopathy (CCC is a fibrogenic inflammation mainly composed of CD8+ and CD4+ T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines CCL2 (rs1024611 and CCL5 (rs2107538, rs2280788 and the CCL5/RANTES receptors CCR1 (rs3181077, rs1491961, rs3136672 and CCR5 (rs1799987 with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A, n = 110 or cardiopathic (mild, B1, n = 163; severe, C, n = 133. Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity, CCL5 −403 (rs2107538 CT heterozygotes (OR = 0.5, P-value = 0.04 and T carriers (OR = 0.5, P-value = 0.01 were associated with protection against CCC. To gain insight into the participation of the CCL5CCR5/CCR1 axis in CCC, mice were infected with the Colombian T. cruzi strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1+ CD8+ T cells and CD14+ macrophages were decreased, while frequencies of CCR5+ cells were increased. Importantly, CCR1+CD14+ macrophages were mainly IL-10+, while CCR5+ cells were mostly TNF+. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy

  16. HIV-1 subtype C envelope characteristics associated with divergent rates of chronic disease progression

    Directory of Open Access Journals (Sweden)

    Goulder Philip JR

    2010-11-01

    Full Text Available Abstract Background HIV-1 envelope diversity remains a significant challenge for the development of an efficacious vaccine. The evolutionary forces that shape the diversity of envelope are incompletely understood. HIV-1 subtype C envelope in particular shows significant differences and unique characteristics compared to its subtype B counterpart. Here we applied the single genome sequencing strategy of plasma derived virus from a cohort of therapy naïve chronically infected individuals in order to study diversity, divergence patterns and envelope characteristics across the entire HIV-1 subtype C gp160 in 4 slow progressors and 4 progressors over an average of 19.5 months. Results Sequence analysis indicated that intra-patient nucleotide diversity within the entire envelope was higher in slow progressors, but did not reach statistical significance (p = 0.07. However, intra-patient nucleotide diversity was significantly higher in slow progressors compared to progressors in the C2 (p = 0.0006, V3 (p = 0.01 and C3 (p = 0.005 regions. Increased amino acid length and fewer potential N-linked glycosylation sites (PNGs were observed in the V1-V4 in slow progressors compared to progressors (p = 0.009 and p = 0.02 respectively. Similarly, gp41 in the progressors was significantly longer and had fewer PNGs compared to slow progressors (p = 0.02 and p = 0.02 respectively. Positive selection hotspots mapped mainly to V1, C3, V4, C4 and gp41 in slow progressors, whereas hotspots mapped mainly to gp41 in progressors. Signature consensus sequence differences between the groups occurred mainly in gp41. Conclusions These data suggest that separate regions of envelope are under differential selective forces, and that envelope evolution differs based on disease course. Differences between slow progressors and progressors may reflect differences in immunological pressure and immune evasion mechanisms. These data also indicate that the pattern of envelope evolution

  17. Limited protective effect of the CCR5Δ32/CCR5Δ32 genotype on human immunodeficiency virus infection incidence in a cohort of patients with hemophilia and selection for genotypic X4 virus

    DEFF Research Database (Denmark)

    Iversen, Astrid K. N.; Christiansen, Claus Bohn; Attermann, Jørn

    2003-01-01

    The relationship among CCR5 genotype, cytomegalovirus infection, and disease progression and death was studied among 159 human immunodeficiency virus (HIV)–infected patients with hemophilia. One patient (0.6%) had the CCR5Δ32/CCR5Δ32 genotype (which occurs in ∼2% of the Scandinavian population...

  18. Evolution of HIV-1 coreceptor usage and coreceptor switching during pregnancy.

    Science.gov (United States)

    Ransy, Doris G; Motorina, Alena; Merindol, Natacha; Akouamba, Bertine S; Samson, Johanne; Lie, Yolanda; Napolitano, Laura A; Lapointe, Normand; Boucher, Marc; Soudeyns, Hugo

    2014-03-01

    Coreceptor switch from CCR5 to CXCR4 is associated with HIV disease progression. To document the evolution of coreceptor tropism during pregnancy, a longitudinal study of envelope gene sequences was performed in a group of pregnant women infected with HIV-1 of clade B (n=10) or non-B (n=9). Polymerase chain reaction (PCR) amplification of the V1-V3 region was performed on plasma viral RNA, followed by cloning and sequencing. Using geno2pheno and PSSMX4R5, the presence of X4 variants was predicted in nine of 19 subjects (X4 subjects) independent of HIV-1 clade. Six of nine X4 subjects exhibited CD4(+) T cell counts pregnancy, invariably accompanied by progressive increases in the PSSMX4R5 score, the net charge of V3, and the relative representation of X4 sequences. Evolution toward X4 tropism was also echoed in the primary structure of V2, as an accumulation of substitutions associated with CXCR4 tropism was seen in X4 subjects. Results from these experiments provide the first evidence of the ongoing evolution of coreceptor utilization from CCR5 to CXCR4 during pregnancy in a significant fraction of HIV-infected women. These results inform changes in host-pathogen interactions that lead to a directional shaping of viral populations and viral tropism during pregnancy, and provide insights into the biology of HIV transmission from mother to child.

  19. Elucidation of the CCR1- and CCR5-binding modes of MIP-1α by application of an NMR spectra reconstruction method to the transferred cross-saturation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiura, Chie; Ueda, Takumi; Kofuku, Yutaka; Matsumoto, Masahiko; Okude, Junya; Kondo, Keita; Shiraishi, Yutaro; Shimada, Ichio, E-mail: shimada@iw-nmr.f.u-tokyo.ac.jp [The University of Tokyo, Graduate School of Pharmaceutical Sciences (Japan)

    2015-12-15

    C–C chemokine receptor 1 (CCR1) and CCR5 are involved in various inflammation and immune responses, and regulate the progression of the autoimmune diseases differently. However, the number of residues identified at the binding interface was not sufficient to clarify the differences in the CCR1- and CCR5-binding modes to MIP-1α, because the NMR measurement time for CCR1 and CCR5 samples was limited to 24 h, due to their low stability. Here we applied a recently developed NMR spectra reconstruction method, Conservation of experimental data in ANAlysis of FOuRier, to the amide-directed transferred cross-saturation experiments of chemokine receptors, CCR1 and CCR5, embedded in lipid bilayers of the reconstituted high density lipoprotein, and MIP-1α. Our experiments revealed that the residues on the N-loop and β-sheets of MIP-1α are close to both CCR1 and CCR5, and those in the C-terminal helix region are close to CCR5. These results suggest that the genetic influence of the single nucleotide polymorphisms of MIP-1α that accompany substitution of residues in the C-terminal helix region, E57 and V63, would provide clues toward elucidating how the CCR5–MIP-1α interaction affects the progress of autoimmune diseases.

  20. Dual R3R5 tropism characterizes cerebrospinal fluid HIV-1 isolates from individuals with high cerebrospinal fluid viral load.

    Science.gov (United States)

    Karlsson, Ulf; Antonsson, Liselotte; Ljungberg, Bengt; Medstrand, Patrik; Esbjörnsson, Joakim; Jansson, Marianne; Gisslen, Magnus

    2012-09-10

    To study the use of major and alternative coreceptors by HIV-1 isolates obtained from paired plasma and cerebrospinal fluid (CSF) samples. Paired plasma and CSF isolates from HIV-1-infected individuals with varying clinical, virologic, and immunologic parameters were assessed for the ability to infect indicator cells expressing a panel of coreceptors with documented expression in the central nervous system (CNS). HIV-1 isolates obtained from plasma and CSF in 28 individuals with varying viral load, CD4 T-cell counts, and with or without AIDS-defining disease were analyzed for the ability to infect NP2.CD4 cells stably expressing a panel of HIV coreceptors (CCR5, CXCR4, CCR3, CXCR6, GPR1, APJ, ChemR23, RDC-1 or BLT1). All isolates from both plasma and CSF utilized CCR5 and/or CXCR4. However, the ability to use both CCR3 and CCR5 (R3R5) was more pronounced in CSF isolates and correlated with high CSF viral load and low CD4 T-cell count. Notably, four out of five CSF isolates of subtype C origin exhibited CXCR6 use, which coincided with high CSF viral load despite preserved CD4 T-cell counts. The use of other alternative coreceptors was less pronounced. Dual-tropic R3R5 HIV-1 isolates in CSF coincide with high CSF viral load and low CD4 T-cell counts. Frequent CXCR6 use by CSF-derived subtype C isolates indicates that subtype-specific differences in coreceptor use may exist that will not be acknowledged when assessing plasma virus isolates. The findings may also bare relevance for HIV-1 replication within the CNS, and consequently, for the neuropathogenesis of AIDS.

  1. Toll-Like Receptor 2 Ligation Enhances HIV-1 Replication in Activated CCR6+ CD4+ T Cells by Increasing Virus Entry and Establishing a More Permissive Environment to Infection.

    Science.gov (United States)

    Bolduc, Jean-François; Ouellet, Michel; Hany, Laurent; Tremblay, Michel J

    2017-02-15

    In this study, we investigated the effect of Toll-like receptor 2 (TLR2) ligation on the permissiveness of activated CD4 + T cells to HIV-1 infection by focusing our experiments on the relative susceptibility of cell subsets based on their expression of CCR6. Purified primary human CD4 + T cells were first subjected to a CD3/CD28 costimulation before treatment with the TLR2 agonist Pam3CSK4. Finally, cells were inoculated with R5-tropic HIV-1 particles that permit us to study the effect of TLR2 triggering on virus production at both population and single-cell levels. We report here that HIV-1 replication is augmented in CD3/CD28-costimulated CCR6 + CD4 + T cells upon engagement of the cell surface TLR2. Additional studies indicate that a higher virus entry and polymerization of the cortical actin are seen in this cell subset following TLR2 stimulation. A TLR2-mediated increase in the level of phosphorylated NF-κB p65 subunit was also detected in CD3/CD28-costimulated CCR6 + CD4 + T cells. We propose that, upon antigenic presentation, an engagement of TLR2 acts specifically on CCR6 + CD4 + T cells by promoting virus entry in an intracellular milieu more favorable for productive HIV-1 infection. Following primary infection, HIV-1 induces an immunological and structural disruption of the gut mucosa, leading to bacterial translocation and release of microbial components in the bloodstream. These pathogen-derived constituents include several agonists of Toll-like receptors that may affect gut-homing CD4 + T cells, such as those expressing the chemokine receptor CCR6, which are highly permissive to HIV-1 infection. We demonstrate that TLR2 ligation in CD3/CD28-costimulated CCR6 + CD4 + T cells leads to enhanced virus production. Our results highlight the potential impact of bacterial translocation on the overall permissiveness of CCR6 + CD4 + T cells to productive HIV-1 infection. Copyright © 2017 American Society for Microbiology.

  2. Epitope mapping and characterization of a novel CD4-induced human monoclonal antibody capable of neutralizing primary HIV-1 strains

    International Nuclear Information System (INIS)

    Xiang Shihua; Wang Liping; Abreu, Mariam; Huang, C.-C.; Kwong, Peter D.; Rosenberg, Eric; Robinson, James E.; Sodroski, Joseph

    2003-01-01

    Human immunodeficiency virus (HIV-1) enters target cells by binding its gp120 exterior envelope glycoprotein to CD4 and one of the chemokine receptors, CCR5 or CXCR4. CD4-induced (CD4i) antibodies bind gp120 more efficiently after CD4 binding and block the interaction with the chemokine receptor. Examples of CD4i antibodies are limited, and the prototypes of the CD4i antibodies exhibit only weak neutralizing activity against primary, clinical HIV-1 isolates. Here we report the identification of a novel antibody, E51, that exhibits CD4-induced binding to gp120 and neutralizes primary HIV-1 more efficiently than the prototypic CD4i antibodies. The E51 antibody blocks the interaction of gp120-CD4 complexes with CCR5 and binds to a highly conserved, basic gp120 element composed of the β19-strand and surrounding structures. Thus, on primary HIV-1 isolates, this gp120 region, which has been previously implicated in chemokine receptor binding, is accessible to a subset of CD4i antibodies

  3. Critical amino acids within the human immunodeficiency virus type 1 envelope glycoprotein V4 N- and C-terminals contribute to virus entry.

    Directory of Open Access Journals (Sweden)

    Yan Li

    Full Text Available The importance of the fourth variable (V4 region of the human immunodeficiency virus 1 (HIV-1 envelope glycoprotein (Env in virus infection has not been well clarified, though the polymorphism of this region has been found to be associated with disease progression to acquired immunodeficiency syndrome (AIDS. In the present work, we focused on the correlation between HIV-1 gp120 V4 region polymorphism and the function of the region on virus entry, and the possible mechanisms for how the V4 region contributes to virus infectivity. Therefore, we analyzed the differences in V4 sequences along with coreceptor usage preference from CCR5 to CXCR4 and examined the importance of the amino acids within the V4 region for CCR5- and CXCR4-tropic virus entry. In addition, we determined the influence of the V4 amino acids on Env expression and gp160 processing intracellularly, as well as the amount of Env on the pseudovirus surface. The results indicated that V4 tended to have a shorter length, fewer potential N-linked glycosylation sites (PNGS, greater evolutionary distance, and a lower negative net charge when HIV-1 isolates switched from a coreceptor usage preference for CCR5 to CXCR4. The N- and C-terminals of the HIV-1 V4 region are highly conserved and critical to maintain virus entry ability, but only the mutation at position 417 in the context of ADA (a R5-tropic HIV-1 strain resulted in the ability to utilize CXCR4. In addition, 390L, 391F, 414I, and 416L are critical to maintain gp160 processing and maturation. It is likely that the hydrophobic properties and the electrostatic surface potential of gp120, rather than the conformational structure, greatly contribute to this V4 functionality. The findings provide information to aid in the understanding of the functions of V4 in HIV-1 entry and offer a potential target to aid in the development of entry inhibitors.

  4. The Isolation of Novel Phage Display-Derived Human Recombinant Antibodies Against CCR5, the Major Co-Receptor of HIV

    OpenAIRE

    Shimoni, Moria; Herschhorn, Alon; Britan-Rosich, Yelena; Kotler, Moshe; Benhar, Itai; Hizi, Amnon

    2013-01-01

    Selecting for antibodies against specific cell-surface proteins is a difficult task due to many unrelated proteins that are expressed on the cell surface. Here, we describe a method to screen antibody-presenting phage libraries against native cell-surface proteins. We applied this method to isolate antibodies that selectively recognize CCR5, which is the major co-receptor for HIV entry (consequently, playing a pivotal role in HIV transmission and pathogenesis). We employed a phage screening s...

  5. Constitutively Active MAVS Inhibits HIV-1 Replication via Type I Interferon Secretion and Induction of HIV-1 Restriction Factors.

    Directory of Open Access Journals (Sweden)

    Sachin Gupta

    Full Text Available Type I interferon is known to inhibit HIV-1 replication through the induction of interferon stimulated genes (ISG, including a number of HIV-1 restriction factors. To better understand interferon-mediated HIV-1 restriction, we constructed a constitutively active form of the RIG-I adapter protein MAVS. Constitutive MAVS was generated by fusion of full length MAVS to a truncated form of the Epstein Barr virus protein LMP1 (ΔLMP1. Supernatant from ΔLMP1-MAVS-transfected 293T cells contained high levels of type I interferons and inhibited HIV replication in both TZM-bl and primary human CD4+ T cells. Supernatant from ΔLMP1-MAVS-transfected 293T cells also inhibited replication of VSV-G pseudotyped single cycle SIV in TZM-bl cells, suggesting restriction was post-entry and common to both HIV and SIV. Gene array analysis of ΔLMP1-MAVS-transfected 293T cells and trans-activated CD4+ T cells showed significant upregulation of ISG, including previously characterized HIV restriction factors Viperin, Tetherin, MxB, and ISG56. Interferon blockade studies implicated interferon-beta in this response. In addition to direct viral inhibition, ΔLMP1-MAVS markedly enhanced secretion of IFN-β and IL-12p70 by dendritic cells and the activation and maturation of dendritic cells. Based on this immunostimulatory activity, an adenoviral vector (Ad5 expressing ΔLMP1-MAVS was tested as a molecular adjuvant in an HIV vaccine mouse model. Ad5-Gag antigen combined with Ad5-ΔLMP1-MAVS enhanced control of vaccinia-gag replication in a mouse challenge model, with 4/5 animals showing undetectable virus following challenge. Overall, ΔLMP1-MAVS is a promising reagent to inhibit HIV-1 replication in infected tissues and enhance vaccine-mediated immune responses, while avoiding toxicity associated with systemic type I interferon administration.

  6. Decreased HIV diversity after allogeneic stem cell transplantation of an HIV-1 infected patient: a case report

    Directory of Open Access Journals (Sweden)

    Thielen Alexander

    2010-03-01

    Full Text Available Abstract The human immunodeficiency virus type 1 (HIV-1 coreceptor use and viral evolution were analyzed in blood samples from an HIV-1 infected patient undergoing allogeneic stem cell transplantation (SCT. Coreceptor use was predicted in silico from sequence data obtained from the third variable loop region of the viral envelope gene with two software tools. Viral diversity and evolution was evaluated on the same samples by Bayesian inference and maximum likelihood methods. In addition, phenotypic analysis was done by comparison of viral growth in peripheral blood mononuclear cells and in a CCR5 (R5-deficient T-cell line which was controlled by a reporter assay confirming viral tropism. In silico coreceptor predictions did not match experimental determinations that showed a consistent R5 tropism. Anti-HIV directed antibodies could be detected before and after the SCT. These preexisting antibodies did not prevent viral rebound after the interruption of antiretroviral therapy during the SCT. Eventually, transplantation and readministration of anti-retroviral drugs lead to sustained increase in CD4 counts and decreased viral load to undetectable levels. Unexpectedly, viral diversity decreased after successful SCT. Our data evidence that only R5-tropic virus was found in the patient before and after transplantation. Therefore, blocking CCR5 receptor during stem cell transplantation might have had beneficial effects and this might apply to more patients undergoing allogeneic stem cell transplantation. Furthermore, we revealed a scenario of HIV-1 dynamic different from the commonly described ones. Analysis of viral evolution shows the decrease of viral diversity even during episodes with bursts in viral load.

  7. HIV-1 Envelope Glycoprotein Trafficking through the Endosomal Recycling Compartment Is Required for Particle Incorporation.

    Science.gov (United States)

    Kirschman, Junghwa; Qi, Mingli; Ding, Lingmei; Hammonds, Jason; Dienger-Stambaugh, Krista; Wang, Jaang-Jiun; Lapierre, Lynne A; Goldenring, James R; Spearman, Paul

    2018-03-01

    The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) encodes specific trafficking signals within its long cytoplasmic tail (CT) that regulate incorporation into HIV-1 particles. Rab11-family interacting protein 1C (FIP1C) and Rab14 are host trafficking factors required for Env particle incorporation, suggesting that Env undergoes sorting from the endosomal recycling compartment (ERC) to the site of particle assembly on the plasma membrane. We disrupted outward sorting from the ERC by expressing a C-terminal fragment of FIP1C (FIP1C 560-649 ) and examined the consequences on Env trafficking and incorporation into particles. FIP1C 560-649 reduced cell surface levels of Env and prevented its incorporation into HIV-1 particles. Remarkably, Env was trapped in an exaggerated perinuclear ERC in a CT-dependent manner. Mutation of either the Yxxϕ endocytic motif or the YW 795 motif in the CT prevented Env trapping in the ERC and restored incorporation into particles. In contrast, simian immunodeficiency virus SIVmac239 Env was not retained in the ERC, while substitution of the HIV-1 CT for the SIV CT resulted in SIV Env retention in this compartment. These results provide the first direct evidence that Env traffics through the ERC and support a model whereby HIV-1 Env is specifically targeted to the ERC prior to FIP1C- and CT-dependent outward sorting to the particle assembly site on the plasma membrane. IMPORTANCE The HIV envelope protein is an essential component of the viral particle. While many aspects of envelope protein structure and function have been established, the pathway it follows in the cell prior to reaching the site of particle assembly is not well understood. The envelope protein has a very long cytoplasmic tail that interacts with the host cell trafficking machinery. Here, we utilized a truncated form of the trafficking adaptor FIP1C protein to arrest the intracellular transport of the envelope protein, demonstrating that it becomes

  8. Evolution of R5 and X4 human immunodeficiency virus type 1 gag sequences in vivo: evidence for recombination

    International Nuclear Information System (INIS)

    Rij, Ronald P. van; Worobey, Michael; Visser, Janny A.; Schuitemaker, Hanneke

    2003-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection is in general established by CCR5-utilizing (R5) virus variants, which persist throughout the course of infection. R5 HIV-1 variants evolve into CXCR4-utilizing (X4) HIV-1 variants in approximately half of the infected individuals. We have previously observed an ongoing genetic evolution with a continuous divergence of envelope gp120 sequences of coexisting R5 and X4 virus variants over time. Here, we studied evolution of gag p17 sequences in two patients who developed X4 variants in the course of infection. In contrast to the envelope gp120 sequences, gag p17 sequences of R5 and X4 virus populations intermingled in phylogenetic trees and did not diverge from each other over time. Statistical evaluation using the Shimodaira-Hasegawa test indicated that the different genomic regions evolved along different topologies, supporting the hypothesis of recombination. Therefore, our data imply that recombination between R5 and X4 HIV-1 variants occurs in vivo

  9. In vivo emergence of vicriviroc resistance in a human immunodeficiency virus type 1 subtype C-infected subject.

    Science.gov (United States)

    Tsibris, Athe M N; Sagar, Manish; Gulick, Roy M; Su, Zhaohui; Hughes, Michael; Greaves, Wayne; Subramanian, Mani; Flexner, Charles; Giguel, Françoise; Leopold, Kay E; Coakley, Eoin; Kuritzkes, Daniel R

    2008-08-01

    Little is known about the in vivo development of resistance to human immunodeficiency virus type 1 (HIV-1) CCR5 antagonists. We studied 29 subjects with virologic failure from a phase IIb study of the CCR5 antagonist vicriviroc (VCV) and identified one individual with HIV-1 subtype C who developed VCV resistance. Studies with chimeric envelopes demonstrated that changes within the V3 loop were sufficient to confer VCV resistance. Resistant virus showed VCV-enhanced replication, cross-resistance to another CCR5 antagonist, TAK779, and increased sensitivity to aminooxypentane-RANTES and the CCR5 monoclonal antibody HGS004. Pretreatment V3 loop sequences reemerged following VCV discontinuation, implying that VCV resistance has associated fitness costs.

  10. HIV type 1 chemokine receptor usage in mother-to-child transmission.

    Science.gov (United States)

    Salvatori, F; Scarlatti, G

    2001-07-01

    To investigate the role of the HIV-1 phenotype in mother-to-child HIV-1 transmission, we evaluated coreceptor usage and replication kinetics in chemokine receptor-expressing U87MG.CD4 cells of primary isolates from 32 HIV-1-infected mothers of Italian origin, none under preventive antiretroviral therapy, and from their infected infants. Five of 15 mothers of infected children and 2 of 17 mothers of uninfected children harbored viruses able to use CXCR4 as coreceptor. However, all isolates used CCR5, alone or in association with CXCR4. The replicative capacity in coreceptor-expressing cells of the viral isolates did not differ between the two groups of mothers. All mothers with an R5 virus transmitted a virus with the same coreceptor usage, whereas those four with a multitropic virus transmitted such a virus in one case. Although the presence of a mixed viral population was documented in the mothers, we did not observe transmission solely of X4 viruses. Interestingly, the only child infected with a multitropic virus carried a defective CCR5 allele. Analysis of the env V3 region of the provirus from this child revealed infection with multiple viral variants with a predominance of R5-type over X4-type sequences. These findings show that CCR5 usage of a viral isolate is not a discriminating risk factor for vertical transmission. Furthermore, X4 viruses can be transmitted to the newborn, although less frequently. In particular, we document the transmission of multiple viral variants with different coreceptor usage in a Delta32 CCR5 heterozygous child, and demonstrate that the heterozygous genotype per se does not contribute to the restriction of R5-type virus spread.

  11. Phenotype and envelope gene diversity of nef-deleted HIV-1 isolated from long-term survivors infected from a single source

    Directory of Open Access Journals (Sweden)

    Sullivan John S

    2007-07-01

    Full Text Available Abstract Background The Sydney blood bank cohort (SBBC of long-term survivors consists of multiple individuals infected with attenuated, nef-deleted variants of human immunodeficiency virus type 1 (HIV-1 acquired from a single source. Long-term prospective studies have demonstrated that the SBBC now comprises slow progressors (SP as well as long-term nonprogressors (LTNP. Convergent evolution of nef sequences in SBBC SP and LTNP indicates the in vivo pathogenicity of HIV-1 in SBBC members is dictated by factors other than nef. To better understand mechanisms underlying the pathogenicity of nef-deleted HIV-1, we examined the phenotype and env sequence diversity of sequentially isolated viruses (n = 2 from 3 SBBC members. Results The viruses characterized here were isolated from two SP spanning a three or six year period during progressive HIV-1 infection (subjects D36 and C98, respectively and from a LTNP spanning a two year period during asymptomatic, nonprogressive infection (subject C18. Both isolates from D36 were R5X4 phenotype and, compared to control HIV-1 strains, replicated to low levels in peripheral blood mononuclear cells (PBMC. In contrast, both isolates from C98 and C18 were CCR5-restricted. Both viruses isolated from C98 replicated to barely detectable levels in PBMC, whereas both viruses isolated from C18 replicated to low levels, similar to those isolated from D36. Analysis of env by V1V2 and V3 heteroduplex tracking assay, V1V2 length polymorphisms, sequencing and phylogenetic analysis showed distinct intra- and inter-patient env evolution. Conclusion Independent evolution of env despite convergent evolution of nef may contribute to the in vivo pathogenicity of nef-deleted HIV-1 in SBBC members, which may not necessarily be associated with changes in replication capacity or viral coreceptor specificity.

  12. Structure and dynamics of the gp120 V3 loop that confers noncompetitive resistance in R5 HIV-1(JR-FL to maraviroc.

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    Yuzhe Yuan

    Full Text Available Maraviroc, an (HIV-1 entry inhibitor, binds to CCR5 and efficiently prevents R5 human immunodeficiency virus type 1 (HIV-1 from using CCR5 as a coreceptor for entry into CD4(+ cells. However, HIV-1 can elude maraviroc by using the drug-bound form of CCR5 as a coreceptor. This property is known as noncompetitive resistance. HIV-1(V3-M5 derived from HIV-1(JR-FLan is a noncompetitive-resistant virus that contains five mutations (I304V/F312W/T314A/E317D/I318V in the gp120 V3 loop alone. To obtain genetic and structural insights into maraviroc resistance in HIV-1, we performed here mutagenesis and computer-assisted structural study. A series of site-directed mutagenesis experiments demonstrated that combinations of V3 mutations are required for HIV-1(JR-FLan to replicate in the presence of 1 µM maraviroc, and that a T199K mutation in the C2 region increases viral fitness in combination with V3 mutations. Molecular dynamic (MD simulations of the gp120 outer domain V3 loop with or without the five mutations showed that the V3 mutations induced (i changes in V3 configuration on the gp120 outer domain, (ii reduction of an anti-parallel β-sheet in the V3 stem region, (iii reduction in fluctuations of the V3 tip and stem regions, and (iv a shift of the fluctuation site at the V3 base region. These results suggest that the HIV-1 gp120 V3 mutations that confer maraviroc resistance alter structure and dynamics of the V3 loop on the gp120 outer domain, and enable interactions between gp120 and the drug-bound form of CCR5.

  13. A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells

    International Nuclear Information System (INIS)

    Mourez, Thomas; Mesel-Lemoine, Mariana; Combredet, Chantal; Najburg, Valerie; Cayet, Nadege; Tangy, Frederic

    2011-01-01

    We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.

  14. CCL3L1 copy number, CCR5 genotype and susceptibility to tuberculosis

    OpenAIRE

    Carpenter, Danielle; Taype, Carmen; Goulding, Jon; Levin, Mike; Eley, Brian; Anderson, Suzanne; Shaw, Marie-Anne; Armour, John AL

    2014-01-01

    Background: Tuberculosis is a major infectious disease and functional studies have provided evidence that both the chemokine MIP-1α and its receptor CCR5 play a role in susceptibility to TB. Thus by measuring copy number variation of CCL3L1, one of the genes that encode MIP-1α, and genotyping a functional promoter polymorphism -2459A > G in CCR5 (rs1799987) we investigate the influence of MIP-1α and CCR5, independently and combined, in susceptibility to clinically active TB in three populatio...

  15. Dynamics of Preferential Substrate Recognition in HIV-1 Protease: Redefining the Substrate Envelope

    Science.gov (United States)

    Özen, Ayşegül; Haliloğlu, Türkan; Schiffer, Celia A.

    2011-01-01

    HIV-1 protease (PR) permits viral maturation by processing the Gag and Gag-Pro-Pol polyproteins. Though HIV-1 PR inhibitors (PIs) are used in combination antiviral therapy, the emergence of drug resistance has limited their efficacy. The rapid evolution of HIV-1 necessitates the consideration of drug resistance in novel drug-design strategies. Drug-resistant HIV-1 PR variants, while no longer efficiently inhibited, continue to efficiently hydrolyze the natural viral substrates. Though highly diverse in sequence, the HIV-1 PR substrates bind in a conserved three-dimensional shape we defined as the “substrate envelope”. We previously showed that resistance mutations arise where PIs protrude beyond the substrate envelope, as these regions are crucial for drug binding but not for substrate recognition. Here, we extend this model by considering the role of protein dynamics in the interaction of HIV-1 PR with its substrates. Seven molecular dynamics simulations of PR-substrate complexes were performed to estimate the conformational flexibility of substrates in their complexes. Interdependency of the substrate-protease interactions may compensate for the variations in cleavage-site sequences, and explain how a diverse set of sequences can be recognized as substrates by the same enzyme. This diversity may be essential for regulating sequential processing of substrates. We also define a dynamic substrate envelope as a more accurate representation of PR-substrate interactions. This dynamic substrate envelope, described by a probability distribution function, is a powerful tool for drug design efforts targeting ensembles of resistant HIV-1 PR variants with the aim of developing drugs that are less susceptible to resistance. PMID:21762811

  16. Association of TGFβ1, TNFα, CCR2 and CCR5 gene polymorphisms in type-2 diabetes and renal insufficiency among Asian Indians

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    Gupta Arvind

    2007-04-01

    Full Text Available Abstract Background Cytokines play an important role in the development of diabetic chronic renal insufficiency (CRI. Transforming growth factor β1 (TGF β1 induces renal hypertrophy and fibrosis, and cytokines like tumor necrosis factor-alpha (TNFα, chemoattractant protein-1 (MCP-1, and regulated upon activation and normal T cell expressed and secreted (RANTES mediate macrophage infiltration into kidney. Over expression of these chemokines leads to glomerulosclerosis and interstitial fibrosis. The effect of MCP-1 and RANTES on kidney is conferred by their receptors i.e., chemokine receptor (CCR-2 and CCR-5 respectively. We tested association of nine single nucleotide polymorphisms (SNPs from TGFβ1, TNFα, CCR2 and CCR5 genes among individuals with type-2 diabetes with and without renal insufficiency. Methods Type-2 diabetes subjects with chronic renal insufficiency (serum creatinine ≥ 3.0 mg/dl constituted the cases, and matched individuals with diabetes of duration ≥ 10 years and normoalbuminuria were evaluated as controls from four centres in India. Allelic and genotypic contributions of nine SNPs from TGFβ1, TNFα, CCR2 and CCR5 genes to diabetic CRI were tested by computing odds ratio (OR and 95% confidence intervals (CI. Sub-analysis of CRI cases diabetic retinopathy status as dependent variable and SNP genotypes as independent variable in a univariate logistic regression was also performed. Results SNPs Tyr81His and Thr263Ile in TGF β1 gene were monomorphic, and Arg25Pro in TGF β1 gene and Δ32 polymorphism in CCR5 gene were minor variants (minor allele frequency A SNP of CCR5 gene has been observed and the allele 59029A seems to confer predisposition to development of diabetic CRI (OR 1.39; CI 1.04–1.84. In CRI subjects a compound group of genotypes "GA and AA" of SNP G>A -800 was found to confer predisposition for proliferative retinopathy (OR 3.03; CI 1.08–8.50, p = 0.035. Conclusion Of the various cytokine gene

  17. Anti-HIV-1 activity of anionic polymers: a comparative study of candidate microbicides

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    Li Yun-Yao

    2002-11-01

    Full Text Available Abstract Background Cellulose acetate phthalate (CAP in soluble form blocks coreceptor binding sites on the virus envelope glycoprotein gp120 and elicits gp41 six-helix bundle formation, processes involved in virus inactivation. CAP is not soluble at pH Methods Enzyme linked immunosorbent assays (ELISA were used to (1 study HIV-1 IIIB and BaL binding to micronized CAP; (2 detect virus disintegration; and (3 measure gp41 six-helix bundle formation. Cells containing integrated HIV-1 LTR linked to the β-gal gene and expressing CD4 and coreceptors CXCR4 or CCR5 were used to measure virus infectivity. Results 1 HIV-1 IIIB and BaL, respectively, effectively bound to micronized CAP. 2 The interaction between HIV-1 and micronized CAP led to: (a gp41 six-helix bundle formation; (b virus disintegration and shedding of envelope glycoproteins; and (c rapid loss of infectivity. Polymers other than CAP, except Carbomer 974P, elicited gp41 six-helix bundle formation in HIV-1 IIIB but only poly(napthalene sulfonate, in addition to CAP, had this effect on HIV-1 BaL. These polymers differed with respect to their virucidal activities, the differences being more pronounced for HIV-1 BaL. Conclusions Micronized CAP is the only candidate topical microbicide with the capacity to remove rapidly by adsorption from physiological fluids HIV-1 of both the X4 and R5 biotypes and is likely to prevent virus contact with target cells. The interaction between micronized CAP and HIV-1 leads to rapid virus inactivation. Among other anionic polymers, cellulose sulfate, BufferGel and aryl sulfonates appear most effective in this respect.

  18. CCL28 induces mucosal homing of HIV-1-specific IgA-secreting plasma cells in mice immunized with HIV-1 virus-like particles.

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    Veronica Rainone

    Full Text Available Mucosae-associated epithelial chemokine (MEC or CCL28 binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASCs in the mucosal lamina propria. The ability of this chemokine to enhance migration of IgA-ASCs to mucosal sites was assessed in a mouse immunization model using HIV-1(IIIB Virus-like particles (VLPs. Mice receiving either HIV-1(IIIB VLPs alone, CCL28 alone, or the irrelevant CCL19 chemokine were used as controls. Results showed a significantly increased CCR3 and CCR10 expression on CD19(+ splenocytes of HIV-1(IIIB VPL-CCL28-treated mice. HIV-1 Env-specific IFN-γ, IL-4 and IL-5 production, total IgA, anti-Env IgA as well as gastro-intestinal mucosal IgA-secreting plasma cells were also significantly augmented in these mice. Notably, sera and vaginal secretions from HIV-1(IIIB VLP-CCL28-treated mice exhibited an enhanced neutralizing activity against both a HIV-1/B-subtype laboratory strain and a heterologous HIV-1/C-subtype primary isolate. These data suggest that CCL28 could be useful in enhancing the IgA immune response that will likely play a pivotal role in prophylactic HIV vaccines.

  19. Host and Viral Factors in HIV-Mediated Bystander Apoptosis

    Science.gov (United States)

    Garg, Himanshu; Joshi, Anjali

    2017-01-01

    Human immunodeficiency virus (HIV) infections lead to a progressive loss of CD4 T cells primarily via the process of apoptosis. With a limited number of infected cells and vastly disproportionate apoptosis in HIV infected patients, it is believed that apoptosis of uninfected bystander cells plays a significant role in this process. Disease progression in HIV infected individuals is highly variable suggesting that both host and viral factors may influence HIV mediated apoptosis. Amongst the viral factors, the role of Envelope (Env) glycoprotein in bystander apoptosis is well documented. Recent evidence on the variability in apoptosis induction by primary patient derived Envs underscores the role of Env glycoprotein in HIV disease. Amongst the host factors, the role of C-C Chemokine Receptor type 5 (CCR5), a coreceptor for HIV Env, is also becoming increasingly evident. Polymorphisms in the CCR5 gene and promoter affect CCR5 cell surface expression and correlate with both apoptosis and CD4 loss. Finally, chronic immune activation in HIV infections induces multiple defects in the immune system and has recently been shown to accelerate HIV Env mediated CD4 apoptosis. Consequently, those factors that affect CCR5 expression and/or immune activation in turn indirectly regulate HIV mediated apoptosis making this phenomenon both complex and multifactorial. This review explores the complex role of various host and viral factors in determining HIV mediated bystander apoptosis. PMID:28829402

  20. Induction of human immunodeficiency virus (HIV-1 envelope specific cell-mediated immunity by a non-homologous synthetic peptide.

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    Ammar Achour

    2007-11-01

    Full Text Available Cell mediated immunity, including efficient CTL response, is required to prevent HIV-1 from cell-to-cell transmission. In previous investigations, we have shown that B1 peptide derived by Fourier transformation of HIV-1 primary structures and sharing no sequence homology with the parent proteins was able to generate antiserum which recognizes envelope and Tat proteins. Here we have investigated cellular immune response towards a novel non-homologous peptide, referred to as cA1 peptide.The 20 amino acid sequence of cA1 peptide was predicted using the notion of peptide hydropathic properties; the peptide is encoded by the complementary anti-sense DNA strand to the sense strand of previously described non-homologous A1 peptide. In this report we demonstrate that the cA1 peptide can be a target for major histocompatibility complex (MHC class I-restricted cytotoxic T lymphocytes in HIV-1-infected or envelope-immunized individuals. The cA1 peptide is recognized in association with different MHC class I allotypes and could prime in vitro CTLs, derived from gp160-immunized individuals capable to recognize virus variants.For the first time a theoretically designed immunogen involved in broad-based cell-immune memory activation is described. Our findings may thus contribute to the advance in vaccine research by describing a novel strategy to develop a synthetic AIDS vaccine.

  1. Delineating CD4 dependency of HIV-1: Adaptation to infect low level CD4 expressing target cells widens cellular tropism but severely impacts on envelope functionality.

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    David Beauparlant

    2017-03-01

    Full Text Available A hallmark of HIV-1 infection is the continuously declining number of the virus' predominant target cells, activated CD4+ T cells. With diminishing CD4+ T cell levels, the capacity to utilize alternate cell types and receptors, including cells that express low CD4 receptor levels such as macrophages, thus becomes crucial. To explore evolutionary paths that allow HIV-1 to acquire a wider host cell range by infecting cells with lower CD4 levels, we dissected the evolution of the envelope-CD4 interaction under in vitro culture conditions that mimicked the decline of CD4high target cells, using a prototypic subtype B, R5-tropic strain. Adaptation to CD4low targets proved to severely alter envelope functions including trimer opening as indicated by a higher affinity to CD4 and loss in shielding against neutralizing antibodies. We observed a strikingly decreased infectivity on CD4high target cells, but sustained infectivity on CD4low targets, including macrophages. Intriguingly, the adaptation to CD4low targets altered the kinetic of the entry process, leading to rapid CD4 engagement and an extended transition time between CD4 and CCR5 binding during entry. This phenotype was also observed for certain central nervous system (CNS derived macrophage-tropic viruses, highlighting that the functional perturbation we defined upon in vitro adaptation to CD4low targets occurs in vivo. Collectively, our findings suggest that CD4low adapted envelopes may exhibit severe deficiencies in entry fitness and shielding early in their evolution. Considering this, adaptation to CD4low targets may preferentially occur in a sheltered and immune-privileged environment such as the CNS to allow fitness restoring compensatory mutations to occur.

  2. Identification and characterization of HIV-2 strains obtained from asymptomatic patients that do not use CCR5 or CXCR4 coreceptors

    International Nuclear Information System (INIS)

    Azevedo-Pereira, J.M.; Santos-Costa, Q.; Mansinho, K.; Moniz-Pereira, J.

    2003-01-01

    In vivo, human immunodeficiency virus type 2 (HIV-2) infection reveals several unique characteristics when compared to HIV-1 infection, the most remarkable of which is the extraordinarily long asymptomatic period. Here we describe two HIV-2 primary isolates, obtained from asymptomatic individuals, which do not infect any coreceptor-expressing cell lines tested. In those cells, we show that the absence of replication is directly related to cell entry events. Furthermore, productive infection observed in peripheral blood mononuclear cells (PBMC) was not inhibited by natural ligands and monoclonal antibodies directed to CCR5 and CXCR4. Finally, viral entry efficiency and viral progeny production of these viruses are markedly impaired in PBMC, indicating a reduced replicative fitness of both viruses. In conclusion, our data suggest that in some HIV-2 asymptomatic individuals, the circulating viruses are unable to use the major coreceptors to infect PBMC. This fact should have important implications in HIV-2 pathogenesis and transmission

  3. Glycosylation in HIV-1 envelope glycoprotein and its biological implications

    KAUST Repository

    Ho, Yung Shwen

    2013-08-01

    Glycosylation of HIV-1 envelope proteins (Env gp120/gp41) plays a vital role in viral evasion from the host immune response, which occurs through the masking of key neutralization epitopes and the presentation of the Env glycosylation as \\'self\\' to the host immune system. Env glycosylation is generally conserved, yet its continual evolution plays an important role in modulating viral infectivity and Env immunogenicity. Thus, it is believed that Env glycosylation, which is a vital part of the HIV-1 architecture, also controls intra- and inter-clade genetic variations. Discerning intra- and inter-clade glycosylation variations could therefore yield important information for understanding the molecular and biological differences between HIV clades and may assist in effectively designing Env-based immunogens and in clearly understanding HIV vaccines. This review provides an in-depth perspective of various aspects of Env glycosylation in the context of HIV-1 pathogenesis. © 2013 Future Medicine Ltd.

  4. Suppression of APOBEC3-mediated restriction of HIV-1 by Vif

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    Yuqing eFeng

    2014-08-01

    Full Text Available The APOBEC3 restriction factors are a family of deoxycytidine deaminases that are able to suppress replication of viruses with a single-stranded DNA intermediate by inducing mutagenesis and functional inactivation of the virus. Of the seven human APOBEC3 enzymes, only APOBEC3-D, -F, -G, and -H appear relevant to restriction of HIV-1 in CD4+ T cells and will be the focus of this review. The restriction of HIV-1 occurs most potently in the absence of HIV-1 Vif that induces polyubiquitination and degradation of APOBEC3 enzymes through the proteasome pathway. To restrict HIV-1, APOBEC3 enzymes must be encapsidated into budding virions. Upon infection of the target cell during reverse transcription of the HIV-1 RNA into (-DNA APOBEC3 enzymes deaminate cytosines to forms uracils in single-stranded (- DNA regions. Upon replication of the (-DNA to (+DNA, the HIV-1 reverse transcriptase incorporates adenines opposite the uracils thereby inducing C/G to T/A mutations that can functionally inactivate HIV-1. APOBEC3G is the most studied APOBEC3 enzyme and it is known that Vif attempts to thwart APOBEC3 function not only by inducing its proteasomal degradation but by several degradation-independent mechanisms such as inhibiting APOBEC3G virion encapsidation, mRNA translation, and for those APOBEC3G molecules that still become virion encapsidated, Vif can inhibit APOBEC3G mutagenic activity. Although most Vif variants can induce efficient degradation of APOBEC3-D, -F, and -G, there appears to be differential sensitivity to Vif-mediated degradation for APOBEC3H. This review examines APOBEC3-mediated HIV restriction mechanisms, how Vif acts as a substrate receptor for a Cullin5 ubiquitin ligase complex to induce degradation of APOBEC3s, and the determinants and functional consequences of the APOBEC3 and Vif interaction from a biological and biochemical perspective.

  5. CCL3L1 copy number, CCR5 genotype and susceptibility to tuberculosis.

    Science.gov (United States)

    Carpenter, Danielle; Taype, Carmen; Goulding, Jon; Levin, Mike; Eley, Brian; Anderson, Suzanne; Shaw, Marie-Anne; Armour, John A L

    2014-01-09

    Tuberculosis is a major infectious disease and functional studies have provided evidence that both the chemokine MIP-1α and its receptor CCR5 play a role in susceptibility to TB. Thus by measuring copy number variation of CCL3L1, one of the genes that encode MIP-1α, and genotyping a functional promoter polymorphism -2459A > G in CCR5 (rs1799987) we investigate the influence of MIP-1α and CCR5, independently and combined, in susceptibility to clinically active TB in three populations, a Peruvian population (n = 1132), a !Xhosa population (n = 605) and a South African Coloured population (n = 221). The three populations include patients with clinically diagnosed pulmonary TB, as well as other, less prevalent forms of extrapulmonary TB. Copy number of CCL3L1 was measured using the paralogue ratio test and exhibited ranges between 0-6 copies per diploid genome (pdg) in Peru, between 0-12 pdg in !Xhosa samples and between 0-10 pdg in South African Coloured samples. The CCR5 promoter polymorphism was observed to differ significantly in allele frequency between populations (*A; Peru f = 0.67, !Xhosa f = 0.38, Coloured f = 0.48). The case-control association studies performed however find, surprisingly, no evidence for an influence of variation in genes coding for MIP-1α or CCR5 individually or together in susceptibility to clinically active TB in these populations.

  6. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein.

    Science.gov (United States)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena

    2014-06-15

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs. Heterologous NAb titers, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of Ab-binding reactivity revealed preferential recognition of the C1, C2, V2, V3, and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

  7. Engineering HIV-1-resistant T-cells from short-hairpin RNA-expressing hematopoietic stem/progenitor cells in humanized BLT mice.

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    Gene-Errol E Ringpis

    Full Text Available Down-regulation of the HIV-1 coreceptor CCR5 holds significant potential for long-term protection against HIV-1 in patients. Using the humanized bone marrow/liver/thymus (hu-BLT mouse model which allows investigation of human hematopoietic stem/progenitor cell (HSPC transplant and immune system reconstitution as well as HIV-1 infection, we previously demonstrated stable inhibition of CCR5 expression in systemic lymphoid tissues via transplantation of HSPCs genetically modified by lentiviral vector transduction to express short hairpin RNA (shRNA. However, CCR5 down-regulation will not be effective against existing CXCR4-tropic HIV-1 and emergence of resistant viral strains. As such, combination approaches targeting additional steps in the virus lifecycle are required. We screened a panel of previously published shRNAs targeting highly conserved regions and identified a potent shRNA targeting the R-region of the HIV-1 long terminal repeat (LTR. Here, we report that human CD4(+ T-cells derived from transplanted HSPC engineered to co-express shRNAs targeting CCR5 and HIV-1 LTR are resistant to CCR5- and CXCR4- tropic HIV-1-mediated depletion in vivo. Transduction with the combination vector suppressed CXCR4- and CCR5- tropic viral replication in cell lines and peripheral blood mononuclear cells in vitro. No obvious cytotoxicity or interferon response was observed. Transplantation of combination vector-transduced HSPC into hu-BLT mice resulted in efficient engraftment and subsequent stable gene marking and CCR5 down-regulation in human CD4(+ T-cells within peripheral blood and systemic lymphoid tissues, including gut-associated lymphoid tissue, a major site of robust viral replication, for over twelve weeks. CXCR4- and CCR5- tropic HIV-1 infection was effectively inhibited in hu-BLT mouse spleen-derived human CD4(+ T-cells ex vivo. Furthermore, levels of gene-marked CD4(+ T-cells in peripheral blood increased despite systemic infection with either

  8. Overcoming hERG affinity in the discovery of maraviroc; a CCR5 antagonist for the treatment of HIV.

    Science.gov (United States)

    Price, David A; Armour, Duncan; de Groot, Marcel; Leishman, Derek; Napier, Carolyn; Perros, Manos; Stammen, Blanda L; Wood, Anthony

    2008-01-01

    Avoiding cardiac liability associated with blockade of hERG (human ether a go-go) is key for successful drug discovery and development. This paper describes the work undertaken in the discovery of a potent CCR5 antagonist, maraviroc 34, for the treatment of HIV. In particular the use of a pharmacophore model of the hERG channel and a high throughput binding assay for the hERG channel are described that were critical to elucidate SAR to overcome hERG liabilities. The key SAR involves the introduction of polar substituents into regions of the molecule where it is postulated to undergo hydrophobic interactions with the ion channel. Within the CCR5 project there appeared to be no strong correlation between hERG affinity and physiochemical parameters such as pKa or lipophilicity. It is believed that chemists could apply these same strategies early in drug discovery to remove hERG interactions associated with lead compounds while retaining potency at the primary target.

  9. B cell clonal lineage alterations upon recombinant HIV-1 envelope immunization of Rhesus macaques

    Science.gov (United States)

    Broadly neutralizing HIV-1 antibodies (bNAbs) isolated from infected subjects display protective potential in animal models. Their elicitation by immunization is thus highly desirable. The HIV-1 envelope glycoprotein (Env) is the sole viral target of bnAbs, but is also targeted by binding, non-neutr...

  10. A Directed Molecular Evolution Approach to Improved Immunogenicity of the HIV-1 Envelope Glycoprotein

    Science.gov (United States)

    Du, Sean X.; Xu, Li; Zhang, Wenge; Tang, Susan; Boenig, Rebecca I.; Chen, Helen; Mariano, Ellaine B.; Zwick, Michael B.; Parren, Paul W. H. I.; Burton, Dennis R.; Wrin, Terri; Petropoulos, Christos J.; Ballantyne, John A.; Chambers, Michael; Whalen, Robert G.

    2011-01-01

    A prophylactic vaccine is needed to slow the spread of HIV-1 infection. Optimization of the wild-type envelope glycoproteins to create immunogens that can elicit effective neutralizing antibodies is a high priority. Starting with ten genes encoding subtype B HIV-1 gp120 envelope glycoproteins and using in vitro homologous DNA recombination, we created chimeric gp120 variants that were screened for their ability to bind neutralizing monoclonal antibodies. Hundreds of variants were identified with novel antigenic phenotypes that exhibit considerable sequence diversity. Immunization of rabbits with these gp120 variants demonstrated that the majority can induce neutralizing antibodies to HIV-1. One novel variant, called ST-008, induced significantly improved neutralizing antibody responses when assayed against a large panel of primary HIV-1 isolates. Further study of various deletion constructs of ST-008 showed that the enhanced immunogenicity results from a combination of effective DNA priming, an enhanced V3-based response, and an improved response to the constant backbone sequences. PMID:21738594

  11. An alternative conformation of the gp41 heptad repeat 1 region coiled coil exists in the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor

    International Nuclear Information System (INIS)

    Mische, Claudia C.; Yuan Wen; Strack, Bettina; Craig, Stewart; Farzan, Michael; Sodroski, Joseph

    2005-01-01

    The human immunodeficiency virus (HIV-1) transmembrane envelope glycoprotein, gp41, which mediates virus-cell fusion, exists in at least three different conformations within the trimeric envelope glycoprotein complex. The structures of the prefusogenic and intermediate states are unknown; structures representing the postfusion state have been solved. In the postfusion conformation, three helical heptad repeat 2 (HR2) regions pack in an antiparallel fashion into the hydrophobic grooves on the surface of a triple-helical coiled coil formed by the heptad repeat 1 (HR1) regions. We studied the prefusogenic conformation of gp41 by mutagenic alteration of membrane-anchored and soluble forms of the HIV-1 envelope glycoproteins. Our results indicate that, in the HIV-1 envelope glycoprotein precursor, the gp41 HR1 region is in a conformation distinct from that of a trimeric coiled coil. Thus, the central gp41 coiled coil is formed during the transition of the HIV-1 envelope glycoproteins from the precursor state to the receptor-bound intermediate

  12. Requirements for capsid-binding and an effector function in TRIMCyp-mediated restriction of HIV-1

    International Nuclear Information System (INIS)

    Diaz-Griffero, Felipe; Vandegraaff, Nick; Li Yuan; McGee-Estrada, Kathleen; Stremlau, Matthew; Welikala, Sohanya; Si Zhihai; Engelman, Alan; Sodroski, Joseph

    2006-01-01

    In owl monkeys, a retrotransposition event replaced the gene encoding the retroviral restriction factor TRIM5α with one encoding TRIMCyp, a fusion between the RING, B-box 2 and coiled-coil domains of TRIM5 and cyclophilin A. TRIMCyp restricts human immunodeficiency virus (HIV-1) infection by a mechanism dependent on the interaction of the cyclophilin A moiety and the HIV-1 capsid protein. Here, we show that infection by retroviruses other than HIV-1 can be restricted by TRIMCyp, providing an explanation for the evolutionary retention of the TRIMCyp gene in owl monkey lineages. The TRIMCyp-mediated block to HIV-1 infection occurs before the earliest step of reverse transcription. TRIMCyp-mediated restriction involves at least two functions: (1) capsid binding, which occurs most efficiently for trimeric TRIMCyp proteins that retain the coiled-coil and cyclophilin A domains, and (2) an effector function that depends upon the B-box 2 domain

  13. Envelope conformational changes induced by human immunodeficiency virus type 1 attachment inhibitors prevent CD4 binding and downstream entry events.

    Science.gov (United States)

    Ho, Hsu-Tso; Fan, Li; Nowicka-Sans, Beata; McAuliffe, Brian; Li, Chang-Ben; Yamanaka, Gregory; Zhou, Nannan; Fang, Hua; Dicker, Ira; Dalterio, Richard; Gong, Yi-Fei; Wang, Tao; Yin, Zhiwei; Ueda, Yasutsugu; Matiskella, John; Kadow, John; Clapham, Paul; Robinson, James; Colonno, Richard; Lin, Pin-Fang

    2006-04-01

    BMS-488043 is a small-molecule human immunodeficiency virus type 1 (HIV-1) CD4 attachment inhibitor with demonstrated clinical efficacy. The compound inhibits soluble CD4 (sCD4) binding to the 11 distinct HIV envelope gp120 proteins surveyed. Binding of BMS-488043 and that of sCD4 to gp120 are mutually exclusive, since increased concentrations of one can completely block the binding of the other without affecting the maximal gp120 binding capacity. Similarly, BMS-488043 inhibited virion envelope trimers from binding to sCD4-immunoglobulin G (IgG), with decreasing inhibition as the sCD4-IgG concentration increased, and BMS-488043 blocked the sCD4-induced exposure of the gp41 groove in virions. In both virion binding assays, BMS-488043 was active only when added prior to sCD4. Collectively, these results indicate that obstruction of gp120-sCD4 interactions is the primary inhibition mechanism of this compound and that compound interaction with envelope must precede CD4 binding. By three independent approaches, BMS-488043 was further shown to induce conformational changes within gp120 in both the CD4 and CCR5 binding regions. These changes likely prevent gp120-CD4 interactions and downstream entry events. However, BMS-488043 could only partially inhibit CD4 binding to an HIV variant containing a specific envelope truncation and altered gp120 conformation, despite effectively inhibiting the pseudotyped virus infection. Taken together, BMS-488043 inhibits viral entry primarily through altering the envelope conformation and preventing CD4 binding, and other downstream entry events could also be inhibited as a result of these induced conformational changes.

  14. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein

    DEFF Research Database (Denmark)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma

    2014-01-01

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycop...

  15. A Linear Epitope in the N-Terminal Domain of CCR5 and Its Interaction with Antibody.

    Directory of Open Access Journals (Sweden)

    Benny Chain

    Full Text Available The CCR5 receptor plays a role in several key physiological and pathological processes and is an important therapeutic target. Inhibition of the CCR5 axis by passive or active immunisation offers one very selective strategy for intervention. In this study we define a new linear epitope within the extracellular domain of CCR5 recognised by two independently produced monoclonal antibodies. A short peptide encoding the linear epitope can induce antibodies which recognise the intact receptor when administered colinear with a tetanus toxoid helper T cell epitope. The monoclonal antibody RoAb 13 is shown to bind to both cells and peptide with moderate to high affinity (6x10^8 and 1.2x107 M-1 respectively, and binding to the peptide is enhanced by sulfation of tyrosines at positions 10 and 14. RoAb13, which has previously been shown to block HIV infection, also blocks migration of monocytes in response to CCR5 binding chemokines and to inflammatory macrophage conditioned medium. A Fab fragment of RoAb13 has been crystallised and a structure of the antibody is reported to 2.1 angstrom resolution.

  16. Structure of CC Chemokine Receptor 5 with a Potent Chemokine Antagonist Reveals Mechanisms of Chemokine Recognition and Molecular Mimicry by HIV

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi; Han, Gye Won; Abagyan, Ruben; Wu, Beili; Stevens, Raymond C.; Cherezov, Vadim; Kufareva, Irina; Handel, Tracy M. (USC); (Chinese Aca. Sci.); (UCSD)

    2017-06-01

    CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases.

  17. Maraviroc is associated with latent HIV-1 reactivation through NF-κB activation in resting CD4+ T cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy.

    Science.gov (United States)

    Madrid-Elena, Nadia; García-Bermejo, María Laura; Serrano-Villar, Sergio; Díaz-de Santiago, Alberto; Sastre, Beatriz; Gutiérrez, Carolina; Dronda, Fernando; Coronel Díaz, María; Domínguez, Ester; López-Huertas, María Rosa; Hernández-Novoa, Beatriz; Moreno, Santiago

    2018-02-14

    Maraviroc is a CCR5 antagonist used in the treatment of HIV-1 infection. We and others have suggested that maraviroc could reactivate latent HIV-1. To test the latency reversing potential of maraviroc and the mechanisms involved, we performed a phase-II, single-center, open-label study in which maraviroc was administered for 10 days to 20 HIV-1-infected individuals on suppressive antiretroviral therapy (Eudra CT: 2012-003215-66). All patients completed full maraviroc dosing and follow up. The primary endpoint was to study whether maraviroc may reactivate HIV-1 latency, eliciting signalling pathways involved in the viral reactivation. An increase in HIV-1 transcription in resting CD4 + T-cells, estimated by HIV-1 unspliced RNA, was observed. Moreover, activation of the NF-κB transcription factor was observed in these cells. In contrast, AP-1 and NFAT activity was not detected. To elucidate the mechanism of NF-κB activation by maraviroc, we have evaluated in HeLa P4 C5 cells, which stably express CCR5, if maraviroc could be acting as a partial CCR5-agonist, with no other mechanisms or pathways involved. Our results show that maraviroc can induce NF-κB activity and NF-κB target genes expression by CCR5 binding, since the use of TAK779, a CCR5 inhibitor, blocked NF-κB activation and functionality. Taken together, we show that maraviroc may have a role in the activation of latent virus transcription through the activation of NF-κB as a result of binding CCR5. Our results strongly support a novel use of maraviroc as a potential latency reversal agent in HIV-1-infected patients. IMPORTANCE HIV-1 persistence in a small pool of long-lived latently infected resting CD4 + T-cells is a major barrier to viral eradication in HIV-1-infected patients on antiretroviral therapy. A potential strategy to cure HIV-1-infection is the use of latency reversing agents to eliminate the reservoirs established in resting CD4 + T-cells. As no drug has been shown to be completely

  18. Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

    Science.gov (United States)

    Joshi, Anjali; Lee, Raphael T. C.; Mohl, Jonathan; Sedano, Melina; Khong, Wei Xin; Ng, Oon Tek; Maurer-Stroh, Sebastian; Garg, Himanshu

    2014-01-01

    The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4+ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4+ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype. PMID:24265318

  19. Frequency of CCR5delta32 in Brazilian populations

    Directory of Open Access Journals (Sweden)

    A.E. Vargas

    2006-03-01

    Full Text Available A sample of 103 randomly chosen healthy individuals from Alegrete, RS, Brazil, was tested for the CCR5delta32 allele, which is known to influence susceptibility to HIV-1 infection. The CCR5delta32 allele was identified by PCR amplification using specific primers flanking the region of deletion, followed by electrophoresis on a 3% agarose gel. The data obtained were compared to those reported for other populations and interpreted in terms of Brazilian history. The individuals studied came from a highly admixed population. Most of them were identified as white (N = 59, while blacks and browns (mulattoes were N = 13 and N = 31, respectively. The observed frequencies, considering the white, black and brown samples (6.8, 3.8, and 6.4%, respectively, suggest an important European parental contribution, even in populations identified as black and brown. However, in Brazil as a whole, this allele shows gradients indicating a relatively good correlation with the classification based on skin color and other physical traits, used here to define major Brazilian population groups.

  20. Analysis of Select Herpes Simplex Virus 1 (HSV-1) Proteins for Restriction of Human Immunodeficiency Virus Type 1 (HIV-1): HSV-1 gM Protein Potently Restricts HIV-1 by Preventing Intracellular Transport and Processing of Env gp160.

    Science.gov (United States)

    Polpitiya Arachchige, Sachith; Henke, Wyatt; Pramanik, Ankita; Kalamvoki, Maria; Stephens, Edward B

    2018-01-15

    Virus-encoded proteins that impair or shut down specific host cell functions during replication can be used as probes to identify potential proteins/pathways used in the replication of viruses from other families. We screened nine proteins from herpes simplex virus 1 (HSV-1) for the ability to enhance or restrict human immunodeficiency virus type 1 (HIV-1) replication. We show that several HSV-1 proteins (glycoprotein M [gM], US3, and UL24) potently restricted the replication of HIV-1. Unlike UL24 and US3, which reduced viral protein synthesis, we observed that gM restriction of HIV-1 occurred through interference with the processing and transport of gp160, resulting in a significantly reduced level of mature gp120/gp41 released from cells. Finally, we show that an HSV-1 gM mutant lacking the majority of the C-terminal domain (HA-gM[Δ345-473]) restricted neither gp160 processing nor the release of infectious virus. These studies identify proteins from heterologous viruses that can restrict viruses through novel pathways. IMPORTANCE HIV-1 infection of humans results in AIDS, characterized by the loss of CD4 + T cells and increased susceptibility to opportunistic infections. Both HIV-1 and HSV-1 can infect astrocytes and microglia of the central nervous system (CNS). Thus, the identification of HSV-1 proteins that directly restrict HIV-1 or interfere with pathways required for HIV-1 replication could lead to novel antiretroviral strategies. The results of this study show that select viral proteins from HSV-1 can potently restrict HIV-1. Further, our results indicate that the gM protein of HSV-1 restricts HIV-1 through a novel pathway by interfering with the processing of gp160 and its incorporation into virus maturing from the cell. Copyright © 2018 American Society for Microbiology.

  1. A new multiplex PCR strategy for the simultaneous determination of four genetic polymorphisms affecting HIV-1 disease progression

    DEFF Research Database (Denmark)

    Kristiansen, Thomas Birk; Knudsen, Troels Bygum; Ohlendorff, Stine Dahl

    2001-01-01

    The CCR5 Delta32, CCR2 64I, SDF1 3'A, and CCR5 promoter 59029 polymorphisms have been suggested to influence HIV-1 disease progression. Furthermore, the CCR5 Delta32 and the CCR2 64I polymorphisms have been associated with various other diseases. The purpose of the present study was to develop......, SDF1 3'A, and CCR5 promoter 59029 A/G polymorphisms....

  2. Design and validation of new genotypic tools for easy and reliable estimation of HIV tropism before using CCR5 antagonists.

    Science.gov (United States)

    Poveda, Eva; Seclén, Eduardo; González, María del Mar; García, Federico; Chueca, Natalia; Aguilera, Antonio; Rodríguez, Jose Javier; González-Lahoz, Juan; Soriano, Vincent

    2009-05-01

    Genotypic tools may allow easier and less expensive estimation of HIV tropism before prescription of CCR5 antagonists compared with the Trofile assay (Monogram Biosciences, South San Francisco, CA, USA). Paired genotypic and Trofile results were compared in plasma samples derived from the maraviroc expanded access programme (EAP) in Europe. A new genotypic approach was built to improve the sensitivity to detect X4 variants based on an optimization of the webPSSM algorithm. Then, the new tool was validated in specimens from patients included in the ALLEGRO trial, a multicentre study conducted in Spain to assess the prevalence of R5 variants in treatment-experienced HIV patients. A total of 266 specimens from the maraviroc EAP were tested. Overall geno/pheno concordance was above 72%. A high specificity was generally seen for the detection of X4 variants using genotypic tools (ranging from 58% to 95%), while sensitivity was low (ranging from 31% to 76%). The PSSM score was then optimized to enhance the sensitivity to detect X4 variants changing the original threshold for R5 categorization. The new PSSM algorithms, PSSM(X4R5-8) and PSSM(SINSI-6.4), considered as X4 all V3 scoring values above -8 or -6.4, respectively, increasing the sensitivity to detect X4 variants up to 80%. The new algorithms were then validated in 148 specimens derived from patients included in the ALLEGRO trial. The sensitivity/specificity to detect X4 variants was 93%/69% for PSSM(X4R5-8) and 93%/70% for PSSM(SINSI-6.4). PSSM(X4R5-8) and PSSM(SINSI-6.4) may confidently assist therapeutic decisions for using CCR5 antagonists in HIV patients, providing an easier and rapid estimation of tropism in clinical samples.

  3. Multiple Restrictions of Human Immunodeficiency Virus Type 1 in Feline Cells▿

    Science.gov (United States)

    Münk, Carsten; Zielonka, Jörg; Constabel, Hannelore; Kloke, Björn-Philipp; Rengstl, Benjamin; Battenberg, Marion; Bonci, Francesca; Pistello, Mauro; Löchelt, Martin; Cichutek, Klaus

    2007-01-01

    The productive replication of human immunodeficiency virus type 1 (HIV-1) occurs exclusively in defined cells of human or chimpanzee origin, explaining why heterologous animal models for HIV replication, pathogenesis, vaccination, and therapy are not available. This lack of an animal model for HIV-1 studies prompted us to examine the susceptibility of feline cells in order to evaluate the cat (Felis catus) as an animal model for studying HIV-1. Here, we report that feline cell lines harbor multiple restrictions with respect to HIV-1 replication. The feline CD4 receptor does not permit virus infection. Feline T-cell lines MYA-1 and FeT-1C showed postentry restrictions resulting in low HIV-1 luciferase reporter activity and low expression of viral Gag-Pol proteins when pseudotyped vectors were used. Feline fibroblastic CrFK and KE-R cells, expressing human CD4 and CCR5, were very permissive for viral entry and HIV-long terminal repeat-driven expression but failed to support spreading infection. KE-R cells displayed a profound block with respect to release of HIV-1 particles. In contrast, CrFK cells allowed very efficient particle production; however, the CrFK cell-derived HIV-1 particles had low specific infectivity. We subsequently identified feline apolipoprotein B-editing catalytic polypeptide 3 (feAPOBEC3) proteins as active inhibitors of HIV-1 particle infectivity. CrFK cells express at least three different APOBEC3s: APOBEC3C, APOBEC3H, and APOBEC3CH. While the feAPOBEC3C did not significantly inhibit HIV-1, the feAPOBEC3H and feAPOBEC3CH induced G to A hypermutations of the viral cDNA and reduced the infectivity ∼10- to ∼40-fold. PMID:17459941

  4. HIV Co-receptor usage in HIV-related non-hodgkin's lymphoma

    Directory of Open Access Journals (Sweden)

    Reid Erin

    2012-03-01

    Full Text Available Abstract In this study 15 banked samples of HIV-related Non-Hodgkin's Lymphoma (NHL cases were tested for HIV co-receptor usage and SDF1 3'A polymorphism. Reportable tropism from 9 plasma samples had 1 (11.1% HIV case with CXCR4 and 8 (88.9% with CCR5 usage, even though most of the cases occurred at a late stage of HIV (2/3 had CD4 counts below 200, where expected CXCR4 usage would be 60%. Based on the expected proportion of less than 50% CCR5 in chronically infected individuals, this would suggest that in NHL may be associated with CCR5 usage (P = 0.04.

  5. P2X1 Receptor Antagonists Inhibit HIV-1 Fusion by Blocking Virus-Coreceptor Interactions.

    Science.gov (United States)

    Giroud, Charline; Marin, Mariana; Hammonds, Jason; Spearman, Paul; Melikyan, Gregory B

    2015-09-01

    HIV-1 Env glycoprotein-mediated fusion is initiated upon sequential binding of Env to CD4 and the coreceptor CXCR4 or CCR5. Whereas these interactions are thought to be necessary and sufficient to promote HIV-1 fusion, other host factors can modulate this process. Previous studies reported potent inhibition of HIV-1 fusion by selective P2X1 receptor antagonists, including NF279, and suggested that these receptors play a role in HIV-1 entry. Here we investigated the mechanism of antiviral activity of NF279 and found that this compound does not inhibit HIV-1 fusion by preventing the activation of P2X1 channels but effectively blocks the binding of the virus to CXCR4 or CCR5. The notion of an off-target effect of NF279 on HIV-1 fusion is supported by the lack of detectable expression of P2X1 receptors in cells used in fusion experiments and by the fact that the addition of ATP or the enzymatic depletion of ATP in culture medium does not modulate viral fusion. Importantly, NF279 fails to inhibit HIV-1 fusion with cell lines and primary macrophages when added at an intermediate stage downstream of Env-CD4-coreceptor engagement. Conversely, in the presence of NF279, HIV-1 fusion is arrested downstream of CD4 binding but prior to coreceptor engagement. NF279 also antagonizes the signaling function of CCR5, CXCR4, and another chemokine receptor, as evidenced by the suppression of calcium responses elicited by specific ligands and by recombinant gp120. Collectively, our results demonstrate that NF279 is a dual HIV-1 coreceptor inhibitor that interferes with the functional engagement of CCR5 and CXCR4 by Env. Inhibition of P2X receptor activity suppresses HIV-1 fusion and replication, suggesting that P2X signaling is involved in HIV-1 entry. However, mechanistic experiments conducted in this study imply that P2X1 receptor is not expressed in target cells or involved in viral fusion. Instead, we found that inhibition of HIV-1 fusion by a specific P2X1 receptor antagonist, NF

  6. Transgene vaccination using Ulex europaeus agglutinin I (UEA-1) for targeted mucosal immunization against HIV-1 envelope.

    Science.gov (United States)

    Wang, Xinhai; Kochetkova, Irina; Haddad, Asmahan; Hoyt, Teri; Hone, David M; Pascual, David W

    2005-05-31

    Receptor-mediated gene transfer using an M cell ligand has been shown to be an efficient method for mucosal DNA immunization. To investigate further into alternative M cell ligands, the plant lectin, Ulex europaeus agglutinin I (UEA-1), was tested. UEA-1 binds to human intestinal Caco-2 cells, and these cells can be transfected with poly-l-lysine (PL)-conjugated UEA-1 for expression of reporter cDNAs. When tested in vivo, mice nasally immunized with UEA-1-PL complexed to plasmid encoding HIV-1 envelope showed elevated systemic and mucosal antibody responses, and these were supported by tissue antibody-forming cells. Likewise, elevated envelope-specific CTLs were induced. Thus, UEA-1 mediated DNA delivery represents an alternative mucosal formulation for inducing humoral and cellular immunity against HIV-1.

  7. Correlating HIV tropism with immunological response under combination antiretroviral therapy.

    Science.gov (United States)

    Bader, J; Schöni-Affolter, F; Böni, J; Gorgievski-Hrisoho, M; Martinetti, G; Battegay, M; Klimkait, T

    2016-09-01

    A significant percentage of patients infected with HIV-1 experience only suboptimal CD4 cell recovery while treated with combination therapy (cART). It is still unclear whether viral properties such as cell tropism play a major role in this incomplete immune response. This study therefore intended to follow the tropism evolution of the HIV-1 envelope during periods of suppressive cART. Viruses from two distinct patient groups, one with good and another one with poor CD4 recovery after 5 years of suppressive cART, were genotypically analysed for viral tropism at baseline and at the end of the study period. Patients with CCR5-tropic CC-motif chemokine receptor 5 viruses at baseline tended to maintain this tropism to the study end. Patients who had a CXCR4-tropic CXC-motif chemokine receptor 4 virus at baseline were overrepresented in the poor CD4 recovery group. Overall, however, the majority of patients presented with CCR5-tropic viruses at follow-up. Our data lend support to the hypothesis that tropism determination can be used as a parameter for disease progression even if analysed long before the establishment of a poorer immune response. Moreover, the lasting predominating CCR5-tropism during periods of full viral control suggests the involvement of cellular mechanisms that preferentially reduce CXCR4-tropic viruses during cART. © 2016 British HIV Association.

  8. Distribution of HIV-1 resistance-conferring polymorphic alleles SDF ...

    Indian Academy of Sciences (India)

    Polymorphic allelic variants of chemokine receptors CCR2 and CCR5, as well as of stromal-derived factor-1 SDF-1, the ligand for the chemokine receptor CXCR4, are known to have protective effects against HIV-1 infection and to be involved with delay in disease progression. We have studied the DNA polymorphisms at ...

  9. Resistance of a human immunodeficiency virus type 1 isolate to a small molecule CCR5 inhibitor can involve sequence changes in both gp120 and gp41

    International Nuclear Information System (INIS)

    Anastassopoulou, Cleo G.; Ketas, Thomas J.; Depetris, Rafael S.; Thomas, Antonia M.; Klasse, Per Johan; Moore, John P.

    2011-01-01

    Here, we describe the genetic pathways taken by a human immunodeficiency virus type 1 (HIV-1) isolate, D101.12, to become resistant to the small molecule CCR5 inhibitor, vicriviroc (VCV), in vitro. Resistant D101.12 variants contained at least one substitution in the gp120 V3 region (H308P), plus one of two patterns of gp41 sequence changes involving the fusion peptide (FP) and a downstream residue: G514V+V535M or M518V+F519L+V535M. Studies of Env-chimeric and point-substituted viruses in peripheral blood mononuclear cells (PBMC) and TZM-bl cells showed that resistance can arise from the cooperative action of gp120 and gp41 changes, while retaining CCR5 usage. Modeling the VCV inhibition data from the two cell types suggests that D101.12 discriminates between high- and low-VCV affinity forms of CCR5 less than D1/85.16, a resistant virus with three FP substitutions.

  10. Effects of CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles on HIV-1 disease progression

    DEFF Research Database (Denmark)

    Ioannidis, J P; Rosenberg, P S; Goedert, J J

    2001-01-01

    BACKGROUND: Studies relating certain chemokine and chemokine receptor gene alleles with the outcome of HIV-1 infection have yielded inconsistent results. OBJECTIVE: To examine postulated associations of genetic alleles with HIV-1 disease progression. DESIGN: Meta-analysis of individual-patient data....... SETTING: 19 prospective cohort studies and case-control studies from the United States, Europe, and Australia. PATIENTS: Patients with HIV-1 infection who were of European or African descent. MEASUREMENTS: Time to AIDS, death, and death after AIDS and HIV-1 RNA level at study entry or soon after...... (relative hazard among seroconverters, 0.64 and 0.74; P HIV-1 RNA levels after seroconversion (difference, -0.18 log(10) copies/mL and -0.14 log(10) copies/mL; P

  11. High frequency of the CCR5delta32 variant among individuals from an admixed Brazilian population with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    J.A.B. Chies

    2003-01-01

    Full Text Available Homozygous sickle cell disease (SCD has a wide spectrum of clinical manifestations. In Brazil, the main cause of death of individuals with SCD is recurrent infection. The CCR5delta32 allele, which confers relative resistance to macrophage-tropic HIV virus infection, probably has reached its frequency and world distribution due to other pathogens that target macrophage in European populations. In the present investigation a relatively higher prevalence (5.1% of the CCR5delta32 allele was identified, by PCR amplification using specific primers, in 79 SCD patients when compared to healthy controls (1.3% with the same ethnic background (Afro-Brazilians. Based on a hypothesis that considers SCD as a chronic inflammatory condition, and since the CCR5 chemokine receptor is involved in directing a Th1-type immune response, we suggest that a Th1/Th2 balance can influence the morbidity of SCD. If the presence of the null CCR5delta32 allele results in a reduction of the chronic inflammation state present in SCD patients, this could lead to differential survival of SCD individuals who are carriers of the CCR5delta32 allele. This differential survival could be due to the development of less severe infections and consequently reduced or less severe vaso-occlusive crises.

  12. Molekulare Klonierung, stabile Transfektion und funktionelle Expression der murinen Chemokinrezeptoren Ccr2 und Ccr5

    OpenAIRE

    Simonis, Christopher

    2009-01-01

    The two chemokine receptors CCR2 and CCR5 play important roles in the recruitment and activation of monocytes/macrophages and T-lymphocytes at sites of infection and inflammation. To further examine their function, I cloned the two murine chemokine receptors Ccr2 and Ccr5 from genomic mouse DNA by a PCR-based cloning strategy and functionally expressed them in stably transfected CHO-cells. These cells were used to generate the first monoclonal antibodies against Ccr2 and Ccr5.

  13. Human immunodeficiency virus type 1 subtype B ancestral envelope protein is functional and elicits neutralizing antibodies in rabbits similar to those elicited by a circulating subtype B envelope.

    Science.gov (United States)

    Doria-Rose, N A; Learn, G H; Rodrigo, A G; Nickle, D C; Li, F; Mahalanabis, M; Hensel, M T; McLaughlin, S; Edmonson, P F; Montefiori, D; Barnett, S W; Haigwood, N L; Mullins, J I

    2005-09-01

    Human immunodeficiency virus type 1 (HIV-1) is a difficult target for vaccine development, in part because of its ever-expanding genetic diversity and attendant capacity to escape immunologic recognition. Vaccine efficacy might be improved by maximizing immunogen antigenic similarity to viruses likely to be encountered by vaccinees. To this end, we designed a prototype HIV-1 envelope vaccine using a deduced ancestral state for the env gene. The ancestral state reconstruction method was shown to be >95% accurate by computer simulation and 99.8% accurate when estimating the known inoculum used in an experimental infection study in rhesus macaques. Furthermore, the deduced ancestor gene differed from the set of sequences used to derive the ancestor by an average of 12.3%, while these latter sequences were an average of 17.3% different from each other. A full-length ancestral subtype B HIV-1 env gene was constructed and shown to produce a glycoprotein of 160 kDa that bound and fused with cells expressing the HIV-1 coreceptor CCR5. This Env was also functional in a virus pseudotype assay. When either gp160- or gp140-expressing plasmids and recombinant gp120 were used to immunize rabbits in a DNA prime-protein boost regimen, the artificial gene induced immunoglobulin G antibodies capable of weakly neutralizing heterologous primary HIV-1 strains. The results were similar for rabbits immunized in parallel with a natural isolate, HIV-1 SF162. Further design efforts to better present conserved neutralization determinants are warranted.

  14. Relevance of CCL3/CCR5 axis in oral carcinogenesis.

    Science.gov (United States)

    da Silva, Janine Mayra; Moreira Dos Santos, Tálita Pollyanna; Sobral, Lays Martin; Queiroz-Junior, Celso Martins; Rachid, Milene Alvarenga; Proudfoot, Amanda E I; Garlet, Gustavo Pompermaier; Batista, Aline Carvalho; Teixeira, Mauro Martins; Leopoldino, Andréia Machado; Russo, Remo Castro; Silva, Tarcília Aparecida

    2017-08-01

    The chemokine CCL3 is a chemotactic cytokine crucial for inflammatory cell recruitment in homeostatic and pathological conditions. CCL3 might stimulate cancer progression by promoting leukocyte accumulation, angiogenesis and tumour growth. The expression of CCL3 and its receptors CCR1 and CCR5 was demonstrated in oral squamous cell carcinoma (OSCC), but their role was not defined. Here, the functions of CCL3 were assessed using a model of chemically induced tongue carcinogenesis with 4-nitroquinoline-1-oxide (4NQO). Lineages of OSCC were used to analyse the effects of CCL3 in vitro . The 4NQO-induced lesions exhibited increased expression of CCL3, CCR1 and CCR5. CCL3 -/- and CCR5 -/- mice presented reduced incidence of tongue tumours compared to wild-type (WT) and CCR1 -/- mice. Consistently, attenuated cytomorphological atypia and reduced cell proliferation were observed in lesions of CCL3 -/- and CCR5 -/- mice. OSCC from CCL3 -/- mice exhibited lower infiltration of eosinophils and reduced expression of Egf, Fgf1, Tgf-β1, Vegfa, Vegfb, Itga-4, Vtn, Mmp-1a, Mmp-2 and Mmp-9 than WT mice. In vitro , CCL3 induced invasion and production of CCL5, IL-6, MMP -2, -8, -9. Blockage of CCL3 in vitro using α-CCL3 or Evasin-1 (a CCL3-binding protein) impaired tumour cell invasion. In conclusion, CCL3/CCR5 axis has pro-tumourigenic effects in oral carcinogenesis. The induction of inflammatory and angiogenic pathways and eosinophils recruitment appear to be the underlying mechanism explaining these effects. These data reveal potential protective effects of CCL3 blockade in oral cancer.

  15. Chimeric HIV-1 envelope glycoproteins with potent intrinsic granulocyte-macrophage colony-stimulating factor (GM-CSF) activity

    NARCIS (Netherlands)

    Isik, Gözde; van Montfort, Thijs; Boot, Maikel; Cobos Jiménez, Viviana; Kootstra, Neeltje A.; Sanders, Rogier W.

    2013-01-01

    HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs) that target the envelope glycoprotein complex (Env). An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env

  16. Presenting native-like HIV-1 envelope trimers on ferritin nanoparticles improves their immunogenicity

    NARCIS (Netherlands)

    Sliepen, Kwinten; Ozorowski, Gabriel; Burger, Judith A.; van Montfort, Thijs; Stunnenberg, Melissa; Labranche, Celia; Montefiori, David C.; Moore, John P.; Ward, Andrew B.; Sanders, Rogier W.

    2015-01-01

    Background: Presenting vaccine antigens in particulate form can improve their immunogenicity by enhancing B cell activation. Findings: We describe ferritin-based protein nanoparticles that display multiple copies of native-like HIV-1 envelope glycoprotein trimers (BG505 SOSIP.664). Trimer-bearing

  17. CCR3, CCR5, CCR8 and CXCR3 expression in memory T helper cells from allergic rhinitis patients, asymptomatically sensitized and healthy individuals

    DEFF Research Database (Denmark)

    Holse, Mille; Assing, Kristian; Poulsen, Lars K.

    2006-01-01

    Chemokine receptors have been suggested to be preferentially expressed on CD4+ T cells with CCR3 and CCR8 linked to the T helper (Th) 2 subset and CCR5 and CXCR3 to the Th1 subset, however this remains controversial....

  18. Effect of HIV-1 envelope cytoplasmic tail on adenovirus primed virus encoded virus-like particle immunizations

    DEFF Research Database (Denmark)

    Andersson, Anne Marie C; Ragonnaud, Emeline; Seaton, Kelly E.

    2016-01-01

    were found between the different priming regimens as both induced high titered tier 1 neutralizing antibodies, but no tier 2 antibodies, possibly reflecting the similar presentation of trimer specific antibody epitopes. The described vaccine regimens provide insight into the effects of the HIV-1 Env......The low number of envelope (Env) spikes presented on native HIV-1 particles is a major impediment for HIV-1 prophylactic vaccine development. We designed virus-like particle encoding adenoviral vectors utilizing SIVmac239 Gag as an anchor for full length and truncated HIV-1 M consensus Env...

  19. The C-terminal sequence of IFITM1 regulates its anti-HIV-1 activity.

    Directory of Open Access Journals (Sweden)

    Rui Jia

    Full Text Available The interferon-inducible transmembrane (IFITM proteins inhibit a wide range of viruses. We previously reported the inhibition of human immunodeficiency virus type 1 (HIV-1 strain BH10 by human IFITM1, 2 and 3. It is unknown whether other HIV-1 strains are similarly inhibited by IFITMs and whether there exists viral countermeasure to overcome IFITM inhibition. We report here that the HIV-1 NL4-3 strain (HIV-1NL4-3 is not restricted by IFITM1 and its viral envelope glycoprotein is partly responsible for this insensitivity. However, HIV-1NL4-3 is profoundly inhibited by an IFITM1 mutant, known as Δ(117-125, which is deleted of 9 amino acids at the C-terminus. In contrast to the wild type IFITM1, which does not affect HIV-1 entry, the Δ(117-125 mutant diminishes HIV-1NL4-3 entry by 3-fold. This inhibition correlates with the predominant localization of Δ(117-125 to the plasma membrane where HIV-1 entry occurs. In spite of strong conservation of IFITM1 among most species, mouse IFITM1 is 19 amino acids shorter at its C-terminus as compared to human IFITM1 and, like the human IFITM1 mutant Δ(117-125, mouse IFITM1 also inhibits HIV-1 entry. This is the first report illustrating the role of viral envelope protein in overcoming IFITM1 restriction. The results also demonstrate the importance of the C-terminal region of IFITM1 in modulating the antiviral function through controlling protein subcellular localization.

  20. Selection of unadapted, pathogenic SHIVs encoding newly transmitted HIV-1 envelope proteins.

    Science.gov (United States)

    Del Prete, Gregory Q; Ailers, Braiden; Moldt, Brian; Keele, Brandon F; Estes, Jacob D; Rodriguez, Anthony; Sampias, Marissa; Oswald, Kelli; Fast, Randy; Trubey, Charles M; Chertova, Elena; Smedley, Jeremy; LaBranche, Celia C; Montefiori, David C; Burton, Dennis R; Shaw, George M; Markowitz, Marty; Piatak, Michael; KewalRamani, Vineet N; Bieniasz, Paul D; Lifson, Jeffrey D; Hatziioannou, Theodora

    2014-09-10

    Infection of macaques with chimeric viruses based on SIVMAC but expressing the HIV-1 envelope (Env) glycoproteins (SHIVs) remains the most powerful model for evaluating prevention and therapeutic strategies against AIDS. Unfortunately, only a few SHIVs are currently available. Furthermore, their generation has required extensive adaptation of the HIV-1 Env sequences in macaques so they may not accurately represent HIV-1 Env proteins circulating in humans, potentially limiting their translational utility. We developed a strategy for generating large numbers of SHIV constructs expressing Env proteins from newly transmitted HIV-1 strains. By inoculating macaques with cocktails of multiple SHIV variants, we selected SHIVs that can replicate and cause AIDS-like disease in immunologically intact rhesus macaques without requiring animal-to-animal passage. One of these SHIVs could be transmitted mucosally. We demonstrate the utility of the SHIVs generated by this method for evaluating neutralizing antibody administration as a protection against mucosal SHIV challenge. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    International Nuclear Information System (INIS)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang; Liu, Yan-Hong; Li, Yan; Wang, Jia-Ye; Hattori, Toshio; Ling, Hong; Zhang, Feng-Min

    2010-01-01

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  2. Targeting CXCR4 in HIV Cell-Entry Inhibition

    DEFF Research Database (Denmark)

    Steen, Anne; Schwartz, T W; Rosenkilde, M M

    2010-01-01

    CXCR4 and CCR5 constitute the two major coreceptors for HIV-1 entry into host cells. In the course of an HIV-infection, a coreceptor switch takes place in approximately half of the patients - from R5 HIV-1 (CCR5 utilizing) strains to X4 HIV-1 (CXCR4 utilizing) strains. Treatment of HIV......-infected individuals with CXCR4 antagonists delays the onset of AIDS by preventing the CCR5 to CXCR4 coreceptor switch. In addition to the endogenous CXCR4 and CCR5 ligands, other chemokines, for example the human herpesvirus 8 encoded CC-chemokine, vCCL2, and modifications hereof, have proven efficient HIV-1 cell...... no oral bioavailability. The hunt for orally active small-molecule CXCR4 antagonists led to the development of monocyclam-based compounds, and recently to the non-cyclam antagonist AMD070, which is orally active and currently in Phase II clinical trial as anti-HIV treatment. Current review provides...

  3. Determination of HIV-1 co-receptor usage.

    Science.gov (United States)

    Cavarelli, Mariangela; Scarlatti, Gabriella

    2014-01-01

    Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly the β-chemokine receptor 5 (CCR5) and the α-chemokine receptor 4 (CXCR4). Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. In this chapter, methods to determine the co-receptor usage of HIV-1 variants are described.

  4. A closed-tube assay for genotyping of the 32-bp deletion polymorphism in the chemokine receptor 5 (CCR5) gene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Werge, Thomas

    2007-01-01

    We have developed a closed-tube assay for determination of the chemokine receptor type 5 (CCR5) 32-bp deletion allele, which protects against infections with HIV and modulates susceptibility to a variety of inflammatory diseases. This assay utilizes dissociation analysis of amplified products...

  5. Influence of Acyclic Nucleoside Phosphonate Antivirals on Gene Expression of Chemokine Receptors CCR5 and CXCR4

    Czech Academy of Sciences Publication Activity Database

    Potměšil, P.; Holý, Antonín; Zídek, Zdeněk

    2015-01-01

    Roč. 61, č. 1 (2015), s. 1-7 ISSN 0015-5500 R&D Projects: GA ČR GA305/03/1470; GA MŠk 1M0508 Institutional support: RVO:61388963 ; RVO:68378041 Keywords : acyclic nucleoside phosphonate * HIV * CCR5 * CXCR4 * cytokine * RT-PCR Subject RIV: CC - Organic Chemistry; FR - Pharmacology ; Medidal Chemistry (UEM-P) Impact factor: 0.833, year: 2015

  6. Genetic factors associated with slow progression of HIV among perinatally-infected Indian children.

    Science.gov (United States)

    Chaudhuri, Riya Pal; Neogi, Ujjwal; Rao, Shwetha D; Shet, Anita

    2014-10-01

    To study the association between common AIDS restriction genes and slow disease progression among perinatally-infected children in India. ART-naïve children were identified and selected host factors including CCR5-∆32, SDF1-3'A, CCR5-59029G, HLA-B*27, B*57 were studied using allele-specific PCR-RFLP and SSPGo HLA typing kits. Among 165 children, 10 (6%) long-term non-progressors and 8 (5%) slow progressors were identified. For comparison, 12 children with normal progression of HIV were included. The frequencies of CCR5-∆32 deletion, SDF1-3'A and CCR5-59029G did not differ significantly. HLA-B*27 and B*57 were observed only in long-term non-progressors or slow progressors, who also harbored either SDF1-3'A and/or CCR5-59029G. There is an association between host genetic factors and slow disease progression in this population.

  7. In silico analysis of HIV-1 Env-gp120 reveals structural bases for viral adaptation in growth-restrictive cells

    Directory of Open Access Journals (Sweden)

    Masaru eYokoyama

    2016-02-01

    Full Text Available Variable V1/V2 and V3 loops on human immunodeficiency virus type 1 (HIV-1 envelope-gp120 core play key roles in modulating viral competence to recognize two infection receptors, CD4 and chemokine-receptors. However, molecular bases for the modulation largely remain unclear. To address these issues, we constructed structural models for a full-length gp120 in CD4-free and -bound states. The models showed topologies of gp120 surface loop that agree with those in reported structural data. Molecular dynamics simulation showed that in the unliganded state, V1/V2 loop settled into a thermodynamically stable arrangement near V3 loop for conformational masking of V3 tip, a potent neutralization epitope. In the CD4-bound state, however, V1/V2 loop was rearranged near the bound CD4 to support CD4 binding. In parallel, cell-based adaptation in the absence of anti-viral antibody pressures led to the identification of amino acid substitutions that individually enhance viral entry and growth efficiencies in association with reduced sensitivity to CCR5 antagonist TAK-779. Notably, all these substitutions were positioned on the receptors binding surfaces in V1/V2 or V3 loop. In silico structural studies predicted some physical changes of gp120 by substitutions with alterations in viral replication phenotypes. These data suggest that V1/V2 loop is critical for creating a gp120 structure that masks co-receptor binding site compatible with maintenance of viral infectivity, and for tuning a functional balance of gp120 between immune escape ability and infectivity to optimize HIV-1 replication fitness.

  8. Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

    International Nuclear Information System (INIS)

    Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor

    2017-01-01

    Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4"+ T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

  9. Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Méndez, David; Rivera-Toledo, Evelyn; Ortega, Enrique; Licona-Limón, Ileana; Huerta, Leonor, E-mail: leonorhh@biomedicas.unam.mx

    2017-03-01

    Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4{sup +} T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling. - Highlights: • Jurkat T cells expressing the HIV-1 envelope fuse with THP-1 monocytes. • Heterokaryons display a dominant myeloid phenotype and monocyte function. • Heterokaryons exhibit activation features in the absence of activation agents. • Activation is not due to cell-cell interaction but requires cell-cell fusion. • The

  10. Human cyclin T1 expression ameliorates a T-cell-specific transcriptional limitation for HIV in transgenic rats, but is not sufficient for a spreading infection of prototypic R5 HIV-1 strains ex vivo

    Directory of Open Access Journals (Sweden)

    Littman Dan R

    2009-01-01

    Full Text Available Abstract Background Cells derived from native rodents have limits at distinct steps of HIV replication. Rat primary CD4 T-cells, but not macrophages, display a profound transcriptional deficit that is ameliorated by transient trans-complementation with the human Tat-interacting protein Cyclin T1 (hCycT1. Results Here, we generated transgenic rats that selectively express hCycT1 in CD4 T-cells and macrophages. hCycT1 expression in rat T-cells boosted early HIV gene expression to levels approaching those in infected primary human T-cells. hCycT1 expression was necessary, but not sufficient, to enhance HIV transcription in T-cells from individual transgenic animals, indicating that endogenous cellular factors are critical co-regulators of HIV gene expression in rats. T-cells from hCD4/hCCR5/hCycT1-transgenic rats did not support productive infection of prototypic wild-type R5 HIV-1 strains ex vivo, suggesting one or more significant limitation in the late phase of the replication cycle in this primary rodent cell type. Remarkably, we identify a replication-competent HIV-1 GFP reporter strain (R7/3 YU-2 Env that displays characteristics of a spreading, primarily cell-to-cell-mediated infection in primary T-cells from hCD4/hCCR5-transgenic rats. Moreover, the replication of this recombinant HIV-1 strain was significantly enhanced by hCycT1 transgenesis. The viral determinants of this so far unique replicative ability are currently unknown. Conclusion Thus, hCycT1 expression is beneficial to de novo HIV infection in a transgenic rat model, but additional genetic manipulations of the host or virus are required to achieve full permissivity.

  11. CCL5 and CCR5 interaction promotes cell motility in human osteosarcoma.

    Directory of Open Access Journals (Sweden)

    Shih-Wei Wang

    Full Text Available BACKGROUND: Osteosarcoma is characterized by a high malignant and metastatic potential. CCL5 (previously called RANTES was originally recognized as a product of activated T cells, and plays a crucial role in the migration and metastasis of human cancer cells. It has been reported that the effect of CCL5 is mediated via CCR receptors. However, the effect of CCL5 on migration activity and integrin expression in human osteosarcoma cells is mostly unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we found that CCL5 increased the migration and expression of αvβ3 integrin in human osteosarcoma cells. Stimulation of cells with CCL5 increased CCR5 but not CCR1 and CCR3 expression. CCR5 mAb, inhibitor, and siRNA reduced the CCL5-enhanced the migration and integrin up-regulation of osteosarcoma cells. Activations of MEK, ERK, and NF-κB pathways after CCL5 treatment were demonstrated, and CCL5-induced expression of integrin and migration activity was inhibited by the specific inhibitor and mutant of MEK, ERK, and NF-κB cascades. In addition, over-expression of CCL5 shRNA inhibited the migratory ability and integrin expression in osteosarcoma cells. CONCLUSIONS/SIGNIFICANCE: CCL5 and CCR5 interaction acts through MEK, ERK, which in turn activates NF-κB, resulting in the activations of αvβ3 integrin and contributing the migration of human osteosarcoma cells.

  12. Chemokine receptor CCR5 in interferon-treated multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, F; Kristiansen, Thomas Birk; Wittenhagen, P

    2007-01-01

    OBJECTIVE: To study the relationship between CC chemokine receptor CCR5 expression and disease activity in multiple sclerosis (MS) patients treated with beta-interferon (IFN-beta). METHODS: The CCR5 Delta32 allele and a CCR5 promoter polymorphism associated with cell surface expression of CCR5 were...

  13. The CC-chemokine receptor 5 (CCR5) is a marker of, but not essential for the development of human Th1 cells

    DEFF Research Database (Denmark)

    Odum, Niels; Bregenholt, S; Eriksen, K W

    1999-01-01

    The CC-chemokine receptor 5 (CCR5) has recently been described as a surface marker of human T cells producing type 1 (Th1) cytokines. Here we confirm that CCR5 is expressed on human Th1 but not on Th2 T-cell clones. Using intracellular cytokine staining, we show that alloantigen specific CD4+ T...

  14. An evolutionary-network model reveals stratified interactions in the V3 loop of the HIV-1 envelope.

    Directory of Open Access Journals (Sweden)

    Art F Y Poon

    2007-11-01

    Full Text Available The third variable loop (V3 of the human immunodeficiency virus type 1 (HIV-1 envelope is a principal determinant of antibody neutralization and progression to AIDS. Although it is undoubtedly an important target for vaccine research, extensive genetic variation in V3 remains an obstacle to the development of an effective vaccine. Comparative methods that exploit the abundance of sequence data can detect interactions between residues of rapidly evolving proteins such as the HIV-1 envelope, revealing biological constraints on their variability. However, previous studies have relied implicitly on two biologically unrealistic assumptions: (1 that founder effects in the evolutionary history of the sequences can be ignored, and; (2 that statistical associations between residues occur exclusively in pairs. We show that comparative methods that neglect the evolutionary history of extant sequences are susceptible to a high rate of false positives (20%-40%. Therefore, we propose a new method to detect interactions that relaxes both of these assumptions. First, we reconstruct the evolutionary history of extant sequences by maximum likelihood, shifting focus from extant sequence variation to the underlying substitution events. Second, we analyze the joint distribution of substitution events among positions in the sequence as a Bayesian graphical model, in which each branch in the phylogeny is a unit of observation. We perform extensive validation of our models using both simulations and a control case of known interactions in HIV-1 protease, and apply this method to detect interactions within V3 from a sample of 1,154 HIV-1 envelope sequences. Our method greatly reduces the number of false positives due to founder effects, while capturing several higher-order interactions among V3 residues. By mapping these interactions to a structural model of the V3 loop, we find that the loop is stratified into distinct evolutionary clusters. We extend our model to

  15. Neutralization of X4- and R5-tropic HIV-1 NL4-3 variants by HOCl-modified serum albumins

    Directory of Open Access Journals (Sweden)

    Schwalbe Birco

    2010-06-01

    Full Text Available Abstract Background Myeloperoxidase (MPO, an important element of the microbicidal activity of neutrophils, generates hypochlorous acid (HOCl from H2O2 and chloride, which is released into body fluids. Besides its direct microbicidal activity, HOCl can react with amino acid residues and HOCl-modified proteins can be detected in vivo. Findings This report is based on binding studies of HOCl-modified serum albumins to HIV-1 gp120 and three different neutralization assays using infectious virus. The binding studies were carried out by surface plasmon resonance spectroscopy and by standard ELISA techniques. Virus neutralization assays were carried out using HIV-1 NL4-3 virus and recombinant strains with CXCR4 and CCR5 coreceptor usage. Viral infection was monitored by a standard p24 or X-gal staining assay. Our data demonstrate that HOCl-modified mouse-, bovine- and human serum albumins all bind to the HIV-1 NL4-3 gp120 (LAV glycoprotein in contrast to non-modified albumin. Binding of HOCl-modified albumin to gp120 correlated to the blockade of CD4 as well as that of V3 loop specific monoclonal antibody binding. In neutralization experiments, HOCl-modified serum albumins inhibited replication and syncytium formation of the X4- and R5-tropic NL4-3 isolates in a dose dependent manner. Conclusions Our data indicate that HOCl-modified serum albumin veils the binding site for CD4 and the V3 loop on gp120. Such masking of the viral gp120/gp41 envelope complex might be a simple but promising strategy to inactivate HIV-1 and therefore prevent infection when HOCl-modified serum albumin is applied, for example, as a topical microbicide.

  16. Temporal expression of HIV-1 envelope proteins in baculovirus-infected insect cells: Implications for glycosylation and CD4 binding

    International Nuclear Information System (INIS)

    Murphy, C.I.; Lennick, M.; Lehar, S.M.; Beltz, G.A.; Young, E.

    1990-01-01

    Three different human immunodeficiency virus type I (HIV-1) envelope derived recombinant proteins and the full length human CD4 polypeptide were expressed in Spodoptera frugiperda (Sf9) cells. DNA constructs encoding CD4, gp120, gp160, and gp160 delta were cloned into the baculovirus expression vector pVL941 or a derivative and used to generate recombinant viruses in a cotransfection with DNA from Autographa californica nuclear polyhedrosis virus (AcMNPV). Western blotting of cell extracts of the recombinant HIV-1 proteins showed that for each construct two major bands specifically reacted with anti-HIV-1 envelope antiserum. These bands corresponded to glycosylated and nonglycosylated versions of the HIV proteins as determined by 3H-mannose labeling and tunicamycin treatment of infected cells. A time course of HIV envelope expression revealed that at early times post-infection (24 hours) the proteins were fully glycosylated and soluble in nonionic detergents. However, at later times postinfection (48 hours), expression levels of recombinant protein reached a maximum but most of the increase was due to a rise in the level of the nonglycosylated species, which was largely insoluble in nonionic detergents. Thus, it appears that Sf9 cells cannot process large amounts of glycosylated recombinant proteins efficiently. As a measure of biological activity, the CD4 binding ability of both glycosylated and nonglycosylated recombinant HIV envelope proteins was tested in a coimmunoprecipitation assay. The results showed that CD4 and the glycosylated versions of recombinant gp120 or gp160 delta specifically associated with one another in this analysis. Nonglycosylated gp120 or gp160 delta proteins from tunicamycin-treated cultures did immunoprecipitate with anti-HIV-1 antiserum but did not interact with CD4

  17. Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial.

    Directory of Open Access Journals (Sweden)

    Sergio Serrano-Villar

    2016-01-01

    Full Text Available Whether initiation of antiretroviral therapy (ART regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6, lipoteichoic acid (LTA, soluble CD14 (sCD14 and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively, with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease

  18. Selective elimination of HIV-1-infected cells by Env-directed, HIV-1-based virus-like particles

    International Nuclear Information System (INIS)

    Peretti, Silvia; Schiavoni, Ilaria; Pugliese, Katherina; Federico, Maurizio

    2006-01-01

    We recently showed that both replicating and resting cells cultivated with ganciclovir (GCV) were killed when challenged with vesicular stomatitis virus G glycoprotein pseudotyped HIV-1-based virus-like particles (VLPs) carrying the Nef7 (i.e., an HIV-1 Nef mutant incorporating in virions at high levels)/herpes simplex virus-1 thymidine kinase (HSV-TK) fusion product. On this basis, a novel anti-HIV therapeutic approach based on Nef7/TK VLPs expressing X4 or R5 HIV cell receptor complexes has been attempted. We here report that (CD4-CXCR4) and (CD4-CCR5) Nef7-based VLPs efficiently enter cells infected by X4- or R5-tropic HIV-1 strains, respectively. Importantly, the delivery of the VLP-associated Nef7/TK led to cell death upon GCV treatment. Of interest, VLPs were effective also against non-replicating, HIV-1-infected primary human monocyte-derived macrophages. HIV-targeted VLPs represent a promising candidate for the treatment of persistently HIV-1-infected cells that are part of virus reservoirs resistant to HAART therapies

  19. Structure-Activity Relationships and Identification of Optmized CC-Chemokine Receptor CCR1, 5, and 8 Metal-Ion Chelators

    DEFF Research Database (Denmark)

    Chalikiopoulos, Alexander; Thiele, Stefanie; Malmgaard-Clausen, Mikkel

    2013-01-01

    Chemokine receptors are involved in trafficking of leukocytes and represent targets for autoimmune conditions, inflammatory diseases, viral infections, and cancer. We recently published CCR1, CCR8, and CCR5 agonists and positive modulators based on a three metal-ion chelator series: 2,2'-bipyridi...

  20. $200,000 Grants Awarded to CCR Researchers for HIV/AIDS Studies | Poster

    Science.gov (United States)

    By Nancy Parrish, Staff Writer Earlier this year, the Office of AIDS Research (OAR) awarded two, two-year grants of $200,000 each to Anu Puri, Ph.D., and Robert Blumenthal, Ph.D., both of the Center for Cancer Research (CCR) Nanobiology Program, and to Eric Freed, Ph.D., of the HIV Drug Resistance Program, for their research on potential new treatments for HIV.

  1. Clinical Case Registries (CCR)

    Data.gov (United States)

    Department of Veterans Affairs — The Clinical Case Registries (CCR) replaced the former Immunology Case Registry and the Hepatitis C Case Registry with local and national databases. The CCR:HIV and...

  2. Demonstration of a novel HIV-1 restriction phenotype from a human T cell line.

    Directory of Open Access Journals (Sweden)

    Yanxing Han

    2008-07-01

    Full Text Available Although retroviruses may invade host cells, a productive infection can be established only after the virus counteracts inhibition from different types of host restriction factors. Fv1, APOBEC3G/F, TRIM5alpha, ZAP, and CD317 inhibit the replication of different retroviruses by interfering with viral uncoating, reverse transcription, nuclear import, RNA stability, and release. In humans, although APOBEC3G/3F and CD317 block HIV-1 replication, their antiviral activities are neutralized by viral proteins Vif and Vpu. So far, no human gene has been found to effectively block wild type HIV-1 replication under natural condition. Thus, identification of such a gene product would be of great medical importance for the development of HIV therapies.In this study, we discovered a new type of host restriction against the wild type HIV-1 from a CD4/CXCR4 double-positive human T cell line. We identified a CEM-derived cell line (CEM.NKR that is highly resistant to productive HIV-1 infection. Viral production was reduced by at least 1000-fold when compared to the other permissive human T cell lines such as H9, A3.01, and CEM-T4. Importantly, this resistance was evident at extremely high multiplicity of infection. Further analyses demonstrated that HIV-1 could finish the first round of replication in CEM.NKR cells, but the released virions were poorly infectious. These virions could enter the target cells, but failed to initiate reverse transcription. Notably, this restriction phenotype was also present in CEM.NKR and 293T heterokaryons.These results clearly indicate that CEM.NKR cells express a HIV inhibitory gene(s. Further characterization of this novel gene product(s will reveal a new antiretroviral mechanism that directly inactivates wild type HIV-1.

  3. Ancient DNA Investigation of a Medieval German Cemetery Confirms Long-Term Stability of CCR5-Δ32 Allele Frequencies in Central Europe.

    Science.gov (United States)

    Bouwman, Abigail; Shved, Natallia; Akgül, Gülfirde; Rühli, Frank; Warinner, Christina

    2017-04-01

    The CCR5-Δ32 mutation present in European populations is among the most prominently debated cases of recent positive selection in humans. This allele, a 32-bp deletion that renders the T-cell CCR5 receptor nonfunctional, has important epidemiological and public health significance, as homozygous carriers are resistant to several HIV strains. However, although the function of this allele in preventing HIV infection is now well described, its human evolutionary origin is poorly understood. Initial attempts to determine the emergence of the CCR5-Δ32 allele pointed to selection during the 14th-century Black Death pandemic; however, subsequent analyses suggest that the allele rose in frequency more than 5,000 years ago, possibly through drift. Recently, three studies have identified populations predating the 14th century CE that are positive for the CCR5-Δ32 allele, supporting the claim for a more ancient origin. However, these studies also suggest poorly understood regional differences in the recent evolutionary history of the CCR5-Δ32 allele. Here a new hydrolysis-probe-based real-time PCR assay was designed to ascertain CCR5 allele frequency in 53 individuals from a 10th- to 12th-century CE church and convent complex in central Germany that predates outbreaks of the Black Death pandemic. High-confidence genotypes were obtained for 32 individuals, and results show that CCR5-Δ32 allele frequency has remained unchanged in this region of Central Europe over the last millennium, suggesting that there has been no strong positive selective pressure over this time period and confirming a more ancient origin for the allele.

  4. The colocalization potential of HIV-specific CD8+ and CD4+ T-cells is mediated by integrin β7 but not CCR6 and regulated by retinoic acid.

    Directory of Open Access Journals (Sweden)

    Vanessa Sue Wacleche

    Full Text Available CD4(+ T-cells from gut-associated lymphoid tissues (GALT are major targets for HIV-1 infection. Recruitment of excess effector CD8(+ T-cells in the proximity of target cells is critical for the control of viral replication. Here, we investigated the colocalization potential of HIV-specific CD8(+ and CD4(+ T-cells into the GALT and explored the role of retinoic acid (RA in regulating this process in a cohort of HIV-infected subjects with slow disease progression. The expression of the gut-homing molecules integrin β7, CCR6, and CXCR3 was identified as a "signature" for HIV-specific but not CMV-specific CD4(+ T-cells thus providing a new explanation for their enhanced permissiveness to infection in vivo. HIV-specific CD8(+ T-cells also expressed high levels of integrin β7 and CXCR3; however CCR6 was detected at superior levels on HIV-specific CD4(+ versus CD8(+ T-cells. All trans RA (ATRA upregulated the expression of integrin β7 but not CCR6 on HIV-specific T-cells. Together, these results suggest that HIV-specific CD8(+ T-cells may colocalize in excess with CD4(+ T-cells into the GALT via integrin β7 and CXCR3, but not via CCR6. Considering our previous findings that CCR6(+CD4(+ T-cells are major cellular targets for HIV-DNA integration in vivo, a limited ability of CD8(+ T-cells to migrate in the vicinity of CCR6(+CD4(+ T-cells may facilitate HIV replication and dissemination at mucosal sites.

  5. The RNA helicase DDX1 is involved in restricted HIV-1 Rev function in human astrocytes

    International Nuclear Information System (INIS)

    Fang Jianhua; Acheampong, Edward; Dave, Rajnish; Wang Fengxiang; Mukhtar, Muhammad; Pomerantz, Roger J.

    2005-01-01

    Productive infection by human immunodeficiency virus type I (HIV-1) in the central nervous system (CNS) involves mainly macrophages and microglial cells. A frequency of less than 10% of human astrocytes is estimated to be infectable with HIV-1. Nonetheless, this relatively low percentage of infected astrocytes, but associated with a large total number of astrocytic cells in the CNS, makes human astrocytes a critical part in the analyses of potential HIV-1 reservoirs in vivo. Investigations in astrocytic cell lines and primary human fetal astrocytes revealed that limited HIV-1 replication in these cells resulted from low-level viral entry, transcription, viral protein processing, and virion maturation. Of note, a low ratio of unspliced versus spliced HIV-1-specific RNA was also investigated, as Rev appeared to act aberrantly in astrocytes, via loss of nuclear and/or nucleolar localization and diminished Rev-mediated function. Host cellular machinery enabling Rev function has become critical for elucidation of diminished Rev activity, especially for those factors leading to RNA metabolism. We have recently identified a DEAD-box protein, DDX1, as a Rev cellular co-factor and now have explored its potential importance in astrocytes. Cells were infected with HIV-1 pseudotyped with envelope glycoproteins of amphotropic murine leukemia viruses (MLV). Semi-quantitative reverse transcriptase-polymerase chain reactions (RT-PCR) for unspliced, singly-spliced, and multiply-spliced RNA clearly showed a lower ratio of unspliced/singly-spliced over multiply-spliced HIV-1-specific RNA in human astrocytes as compared to Rev-permissive, non-glial control cells. As well, the cellular localization of Rev in astrocytes was cytoplasmically dominant as compared to that of Rev-permissive, non-glial controls. This endogenous level of DDX1 expression in astrocytes was demonstrated directly to lead to a shift of Rev sub-cellular distribution dominance from nuclear and/or nucleolar to

  6. Influence of the CCR-5/MIP-1 α axis in the pathogenesis of Rocio virus encephalitis in a mouse model.

    Science.gov (United States)

    Chávez, Juliana H; França, Rafael F O; Oliveira, Carlo J F; de Aquino, Maria T P; Farias, Kleber J S; Machado, Paula R L; de Oliveira, Thelma F M; Yokosawa, Jonny; Soares, Edson G; da Silva, João S; da Fonseca, Benedito A L; Figueiredo, Luiz T M

    2013-11-01

    Rocio virus (ROCV) caused an outbreak of human encephalitis during the 1970s in Brazil and its immunopathogenesis remains poorly understood. CC-chemokine receptor 5 (CCR5) is a chemokine receptor that binds to macrophage inflammatory protein (MIP-1 α). Both molecules are associated with inflammatory cells migration during infections. In this study, we demonstrated the importance of the CCR5 and MIP-1 α, in the outcome of viral encephalitis of ROCV-infected mice. CCR5 and MIP-1 α knockout mice survived longer than wild-type (WT) ROCV-infected animals. In addition, knockout mice had reduced inflammation in the brain. Assessment of brain viral load showed mice virus detection five days post-infection in wild-type and CCR5-/- mice, while MIP-1 α-/- mice had lower viral loads seven days post-infection. Knockout mice required a higher lethal dose than wild-type mice as well. The CCR5/MIP-1 α axis may contribute to migration of infected cells to the brain and consequently affect the pathogenesis during ROCV infection.

  7. A stable CC-chemokine receptor (CCR)-5 tropic virus is correlated with the persistence of HIV RNA at less than 2.5 copies in successfully treated naïve subjects.

    Science.gov (United States)

    Parisi, Saverio Giuseppe; Andreis, Samantha; Mengoli, Carlo; Scaggiante, Renzo; Cruciani, Mario; Ferretto, Roberto; Manfrin, Vinicio; Panese, Sandro; Basso, Monica; Boldrin, Caterina; Bressan, Stefania; Sarmati, Loredana; Andreoni, Massimo; Palù, Giorgio

    2013-07-11

    To determine if tropism for CXCR4 or CCR5 correlates with cellular HIV DNA load, residual viraemia and CD4 count in 219 successfully treated naive subjects with HIV infection enrolled in five infectious diseases units in Northeastern Italy. A subset of subjects, achieving plasma HIV RNA level <50 copies/ml after initiation of first-line therapy and maintaining it until follow-up time points, was retrospectively selected from a prospective cohort. Blood samples were collected before the beginning of therapy (T0), at the first follow-up time (T1) and, when available, at a second (T2) follow-up time. HIV DNA, CD4 count and plasma viraemia were available from all 219 patients at T0 and T1, and in 86 subjects at T2, while tropism determinations were available from 109 subjects at T0, 219 at T1, and from 86 subjects at T2. Achieving residual viraemia <2.5 copies/ml at T1 correlated with having the same condition at T2 (p = 0.0007). X4 tropism at T1 was negatively correlated with the possibility of achieving viraemia<2.5 copies/ml at T2 (p = 0.0076). T1-T2 tropism stability was significant (p <0.0001). T0 tropism correlated with T1 and T2 tropism (p < 0.001); therefore the stability of the tropism over the two follow-up periods was significant (p = 0.0003). An effective viremic suppression (viraemia<2.5 copies/ml) correlated with R5 coreceptor affinity (p= 0.047). The tropism of archived virus was stable during an effective treatment, with 15-18% of subjects switching over time, despite a viraemia<50 copies/ml. R5 tropism and its stability were related to achieving and maintaining viraemia<2.5 copies/ml.

  8. Prediction of exposed domains of envelope glycoprotein in Indian HIV-1 isolates and experimental confirmation of their immunogenicity in humans

    Directory of Open Access Journals (Sweden)

    Mohabatkar H.

    2004-01-01

    Full Text Available We describe the impact of subtype differences on the seroreactivity of linear antigenic epitopes in envelope glycoprotein of HIV-1 isolates from different geographical locations. By computer analysis, we predicted potential antigenic sites of envelope glycoprotein (gp120 and gp4l of this virus. For this purpose, after fetching sequences of proteins of interest from data banks, values of hydrophilicity, flexibility, accessibility, inverted hydrophobicity, and secondary structure were considered. We identified several potential antigenic epitopes in a B subtype strain of envelope glycoprotein of HIV-1 (IIIB. Solid- phase peptide synthesis methods of Merrifield and Fmoc chemistry were used for synthesizing peptides. These synthetic peptides corresponded mainly to the C2, V3 and CD4 binding sites of gp120 and some parts of the ectodomain of gp41. The reactivity of these peptides was tested by ELISA against different HIV-1-positive sera from different locations in India. For two of these predicted epitopes, the corresponding Indian consensus sequences (LAIERYLKQQLLGWG and DIIGDIRQAHCNISEDKWNET (subtype C were also synthesized and their reactivity was tested by ELISA. These peptides also distinguished HIV-1-positive sera of Indians with C subtype infections from sera from HIV-negative subjects.

  9. Creation of chimeric human/rabbit APOBEC1 with HIV-1 restriction and DNA mutation activities

    Science.gov (United States)

    Ikeda, Terumasa; Ong, Eugene Boon Beng; Watanabe, Nobumoto; Sakaguchi, Nobuo; Maeda, Kazuhiko; Koito, Atsushi

    2016-01-01

    APOBEC1 (A1) proteins from lagomorphs and rodents have deaminase-dependent restriction activity against HIV-1, whereas human A1 exerts a negligible effect. To investigate these differences in the restriction of HIV-1 by A1 proteins, a series of chimeric proteins combining rabbit and human A1s was constructed. Homology models of the A1s indicated that their activities derive from functional domains that likely act in tandem through a dimeric interface. The C-terminal region containing the leucine-rich motif and the dimerization domains of rabbit A1 is important for its anti-HIV-1 activity. The A1 chimeras with strong anti-HIV-1 activity were incorporated into virions more efficiently than those without anti-HIV-1 activity, and exhibited potent DNA-mutator activity. Therefore, the C-terminal region of rabbit A1 is involved in both its packaging into the HIV-1 virion and its deamination activity against both viral cDNA and genomic RNA. This study identifies the novel molecular mechanism underlying the target specificity of A1.

  10. Evolutionary genomics and HIV restriction factors.

    Science.gov (United States)

    Pyndiah, Nitisha; Telenti, Amalio; Rausell, Antonio

    2015-03-01

    To provide updated insights into innate antiviral immunity and highlight prototypical evolutionary features of well characterized HIV restriction factors. Recently, a new HIV restriction factor, Myxovirus resistance 2, has been discovered and the region/residue responsible for its activity identified using an evolutionary approach. Furthermore, IFI16, an innate immunity protein known to sense several viruses, has been shown to contribute to the defense to HIV-1 by causing cell death upon sensing HIV-1 DNA. Restriction factors against HIV show characteristic signatures of positive selection. Different patterns of accelerated sequence evolution can distinguish antiviral strategies--offense or defence--as well as the level of specificity of the antiviral properties. Sequence analysis of primate orthologs of restriction factors serves to localize functional domains and sites responsible for antiviral action. We use recent discoveries to illustrate how evolutionary genomic analyses help identify new antiviral genes and their mechanisms of action.

  11. Engineering and Characterization of a Fluorescent Native-Like HIV-1 Envelope Glycoprotein Trimer

    Directory of Open Access Journals (Sweden)

    Kwinten Sliepen

    2015-10-01

    Full Text Available Generation of a stable, soluble mimic of the HIV-1 envelope glycoprotein (Env trimer on the virion surface has been considered an important first step for developing a successful HIV-1 vaccine. Recently, a soluble native-like Env trimer (BG505 SOSIP.664 has been described. This protein has facilitated major advances in the HIV-1 vaccine field, since it was the first Env immunogen that induced consistent neutralizing antibodies against a neutralization-resistant (tier 2 virus. Moreover, BG505 SOSIP.664 enabled elucidation of the atomic resolution structure of the Env trimer and facilitated the isolation and characterization of new broadly neutralizing antibodies against HIV-1. Here, we designed and characterized the BG505 SOSIP.664 trimer fused to fluorescent superfolder GFP (sfGFP, a GFP variant that allows efficient folding (BG505 SOSIP.664-sfGFP. Despite the presence of the sfGFP, the Env protein largely retained its morphology, antigenicity, glycan composition, and thermostability. In addition, we show that BG505 SOSIP.664-sfGFP can be used for fluorescence-based assays, such as flow cytometry.

  12. Distribution of the CCR5delta32 allele (gene variant CCR5) in Rondônia, Western Amazonian region, Brazil

    Science.gov (United States)

    de Farias, Josileide Duarte; Santos, Marlene Guimarães; de França, Andonai Krauze; Delani, Daniel; Tada, Mauro Shugiro; Casseb, Almeida Andrade; Simões, Aguinaldo Luiz; Engracia, Vera

    2012-01-01

    Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants. We analyzed the frequency of the CCR5Δ32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in five sample sets from the population. Four were collected in Porto Velho, the state capital and the site of several waves of migration. Of these, two, from the Hospital de Base were comprised of HB Mothers and HB Newborns presenting allele frequencies of 3.5% and 3.1%, respectively, a third from the peri-urban neighborhoods of Candelária/Bate-Estaca (1.8%), whereas a fourth, from the Research Center on Tropical Medicine/CEPEM (0.6%), was composed of malaria patients under treament. The fifth sample (3.4%) came from the inland Quilombola village of Pedras Negras. Two homozygous individuals (CCR5Δ32/CCR5Δ32) were detected among the HB Mother samples. The frequency of this allele was heterogeneous and higher where the European inflow was more pronounced. The presence of the allele in Pedras Negras revealed European miscegenation in a community largely comprising Quilombolas. PMID:22481870

  13. A putative SUMO interacting motif in the B30.2/SPRY domain of rhesus macaque TRIM5α important for NF-κB/AP-1 signaling and HIV-1 restriction

    Directory of Open Access Journals (Sweden)

    Marie-Édith Nepveu-Traversy

    2016-01-01

    Full Text Available TRIM5α from the rhesus macaque (TRIM5αRh is a restriction factor that shows strong activity against HIV-1. TRIM5αRh binds specifically to HIV-1 capsid (CA through its B30.2/PRYSPRY domain shortly after entry of the virus into the cytoplasm. Recently, three putative SUMO interacting motifs (SIMs have been identified in the PRYSPRY domain of human and macaque TRIM5α. However, structural modeling of this domain suggested that two of them were buried in the hydrophobic core of the protein, implying that interaction with SUMO was implausible, while the third one was not relevant to restriction. In light of these results, we re-analyzed the TRIM5αRh PRYSPRY sequence and identified an additional putative SIM (435VIIC438 which we named SIM4. This motif is exposed at the surface of the PRYSPRY domain, allowing potential interactions with SUMO or SUMOylated proteins. Introducing a double mutation in SIM4 (V435K, I436K did not alter stability, unlike mutations in SIM1. SIM4-mutated TRIM5αRh failed to bind HIV-1CA and lost the ability to restrict this virus. Accordingly, SIM4 undergoes significant variation among primates and substituting this motif with naturally occurring SIM4 variants affected HIV-1 restriction by TRIM5αRh, suggesting a direct role in capsid recognition. Interestingly, SIM4-mutated TRIM5αRh also failed to activate NF-κB and AP-1-mediated transcription. Although there is no direct evidence that SIM4 is involved in direct interaction with SUMO or a SUMOylated protein, mutating this motif strongly reduced co-localization of TRIM5αRh with SUMO-1 and with PML, a SUMOylated nuclear protein. In conclusion, this new putative SIM is crucial for both direct interaction with incoming capsids and for NF-κB/AP-1 signaling. We speculate that the latter function is mediated by interactions of SIM4 with a SUMOylated protein involved in the NF-κB/AP-1 signaling pathways.

  14. The G1/S Specific Cyclin D2 Is a Regulator of HIV-1 Restriction in Non-proliferating Cells

    Science.gov (United States)

    Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M.; Ballana, Ester

    2016-01-01

    Macrophages are a heterogeneous cell population strongly influenced by differentiation stimuli that become susceptible to HIV-1 infection after inactivation of the restriction factor SAMHD1 by cyclin-dependent kinases (CDK). Here, we have used primary human monocyte-derived macrophages differentiated through different stimuli to evaluate macrophage heterogeneity on cell activation and proliferation and susceptibility to HIV-1 infection. Stimulation of monocytes with GM-CSF induces a non-proliferating macrophage population highly restrictive to HIV-1 infection, characterized by the upregulation of the G1/S-specific cyclin D2, known to control early steps of cell cycle progression. Knockdown of cyclin D2, enhances HIV-1 replication in GM-CSF macrophages through inactivation of SAMHD1 restriction factor by phosphorylation. Co-immunoprecipitation experiments show that cyclin D2 forms a complex with CDK4 and p21, a factor known to restrict HIV-1 replication by affecting the function of the downstream cascade that leads to SAMHD1 deactivation. Thus, we demonstrate that cyclin D2 acts as regulator of cell cycle proteins affecting SAMHD1-mediated HIV-1 restriction in non-proliferating macrophages. PMID:27541004

  15. Electron tomography of the contact between T cells and SIV/HIV-1: implications for viral entry.

    Directory of Open Access Journals (Sweden)

    Rachid Sougrat

    2007-05-01

    Full Text Available The envelope glycoproteins of primate lentiviruses, including human and simian immunodeficiency viruses (HIV and SIV, are heterodimers of a transmembrane glycoprotein (usually gp41, and a surface glycoprotein (gp120, which binds CD4 on target cells to initiate viral entry. We have used electron tomography to determine the three-dimensional architectures of purified SIV virions in isolation and in contact with CD4+ target cells. The trimeric viral envelope glycoprotein surface spikes are heterogeneous in appearance and typically approximately 120 A long and approximately 120 A wide at the distal end. Docking of SIV or HIV-1 on the T cell surface occurs via a neck-shaped contact region that is approximately 400 A wide and consistently consists of a closely spaced cluster of five to seven rod-shaped features, each approximately 100 A long and approximately 100 A wide. This distinctive structure is not observed when viruses are incubated with T lymphocytes in the presence of anti-CD4 antibodies, the CCR5 antagonist TAK779, or the peptide entry inhibitor SIVmac251 C34. For virions bound to cells, few trimers were observed away from this cluster at the virion-cell interface, even in cases where virus preparations showing as many as 70 envelope glycoprotein trimers per virus particle were used. This contact zone, which we term the "entry claw", provides a spatial context to understand the molecular mechanisms of viral entry. Determination of the molecular composition and structure of the entry claw may facilitate the identification of improved drugs for the inhibition of HIV-1 entry.

  16. Mosaic HIV envelope immunogenic polypeptides

    Science.gov (United States)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  17. Engineering HIV-resistant human CD4+ T cells with CXCR4-specific zinc-finger nucleases.

    Directory of Open Access Journals (Sweden)

    Craig B Wilen

    2011-04-01

    Full Text Available HIV-1 entry requires the cell surface expression of CD4 and either the CCR5 or CXCR4 coreceptors on host cells. Individuals homozygous for the ccr5Δ32 polymorphism do not express CCR5 and are protected from infection by CCR5-tropic (R5 virus strains. As an approach to inactivating CCR5, we introduced CCR5-specific zinc-finger nucleases into human CD4+ T cells prior to adoptive transfer, but the need to protect cells from virus strains that use CXCR4 (X4 in place of or in addition to CCR5 (R5X4 remains. Here we describe engineering a pair of zinc finger nucleases that, when introduced into human T cells, efficiently disrupt cxcr4 by cleavage and error-prone non-homologous DNA end-joining. The resulting cells proliferated normally and were resistant to infection by X4-tropic HIV-1 strains. CXCR4 could also be inactivated in ccr5Δ32 CD4+ T cells, and we show that such cells were resistant to all strains of HIV-1 tested. Loss of CXCR4 also provided protection from X4 HIV-1 in a humanized mouse model, though this protection was lost over time due to the emergence of R5-tropic viral mutants. These data suggest that CXCR4-specific ZFNs may prove useful in establishing resistance to CXCR4-tropic HIV for autologous transplant in HIV-infected individuals.

  18. Soluble HIV-1 envelope immunogens derived from an elite neutralizer elicit cross-reactive V1V2 antibodies and low potency neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Sara Carbonetti

    Full Text Available We evaluated four gp140 Envelope protein vaccine immunogens that were derived from an elite neutralizer, subject VC10042, whose plasma was able to potently neutralize a wide array of genetically distinct HIV-1 isolates. We sought to determine whether soluble Envelope proteins derived from the viruses circulating in VC10042 could be used as immunogens to elicit similar neutralizing antibody responses by vaccination. Each gp140 was tested in its trimeric and monomeric forms, and we evaluated two gp140 trimer vaccine regimens in which adjuvant was supplied at all four immunizations or at only the first two immunizations. Interestingly, all four Envelope immunogens elicited high titers of cross-reactive antibodies that recognize the variable regions V1V2 and are potentially similar to antibodies linked with a reduced risk of HIV-1 acquisition in the RV144 vaccine trial. Two of the four immunogens elicited neutralizing antibody responses that neutralized a wide array of HIV-1 isolates from across genetic clades, but those responses were of very low potency. There were no significant differences in the responses elicited by trimers or monomers, nor was there a significant difference between the two adjuvant regimens. Our study identified two promising Envelope immunogens that elicited anti-V1V2 antibodies and broad, but low potency, neutralizing antibody responses.

  19. Anti-HIV Effect of Liposomes Bearing CXCR4 Receptor Antagonist ...

    African Journals Online (AJOL)

    Keywords: Antagonist, CXCR4, Liposomes, Receptor, Inflammation, HIV. Tropical Journal of ... receptors and inhibits HIV-1 entry mediated through CCR3, CCR5, and ..... circulation, facilitating HIV-targeted drug delivery. By tissue distribution ...

  20. Association study of common genetic variants and HIV-1 acquisition in 6,300 infected cases and 7,200 controls

    DEFF Research Database (Denmark)

    McLaren, Paul J; Coulonges, Cédric; Ripke, Stephan

    2013-01-01

    Multiple genome-wide association studies (GWAS) have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although...... of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6 × 10(-11)). However, restricting analysis to individuals with a known date of seroconversion suggested...... no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity). Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size....

  1. Optimization and validation of a neutralizing antibody assay for HIV-1 in A3R5 cells.

    Science.gov (United States)

    Sarzotti-Kelsoe, Marcella; Daniell, Xiaoju; Todd, Christopher A; Bilska, Miroslawa; Martelli, Amanda; LaBranche, Celia; Perez, Lautaro G; Ochsenbauer, Christina; Kappes, John C; Rountree, Wes; Denny, Thomas N; Montefiori, David C

    2014-07-01

    A3R5 is a human CD4(+) lymphoblastoid cell line that was engineered to express CCR5 and is useful for the detection of weak neutralizing antibody responses against tier 2 strains of HIV-1. Here we describe the optimization and validation of the HIV-1 neutralizing antibody assay that utilizes A3R5 cells, performed in compliance with Good Clinical Laboratory Practice (GCLP) guidelines. The assay utilizes Renilla luciferase-expressing replication competent infectious molecular clones (IMC) encoding heterologous env genes from different HIV-1 clades. Key assay validation parameters tested included specificity, accuracy, precision, limit of detection and quantitation, specificity, linearity and range, and robustness. Plasma samples demonstrated higher non-specific activity than serum samples in the A3R5 assay. This assay can tolerate a wide range of virus input but is more sensitive to cell concentration. The higher sensitivity of the A3R5 assay in neutralization responses to tier 2 strains of HIV-1 makes it complementary to, but not a substitute for the TZM-bl assay. The validated A3R5 assay is employed as an endpoint immunogenicity test for vaccine-elicited neutralizing antibodies against tier 2 strains of HIV-1, and to identify correlates of protection in HIV-1 vaccine trials conducted globally. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. African Ancestry Influences CCR5 –2459G>A Genotype-Associated Virologic Success of Highly Active Antiretroviral Therapy

    Science.gov (United States)

    Cheruvu, Vinay K.; Igo, Robert P.; Jurevic, Richard J.; Serre, David; Zimmerman, Peter A.; Rodriguez, Benigno; Mehlotra, Rajeev K.

    2014-01-01

    Introduction In a North American, HIV-positive, highly active antiretroviral therapy (HAART)-treated, adherent cohort of self-identified white and black patients, we previously observed that chemokine (C-C motif) receptor 5 (CCR5) –2459G>A genotype had a strong association with time to achieve virologic success (TVLS) in black but not in white patients. Methods Using 128 genome-wide ancestry informative markers, we performed a quantitative assessment of ancestry in these patients (n = 310) to determine (1) whether CCR5 –2459G>A genotype is still associated with TVLS of HAART when ancestry, not self-identified race, is considered and (2) whether this association is influenced by varying African ancestry. Results We found that the interaction between CCR5 –2459G>A genotype and African ancestry (≤0.125 vs. ≥0.425 and A genotype and TVLS was stronger in patients with African ancestry ≥0.71 than in patients with African ancestry ≥0.452, in both Kaplan-Meier (log-rank P = 0.039 and 0.057, respectively, for AA, GA, and GG) and Cox proportional hazards regression (relative hazard for GG compared with AA 2.59 [95% CI, 1.27–5.22; P = 0.01] and 2.26 [95% CI, 1.18–4.32; P = 0.01], respectively) analyses. Conclusions We observed that the association between CCR5 –2459G>A genotype and TVLS of HAART increased with stronger African ancestry. Understanding the genomic mechanisms by which African ancestry influences this association is critical, and requires further studies. PMID:24714069

  3. Effect of female genital schistosomiasis and anti-schistosomal treatment on monocytes, CD4+ T-cells and CCR5 expression in the female genital tract.

    Science.gov (United States)

    Kleppa, Elisabeth; Ramsuran, Veron; Zulu, Siphosenkosi; Karlsen, Gunn Hege; Bere, Alfred; Passmore, Jo-Ann S; Ndhlovu, Patricia; Lillebø, Kristine; Holmen, Sigve D; Onsrud, Mathias; Gundersen, Svein Gunnar; Taylor, Myra; Kjetland, Eyrun F; Ndung'u, Thumbi

    2014-01-01

    Schistosoma haematobium is a waterborne parasite that may cause female genital schistosomiasis (FGS), characterized by genital mucosal lesions. There is clinical and epidemiological evidence for a relationship between FGS and HIV. We investigated the impact of FGS on HIV target cell density and expression of the HIV co-receptor CCR5 in blood and cervical cytobrush samples. Furthermore we evaluated the effect of anti-schistosomal treatment on these cell populations. The study followed a case-control design with post treatment follow-up, nested in an on-going field study on FGS. Blood and cervical cytobrush samples were collected from FGS negative and positive women for flow cytometry analyses. Urine samples were investigated for schistosome ova by microscopy and polymerase chain reaction (PCR). FGS was associated with a higher frequency of CD14+ cells (monocytes) in blood (11.5% in FGS+ vs. 2.2% in FGS-, p = 0.042). Frequencies of CD4+ cells expressing CCR5 were higher in blood samples from FGS+ than from FGS- women (4.7% vs. 1.5%, p = 0.018). The CD14+ cell population decreased significantly in both compartments after anti-schistosomal treatment (p = 0.043). Although the frequency of CD4+ cells did not change after treatment, frequencies of CCR5 expression by CD4+ cells decreased significantly in both compartments (from 3.4% to 0.5% in blood, p = 0.036; and from 42.4% to 5.6% in genital samples, p = 0.025). The results support the hypothesis that FGS may increase the risk of HIV acquisition, not only through damage of the mucosal epithelial barrier, but also by affecting HIV target cell populations, and that anti-schistosomal treatment can modify this.

  4. 27-Hydroxycholesterol and 7alpha-hydroxycholesterol trigger a sequence of events leading to migration of CCR5-expressing Th1 lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun-Mi, E-mail: lala1647@hanmail.net [Department of Pharmacology, Pusan National University, School of Medicine, Yangsan, Gyeongnam 626-870 (Korea, Republic of); Kim, Bo-Young, E-mail: kimboyoung@pusan.ac.kr [Department of Pharmacology, Pusan National University, School of Medicine, Yangsan, Gyeongnam 626-870 (Korea, Republic of); Lee, Sae-A, E-mail: saeah486@nate.com [Department of Pharmacology, Pusan National University, School of Medicine, Yangsan, Gyeongnam 626-870 (Korea, Republic of); Eo, Seong-Kug, E-mail: vetvirus@chonbuk.ac.kr [Laboratory of Microbiology, College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Yun, Yungdae, E-mail: yunyung@ewha.ac.kr [Department of Life Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of); Kim, Chi-Dae, E-mail: chidkim@pusan.ac.kr [Department of Pharmacology, Pusan National University, School of Medicine, Yangsan, Gyeongnam 626-870 (Korea, Republic of); Kim, Koanhoi, E-mail: koanhoi@pusan.ac.kr [Department of Pharmacology, Pusan National University, School of Medicine, Yangsan, Gyeongnam 626-870 (Korea, Republic of)

    2014-02-01

    Th1 lymphocytes are predominant in atherosclerotic lesions. However, mechanisms involved in the Th1 predominance are unknown. We have investigated the possibility of Th1 lymphocyte recruitment in a cholesterol-rich milieu. A high cholesterol diet resulted in enhanced expression of CCR5 ligands, including CCL3 and CCL4, but not of proatherogenic CXCR3 ligands, in atherosclerotic arteries of ApoE{sup −/−} mice. 27-Hydroxycholesterol and 7α-hydroxycholesterol, cholesterol oxides (oxysterols) detected in abundance in atherosclerotic lesions, greatly induced the transcription of CCL3 and CCL4 genes in addition to enhancing secretion of corresponding proteins by THP-1 monocytic cells. However, an identical or even higher concentration of cholesterol, 7β-hydroxycholesterol, and 7-ketocholsterol did not influence expression of these chemokines. Conditioned media containing the CCR5 ligands secreted from THP-1 cells induced migration of Jurkat T cells expressing CCR5, a characteristic chemokine receptor of Th1 cells, but not of Jurkat T cells that do not express CCR5. The migration of CCR5-expressing Jurkat T cells was abrogated in the presence of a CCR5-neutralizing antibody. 27-Hydroxycholesterol and 7α-hydroxycholesterol enhanced phosphorylation of Akt. Pharmacological inhibitors of phosphoinositide-3-kinase/Akt pathways blocked transcription as well as secretion of CCL3 and CCL4 in conjunction with attenuated migration of CCR5-expressing Jurkat T cells. This is the first report on the involvement of cholesterol oxides in migration of distinct subtype of T cells. We propose that 27-hydroxycholesterol and 7α-hydroxycholesterol can trigger a sequence of events that leads to recruitment of Th1 lymphocytes and phosphoinositide-3-kinase/Akt pathways play a major role in the process. - Graphical abstract: Th1 lymphocytes are predominant in atherosclerotic lesions. However, mechanisms involved in the Th1 predominance are unknown. We have investigated the possibility of

  5. 27-Hydroxycholesterol and 7alpha-hydroxycholesterol trigger a sequence of events leading to migration of CCR5-expressing Th1 lymphocytes

    International Nuclear Information System (INIS)

    Kim, Sun-Mi; Kim, Bo-Young; Lee, Sae-A; Eo, Seong-Kug; Yun, Yungdae; Kim, Chi-Dae; Kim, Koanhoi

    2014-01-01

    Th1 lymphocytes are predominant in atherosclerotic lesions. However, mechanisms involved in the Th1 predominance are unknown. We have investigated the possibility of Th1 lymphocyte recruitment in a cholesterol-rich milieu. A high cholesterol diet resulted in enhanced expression of CCR5 ligands, including CCL3 and CCL4, but not of proatherogenic CXCR3 ligands, in atherosclerotic arteries of ApoE −/− mice. 27-Hydroxycholesterol and 7α-hydroxycholesterol, cholesterol oxides (oxysterols) detected in abundance in atherosclerotic lesions, greatly induced the transcription of CCL3 and CCL4 genes in addition to enhancing secretion of corresponding proteins by THP-1 monocytic cells. However, an identical or even higher concentration of cholesterol, 7β-hydroxycholesterol, and 7-ketocholsterol did not influence expression of these chemokines. Conditioned media containing the CCR5 ligands secreted from THP-1 cells induced migration of Jurkat T cells expressing CCR5, a characteristic chemokine receptor of Th1 cells, but not of Jurkat T cells that do not express CCR5. The migration of CCR5-expressing Jurkat T cells was abrogated in the presence of a CCR5-neutralizing antibody. 27-Hydroxycholesterol and 7α-hydroxycholesterol enhanced phosphorylation of Akt. Pharmacological inhibitors of phosphoinositide-3-kinase/Akt pathways blocked transcription as well as secretion of CCL3 and CCL4 in conjunction with attenuated migration of CCR5-expressing Jurkat T cells. This is the first report on the involvement of cholesterol oxides in migration of distinct subtype of T cells. We propose that 27-hydroxycholesterol and 7α-hydroxycholesterol can trigger a sequence of events that leads to recruitment of Th1 lymphocytes and phosphoinositide-3-kinase/Akt pathways play a major role in the process. - Graphical abstract: Th1 lymphocytes are predominant in atherosclerotic lesions. However, mechanisms involved in the Th1 predominance are unknown. We have investigated the possibility of Th1

  6. Nef does not contribute to replication differences between R5 pre-AIDS and AIDS HIV-1 clones from patient ACH142

    Directory of Open Access Journals (Sweden)

    Rekosh David

    2008-05-01

    Full Text Available Abstract AIDS-associated, CCR5-tropic (R5 HIV-1 clones, isolated from a patient that never developed CXCR4-tropic HIV-1, replicate to a greater extent and cause greater cytopathic effects than R5 HIV-1 clones isolated before the onset of AIDS. Previously, we showed that HIV-1 Env substantially contributed to the enhanced replication of an AIDS clone. In order to determine if Nef makes a similar contribution, we cloned and phenotypically analyzed nef genes from a series of patient ACH142 derived R5 HIV-1 clones. The AIDS-associated Nef contains a series of residues found in Nef proteins from progressors 1. In contrast to other reports 123, this AIDS-associated Nef downmodulated MHC-I to a greater extent and CD4 less than pre-AIDS Nef proteins. Additionally, all Nef proteins enhanced infectivity similarly in a single round of replication. Combined with our previous study, these data show that evolution of the HIV-1 env gene, but not the nef gene, within patient ACH142 significantly contributed to the enhanced replication and cytopathic effects of the AIDS-associated R5 HIV-1 clone.

  7. Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes

    DEFF Research Database (Denmark)

    Pfleger, C.; Kaas, A.; Hansen, L.

    2008-01-01

    Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated...... longitudinally circulating concentrations of CCR5 ligands of 256 newly diagnosed patients with type 1 diabetes. CCR5 ligands were differentially associated with beta-cell function and clinical remission. CCL5 was decreased in remitters and positively associated with HbA1c suggestive of a Th1 associated...... of CCR5 by therapeutic agents such as maraviroc may provide a new therapeutic target to ameliorate disease progression in type 1 diabetes. (C) 2008 Elsevier Inc. All rights reserved Udgivelsesdato: 2008/7...

  8. Replacement of the murine leukemia virus (MLV) envelope gene with a truncated HIV envelope gene in MLV generates a virus with impaired replication capacity

    International Nuclear Information System (INIS)

    Nack, Ursula; Schnierle, Barbara S.

    2003-01-01

    Murine leukemia virus (MLV) capsid particles can be efficiently pseudotyped with a variant of the HIV-1 envelope protein (Env) containing the surface glycoprotein gp120-SU and a carboxyl-terminally truncated transmembrane (TM) protein, with only seven cytoplasmic amino acids. MLV/HIV pseudotyped vector particles acquire the natural host tropism of HIV-1 and their entry is dependent on the presence of CD4 and an appropriate co-receptor on the surface of the target cell. We describe here the construction of chimeric MLV/HIV proviruses containing the truncated HIV envelope gene. The MLV/HIV provirus was generated by direct replacement of the MLV envelope gene with HIV Env coding sequences either with or without the additional inclusion of the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Chimeric MLV/HIV particles could be generated from transfected 293T cells and were able to infect CD4/CXCR4-positive target cells. However, the second round of infection of target cells was severely impaired, despite the fact that the WPRE element enhanced the amount of viral mRNA detected. Viral particles released from infected cells showed reduced HIV Env incorporation, indicating that additional factors required for efficient replication of MLV/HIV pseudotyped viruses are missing

  9. Accelerated in vivo proliferation of memory phenotype CD4+ T-cells in human HIV-1 infection irrespective of viral chemokine co-receptor tropism.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available CD4(+ T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5(+ cells, and (ii that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4(+ compartment. To test these hypotheses we measured in vivo turnover rates of CD4(+ T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p and disappearance (d* rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143-569 cells/ul participated. CCR5-expression defined a CD4(+ subpopulation of predominantly CD45R0(+ memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5(+ vs CCR5(-; healthy controls; P<0.01. Conversely, CXCR4 expression defined CD4(+ T-cells (predominantly CD45RA(+ naive cells with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5(+CD45R0(+CD4(+ memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05, naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9 or X4-tropic (n = 4. Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively. Our data are most consistent with models in which CD4(+ T-cell loss is primarily driven by non-specific immune activation.

  10. Conglutinin binds the HIV-1 envelope glycoprotein gp 160 and inhibits its interaction with cell membrane CD4

    DEFF Research Database (Denmark)

    Andersen, Ove; Sørensen, A M; Svehag, S E

    1991-01-01

    The highly glycosylated envelope glycoprotein (gp 160) of human immunodeficiency virus (HIV) interacts with the CD4 molecule present on the membrane of CD4+ cells and is involved in the pathobiology of HIV infection. Lectins bind glycoproteins through non-covalent interactions with specific hexose...... residues. The mammalian C-type lectin bovine conglutinin was examined for its ability to interact with recombinant gp160 (rgp160) produced in vaccinia virus-infected BHK21 cells. Specific binding of conglutinin to rgp160 was demonstrated by ELISA. The interaction of bovine conglutinin with rgp160...... of the binding of rgp160 to the CD4 receptor on CEM 13 cells, as demonstrated by FACS analyses. These results indicate that conglutinin may inhibit the infection with HIV-1 through its interaction with the viral envelope glycoprotein....

  11. Role of the chemokine receptors CCR1, CCR2 and CCR4 in the pathogenesis of experimental dengue infection in mice.

    Directory of Open Access Journals (Sweden)

    Rodrigo Guabiraba

    Full Text Available Dengue virus (DENV, a mosquito-borne flavivirus, is a public health problem in many tropical countries. Recent clinical data have shown an association between levels of different chemokines in plasma and severity of dengue. We evaluated the role of CC chemokine receptors CCR1, CCR2 and CCR4 in an experimental model of DENV-2 infection in mice. Infection of mice induced evident clinical disease and tissue damage, including thrombocytopenia, hemoconcentration, lymphopenia, increased levels of transaminases and pro-inflammatory cytokines, and lethality in WT mice. Importantly, infected WT mice presented increased levels of chemokines CCL2/JE, CCL3/MIP-1α and CCL5/RANTES in spleen and liver. CCR1⁻/⁻ mice had a mild phenotype with disease presentation and lethality similar to those of WT mice. In CCR2⁻/⁻ mice, lethality, liver damage, levels of IL-6 and IFN-γ, and leukocyte activation were attenuated. However, thrombocytopenia, hemoconcentration and systemic TNF-α levels were similar to infected WT mice. Infection enhanced levels of CCL17/TARC, a CCR4 ligand. In CCR4⁻/⁻ mice, lethality, tissue injury and systemic inflammation were markedly decreased. Despite differences in disease presentation in CCR-deficient mice, there was no significant difference in viral load. In conclusion, activation of chemokine receptors has discrete roles in the pathogenesis of dengue infection. These studies suggest that the chemokine storm that follows severe primary dengue infection associates mostly to development of disease rather than protection.

  12. Isolation and characterization of 20'-F-RNA aptamers against whole HIV-1 subtype C envelope pseudovirus

    CSIR Research Space (South Africa)

    London, GM

    2015-01-01

    Full Text Available Aptamers, which are artificial nucleic acid ligands akin to antibodies in function, represent a new class of molecules that can prevent HIV infection. In this study, we isolated RNA aptamers against whole HV-1CAP45 enveloped pseudotyped virus...

  13. CCR5 and CXCR3 are dispensable for liver infiltration, but CCR5 protects against virus-induced T-cell-mediated hepatic steatosis

    DEFF Research Database (Denmark)

    Holst, P J; Orskov, C; Qvortrup, K

    2007-01-01

    CCR5 and CXCR3 are important molecules in regulating the migration of activated lymphocytes. Thus, the majority of tissue-infiltrating T cells found in the context of autoimmune conditions and viral infections express CCR5 and CXCR3, and the principal chemokine ligands are expressed within inflam...... of CCR5 is associated with the induction of CD8(+) T-cell-mediated immunopathology consisting of marked hepatic microvesicular steatosis....

  14. Glycosylphosphatidylinositol-Anchored Anti-HIV scFv Efficiently Protects CD4 T Cells from HIV-1 Infection and Deletion in hu-PBL Mice

    Science.gov (United States)

    Ye, Chaobaihui; Wang, Weiming; Cheng, Liang; Li, Guangming; Wen, Michael; Wang, Qi; Zhang, Qing; Li, Dan

    2016-01-01

    ABSTRACT Despite success in viral inhibition and CD4 T cell recovery by highly active antiretroviral treatment (HAART), HIV-1 is still not curable due to the persistence of the HIV-1 reservoir during treatment. One patient with acute myeloid leukemia who received allogeneic hematopoietic stem cell transplantation from a homozygous CCR5 Δ32 donor has had no detectable viremia for 9 years after HAART cessation. This case has inspired a field of HIV-1 cure research focusing on engineering HIV-1 resistance in permissive cells. Here, we employed a glycosylphosphatidylinositol (GPI)-scFv X5 approach to confer resistance of human primary CD4 T cells to HIV-1. We showed that primary CD4 T cells expressing GPI-scFv X5 were resistant to CCR5 (R5)-, CXCR4 (X4)-, and dual-tropic HIV-1 and had a survival advantage compared to control cells ex vivo. In a hu-PBL mouse study, GPI-scFv X5-transduced CD4 T cells were selected in peripheral blood and lymphoid tissues upon HIV-1 infection. Finally, GPI-scFv X5-transduced CD4 T cells, after being cotransfused with HIV-infected cells, showed significantly reduced viral loads and viral RNA copy numbers relative to CD4 cells in hu-PBL mice compared to mice with GPI-scFv AB65-transduced CD4 T cells. We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections. IMPORTANCE Blocking of HIV-1 entry is one of most promising approaches for therapy. Genetic disruption of the HIV-1 coreceptor CCR5 by nucleases in T cells is under 2 clinical trials and leads to reduced viremia in patients. However, the emergence of viruses using the CXCR4 coreceptor is a concern for therapies applying single-coreceptor disruption. Here, we report that HIV-1-permissive CD4 T cells engineered with GPI-scFv X5 are resistant to R5-, X4-, or dual-tropic virus infection ex vivo. In a preclinical study using hu-PBL mice, we show that CD4 T cells were protected and that GPI-scFv X5

  15. Multicohort Genomewide Association Study Reveals a New Signal of Protection Against HIV-1 Acquisition

    Science.gov (United States)

    Limou, Sophie; Delaneau, Olivier; van Manen, Daniëlle; An, Ping; Sezgin, Efe; Le Clerc, Sigrid; Coulonges, Cédric; Troyer, Jennifer L.; Veldink, Jan H.; van den Berg, Leonard H.; Spadoni, Jean-Louis; Taing, Lieng; Labib, Taoufik; Montes, Matthieu; Delfraissy, Jean-François; Schachter, François; O’Brien, Stephen J.; Buchbinder, Susan; van Natta, Mark L.; Jabs, Douglas A.; Froguel, Philippe; Schuitemaker, Hanneke; Winkler, Cheryl A.

    2012-01-01

    Background. To date, only mutations in CCR5 have been shown to confer resistance to human immunodeficiency virus type 1 (HIV-1) infection, and these explain only a small fraction of the observed variability in HIV susceptibility. Methods. We performed a meta-analysis between 2 independent European genomewide association studies, each comparing HIV-1 seropositive cases with normal population controls known to be HIV uninfected, to identify single-nucleotide polymorphisms (SNPs) associated with the HIV-1 acquisition phenotype. SNPs exhibiting P < 10−5 in this first stage underwent second-stage analysis in 2 independent US cohorts of European descent. Results. After the first stage, a single highly significant association was revealed for the chromosome 8 rs6996198 with HIV-1 acquisition and was replicated in both second-stage cohorts. Across the 4 groups, the rs6996198-T allele was consistently associated with a significant reduced risk of HIV-1 infection, and the global meta-analysis reached genomewide significance: Pcombined = 7.76 × 10−8. Conclusions. We provide strong evidence of association for a common variant with HIV-1 acquisition in populations of European ancestry. This protective signal against HIV-1 infection is the first identified outside the CCR5 nexus. First clues point to a potential functional role for a nearby candidate gene, CYP7B1, but this locus warrants further investigation. PMID:22362864

  16. CCR5 internalisation and signalling have different dependence on membrane lipid raft integrity.

    Science.gov (United States)

    Cardaba, Clara Moyano; Kerr, Jason S; Mueller, Anja

    2008-09-01

    The chemokine receptor, CCR5, acts as a co-receptor for human immunodeficiency virus entry into cells. CCR5 has been shown to be targeted to cholesterol- and sphingolipid-rich membrane microdomains termed lipid rafts or caveolae. Cholesterol is essential for CCL4 binding to CCR5 and for keeping the conformational integrity of the receptor. Filipin treatment leads to loss of caveolin-1 from the membrane and therefore to a collapse of the caveolae. We have found here that sequestration of membrane cholesterol with filipin did not affect receptor signalling, however a loss of ligand-induced internalisation of CCR5 was observed. Cholesterol extraction with methyl-beta-cyclodextrin (MCD) reduced signalling through CCR5 as measured by release of intracellular Ca(2+) and completely abolished the inhibition of forskolin-stimulated cAMP accumulation with no effect on internalisation. Pertussis toxin (PTX) treatment inhibited the intracellular release of calcium that is transduced via Galphai G-proteins. Depletion of cholesterol destroyed microdomains in the membrane and switched CCR5/G-protein coupling to a PTX-independent G-protein. We conclude that cholesterol in the membrane is essential for CCR5 signalling via the Galphai G-protein subunit, and that integrity of lipid rafts is not essential for effective CCR5 internalisation however it is crucial for proper CCR5 signal transduction via Galphai G-proteins.

  17. Role of protein disulfide isomerase and other thiol-reactive proteins in HIV-1 envelope protein-mediated fusion

    International Nuclear Information System (INIS)

    Ou Wu; Silver, Jonathan

    2006-01-01

    Cell-surface protein disulfide isomerase (PDI) has been proposed to promote disulfide bond rearrangements in HIV-1 envelope protein (Env) that accompany Env-mediated fusion. We evaluated the role of PDI in ways that have not been previously tested by downregulating PDI with siRNA and by overexpressing wild-type or variant forms of PDI in transiently and stably transfected cells. These manipulations, as well as treatment with anti-PDI antibodies, had only small effects on infection or cell fusion mediated by NL4-3 or AD8 strains of HIV-1. However, the cell-surface thiol-reactive reagent 5, 5'-dithiobis(2-nitrobenzoic acid) (DTNB) had a much stronger inhibitory effect in our system, suggesting that cell-surface thiol-containing molecules other than PDI, acting alone or in concert, have a greater effect than PDI on HIV-1 Env-mediated fusion. We evaluated one such candidate, thioredoxin, a PDI family member reported to reduce a labile disulfide bond in CD4. We found that the ability of thioredoxin to reduce the disulfide bond in CD4 is enhanced in the presence of HIV-1 Env gp120 and that thioredoxin also reduces disulfide bonds in gp120 directly in the absence of CD4. We discuss the implications of these observations for identification of molecules involved in disulfide rearrangements in Env during fusion

  18. Characterization of emergent HIV resistance in treatment-naive subjects enrolled in a vicriviroc phase 2 trial.

    Science.gov (United States)

    McNicholas, Paul; Wei, Yi; Whitcomb, Jeannette; Greaves, Wayne; Black, Todd A; Tremblay, Cecile L; Strizki, Julie M

    2010-05-15

    Vicriviroc is a C-C motif chemokine receptor 5 (CCR5) antagonist that is in clinical development for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. This study explored the molecular basis for the development of phenotypically resistant virus. HIV-1 RNA from treatment-naive subjects who experienced virological failure in a phase 2 dose-finding trial was evaluated for coreceptor usage and susceptibility. For viruses that exhibited reduced susceptibility to vicriviroc, envelope clones were phenotypically and genotypically characterized. Twenty-six vicriviroc-treated subjects experienced virological failure; for 24 the virus remained CCR5-tropic, and 2 had dual/X4 virus. Reduced susceptibility to vicriviroc, manifested as decreases in the maximum percent inhibition value (no increase in median inhibitory concentration), was detected in 4 of the 26 subjects who experienced virological failure. Clonal analysis of envelopes in samples from these 4 subjects revealed multiple sequence changes in gp160, principally within the variable domain 1/variable domain 2, variable domain 3, and variable domain 4 loops. However, no consistent pattern of mutations was observed across subjects. In this study, only a small proportion of treatment failures were associated with tropism changes or reduced susceptibility to vicriviroc. Genotypic analysis of cloned env sequences revealed no specific mutational pattern associated with reduced susceptibility to vicriviroc, although numerous changes were observed in the variable domain 3 loop and in other regions of gp160.

  19. SAMHD1 restricts HIV-1 replication and regulates interferon production in mouse myeloid cells.

    Directory of Open Access Journals (Sweden)

    Ruonan Zhang

    Full Text Available SAMHD1 restricts the replication of HIV-1 and other retroviruses in human myeloid and resting CD4(+ T cells and that is counteracted in SIV and HIV-2 by the Vpx accessory protein. The protein is a phosphohydrolase that lowers the concentration of deoxynucleoside triphosphates (dNTP, blocking reverse transcription of the viral RNA genome. Polymorphisms in the gene encoding SAMHD1 are associated with Aicardi-Goutières Syndrome, a neurological disorder characterized by increased type-I interferon production. SAMHD1 is conserved in mammals but its role in restricting virus replication and controlling interferon production in non-primate species is not well understood. We show that SAMHD1 is catalytically active and expressed at high levels in mouse spleen, lymph nodes, thymus and lung. siRNA knock-down of SAMHD1 in bone marrow-derived macrophages increased their susceptibility to HIV-1 infection. shRNA knock-down of SAMHD1 in the murine monocytic cell-line RAW264.7 increased its susceptibility to HIV-1 and murine leukemia virus and increased the levels of the dNTP pool. In addition, SAMHD1 knock-down in RAW264.7 cells induced the production of type-I interferon and several interferon-stimulated genes, modeling the situation in Aicardi-Goutières Syndrome. Our findings suggest that the role of SAMHD1 in restricting viruses is conserved in the mouse. The RAW264.7 cell-line serves as a useful tool to study the antiviral and innate immune response functions of SAMHD1.

  20. [The expression of periphery blood leucocyte CCR3 and CCR5 in the children with Epstein-Barr virus associated infectious mononucleosis].

    Science.gov (United States)

    Qi, Tie-xiong; Gao, Guo-hua; Liu, Shi-hua

    2010-10-01

    To explore the expression of periphery blood leucocyte CCR3 and CCR5 and to comprehend T helper cell in the Children with Epstein-Barr virus associated infectious mononucleosis. We defined the children according to the diagnosis criterion through Paul-Bunnell test inspecting the children's periphery blood unusual lymphocyte and detecting their anti-EBV-CA-IgM, anti-EBV-CA-IgG and anti-EBV-NA-IgG by ELISA and counted the ratio of CCR3 + and CCR5 + cells in lymphocytes with flow cytometry. The ratio of unusual lymphocyte in IM was higher than that of the healthy control group (P < 0.05). The ratio of CCR3 + cells in IM group was higher than that of the healthy control group (P < 0.05). The ratio of CCR5 + cells in IM group was significantly lower than that of the healthy control group. CCR3 + had direct interrelation with fever continued time and the ratio of unusual lymphocyte. There was a negative interrelation between CCR5 and fever continued time (P < 0.05). Children infectious of IM expressed higher level of CCR3 + and lower level of CCR5 + and there was a tendency of Th2 polarization with over production of T helper cell divide imbalance. CCR3 + and CCR5 + may be important targets to judge the degree of seriousness of IM.

  1. Punica granatum (Pomegranate juice provides an HIV-1 entry inhibitor and candidate topical microbicide

    Directory of Open Access Journals (Sweden)

    Li Yun-Yao

    2004-10-01

    Full Text Available Abstract Background For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. Methods Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1 infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2 binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. Results HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. Conclusion These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored.

  2. Chemokine receptor CCR2b 64I polymorphism and its relation to CD4 T-cell counts and disease progression in a Danish cohort of HIV-infected individuals. Copenhagen AIDS cohort

    DEFF Research Database (Denmark)

    Eugen-Olsen, J; Iversen, Anton; Benfield, Thomas

    1998-01-01

    We have investigated the role of the recently described mutation in CCR2b named 64I in relation to HIV resistance, CD4 T-cell counts, and disease progression in Danish individuals by polymerase chain reaction (PCR)-based methods as well as sequenced full-length CXCR4 and CCR5 genes from HIV...... of AIDS, in AIDS-free survival as well as survival with AIDS, between 64I allele carriers and wild-type individuals. Among 9 long-term nonprogressors, 2 carried the 64I allele, while none of 9 fast progressors carried the 64I allele. However, this was not significantly different (p=.47). Long......-term nonprogression could not be explained by CXCR4 polymorphism or other polymorphisms in the CCR5 gene than the CCR5delta32 allele. Furthermore, we were not able to detect any significant independent effect of the 64I allele on development to AIDS, overall survival, and annual CD4 T-cell decline in this cohort....

  3. CCR2+ and CCR5+ CD8+ T cells increase during viral infection and migrate to sites of infection

    DEFF Research Database (Denmark)

    Nansen, A; Marker, O; Bartholdy, C

    2000-01-01

    Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic choriomeningi......Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic...... a rapidly lethal, T cell-independent encephalitis, and infection resulted in a dramatic early up-regulation of chemokine gene expression. Similar marked up-regulation of chemokine expression was not seen until late after LCMV infection and required the presence of activated T cells. Cerebral CCR gene...... expression was dominated by CCR1, CCR2 and CCR5. However, despite a stronger initial chemokine signal in VSV-infected mice, only LCMV-induced T cell-dependent inflammation was found to be associated with substantially increased expression of CCR genes. Virus-activated CD8+ T cells were found to express CCR2...

  4. Identification of conserved subdominant HIV Type 1 CD8(+) T Cell epitopes restricted within common HLA Supertypes for therapeutic HIV Type 1 vaccines

    DEFF Research Database (Denmark)

    Karlsson, Ingrid; Kløverpris, Henrik; Jensen, Kristoffer Jarlov

    2012-01-01

    The high HIV-1 prevalence, up to 4.6% in Guinea-Bissau, West Africa, makes it a relevant location for testing of therapeutic vaccines. With the aim of performing a clinical study in Guinea-Bissau, after first testing the vaccine for safety in Denmark, Europe, we here describe the design...... of a universal epitope peptide-based T cell vaccine with relevance for any geographic locations. The two major obstacles when designing such a vaccine are the high diversities of the HIV-1 genome and of the human major histocompatibility complex (MHC) class I. We selected 15 CD8-restricted epitopes predicted......-specific, HLA-restricted T cell specificities using peptide-MHC class I tetramer labeling of CD8(+) T cells from HIV-1-infected individuals. The selected vaccine epitopes are infrequently targeted in HIV-1-infected individuals from both locations. Moreover, we HLA-typed HIV-1-infected individuals...

  5. Associations of fractalkine receptor (CX3CR1) and CCR5 gene variants with hypertension, diabetes and atherosclerosis in chronic renal failure patients undergoing hemodialysis.

    Science.gov (United States)

    Bagci, Binnur; Bagci, Gokhan; Huzmeli, Can; Sezgin, Ilhan; Ozdemir, Ozturk

    2016-07-01

    We aimed to investigate the associations of fractalkine receptor (CX3CR1) V249I, T280M and CCR5-59029 A/G gene polymorphisms in chronic renal failure (CRF) subjects undergoing hemodialysis and to evaluate possible associations of these polymorphisms with hypertension (HT), diabetes mellitus (DM) and atherosclerosis (AS). A total of 225 CRF subjects undergoing hemodialysis and 201 healthy controls were enrolled in the study. CRF subjects were divided into three major subgroups according to comorbidities including HT (n = 127), DM (n = 65) and AS (n = 33). Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism method. The II genotype and I allele frequencies of CX3CR1 V249I polymorphism were found significantly more frequent in CRF subjects, CRF subjects with DM and CRF subjects with AS compared with controls (p < 0.05 for all comparisons). G allele frequency of CCR5 polymorphism was found significantly more prevalent in CRF subjects with DM than that of controls. Further, GG genotype and G allele frequencies of CCR5 polymorphism were significantly more prevalent in CRF subjects with AS compared with controls (p < 0.05). We also explored these polymorphisms among CRF subjects with and without following comorbidities: HT, DM, AS. We found significant association between CRF subjects with HT and without HT in terms of genotype and allele frequencies of V249I polymorphism (p < 0.05). CX3CR1 T280M polymorphism was not found significantly different in none of the comparisons. These data demonstrate possible associations between CX3CR1 V249I and CCR5-59029 A/G polymorphisms and/or HT, DM and AS in CRF subjects.

  6. Tetherin restricts productive HIV-1 cell-to-cell transmission.

    Directory of Open Access Journals (Sweden)

    Nicoletta Casartelli

    2010-06-01

    Full Text Available The IFN-inducible antiviral protein tetherin (or BST-2/CD317/HM1.24 impairs release of mature HIV-1 particles from infected cells. HIV-1 Vpu antagonizes the effect of tetherin. The fate of virions trapped at the cell surface remains poorly understood. Here, we asked whether tetherin impairs HIV cell-to-cell transmission, a major means of viral spread. Tetherin-positive or -negative cells, infected with wild-type or DeltaVpu HIV, were used as donor cells and cocultivated with target lymphocytes. We show that tetherin inhibits productive cell-to-cell transmission of DeltaVpu to targets and impairs that of WT HIV. Tetherin accumulates with Gag at the contact zone between infected and target cells, but does not prevent the formation of virological synapses. In the presence of tetherin, viruses are then mostly transferred to targets as abnormally large patches. These viral aggregates do not efficiently promote infection after transfer, because they accumulate at the surface of target cells and are impaired in their fusion capacities. Tetherin, by imprinting virions in donor cells, is the first example of a surface restriction factor limiting viral cell-to-cell spread.

  7. Deficient Fas expression by CD4+ CCR5+ T cells in multiple sclerosis

    DEFF Research Database (Denmark)

    Julià, Eva; Montalban, Xavier; Al-Zayat, Hammad

    2006-01-01

    OBJECTIVE: To evaluate whether T cells expressing CCR5 and CXCR3 from multiple sclerosis (MS) patients are more resistant to apoptosis. METHODS: Expression of CD69, TNF-R1, Fas, FasL, bcl-2, and bax was investigated in 41 MS patients and 12 healthy controls by flow cytometry in CD4+ and CD8+ T...... cells expressing CCR5 and CXCR3. RESULTS: In MS patients, the percentage of CD69 was increased and Fas expression decreased in CD4+ CCR5+ T cells. INTERPRETATION: The lower Fas expression in activated CD4+ CCR5+ T cells might contribute to disease pathogenesis by prolonging cell survival and favoring...

  8. Picomolar dichotomous activity of gnidimacrin against HIV-1.

    Directory of Open Access Journals (Sweden)

    Li Huang

    Full Text Available Highly active antiretroviral therapy (HAART has offered a promising approach for controlling HIV-1 replication in infected individuals. However, with HARRT, HIV-1 is suppressed rather than eradicated due to persistence of HIV-1 in latent viral reservoirs. Thus, purging the virus from latent reservoirs is an important strategy toward eradicating HIV-1 infection. In this study, we discovered that the daphnane diterpene gnidimacrin, which was previously reported to have potent anti-cancer cell activity, activated HIV-1 replication and killed persistently-infected cells at picomolar concentrations. In addition to its potential to purge HIV-1 from latently infected cells, gnidimacrin potently inhibited a panel of HIV-1 R5 virus infection of peripheral blood mononuclear cells (PBMCs at an average concentration lower than 10 pM. In contrast, gnidimacrin only partially inhibited HIV-1 ×4 virus infection of PBMCs. The strong anti-HIV-1 R5 virus activity of gnidimacrin was correlated with its effect on down-regulation of the HIV-1 coreceptor CCR5. The anti-R5 virus activity of gnidimacrin was completely abrogated by a selective protein kinase C beta inhibitor enzastaurin, which suggests that protein kinase C beta plays a key role in the potent anti-HIV-1 activity of gnidimacrin in PBMCs. In summary, these results suggest that gnidimacrin could activate latent HIV-1, specifically kill HIV-1 persistently infected cells, and inhibit R5 viruses at picomolar concentrations.

  9. Increased brain damage after ischaemic stroke in mice lacking the chemokine receptor CCR5

    Science.gov (United States)

    Sorce, S; Bonnefont, J; Julien, S; Marq-Lin, N; Rodriguez, I; Dubois-Dauphin, M; Krause, KH

    2010-01-01

    Background and purpose: The chemokine receptor CCR5 is well known for its function in immune cells; however, it is also expressed in the brain, where its specific role remains to be elucidated. Because genetic factors may influence the risk of developing cerebral ischaemia or affect its clinical outcome, we have analysed the role of CCR5 in experimental stroke. Experimental approach: Permanent cerebral ischaemia was performed by occlusion of the middle cerebral artery in wild-type and CCR5-deficient mice. Locomotor behaviour, infarct size and histochemical alterations were analysed at different time points after occlusion. Key results: The cerebral vasculature was comparable in wild-type and CCR5-deficient mice. However, the size of the infarct and the motor deficits after occlusion were markedly increased in CCR5-deficient mice as compared with wild type. No differences between wild-type and CCR5-deficient mice were elicited by occlusion with respect to the morphology and abundance of astrocytes and microglia. Seven days after occlusion the majority of CCR5-deficient mice displayed neutrophil invasion in the infarct region, which was not observed in wild type. As compared with wild type, the infarct regions of CCR5-deficient mice were characterized by increased neuronal death. Conclusions and implications: Lack of CCR5 increased the severity of brain injury following occlusion of the middle cerebral artery. This is of particular interest with respect to the relatively frequent occurrence of CCR5 deficiency in the human population (1–2% of the Caucasian population) and the advent of CCR5 inhibitors as novel drugs. PMID:20423342

  10. CCR1

    African Journals Online (AJOL)

    inflammatory protein II; Bioinformatics; Protease digestion; HEK293 cells; Radioligand binding. Tropical ... development of many diseases. ... diseases, antagonism of CCR1 has become an ..... importance of molecular conformation in terms of.

  11. Biochemistry and biophysics of HIV-1 gp41 - membrane interactions and implications for HIV-1 envelope protein mediated viral-cell fusion and fusion inhibitor design.

    Science.gov (United States)

    Cai, Lifeng; Gochin, Miriam; Liu, Keliang

    2011-12-01

    Human immunodeficiency virus type 1 (HIV-1), the pathogen of acquired immunodeficiency syndrome (AIDS), causes ~2 millions death every year and still defies an effective vaccine. HIV-1 infects host cells through envelope protein - mediated virus-cell fusion. The transmembrane subunit of envelope protein, gp41, is the molecular machinery which facilitates fusion. Its ectodomain contains several distinguishing functional domains, fusion peptide (FP), Nterminal heptad repeat (NHR), C-terminal heptad repeat (CHR) and membrane proximal extracellular region (MPER). During the fusion process, FP inserts into the host cell membrane, and an extended gp41 prehairpin conformation bridges the viral and cell membranes through MPER and FP respectively. Subsequent conformational change of the unstable prehairpin results in a coiled-coil 6-helix bundle (6HB) structure formed between NHR and CHR. The energetics of 6HB formation drives membrane apposition and fusion. Drugs targeting gp41 functional domains to prevent 6HB formation inhibit HIV-1 infection. T20 (enfuvirtide, Fuzeon) was approved by the US FDA in 2003 as the first fusion inhibitor. It is a 36-residue peptide from the gp41 CHR, and it inhibits 6HB formation by targeting NHR and lipids. Development of new fusion inhibitors, especially small molecule drugs, is encouraged to overcome the shortcomings of T20 as a peptide drug. Hydrophobic characteristics and membrane association are critical for gp41 function and mechanism of action. Research in gp41-membrane interactions, using peptides corresponding to specific functional domains, or constructs including several interactive domains, are reviewed here to get a better understanding of gp41 mediated virus-cell fusion that can inform or guide the design of new HIV-1 fusion inhibitors.

  12. Construction and immunogenicity of replication-competent adenovirus 5 host range mutant recombinants expressing HIV-1 gp160 of SF162 and TV1 strains.

    Science.gov (United States)

    Hidajat, Rachmat; Kuate, Seraphin; Venzon, David; Kalyanaraman, Vaniambadi; Kalisz, Irene; Treece, James; Lian, Ying; Barnett, Susan W; Robert-Guroff, Marjorie

    2010-05-21

    An HIV Env immunogen capable of eliciting broad immunity is critical for a successful vaccine. We constructed and characterized adenovirus 5 host range mutant (Ad5hr) recombinants encoding HIV(SF162) gp160 (subtype B) and HIV(TV1) gp160 (subtype C). Immunization of mice with one or both induced cellular immunity to subtype B and C peptides by ELISpot, and antibody responses with high binding titers to HIV Env of subtypes A, B, C, and E. Notably, Ad5hr-HIV(TV1) gp160 induced better cellular immunity than Ad5hr-HIV(SF162) gp160, either alone or following co-administration. Thus, the TV1 Env recombinant alone may be sufficient for eliciting immune responses against both subtype B and C envelopes. Further studies of Ad5hr-HIV(TV1) gp160 in rhesus macaques will evaluate the suitability of this insert for a future phase I clinical trial using a replication-competent Ad4 vector. Published by Elsevier Ltd.

  13. The role of CC chemokine receptor 5 in antiviral immunity

    DEFF Research Database (Denmark)

    Nansen, Anneline; Christensen, Jan Pravsgaard; Andreasen, Susanne Ørding

    2002-01-01

    The CC chemokine receptor CCR5 is an important coreceptor for human immunodeficiency virus (HIV), and there is a major thrust to develop anti-CCR5-based therapies for HIV-1. However, it is not known whether CCR5 is critical for a normal antiviral T-cell response. This study investigated the immune...

  14. Recurrent signature patterns in HIV-1 B clade envelope glycoproteins associated with either early or chronic infections.

    Directory of Open Access Journals (Sweden)

    S Gnanakaran

    2011-09-01

    Full Text Available Here we have identified HIV-1 B clade Envelope (Env amino acid signatures from early in infection that may be favored at transmission, as well as patterns of recurrent mutation in chronic infection that may reflect common pathways of immune evasion. To accomplish this, we compared thousands of sequences derived by single genome amplification from several hundred individuals that were sampled either early in infection or were chronically infected. Samples were divided at the outset into hypothesis-forming and validation sets, and we used phylogenetically corrected statistical strategies to identify signatures, systematically scanning all of Env. Signatures included single amino acids, glycosylation motifs, and multi-site patterns based on functional or structural groupings of amino acids. We identified signatures near the CCR5 co-receptor-binding region, near the CD4 binding site, and in the signal peptide and cytoplasmic domain, which may influence Env expression and processing. Two signatures patterns associated with transmission were particularly interesting. The first was the most statistically robust signature, located in position 12 in the signal peptide. The second was the loss of an N-linked glycosylation site at positions 413-415; the presence of this site has been recently found to be associated with escape from potent and broad neutralizing antibodies, consistent with enabling a common pathway for immune escape during chronic infection. Its recurrent loss in early infection suggests it may impact fitness at the time of transmission or during early viral expansion. The signature patterns we identified implicate Env expression levels in selection at viral transmission or in early expansion, and suggest that immune evasion patterns that recur in many individuals during chronic infection when antibodies are present can be selected against when the infection is being established prior to the adaptive immune response.

  15. Contrasting roles for TLR ligands in HIV-1 pathogenesis.

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    Beda Brichacek

    2010-09-01

    Full Text Available The first line of a host's response to various pathogens is triggered by their engagement of cellular pattern recognition receptors (PRRs. Binding of microbial ligands to these receptors leads to the induction of a variety of cellular factors that alter intracellular and extracellular environment and interfere directly or indirectly with the life cycle of the triggering pathogen. Such changes may also affect any coinfecting microbe. Using ligands to Toll-like receptors (TLRs 5 and 9, we examined their effect on human immunodeficiency virus (HIV-1 replication in lymphoid tissue ex vivo. We found marked differences in the outcomes of such treatment. While flagellin (TLR5 agonist treatment enhanced replication of CC chemokine receptor 5 (CCR 5-tropic and CXC chemokine receptor 4 (CXCR4-tropic HIV-1, treatment with oligodeoxynucleotide (ODN M362 (TLR9 agonist suppressed both viral variants. The differential effects of these TLR ligands on HIV-1 replication correlated with changes in production of CC chemokines CCL3, CCL4, CCL5, and of CXC chemokines CXCL10, and CXCL12 in the ligand-treated HIV-1-infected tissues. The nature and/or magnitude of these changes were dependent on the ligand as well as on the HIV-1 viral strain. Moreover, the tested ligands differed in their ability to induce cellular activation as evaluated by the expression of the cluster of differentiation markers (CD 25, CD38, CD39, CD69, CD154, and human leukocyte antigen D related (HLA-DR as well as of a cell proliferation marker, Ki67, and of CCR5. No significant effect of the ligand treatment was observed on apoptosis and cell death/loss in the treated lymphoid tissue ex vivo. Our results suggest that binding of microbial ligands to TLRs is one of the mechanisms that mediate interactions between coinfected microbes and HIV-1 in human tissues. Thus, the engagement of appropriate TLRs by microbial molecules or their mimetic might become a new strategy for HIV therapy or prevention.

  16. NF-κB and p53 Are the Dominant Apoptosis-inducing Transcription Factors Elicited by the HIV-1 Envelope

    OpenAIRE

    Perfettini, Jean-Luc; Roumier, Thomas; Castedo, Maria; Larochette, Nathanael; Boya, Patricia; Raynal, Brigitte; Lazar, Vladimir; Ciccosanti, Fabiola; Nardacci, Roberta; Penninger, Josef; Piacentini, Mauro; Kroemer, Guido

    2004-01-01

    The coculture of cells expressing the HIV-1 envelope glycoprotein complex (Env) with cells expressing CD4 results into cell fusion, deregulated mitosis, and subsequent cell death. Here, we show that NF-κB, p53, and AP1 are activated in Env-elicited apoptosis. The nuclear factor κB (NF-κB) super repressor had an antimitotic and antiapoptotic effect and prevented the Env-elicited phosphorylation of p53 on serine 15 and 46, as well as the activation of AP1. Transfection with dominant-negative p5...

  17. A Universal Approach to Optimize the Folding and Stability of Prefusion-Closed HIV-1 Envelope Trimers

    Directory of Open Access Journals (Sweden)

    Lucy Rutten

    2018-04-01

    Full Text Available Summary: The heavily glycosylated native-like envelope (Env trimer of HIV-1 is expected to have low immunogenicity, whereas misfolded forms are often highly immunogenic. High-quality correctly folded Envs may therefore be critical for developing a vaccine that induces broadly neutralizing antibodies. Moreover, the high variability of Env may require immunizations with multiple Envs. Here, we report a universal strategy that provides for correctly folded Env trimers of high quality and yield through a repair-and-stabilize approach. In the repair stage, we utilized a consensus strategy that substituted rare strain-specific residues with more prevalent ones. The stabilization stage involved structure-based design and experimental assessment confirmed by crystallographic feedback. Regions important for the refolding of Env were targeted for stabilization. Notably, the α9-helix and an intersubunit β sheet proved to be critical for trimer stability. Our approach provides a means to produce prefusion-closed Env trimers from diverse HIV-1 strains, a substantial advance for vaccine development. : Rutten et al. describe a universal repair and stabilize approach that corrects rare mutations and stabilizes refolding regions to obtain high-quality HIV Envs with high yields. The crystal structure shows how the optimization of the trimer interface between α9, α6, and the intersubunit β-sheet stabilizes the membrane-proximal base. Keywords: envelope protein, chronic, ConC_base, HIV, SOSIP, stabilization, transmitted/founder, vaccine, X-ray structure, hybrid sheet

  18. Oral keratinocytes support non-replicative infection and transfer of harbored HIV-1 to permissive cells.

    Science.gov (United States)

    Vacharaksa, Anjalee; Asrani, Anil C; Gebhard, Kristin H; Fasching, Claudine E; Giacaman, Rodrigo A; Janoff, Edward N; Ross, Karen F; Herzberg, Mark C

    2008-07-17

    Oral keratinocytes on the mucosal surface are frequently exposed to HIV-1 through contact with infected sexual partners or nursing mothers. To determine the plausibility that oral keratinocytes are primary targets of HIV-1, we tested the hypothesis that HIV-1 infects oral keratinocytes in a restricted manner. To study the fate of HIV-1, immortalized oral keratinocytes (OKF6/TERT-2; TERT-2 cells) were characterized for the fate of HIV-specific RNA and DNA. At 6 h post inoculation with X4 or R5-tropic HIV-1, HIV-1gag RNA was detected maximally within TERT-2 cells. Reverse transcriptase activity in TERT-2 cells was confirmed by VSV-G-mediated infection with HIV-NL4-3Deltaenv-EGFP. AZT inhibited EGFP expression in a dose-dependent manner, suggesting that viral replication can be supported if receptors are bypassed. Within 3 h post inoculation, integrated HIV-1 DNA was detected in TERT-2 cell nuclei and persisted after subculture. Multiply spliced and unspliced HIV-1 mRNAs were not detectable up to 72 h post inoculation, suggesting that HIV replication may abort and that infection is non-productive. Within 48 h post inoculation, however, virus harbored by CD4 negative TERT-2 cells trans infected co-cultured peripheral blood mononuclear cells (PBMCs) or MOLT4 cells (CD4+ CCR5+) by direct cell-to-cell transfer or by releasing low levels of infectious virions. Primary tonsil epithelial cells also trans infected HIV-1 to permissive cells in a donor-specific manner. Oral keratinocytes appear, therefore, to support stable non-replicative integration, while harboring and transmitting infectious X4- or R5-tropic HIV-1 to permissive cells for up to 48 h.

  19. Oral keratinocytes support non-replicative infection and transfer of harbored HIV-1 to permissive cells

    Directory of Open Access Journals (Sweden)

    Giacaman Rodrigo A

    2008-07-01

    Full Text Available Abstract Background Oral keratinocytes on the mucosal surface are frequently exposed to HIV-1 through contact with infected sexual partners or nursing mothers. To determine the plausibility that oral keratinocytes are primary targets of HIV-1, we tested the hypothesis that HIV-1 infects oral keratinocytes in a restricted manner. Results To study the fate of HIV-1, immortalized oral keratinocytes (OKF6/TERT-2; TERT-2 cells were characterized for the fate of HIV-specific RNA and DNA. At 6 h post inoculation with X4 or R5-tropic HIV-1, HIV-1gag RNA was detected maximally within TERT-2 cells. Reverse transcriptase activity in TERT-2 cells was confirmed by VSV-G-mediated infection with HIV-NL4-3Δenv-EGFP. AZT inhibited EGFP expression in a dose-dependent manner, suggesting that viral replication can be supported if receptors are bypassed. Within 3 h post inoculation, integrated HIV-1 DNA was detected in TERT-2 cell nuclei and persisted after subculture. Multiply spliced and unspliced HIV-1 mRNAs were not detectable up to 72 h post inoculation, suggesting that HIV replication may abort and that infection is non-productive. Within 48 h post inoculation, however, virus harbored by CD4 negative TERT-2 cells trans infected co-cultured peripheral blood mononuclear cells (PBMCs or MOLT4 cells (CD4+ CCR5+ by direct cell-to-cell transfer or by releasing low levels of infectious virions. Primary tonsil epithelial cells also trans infected HIV-1 to permissive cells in a donor-specific manner. Conclusion Oral keratinocytes appear, therefore, to support stable non-replicative integration, while harboring and transmitting infectious X4- or R5-tropic HIV-1 to permissive cells for up to 48 h.

  20. A Cinnamon-Derived Procyanidin Compound Displays Anti-HIV-1 Activity by Blocking Heparan Sulfate- and Co-Receptor- Binding Sites on gp120 and Reverses T Cell Exhaustion via Impeding Tim-3 and PD-1 Upregulation.

    Directory of Open Access Journals (Sweden)

    Bridgette Janine Connell

    Full Text Available Amongst the many strategies aiming at inhibiting HIV-1 infection, blocking viral entry has been recently recognized as a very promising approach. Using diverse in vitro models and a broad range of HIV-1 primary patient isolates, we report here that IND02, a type A procyanidin polyphenol extracted from cinnamon, that features trimeric and pentameric forms displays an anti-HIV-1 activity against CXCR4 and CCR5 viruses with 1-7 μM ED50 for the trimer. Competition experiments, using a surface plasmon resonance-based binding assay, revealed that IND02 inhibited envelope binding to CD4 and heparan sulphate (HS as well as to an antibody (mAb 17b directed against the gp120 co-receptor binding site with an IC50 in the low μM range. IND02 has thus the remarkable property of simultaneously blocking gp120 binding to its major host cell surface counterparts. Additionally, the IND02-trimer impeded up-regulation of the inhibitory receptors Tim-3 and PD-1 on CD4+ and CD8+ cells, thereby demonstrating its beneficial effect by limiting T cell exhaustion. Among naturally derived products significantly inhibiting HIV-1, the IND02-trimer is the first component demonstrating an entry inhibition property through binding to the viral envelope glycoprotein. These data suggest that cinnamon, a widely consumed spice, could represent a novel and promising candidate for a cost-effective, natural entry inhibitor for HIV-1 which can also down-modulate T cell exhaustion markers Tim-3 and PD-1.

  1. Short communication: Anti-HIV-1 envelope immunoglobulin Gs in blood and cervicovaginal samples of Beninese commercial sex workers.

    Science.gov (United States)

    Batraville, Laurie-Anne; Richard, Jonathan; Veillette, Maxime; Labbé, Annie-Claude; Alary, Michel; Guédou, Fernand; Kaufmann, Daniel E; Poudrier, Johanne; Finzi, Andrés; Roger, Michel

    2014-11-01

    Characterization of the immune correlates of protection against HIV infection is crucial for the development of preventive strategies. This study examined HIV-1 envelope (Env) glycoproteins, specifically immunoglobulin G (IgG), in systemic and mucosal compartments of female Beninese commercial sex workers (CSWs). Samples of 23 HIV-1-positive and 20 highly exposed HIV-1-seronegative (HESN) CSWs were studied. HIV-1 Env-specific IgG detection in sera and cervicovaginal lavages (CVLs) from the study population was done by cell-based ELISA. The HIV neutralizing activity was evaluated with a neutralization assay. The HIV-1-specific antibody-dependent cellular cytotoxicity (ADCC) response of the cohort was measured with a FACS-based assay evaluating the ADCC-mediated elimination of gp120-coated target cells. No anti-HIV-1 Env-specific IgG neutralizing or ADCC activities were detected in samples from HESN CSWs. Samples from HIV-1-infected CSWs presented ADCC activity in both sera and CVLs. Anti-Env IgG from sera and CVLs from HIV-1-infected CSWs preferentially recognized Env in its CD4-bound conformation. HIV-1-infected CSWs have ADCC-mediating IgG that preferentially recognizes Env in its CD4-bound conformation at the mucosal site.

  2. Selective Loss of Early Differentiated, Highly Functional PD1high CD4 T Cells with HIV Progression.

    Directory of Open Access Journals (Sweden)

    Robert M Paris

    Full Text Available The role of PD-1 expression on CD4 T cells during HIV infection is not well understood. Here, we describe the differential expression of PD-1 in CD127high CD4 T cells within the early/intermediate differentiated (EI (CD27highCD45RAlow T cell population among uninfected and HIV-infected subjects, with higher expression associated with decreased viral replication (HIV-1 viral load. A significant loss of circulating PD-1highCTLA-4low CD4 T cells was found specifically in the CD127highCD27highCD45RAlow compartment, while initiation of antiretroviral treatment, particularly in subjects with advanced disease, reversed these dynamics. Increased HIV-1 Gag DNA was also found in PD-1high compared to PD-1low ED CD4 T cells. In line with an increased susceptibility to HIV infection, PD-1 expression in this CD4 T cell subset was associated with increased activation and expression of the HIV co-receptor, CCR5. Rather than exhaustion, this population produced more IFN-g, MIP1-a, IL-4, IL-10, and IL-17a compared to PD-1low EI CD4 T cells. In line with our previous findings, PD-1high EI CD4 T cells were also characterized by a high expression of CCR7, CXCR5 and CCR6, a phenotype associated with increased in vitro B cell help. Our data show that expression of PD-1 on early-differentiated CD4 T cells may represent a population that is highly functional, more susceptible to HIV infection and selectively lost in chronic HIV infection.

  3. Pushing it back. Dating the CCR5–32 bp deletion to the Mesolithic in Sweden and its implications for the Meso\\Neo transition

    Directory of Open Access Journals (Sweden)

    Kerstin Lidén

    2006-12-01

    Full Text Available Genetic variation in the chemokine receptor gene CCR5 has received considerable scientific interest during the last few years. Protection against HIV-infection and AIDS, together with specific geographic distribution are the major reasons for the great interest in CCR5 32bp deletion. The event for the occurrence of this mutation has been postulated by coalescence dating to the 14th century, or 5000 BP. In our prehistoric Swedish samples we show that the frequency of 32pb deletion in CCR5 in the Neolithic population does not deviate from the frequency in a modern Swedish population, and that the deletion existed in Sweden already during the Mesolithic period.

  4. Absence of HIV-1 evolution in the gut-associated lymphoid tissue from patients on combination antiviral therapy initiated during primary infection.

    Directory of Open Access Journals (Sweden)

    Teresa H Evering

    2012-02-01

    Full Text Available Mucosal mononuclear (MMC CCR5+CD4+ T cells of the gastrointestinal (GI tract are selectively infected and depleted during acute HIV-1 infection. Despite early initiation of combination antiretroviral therapy (cART, gut-associated lymphoid tissue (GALT CD4+ T cell depletion and activation persist in the majority of HIV-1 positive individuals studied. This may result from ongoing HIV-1 replication and T-cell activation despite effective cART. We hypothesized that ongoing viral replication in the GI tract during cART would result in measurable viral evolution, with divergent populations emerging over time. Subjects treated during early HIV-1 infection underwent phlebotomy and flexible sigmoidoscopy with biopsies prior to and 15-24 months post initiation of cART. At the 2(nd biopsy, three GALT phenotypes were noted, characterized by high, intermediate and low levels of immune activation. A representative case from each phenotype was analyzed. Each subject had plasma HIV-1 RNA levels <50 copies/ml at 2(nd GI biopsy and CD4+ T cell reconstitution in the peripheral blood. Single genome amplification of full-length HIV-1 envelope was performed for each subject pre- and post-initiation of cART in GALT and PBMC. A total of 280 confirmed single genome sequences (SGS were analyzed for experimental cases. For each subject, maximum likelihood phylogenetic trees derived from molecular sequence data showed no evidence of evolved forms in the GALT over the study period. During treatment, HIV-1 envelope diversity in GALT-derived SGS did not increase and post-treatment GALT-derived SGS showed no substantial genetic divergence from pre-treatment sequences within transmitted groups. Similar results were obtained from PBMC-derived SGS. Our results reveal that initiation of cART during acute/early HIV-1 infection can result in the interruption of measurable viral evolution in the GALT, suggesting the absence of de-novo rounds of HIV-1 replication in this compartment

  5. Absence of HIV-1 evolution in the gut-associated lymphoid tissue from patients on combination antiviral therapy initiated during primary infection.

    Science.gov (United States)

    Evering, Teresa H; Mehandru, Saurabh; Racz, Paul; Tenner-Racz, Klara; Poles, Michael A; Figueroa, Amir; Mohri, Hiroshi; Markowitz, Martin

    2012-02-01

    Mucosal mononuclear (MMC) CCR5+CD4+ T cells of the gastrointestinal (GI) tract are selectively infected and depleted during acute HIV-1 infection. Despite early initiation of combination antiretroviral therapy (cART), gut-associated lymphoid tissue (GALT) CD4+ T cell depletion and activation persist in the majority of HIV-1 positive individuals studied. This may result from ongoing HIV-1 replication and T-cell activation despite effective cART. We hypothesized that ongoing viral replication in the GI tract during cART would result in measurable viral evolution, with divergent populations emerging over time. Subjects treated during early HIV-1 infection underwent phlebotomy and flexible sigmoidoscopy with biopsies prior to and 15-24 months post initiation of cART. At the 2(nd) biopsy, three GALT phenotypes were noted, characterized by high, intermediate and low levels of immune activation. A representative case from each phenotype was analyzed. Each subject had plasma HIV-1 RNA levels <50 copies/ml at 2(nd) GI biopsy and CD4+ T cell reconstitution in the peripheral blood. Single genome amplification of full-length HIV-1 envelope was performed for each subject pre- and post-initiation of cART in GALT and PBMC. A total of 280 confirmed single genome sequences (SGS) were analyzed for experimental cases. For each subject, maximum likelihood phylogenetic trees derived from molecular sequence data showed no evidence of evolved forms in the GALT over the study period. During treatment, HIV-1 envelope diversity in GALT-derived SGS did not increase and post-treatment GALT-derived SGS showed no substantial genetic divergence from pre-treatment sequences within transmitted groups. Similar results were obtained from PBMC-derived SGS. Our results reveal that initiation of cART during acute/early HIV-1 infection can result in the interruption of measurable viral evolution in the GALT, suggesting the absence of de-novo rounds of HIV-1 replication in this compartment during

  6. Plasticity and Epitope Exposure of the HIV-1 Envelope Trimer.

    Science.gov (United States)

    Powell, Rebecca L R; Totrov, Maxim; Itri, Vincenza; Liu, Xiaomei; Fox, Alisa; Zolla-Pazner, Susan

    2017-09-01

    We recently showed that mutations in the HIV-1 envelope (Env) destabilize the V3 loop, rendering neutralization-resistant viruses sensitive to V3-directed monoclonal antibodies (MAbs). Here, we investigated the propagation of this effect on other Env epitopes, with special emphasis on V2 loop exposure. Wild-type JR-FL and 19 mutant JR-FL pseudoviruses were tested for neutralization sensitivity to 21 MAbs specific for epitopes in V2, the CD4 binding site (CD4bs), and the CD4-induced (CD4i) region. Certain glycan mutants, mutations in the gp120 hydrophobic core, and mutations in residues involved in intraprotomer interactions exposed epitopes in the V2i region (which overlies the α4β7 integrin binding site) and the V3 crown, suggesting general destabilization of the distal region of the trimer apex. In contrast, other glycan mutants, mutations affecting interprotomer interactions, and mutations affecting the CD4bs exposed V3 but not V2i epitopes. These data indicate for the first time that V3 can move independently of V2, with V3 pivoting out from its "tucked" position in the trimer while apparently leaving the V2 apex intact. Notably, none of the mutations exposed V2 epitopes without also exposing V3, suggesting that movement of V2 releases V3. Most mutations increased sensitivity to CD4bs-directed MAbs without exposure of the CD4i epitope, implying these mutations facilitate the trimers' maintenance of an intermediate energy state between open and closed conformations. Taken together, these data indicate that several transient Env epitopes can be rendered more accessible to antibodies (Abs) via specific mutations, and this may facilitate the design of V1V2-targeting immunogens. IMPORTANCE Many epitopes of the HIV envelope (Env) spike are relatively inaccessible to antibodies (Abs) compared to their exposure in the open Env conformation induced by receptor binding. However, the reduced infection rate that resulted from the vaccine used in the RV144 HIV-1 vaccine

  7. A whole genome screen for HIV restriction factors

    Directory of Open Access Journals (Sweden)

    Liu Li

    2011-11-01

    Full Text Available Abstract Background Upon cellular entry retroviruses must avoid innate restriction factors produced by the host cell. For human immunodeficiency virus (HIV human restriction factors, APOBEC3 (apolipoprotein-B-mRNA-editing-enzyme, p21 and tetherin are well characterised. Results To identify intrinsic resistance factors to HIV-1 replication we screened 19,121 human genes and identified 114 factors with significant inhibition of infection. Those with a known function are involved in a broad spectrum of cellular processes including receptor signalling, vesicle trafficking, transcription, apoptosis, cross-nuclear membrane transport, meiosis, DNA damage repair, ubiquitination and RNA processing. We focused on the PAF1 complex which has been previously implicated in gene transcription, cell cycle control and mRNA surveillance. Knockdown of all members of the PAF1 family of proteins enhanced HIV-1 reverse transcription and integration of provirus. Over-expression of PAF1 in host cells renders them refractory to HIV-1. Simian Immunodeficiency Viruses and HIV-2 are also restricted in PAF1 expressing cells. PAF1 is expressed in primary monocytes, macrophages and T-lymphocytes and we demonstrate strong activity in MonoMac1, a monocyte cell line. Conclusions We propose that the PAF1c establishes an anti-viral state to prevent infection by incoming retroviruses. This previously unrecognised mechanism of restriction could have implications for invasion of cells by any pathogen.

  8. Allosteric and orthosteric sites in CC chemokine receptor (CCR5), a chimeric receptor approach

    DEFF Research Database (Denmark)

    Thiele, Stefanie; Steen, Anne; Jensen, Pia C

    2011-01-01

    -allosteric molecules. A chimera was successfully constructed between CCR5 and the closely related CCR2 by transferring all extracellular regions of CCR2 to CCR5, i.e. a Trojan horse that resembles CCR2 extracellularly but signals through a CCR5 transmembrane unit. The chimera bound CCR2 (CCL2 and CCL7), but not CCR5...... preserved, the allosteric enhancement of chemokine binding was disrupted. In summary, the Trojan horse chimera revealed that orthosteric and allosteric sites could be structurally separated and still act together with transmission of agonism and antagonism across the different receptor units....

  9. Chemokine receptor CCR5 in interferon-treated multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, F; Kristiansen, T B; Wittenhagen, P

    2007-01-01

    To study the relationship between CC chemokine receptor CCR5 expression and disease activity in multiple sclerosis (MS) patients treated with beta-interferon (IFN-beta).......To study the relationship between CC chemokine receptor CCR5 expression and disease activity in multiple sclerosis (MS) patients treated with beta-interferon (IFN-beta)....

  10. Functional impact of HIV coreceptor-binding site mutations

    International Nuclear Information System (INIS)

    Biscone, Mark J.; Miamidian, John L.; Muchiri, John M.; Baik, Sarah S.W.; Lee, Fang-Hua; Doms, Robert W.; Reeves, Jacqueline D.

    2006-01-01

    The bridging sheet region of the gp120 subunit of the HIV-1 Env protein interacts with the major virus coreceptors, CCR5 and CXCR4. We examined the impact of mutations in and adjacent to the bridging sheet region of an X4 tropic HIV-1 on membrane fusion and entry inhibitor susceptibility. When the V3-loop of this Env was changed so that CCR5 was used, the effects of these same mutations on CCR5 use were assayed as well. We found that coreceptor-binding site mutations had greater effects on CXCR4-mediated fusion and infection than when CCR5 was used as a coreceptor, perhaps related to differences in coreceptor affinity. The mutations also reduced use of the alternative coreceptors CCR3 and CCR8 to varying degrees, indicating that the bridging sheet region is important for the efficient utilization of both major and minor HIV coreceptors. As seen before with a primary R5 virus strain, bridging sheet mutations increased susceptibility to the CCR5 inhibitor TAK-779, which correlated with CCR5 binding efficiency. Bridging sheet mutations also conferred increased susceptibility to the CXCR4 ligand AMD-3100 in the context of the X4 tropic Env. However, these mutations had little effect on the rate of membrane fusion and little effect on susceptibility to enfuvirtide, a membrane fusion inhibitor whose activity is dependent in part on the rate of Env-mediated membrane fusion. Thus, mutations that reduce coreceptor binding and enhance susceptibility to coreceptor inhibitors can affect fusion and enfuvirtide susceptibility in an Env context-dependent manner

  11. Covariance of charged amino acids at positions 322 and 440 of HIV-1 Env contributes to coreceptor specificity of subtype B viruses, and can be used to improve the performance of V3 sequence-based coreceptor usage prediction algorithms.

    Directory of Open Access Journals (Sweden)

    Kieran Cashin

    Full Text Available The ability to determine coreceptor usage of patient-derived human immunodeficiency virus type 1 (HIV-1 strains is clinically important, particularly for the administration of the CCR5 antagonist maraviroc. The envelope glycoprotein (Env determinants of coreceptor specificity lie primarily within the gp120 V3 loop region, although other Env determinants have been shown to influence gp120-coreceptor interactions. Here, we determined whether conserved amino acid alterations outside the V3 loop that contribute to coreceptor usage exist, and whether these alterations improve the performance of V3 sequence-based coreceptor usage prediction algorithms. We demonstrate a significant covariant association between charged amino acids at position 322 in V3 and position 440 in the C4 Env region that contributes to the specificity of HIV-1 subtype B strains for CCR5 or CXCR4. Specifically, positively charged Lys/Arg at position 322 and negatively charged Asp/Glu at position 440 occurred more frequently in CXCR4-using viruses, whereas negatively charged Asp/Glu at position 322 and positively charged Arg at position 440 occurred more frequently in R5 strains. In the context of CD4-bound gp120, structural models suggest that covariation of amino acids at Env positions 322 and 440 has the potential to alter electrostatic interactions that are formed between gp120 and charged amino acids in the CCR5 N-terminus. We further demonstrate that inclusion of a "440 rule" can improve the sensitivity of several V3 sequence-based genotypic algorithms for predicting coreceptor usage of subtype B HIV-1 strains, without compromising specificity, and significantly improves the AUROC of the geno2pheno algorithm when set to its recommended false positive rate of 5.75%. Together, our results provide further mechanistic insights into the intra-molecular interactions within Env that contribute to coreceptor specificity of subtype B HIV-1 strains, and demonstrate that incorporation

  12. Variations in CCR5, but not HFE, ELMO1, or SLC12A3, are associated with susceptibility to kidney disease in north Indian individuals with type 2 diabetes.

    Science.gov (United States)

    Yadav, Ashok K; Kumar, Vinod; Dutta, Pinaki; Bhansali, Anil; Jha, Vivekanand

    2014-11-01

    Diabetic nephropathy (DN), the leading cause of end-stage renal disease worldwide, may have a genetic component. In the present study, we investigated variations in a set of genes with susceptibility to DN in a north Indian population. Four genes (HFE, ELMO1, SLC12A3, and CCR5) were selected on the basis of reported association with type 2 diabetes and nephropathy. In all, 417 diabetic subjects (215 without kidney disease [DM] and 202 with DN) and 197 healthy controls (HC) were evaluated for variations in HFE (845 G>A and 187G>C), SLC12A3 (g.34372G>A), CCR5 (59029A>G), and ELMO1 (+9170 G>A). Polymorphism analysis was performed by polymerase chain reaction-restriction fragment length polymorphism and Taqman allele discrimination assays. Significant differences were found in genotype and allelic frequency in SLC12A3 (g.34372G>A) between diabetic subjects and HC (P A (AA+GA) genotype between diabetic subjects with and without nephropathy. However, the CCR5 59029AA genotype and A allele were significantly more frequent in diabetics compared with the HC (P = 0.01 and 0.03, respectively) and subjects with DN versus DM (P = 0.002 and 0.01, respectively). For ELMO1 (+9170 G>A), the GG genotype frequency was higher in the diabetic versus HC group. There were no differences in the frequency of HFE-845 G>A and HFE-187G>C among the groups. This study shows that the CCR5 AA genotype is over-represented in subjects with kidney disease due to type 2 diabetes. The CCR5 59029G>A and ELMO1 (+9170 G>A) loci are more frequent, and the SLC12A3 34372 AA genotype is associated with a reduced risk of diabetes. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  13. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Science.gov (United States)

    Burastero, Samuele E; Frigerio, Barbara; Lopalco, Lucia; Sironi, Francesca; Breda, Daniela; Longhi, Renato; Scarlatti, Gabriella; Canevari, Silvana; Figini, Mariangela; Lusso, Paolo

    2011-01-01

    To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs) directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env) bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ) was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  14. Broad-spectrum inhibition of HIV-1 by a monoclonal antibody directed against a gp120-induced epitope of CD4.

    Directory of Open Access Journals (Sweden)

    Samuele E Burastero

    Full Text Available To penetrate susceptible cells, HIV-1 sequentially interacts with two highly conserved cellular receptors, CD4 and a chemokine receptor like CCR5 or CXCR4. Monoclonal antibodies (MAbs directed against such receptors are currently under clinical investigation as potential preventive or therapeutic agents. We immunized Balb/c mice with molecular complexes of the native, trimeric HIV-1 envelope (Env bound to a soluble form of the human CD4 receptor. Sera from immunized mice were found to contain gp120-CD4 complex-enhanced antibodies and showed broad-spectrum HIV-1-inhibitory activity. A proportion of MAbs derived from these mice preferentially recognized complex-enhanced epitopes. In particular, a CD4-specific MAb designated DB81 (IgG1Κ was found to preferentially bind to a complex-enhanced epitope on the D2 domain of human CD4. MAb DB81 also recognized chimpanzee CD4, but not baboon or macaque CD4, which exhibit sequence divergence in the D2 domain. Functionally, MAb DB81 displayed broad HIV-1-inhibitory activity, but it did not exert suppressive effects on T-cell activation in vitro. The variable regions of the heavy and light chains of MAb DB81 were sequenced. Due to its broad-spectrum anti-HIV-1 activity and lack of immunosuppressive effects, a humanized derivative of MAb DB81 could provide a useful complement to current preventive or therapeutic strategies against HIV-1.

  15. The chemokine receptor CCR5 Δ32 allele in natalizumab-treated multiple sclerosis

    DEFF Research Database (Denmark)

    Møller, M; Søndergaard, Helle B; Koch-Henriksen, N

    2014-01-01

    OBJECTIVE: The chemokine receptor CCR5 may be important for the recruitment of pathogenic T cells to the CNS in multiple sclerosis (MS). We hypothesized that this chemokine receptor might still be important for T-cell migration during treatment with anti-very late antigen (VLA)-4 antibody. We...... impact on the frequency of relapses 1 year prior to natalizumab treatment or during the first 48 weeks of treatment. The multiple sclerosis severity score (MSSS) was significantly lower at baseline in patients carrying CCR5 Δ32 (P = 0.031). CONCLUSIONS: CCR5 Δ32 is not associated with lower disease...

  16. HIV-1 CCR5 gene therapy will fail unless it is combined with a suicide gene

    NARCIS (Netherlands)

    Pandit, Aridaman; de Boer, Rob J

    2015-01-01

    Highly active antiretroviral therapy (ART) has successfully turned Human immunodeficiency virus type 1 (HIV-1) from a deadly pathogen into a manageable chronic infection. ART is a lifelong therapy which is both expensive and toxic, and HIV can become resistant to it. An alternative to lifelong ART

  17. CCR5 controls immune and metabolic functions during Toxoplasma gondii infection.

    Directory of Open Access Journals (Sweden)

    Giuliano Bonfá

    Full Text Available CCR5, an important receptor related to cell recruitment and inflammation, is expressed during experimental Toxoplasma gondii infection. However, its role in the immunopathology of toxoplasmosis is not clearly defined yet. Thus, we inoculated WT and CCR5(-/- mice with a sub lethal dose of the parasite by oral route. CCR5(-/- mice were extremely susceptible to infection, presenting higher parasite load and lower tissue expression of IL-12p40, IFN-γ, TNF, IL-6, iNOS, Foxp3, T-bet, GATA-3 and PPARα. Although both groups presented inflammation in the liver with prominent neutrophil infiltration, CCR5(-/- mice had extensive tissue damage with hepatocyte vacuolization, steatosis, elevated serum triglycerides and transaminases. PPARα agonist Gemfibrozil improved the vacuolization but did not rescue CCR5(-/- infected mice from high serum triglycerides levels and enhanced mortality. We also found intense inflammation in the ileum of CCR5(-/- infected mice, with epithelial ulceration, augmented CD4 and decreased frequency of NK cells in the gut lamina propria. Most interestingly, these findings were accompanied by an outstanding accumulation of neutrophils in the ileum, which seemed to be involved in the gut immunopathology, once the depletion of these cells was accompanied by reduced local damage. Altogether, these data demonstrated that CCR5 is essential to the control of T. gondii infection and to maintain the metabolic, hepatic and intestinal integrity. These findings add novel information on the disease pathogenesis and may be relevant for directing future approaches to the treatment of multi-deregulated diseases.

  18. Alterations of HIV-1 envelope phenotype and antibody-mediated neutralization by signal peptide mutations.

    Directory of Open Access Journals (Sweden)

    Chitra Upadhyay

    2018-01-01

    Full Text Available HIV-1 envelope glycoprotein (Env mediates virus attachment and entry into the host cells. Like other membrane-bound and secreted proteins, HIV-1 Env contains at its N terminus a signal peptide (SP that directs the nascent Env to the endoplasmic reticulum (ER where Env synthesis and post-translational modifications take place. SP is cleaved during Env biosynthesis but potentially influences the phenotypic traits of the Env protein. The Env SP sequences of HIV-1 isolates display high sequence variability, and the significance of such variability is unclear. We postulate that changes in the Env SP influence Env transport through the ER-Golgi secretory pathway and Env folding and/or glycosylation that impact on Env incorporation into virions, receptor binding and antibody recognition. We first evaluated the consequences of mutating the charged residues in the Env SP in the context of infectious molecular clone HIV-1 REJO.c/2864. Results show that three different mutations affecting histidine at position 12 affected Env incorporation into virions that correlated with reduction of virus infectivity and DC-SIGN-mediated virus capture and transmission. Mutations at positions 8, 12, and 15 also rendered the virus more resistant to neutralization by monoclonal antibodies against the Env V1V2 region. These mutations affected the oligosaccharide composition of N-glycans as shown by changes in Env reactivity with specific lectins and by mass spectrometry. Increased neutralization resistance and N-glycan composition changes were also observed when analogous mutations were introduced to another HIV-1 strain, JRFL. To the best of our knowledge, this is the first study showing that certain residues in the HIV-1 Env SP can affect virus neutralization sensitivity by modulating oligosaccharide moieties on the Env N-glycans. The HIV-1 Env SP sequences thus may be under selective pressure to balance virus infectiousness with virus resistance to the host antibody

  19. Identification of N-phenyl-N'-(2,2,6,6-tetramethyl-piperidin-4-yl)-oxalamides as a new class of HIV-1 entry inhibitors that prevent gp120 binding to CD4

    International Nuclear Information System (INIS)

    Zhao Qian; Ma Liying; Jiang Shibo; Lu Hong; Liu Shuwen; He Yuxian; Strick, Nathan; Neamati, Nouri; Debnath, Asim Kumar

    2005-01-01

    We have identified two N-phenyl-N'-(2,2,6,6-tetramethyl-piperidin-4-yl)-oxalamide analogs as a novel class of human immunodeficiency virus type 1 (HIV-1) entry inhibitors that block the gp120-CD4 interaction, using database screening techniques. The lead compounds, NBD-556 and NBD-557, are small molecule organic compounds with drug-like properties. These compounds showed potent cell fusion and virus-cell fusion inhibitory activity at low micromolar levels. A systematic study showed that these compounds target viral entry by inhibiting the binding of HIV-1 envelope glycoprotein gp120 to the cellular receptor CD4 but did not inhibit reverse transcriptase, integrase, or protease, indicating that they do not target the later stages of the HIV-1 life cycle to inhibit HIV-1 infection. These compounds were equally potent inhibitors of both X4 and R5 viruses tested in CXCR4 and CCR5 expressing cell lines, respectively, indicating that their anti-HIV-1 activity is not dependent on the coreceptor tropism of the virus. A surface plasmon resonance study, which measures binding affinity, clearly demonstrated that these compounds bind to unliganded HIV-1 gp120 but not to the cellular receptor CD4. NBD-556 and NBD-557 were active against HIV-1 laboratory-adapted strains including an AZT-resistant strain and HIV-1 primary isolates, indicating that these compounds can potentially be further modified to become potent HIV-1 entry inhibitors

  20. Variations in the Biological Functions of HIV-1 Clade C Envelope in a SHIV-Infected Rhesus Macaque during Disease Progression.

    Directory of Open Access Journals (Sweden)

    For Yue Tso

    Full Text Available A better understanding of how the biological functions of the HIV-1 envelope (Env changes during disease progression may aid the design of an efficacious anti-HIV-1 vaccine. Although studies from patient had provided some insights on this issue, the differences in the study cohorts and methodology had make it difficult to reach a consensus of the variations in the HIV-1 Env functions during disease progression. To this end, an animal model that can be infected under controlled environment and reflect the disease course of HIV-1 infection in human will be beneficial. Such an animal model was previously demonstrated by the infection of macaque with SHIV, expressing HIV-1 clade C Env V1-V5 region. By using this model, we examined the changes in biological functions of Env in the infected animal over the entire disease course. Our data showed an increase in the neutralization resistance phenotype over time and coincided with the decrease in the net charges of the V1-V5 region. Infection of PBMC with provirus expressing various Env clones, isolated from the infected animal over time, showed a surprisingly better replicative fitness for viruses expressing the Env from early time point. Biotinylation and ELISA data also indicated a decrease of cell-surface-associated Env and virion-associated gp120 content with disease progression. This decrease did not affect the CD4-binding capability of Env, but were positively correlated with the decrease of Env fusion ability. Interestingly, some of these changes in biological functions reverted to the pre-AIDS level during advance AIDS. These data suggested a dynamic relationship between the Env V1-V5 region with the host immune pressure. The observed changes of biological functions in this setting might reflect and predict those occurring during natural disease progression in human.

  1. Expanded breadth of the T-cell response to mosaic HIV-1 envelope DNA vaccination

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory; Fischer, William [Los Alamos National Laboratory; Wallstrom, Timothy [Los Alamos National Laboratory

    2009-01-01

    An effective AIDS vaccine must control highly diverse circulating strains of HIV-1. Among HIV -I gene products, the envelope (Env) protein contains variable as well as conserved regions. In this report, an informatic approach to the design of T-cell vaccines directed to HIV -I Env M group global sequences was tested. Synthetic Env antigens were designed to express mosaics that maximize the inclusion of common potential Tcell epitope (PTE) 9-mers and minimize the inclusion of rare epitopes likely to elicit strain-specific responses. DNA vaccines were evaluated using intracellular cytokine staining (ICS) in inbred mice with a standardized panel of highly conserved 15-mer PTE peptides. I, 2 and 3 mosaic sets were developed that increased theoretical epitope coverage. The breadth and magnitude ofT-cell immunity stimulated by these vaccines were compared to natural strain Env's; additional comparisons were performed on mutant Env's, including gpl60 or gpl45 with or without V regions and gp41 deletions. Among them, the 2 or 3 mosaic Env sets elicited the optimal CD4 and CD8 responses. These responses were most evident in CD8 T cells; the 3 mosaic set elicited responses to an average of 8 peptide pools compared to 2 pools for a set of3 natural Env's. Synthetic mosaic HIV -I antigens can therefore induce T-cell responses with expanded breadth and may facilitate the development of effective T -cell-based HIV -1 vaccines.

  2. Molecular characterization and expression analysis of four fish-specific CC chemokine receptors CCR4La, CCR4Lc1, CCR4Lc2 and CCR11 in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Qi, Zhitao; Holland, Jason W; Jiang, Yousheng; Secombes, Christopher J; Nie, Pin; Wang, Tiehui

    2017-09-01

    The chemokine and chemokine receptor networks regulate leukocyte trafficking, inflammation, immune cell differentiation, cancer and other biological processes. Comparative immunological studies have revealed that both chemokines and their receptors have expanded greatly in a species/lineage specific way. Of the 10 human CC chemokine receptors (CCR1-10) that bind CC chemokines, orthologues only to CCR6, 7, 9 and 10 are present in teleost fish. In this study, four fish-specific CCRs, termed as CCR4La, CCR4Lc1, CCR4Lc2 and CCR11, with a close link to human CCR1-5 and 8, in terms of amino acid homology and syntenic conservation, have been identified and characterized in rainbow trout (Oncorhynchus mykiss). These CCRs were found to possess the conserved features of the G protein-linked receptor family, including an extracellular N-terminal, seven TM domains, three extracellular loops and three intracellular loops, and a cytoplasmic carboxyl tail with multiple potential serine/threonine phosphorylation sites. Four cysteine residues known to be involved in forming two disulfide bonds are present in the extracellular domains and a DRY motif is present in the second intracellular loop. Signaling mediated by these receptors might be regulated by N-glycosylation, tyrosine sulfation, S-palmitoylation, a PDZ ligand motif and di-leucine motifs. Studies of intron/exon structure revealed distinct fish-specific CCR gene organization in different fish species/lineages that might contribute to the diversification of the chemokine ligand-receptor networks in different fish lineages. Fish-specific trout CCRs are highly expressed in immune tissues/organs, such as thymus, spleen, head kidney and gills. Their expression can be induced by the pro-inflammatory cytokines, IL-1β, IL-6 and IFNγ, by the pathogen associated molecular patterns, PolyIC and peptidoglycan, and by bacterial infection. These data suggest that fish-specific CCRs are likely to have an important role in immune

  3. Gating function of isoleucine-116 in TM-3 (position III:16/3.40) for the activity state of the CC-chemokine receptor 5 (CCR5)

    DEFF Research Database (Denmark)

    Steen, A; Sparre-Ulrich, A H; Thiele, Stefanie

    2014-01-01

    TM receptors - it is a leucine indicating an altered function. Here, we describe the significance of this position and its possible interaction with TM-3 for CCR5 activity. EXPERIMENTAL APPROACH: The effects of [L203F]-CCR5 in TM-5 (position V:13/5.47), [I116A]-CCR5 in TM-3 (III:16/3.40) and [L203F...... ) with a threefold increase in agonist potency. In silico, [I116A]-CCR5 switched χ1-angle in [L203F]-CCR5. Furthermore, [I116A]-CCR5 was constitutively active to a similar degree as [L203F]-CCR5. Tyr(244) in TM-6 (VI:09/6.44) moved towards TM-5 in silico, consistent with its previously shown function for CCR5...... in the active state, a mechanism proposed previously for the β2 -adrenoceptor. The results provide an understanding of chemokine receptor function and thereby information for the development of biased and non-biased antagonists and inverse agonists....

  4. Circulating Cxcr5-Expressing Cd8+T-Cells are Major Producers of Il-21 and Associate with Limited Hiv Replication.

    Science.gov (United States)

    Perdomo-Celis, Federico; Taborda, Natalia A; Rugeles, Maria T

    2018-04-10

    Despite advances made with the highly active anti-retroviral therapy (HAART) in the control of the human immunodeficiency virus 1 (HIV) infection, a cure has not been achieved due to the persistence of viral reservoirs. The major HIV reservoirs remain in the lymphoid follicles due to, among other factors, the partial absence of CD8T-cells in these structures. Recently, lymphoid follicle-confined and circulating CD8T-cells expressing the C-X-C chemokine receptor type 5 (CXCR5) were described, possessing antiviral mechanisms which could help to control HIV replication. and methods: By flow cytometry, we characterized the phenotype and function of circulating CXCR5-expressing CD8T-cells in HIV-infected patients with natural or HAART-induced control of HIV replication. Circulating CXCR5-expressing CD8T-cells exhibited low or null expression of the C-C chemokine receptor type 7 (CCR7) and had a transitional memory phenotype. Particular redistributions of CXCR5-expressing CD8T-cells were found in HIV-infected patients, and they were partially restored by HAART. The frequency of CXCR5CCR7CD8T-cells was higher in spontaneous HIV controllers and negatively correlated with plasma HIV RNA levels. Total and HIV-specific CXCR5CD8T-cells were major producers of interleukin-21, and this function was positively associated with their interferon-γ production. Circulating CXCR5-expressing CD8T-cells are associated with low level HIV replication, could be novel correlates of protection and potentially useful in the eradication of HIV reservoirs.

  5. Preclinical discovery and development of maraviroc for the treatment of HIV.

    Science.gov (United States)

    Veljkovic, Nevena; Vucicevic, Jelica; Tassini, Sabrina; Glisic, Sanja; Veljkovic, Veljko; Radi, Marco

    2015-06-01

    Maraviroc is a first-in-class antiretroviral (ARV) drug acting on a host cell target (CCR5), which blocks the entry of the HIV virus into the cell. Maraviroc is currently indicated for combination ARV treatment in adults infected only with CCR5-tropic HIV-1. This drug discovery case history focuses on the key studies that led to the discovery and approval of maraviroc, as well as on post-launch clinical reports. The article is based on the data reported in published preclinical and clinical studies, conference posters and on drug package data. The profound understanding of HIV's entry mechanisms has provided a strong biological rationale for targeting the chemokine receptor CCR5. The CCR5-antagonist mariviroc, with its unique mode of action and excellent safety profile, is an important therapeutic option for HIV patients. In general, the authors believe that targeting host factors is a useful approach for combating new and re-emerging transmissible diseases, as well as pathogens that easily become resistant to common antiviral drugs. Maraviroc, offering a potent and safe cellular receptor-mediated pharmacological response to HIV, has paved the way for the development of a new generation of host-targeting antivirals.

  6. [CCR5, CCR2, apoe, p53, ITGB3 and HFE gene polymorphism in Western Siberia long-livers].

    Science.gov (United States)

    Ivanoshchuk, D E; Mikhaĭlova, S V; Kulikov, I V; Maksimov, V N; Voevoda, M I; Romashchenko, A G

    2012-01-01

    In order to estimate the distribution of some polymorphisms for the CCR5, CCR2, apoE, p53, ITGB3, and HFE genes in Russian long-livers from Western Siberia, a sample of 271 individuals (range 90-105 years) was examined. It was demonstrated that carriage of the delta32 polymorphism for the CCR5 gene, V64/polymorphism for the CCR2 gene, e2/e3/e4 for the apoE gene, L33P for the ITGB3 gene, as well as H63D and S65C polymorphisms for the HFE gene does not influence on predisposition to the longevity; carriage of the 282 Y allele for the HFE gene negatively influences on the longevity; carriage of the heterozygous genotype for the R72P polymorphism for the p53 gene correlates with the longevity of elderly people.

  7. Brugia malayi Antigen (BmA Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    Directory of Open Access Journals (Sweden)

    Emily E I M Mouser

    Full Text Available One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA and excretory-secretory product 62 (ES-62 from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs.

  8. Dengue virus requires the CC-chemokine receptor CCR5 for replication and infection development.

    Science.gov (United States)

    Marques, Rafael E; Guabiraba, Rodrigo; Del Sarto, Juliana L; Rocha, Rebeca F; Queiroz, Ana Luiza; Cisalpino, Daniel; Marques, Pedro E; Pacca, Carolina C; Fagundes, Caio T; Menezes, Gustavo B; Nogueira, Maurício L; Souza, Danielle G; Teixeira, Mauro M

    2015-08-01

    Dengue is a mosquito-borne disease that affects millions of people worldwide yearly. Currently, there is no vaccine or specific treatment available. Further investigation on dengue pathogenesis is required to better understand the disease and to identify potential therapeutic targets. The chemokine system has been implicated in dengue pathogenesis, although the specific role of chemokines and their receptors remains elusive. Here we describe the role of the CC-chemokine receptor CCR5 in Dengue virus (DENV-2) infection. In vitro experiments showed that CCR5 is a host factor required for DENV-2 replication in human and mouse macrophages. DENV-2 infection induces the expression of CCR5 ligands. Incubation with an antagonist prevents CCR5 activation and reduces DENV-2 positive-stranded (+) RNA inside macrophages. Using an immunocompetent mouse model of DENV-2 infection we found that CCR5(-/-) mice were resistant to lethal infection, presenting at least 100-fold reduction of viral load in target organs and significant reduction in disease severity. This phenotype was reproduced in wild-type mice treated with CCR5-blocking compounds. Therefore, CCR5 is a host factor required for DENV-2 replication and disease development. Targeting CCR5 might represent a therapeutic strategy for dengue fever. These data bring new insights on the association between viral infections and the chemokine receptor CCR5. © 2015 John Wiley & Sons Ltd.

  9. Comprehensive Cross-Clade Characterization of Antibody-Mediated Recognition, Complement-Mediated Lysis, and Cell-Mediated Cytotoxicity of HIV-1 Envelope-Specific Antibodies toward Eradication of the HIV-1 Reservoir.

    Science.gov (United States)

    Mujib, Shariq; Liu, Jun; Rahman, A K M Nur-Ur; Schwartz, Jordan A; Bonner, Phil; Yue, Feng Yun; Ostrowski, Mario A

    2017-08-15

    Immunotherapy with passive administration of broadly neutralizing HIV-1 envelope-specific antibodies (bnAbs) in the setting of established infection in vivo has yielded mixed results. The contribution of different antibodies toward the direct elimination of infected cells is poorly understood. In this study, we determined the ability of 12 well-characterized anti-HIV-1 neutralizing antibodies to recognize and eliminate primary CD4 T cells infected with HIV-1 belonging to clades A, B, C, and D, via antibody-dependent complement-mediated lysis (ADCML) and antibody-dependent cell-mediated cytotoxicity (ADCC), in vitro We further tested unique combinations of these antibodies to determine the optimal antibody cocktails to be tested in future clinical trials. We report that antibody binding to infected CD4 T cells is highly variable and correlates with ADCML and ADCC processes. Particularly, antibodies targeting the envelope glycan shield (2G12) and V1/V2 site (PG9, PG16, and PGT145) are best at recognizing HIV-1-infected CD4 T cells. However, only PG9 and PG16 and their combinations with other bnAbs sufficiently induced the elimination of HIV-1-infected CD4 T cells by ADCML, ADCC, or both. Notably, CD4 binding site antibodies VRC01, 3BNC117, and NIH45-46 G54W did not exhibit recognition of infected cells and were unable to induce their killing. Future trials geared toward the development of a cure for HIV/AIDS should incorporate V1/V2 antibodies for maximal clearance of infected cells. With the use of only primary immune cells, we conducted a comprehensive cross-clade physiological analysis to aid the direction of antibodies as therapeutics toward the development of a cure for HIV/AIDS. IMPORTANCE Several antibodies capable of neutralizing the majority of circulating HIV-1 strains have been identified to date and have been shown to prevent infection in animal models. However, the use of combinations of such broadly neutralizing antibodies (bnAbs) for the treatment and

  10. Lack of CCR5 modifies glial phenotypes and population of the nigral dopaminergic neurons, but not MPTP-induced dopaminergic neurodegeneration.

    Science.gov (United States)

    Choi, Dong-Young; Lee, Myung Koo; Hong, Jin Tae

    2013-01-01

    Constitutive expression of C-C chemokine receptor (CCR) 5 has been detected in astrocytes, microglia and neurons, but its physiological roles in the central nervous system are obscure. The bidirectional interactions between neuron and glial cells through CCR5 and its ligands were thought to be crucial for maintaining normal neuronal activities. No study has described function of CCR5 in the dopaminergic neurodegeneration in Parkinson's disease. In order to examine effects of CCR5 on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurodegeneration, we employed CCR5 wild type (WT) and knockout (KO) mice. Immunostainings for tyrosine hydroxylase (TH) exhibited that CCR5 KO mice had lower number of TH-positive neurons even in the absence of MPTP. Difference in MPTP (15mg/kg×4 times, 2hr interval)-mediated loss of TH-positive neurons was subtle between CCR5 WT and KO mice, but there was larger dopamine depletion, behavioral impairments and microglial activation in CCR5 deficient mice. Intriguingly, CCR5 KO brains contained higher immunoreactivity for monoamine oxidase (MAO) B which was mainly localized within astrocytes. In agreement with upregulation of MAO B, concentration of MPP+ was higher in the substantia nigra and striatum of CCR5 KO mice after MPTP injection. We found remarkable activation of p38 MAPK in CCR5 deficient mice, which positively regulates MAO B expression. These results indicate that CCR5 deficiency modifies the nigrostriatal dopaminergic neuronal system and bidirectional interaction between neurons and glial cells via CCR5 might be important for dopaminergic neuronal survival. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Virucidal activity of the dendrimer microbicide SPL7013 against HIV-1.

    Science.gov (United States)

    Telwatte, Sushama; Moore, Katie; Johnson, Adam; Tyssen, David; Sterjovski, Jasminka; Aldunate, Muriel; Gorry, Paul R; Ramsland, Paul A; Lewis, Gareth R; Paull, Jeremy R A; Sonza, Secondo; Tachedjian, Gilda

    2011-06-01

    Topical microbicides for use by women to prevent the transmission of human immunodeficiency virus (HIV) and other sexually transmitted infections are urgently required. Dendrimers are highly branched nanoparticles being developed as microbicides. SPL7013 is a dendrimer with broad-spectrum activity against HIV type I (HIV-1) and -2 (HIV-2), herpes simplex viruses type-1 (HSV-1) and -2 (HSV-2) and human papillomavirus. SPL7013 [3% (w/w)] has been formulated in a mucoadhesive carbopol gel (VivaGel®) for use as a topical microbicide. Previous studies showed that SPL7013 has similar potency against CXCR4-(X4) and CCR5-using (R5) strains of HIV-1 and that it blocks viral entry. However, the ability of SPL7013 to directly inactivate HIV-1 is unknown. We examined whether SPL7013 demonstrates virucidal activity against X4 (NL4.3, MBC200, CMU02 clade EA and 92UG046 clade D), R5 (Ba-L, NB25 and 92RW016 clade A) and dual-tropic (R5X4; MACS1-spln) HIV-1 using a modified HLA-DR viral capture method and by polyethylene glycol precipitation. Evaluation of virion integrity was determined by ultracentrifugation through a sucrose cushion and detection of viral proteins by Western blot analysis. SPL7013 demonstrated potent virucidal activity against X4 and R5X4 strains, although virucidal activity was less potent for the 92UG046 X4 clade D isolate. Where potent virucidal activity was observed, the 50% virucidal concentrations were similar to the 50% effective concentrations previously reported in drug susceptibility assays, indicating that the main mode of action of SPL7013 is by direct viral inactivation for these strains. In contrast, SPL7013 lacked potent virucidal activity against R5 HIV-1 strains. Evaluation of the virucidal mechanism showed that SPL7013-treated NL4.3, 92UG046 and MACS1-spln virions were intact with no significant decrease in gp120 surface protein with respect to p24 capsid content compared to the corresponding untreated virus. These studies demonstrate that SPL

  12. Lignosulfonic acid exhibits broadly anti-HIV-1 activity--potential as a microbicide candidate for the prevention of HIV-1 sexual transmission.

    Directory of Open Access Journals (Sweden)

    Min Qiu

    Full Text Available Some secondary metabolites from plants show to have potent inhibitory activities against microbial pathogens, such as human immunodeficiency virus (HIV, herpes simplex virus (HSV, Treponema pallidum, Neisseria gonorrhoeae, etc. Here we report that lignosulfonic acid (LSA, a polymeric lignin derivative, exhibits potent and broad activity against HIV-1 isolates of diverse subtypes including two North America strains and a number of Chinese clinical isolates values ranging from 21.4 to 633 nM. Distinct from other polyanions, LSA functions as an entry inhibitor with multiple targets on viral gp120 as well as on host receptor CD4 and co-receptors CCR5/CXCR4. LSA blocks viral entry as determined by time-of-drug addiction and cell-cell fusion assays. Moreover, LSA inhibits CD4-gp120 interaction by blocking the binding of antibodies specific for CD4-binding sites (CD4bs and for the V3 loop of gp120. Similarly, LSA interacts with CCR5 and CXCR4 via its inhibition of specific anti-CCR5 and anti-CXCR4 antibodies, respectively. Interestingly, the combination of LSA with AZT and Nevirapine exhibits synergism in viral inhibition. For the purpose of microbicide development, LSA displays low in vitro cytotoxicity to human genital tract epithelial cells, does not stimulate NF-κB activation and has no significant up-regulation of IL-1α/β and IL-8 as compared with N-9. Lastly, LSA shows no adverse effect on the epithelial integrity and the junctional protein expression. Taken together, our findings suggest that LSA can be a potential candidate for tropical microbicide.

  13. Lack of association between the chemokine receptor 5 polymorphism CCR5delta32 in rheumatoid arthritis and juvenile idiopathic arthritis

    Directory of Open Access Journals (Sweden)

    Kvien Tore K

    2007-06-01

    Full Text Available Abstract Background The chemokine receptor CCR5 has been detected at elevated levels on synovial T cells, and a 32 bp deletion in the CCR5 gene leads to a non-functional receptor. A negative association between the CCR5Δ32 and rheumatoid arthritis (RA has been reported, although with conflicting results. In juvenile idiopathic arthritis (JIA, an association with CCR5 was recently reported. The purpose of this study was to investigate if the CCR5Δ32 polymorphism is associated with RA or JIA in Norwegian cohorts. Methods 853 RA patients, 524 JIA patients and 658 controls were genotyped for the CCR5Δ32 polymorphism. Results The CCR5Δ32 allele frequency was 11.5% in the controls vs. 10.4% in RA patients (OR = 0.90; P = 0.36 and 9.7% in JIA patients (OR = 0.85; P = 0.20. No decreased homozygosity was observed for CCR5Δ32, as previously suggested. Conclusion Our data do not support an association between the CCR5Δ32 allele and Norwegian RA or JIA patients. Combining our results with those from a recently published meta-analysis still provide evidence for a role for CCR5Δ32 in RA, albeit substantially weaker than the effect first reported.

  14. Circulating precursor CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells indicate Tfh cell activity and promote antibody responses upon antigen reexposure.

    Science.gov (United States)

    He, Jing; Tsai, Louis M; Leong, Yew Ann; Hu, Xin; Ma, Cindy S; Chevalier, Nina; Sun, Xiaolin; Vandenberg, Kirsten; Rockman, Steve; Ding, Yan; Zhu, Lei; Wei, Wei; Wang, Changqi; Karnowski, Alexander; Belz, Gabrielle T; Ghali, Joanna R; Cook, Matthew C; Riminton, D Sean; Veillette, André; Schwartzberg, Pamela L; Mackay, Fabienne; Brink, Robert; Tangye, Stuart G; Vinuesa, Carola G; Mackay, Charles R; Li, Zhanguo; Yu, Di

    2013-10-17

    Follicular B helper T (Tfh) cells support high affinity and long-term antibody responses. Here we found that within circulating CXCR5⁺ CD4⁺ T cells in humans and mice, the CCR7(lo)PD-1(hi) subset has a partial Tfh effector phenotype, whereas CCR7(hi)PD-1(lo) cells have a resting phenotype. The circulating CCR7(lo)PD-1(hi) subset was indicative of active Tfh differentiation in lymphoid organs and correlated with clinical indices in autoimmune diseases. Thus the CCR7(lo)PD-1(hi) subset provides a biomarker to monitor protective antibody responses during infection or vaccination and pathogenic antibody responses in autoimmune diseases. Differentiation of both CCR7(hi)PD-1(lo) and CCR7(lo)PD-1(hi) subsets required ICOS and BCL6, but not SAP, suggesting that circulating CXCR5⁺ helper T cells are primarily generated before germinal centers. Upon antigen reencounter, CCR7(lo)PD-1(hi) CXCR5⁺ precursors rapidly differentiate into mature Tfh cells to promote antibody responses. Therefore, circulating CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells are generated during active Tfh differentiation and represent a new mechanism of immunological early memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Inhibition of a NEDD8 Cascade Restores Restriction of HIV by APOBEC3G.

    Directory of Open Access Journals (Sweden)

    David J Stanley

    2012-12-01

    Full Text Available Cellular restriction factors help to defend humans against human immunodeficiency virus (HIV. HIV accessory proteins hijack at least three different Cullin-RING ubiquitin ligases, which must be activated by the small ubiquitin-like protein NEDD8, in order to counteract host cellular restriction factors. We found that conjugation of NEDD8 to Cullin-5 by the NEDD8-conjugating enzyme UBE2F is required for HIV Vif-mediated degradation of the host restriction factor APOBEC3G (A3G. Pharmacological inhibition of the NEDD8 E1 by MLN4924 or knockdown of either UBE2F or its RING-protein binding partner RBX2 bypasses the effect of Vif, restoring the restriction of HIV by A3G. NMR mapping and mutational analyses define specificity determinants of the UBE2F NEDD8 cascade. These studies demonstrate that disrupting host NEDD8 cascades presents a novel antiretroviral therapeutic approach enhancing the ability of the immune system to combat HIV.

  16. Induction of experimental autoimmune encephalomyelitis in C57BL/6 mice deficient in either the chemokine macrophage inflammatory protein-1alpha or its CCR5 receptor

    DEFF Research Database (Denmark)

    Tran, E H; Kuziel, W A; Owens, T

    2000-01-01

    -type mice in Th1 cytokine gene expression, the kinetics and severity of disease, and infiltration of the central nervous system by lymphocytes, macrophages and granulocytes. RNase protection assays showed comparable accumulation of mRNA for the chemokines interferon-inducible protein-10, RANTES, macrophage...... and its CCR5 receptor in the induction of EAE by immunizing C57BL / 6 mice deficient in either MIP-1alpha or CCR5 with myelin oligodendrocyte glycoprotein (MOG). We found that MIP-1alpha-deficient mice were fully susceptible to MOG-induced EAE. These knockout animals were indistinguishable from wild...... chemoattractant protein-1, MIP-1beta, MIP-2, lymphotactin and T cell activation gene-3 during the course of the disease. CCR5-deficient mice were also susceptible to disease induction by MOG. The dispensability of MIP-1alpha and CCR5 for MOG-induced EAE in C57BL / 6 mice supports the idea that differential...

  17. Optimization of HIV-1 Envelope DNA Vaccine Candidates within Three Different Animal Models, Guinea Pigs, Rabbits and Cynomolgus Macaques.

    Science.gov (United States)

    Borggren, Marie; Vinner, Lasse; Andresen, Betina Skovgaard; Grevstad, Berit; Repits, Johanna; Melchers, Mark; Elvang, Tara Laura; Sanders, Rogier W; Martinon, Frédéric; Dereuddre-Bosquet, Nathalie; Bowles, Emma Joanne; Stewart-Jones, Guillaume; Biswas, Priscilla; Scarlatti, Gabriella; Jansson, Marianne; Heyndrickx, Leo; Grand, Roger Le; Fomsgaard, Anders

    2013-07-19

    HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb). We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

  18. Optimization of HIV-1 Envelope DNA Vaccine Candidates within Three Different Animal Models, Guinea Pigs, Rabbits and Cynomolgus Macaques

    Directory of Open Access Journals (Sweden)

    Roger Le Grand

    2013-07-01

    Full Text Available HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb. We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

  19. Transfer of the amino-terminal nuclear envelope targeting domain of human MX2 converts MX1 into an HIV-1 resistance factor.

    Science.gov (United States)

    Goujon, Caroline; Moncorgé, Olivier; Bauby, Hélène; Doyle, Tomas; Barclay, Wendy S; Malim, Michael H

    2014-08-01

    The myxovirus resistance 2 (MX2) protein of humans has been identified recently as an interferon (IFN)-inducible inhibitor of human immunodeficiency virus type 1 (HIV-1) that acts at a late postentry step of infection to prevent the nuclear accumulation of viral cDNA (C. Goujon et al., Nature 502:559-562, 2013, http://dx.doi.org/10.1038/nature12542; M. Kane et al., Nature 502:563-566, 2013, http://dx.doi.org/10.1038/nature12653; Z. Liu et al., Cell Host Microbe 14:398-410, 2013, http://dx.doi.org/10.1016/j.chom.2013.08.015). In contrast, the closely related human MX1 protein, which suppresses infection by a range of RNA and DNA viruses (such as influenza A virus [FluAV]), is ineffective against HIV-1. Using a panel of engineered chimeric MX1/2 proteins, we demonstrate that the amino-terminal 91-amino-acid domain of MX2 confers full anti-HIV-1 function when transferred to the amino terminus of MX1, and that this fusion protein retains full anti-FluAV activity. Confocal microscopy experiments further show that this MX1/2 fusion, similar to MX2 but not MX1, can localize to the nuclear envelope (NE), linking HIV-1 inhibition with MX accumulation at the NE. MX proteins are dynamin-like GTPases, and while MX1 antiviral function requires GTPase activity, neither MX2 nor MX1/2 chimeras require this attribute to inhibit HIV-1. This key discrepancy between the characteristics of MX1- and MX2-mediated viral resistance, together with previous observations showing that the L4 loop of the stalk domain of MX1 is a critical determinant of viral substrate specificity, presumably reflect fundamental differences in the mechanisms of antiviral suppression. Accordingly, we propose that further comparative studies of MX proteins will help illuminate the molecular basis and subcellular localization requirements for implementing the noted diversity of virus inhibition by MX proteins. Interferon (IFN) elicits an antiviral state in cells through the induction of hundreds of IFN

  20. Functional analysis of the CC chemokine receptor 5 (CCR5) on virus-specific CD8+ T cells following coronavirus infection of the central nervous system

    International Nuclear Information System (INIS)

    Glass, William G.; Lane, Thomas E.

    2003-01-01

    Intracranial infection of C57BL/6 mice with mouse hepatitis virus (MHV) results in an acute encephalomyelitis followed by a demyelinating disease similar in pathology to the human disease multiple sclerosis (MS). T cells participate in both defense and disease progression following MHV infection. Expression of chemokine receptors on activated T cells is important in allowing these cells to traffic into and accumulate within the central nervous system (CNS) of MHV-infected mice. The present study evaluated the contributions of CCR5 to the activation and trafficking of virus-specific CD8 + T cells into the MHV-infected CNS mice. Comparable numbers of virus-specific CD8 + T cells derived from immunized CCR5 +/+ or CCR5 -/- mice were present within the CNS of MHV-infected RAG1 -/- mice following adoptive transfer, indicating that CCR5 is not required for trafficking of these cells into the CNS. RAG1 -/- recipients of CCR5 -/- -derived CD8 + T cells exhibited a modest, yet significant (P ≤ 0.05), reduction in viral burden within the brain which correlated with increased CTL activity and IFN-γ expression. Histological analysis of RAG1 -/- recipients of either CCR5 +/+ or CCR5 -/- -derived CD8 + T cells revealed only focal areas of demyelination with no significant differences in white matter destruction. These data indicate that CCR5 signaling on CD8 + T cells modulates antiviral activities but is not essential for entry into the CNS

  1. Downregulation of CCR1 inhibits human hepatocellular carcinoma cell invasion

    International Nuclear Information System (INIS)

    Wu Xiaofeng; Fan Jia; Wang Xiaoying; Zhou Jian; Qiu Shuangjian; Yu Yao; Liu Yinkun; Tang Zhaoyou

    2007-01-01

    CC chemokine receptor 1 (CCR1) has an important role in the recruitment of leukocytes to the site of inflammation. The migration and metastasis of tumor cells shares many similarities with leukocyte trafficking, which is mainly regulated by chemokine receptor-ligand interactions. CCR1 is highly expressed in hepatocellular carcinoma (HCC) cells and tissues with unknown functions. In this study, we silenced CCR1 expression in the human HCC cell line HCCLM3 using artificial microRNA (miRNA)-mediated RNA interference (RNAi) and examined the invasiveness and proliferation of CCR1-silenced HCCLM3 cells and the matrix metalloproteinase (MMP) activity. The miRNA-mediated knockdown expression of CCR1 significantly inhibited the invasive ability of HCCLM3 cells, but had only a minor effect on the cellular proliferation rate. Moreover, CCR1 knockdown significantly reduced the secretion of MMP-2. Together, these findings indicate that CCR1 has an important role in HCCLM3 invasion and that CCR1 might be a new target of HCC treatment

  2. Stable 293 T and CHO cell lines expressing cleaved, stable HIV-1 envelope glycoprotein trimers for structural and vaccine studies

    NARCIS (Netherlands)

    Chung, Nancy P. Y.; Matthews, Katie; Kim, Helen J.; Ketas, Thomas J.; Golabek, Michael; de Los Reyes, Kevin; Korzun, Jacob; Yasmeen, Anila; Sanders, Rogier W.; Klasse, Per Johan; Wilson, Ian A.; Ward, Andrew B.; Marozsan, Andre J.; Moore, John P.; Cupo, Albert

    2014-01-01

    Recombinant soluble, cleaved HIV-1 envelope glycoprotein SOSIP.664 gp140 trimers based on the subtype A BG505 sequence are being studied structurally and tested as immunogens in animals. For these trimers to become a vaccine candidate for human trials, they would need to be made in appropriate

  3. Systemic MCP1/CCR2 blockade and leukocyte specific MCP1/CCR2 inhibition affect aortic aneurysm formation differently

    NARCIS (Netherlands)

    de Waard, Vivian; Bot, Ilze; de Jager, Saskia C. A.; Talib, Sara; Egashira, Kensuke; de Vries, Margreet R.; Quax, Paul H. A.; Biessen, Erik A. L.; van Berkel, Theo J. C.

    2010-01-01

    Objective: CCR2, the receptor for monocyte chemoattractant protein 1 (MCP1), is involved in atherosclerosis and abdominal aortic aneurysms (AAAs). Here, we explored the potential beneficial blockade of the MCP1/CCR2 pathway. Methods: We applied an AAA model in aging apolipoprotein E deficient mice

  4. Plasmacytoid dendritic cells accumulate and secrete interferon alpha in lymph nodes of HIV-1 patients.

    Directory of Open Access Journals (Sweden)

    Clara Lehmann

    2010-06-01

    Full Text Available Circulating plasmacytoid dendritic cells (pDC decline during HIV-1 infection, but at the same time they express markedly higher levels of interferon alpha (IFNalpha, which is associated with HIV-1 disease progression. Here we show an accumulation of pDC in lymph nodes (LN of treatment-naïve HIV-1 patients. This phenomenon was associated with elevated expression of the LN homing marker, CCR7, on pDC in peripheral blood of HIV-1 patients, which conferred increased migratory capacity in response to CCR7 ligands in ex vivo functional assays. LN-homed pDC of HIV-1 patients presented higher CD40 and lower BDCA2 levels, but unchanged CD83 and CD86 expression. In addition, these cells expressed markedly higher amounts of IFNalpha compared to uninfected individuals, and were undergoing faster rates of cell death. These results demonstrate for the first time that in asymptomatic, untreated HIV-1 patients circulating pDC up-regulate CCR7 expression, accumulate in lymph nodes, and express high amounts of IFNalpha before undergoing cell death. Since IFNalpha inhibits cell proliferation and modulates immune responses, chronically high levels of this cytokine in LN of HIV-1 patients may impair differentiation and immune function of bystander CD4(+ T cells, thus playing into the mechanisms of AIDS immunopathogenesis.

  5. HIV-related travel restrictions: trends and country characteristics.

    Science.gov (United States)

    Chang, Felicia; Prytherch, Helen; Nesbitt, Robin C; Wilder-Smith, Annelies

    2013-06-03

    Increasingly, HIV-seropositive individuals cross international borders. HIV-related restrictions on entry, stay, and residence imposed by countries have important consequences for this mobile population. Our aim was to describe the geographical distribution of countries with travel restrictions and to examine the trends and characteristics of countries with such restrictions. In 2011, data presented to UNAIDS were used to establish a list of countries with and without HIV restrictions on entry, stay, and residence and to describe their geographical distribution. The following indicators were investigated to describe the country characteristics: population at mid-year, international migrants as a percentage of the population, Human Development Index, estimated HIV prevalence (age: 15-49), presence of a policy prohibiting HIV screening for general employment purposes, government and civil society responses to having non-discrimination laws/regulations which specify migrants/mobile populations, government and civil society responses to having laws/regulations/policies that present obstacles to effective HIV prevention, treatment, care, and support for migrants/mobile populations, Corruption Perception Index, and gross national income per capita. HIV-related restrictions exist in 45 out of 193 WHO countries (23%) in all regions of the world. We found that the Eastern Mediterranean and Western Pacific Regions have the highest proportions of countries with these restrictions. Our analyses showed that countries that have opted for restrictions have the following characteristics: smaller populations, higher proportions of migrants in the population, lower HIV prevalence rates, and lack of legislation protecting people living with HIV from screening for employment purposes, compared with countries without restrictions. Countries with a high proportion of international migrants tend to have travel restrictions - a finding that is relevant to migrant populations and travel

  6. The N-terminal domain of APJ, a CNS-based coreceptor for HIV-1, is essential for its receptor function and coreceptor activity

    International Nuclear Information System (INIS)

    Zhou Naiming; Zhang Xiaoling; Fan Xuejun; Argyris, Elias; Fang Jianhua; Acheampong, Edward; DuBois, Garrett C.; Pomerantz, Roger J.

    2003-01-01

    The human APJ, a G protein-coupled seven-transmembrane receptor, has been found to be dramatically expressed in the human central nervous system (CNS) and also to serve as a coreceptor for the entry of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV). Studies with animal models suggested that APJ and its natural ligand, apelin, play an important role in the central control of body fluid homeostasis, and in regulation of blood pressure and cardiac contractility. In this study, we characterize the structural and functional determinants of the N-terminal domain of APJ in interactions with its natural ligand and HIV-1 envelope glycoprotein. We demonstrate that the second 10 residues of the N-terminal domain of APJ are critical for association with apelin, while the first 20 amino acids play an important role in supporting cell-cell fusion mediated by HIV-1 gp120. With site-directed mutagenesis, we have identified that the negatively charged amino acid residues Glu20 and Asp23 are involved in receptor and coreceptor functions, but residues Tyr10 and Tyr11 substantially contribute to coreceptor function for both T-tropic (CXCR4) and dual-tropic (CXCR4 and CCR5) HIV-1 isolates. Thus, this study provides potentially important information for further characterizing APJ-apelin functions in vitro and in vivo and designing small molecules for treatment of HIV-1 infection in the CNS

  7. Murine Antibody Responses to Cleaved Soluble HIV-1 Envelope Trimers Are Highly Restricted in Specificity

    NARCIS (Netherlands)

    Hu, Joyce K.; Crampton, Jordan C.; Cupo, Albert; Ketas, Thomas; van Gils, Marit J.; Sliepen, Kwinten; de Taeye, Steven W.; Sok, Devin; Ozorowski, Gabriel; Deresa, Isaiah; Stanfield, Robyn; Ward, Andrew B.; Burton, Dennis R.; Klasse, Per Johan; Sanders, Rogier W.; Moore, John P.; Crotty, Shane

    2015-01-01

    Generating neutralizing antibodies (nAbs) is a major goal of many current HIV-1 vaccine efforts. To be of practical value, these nAbs must be both potent and cross-reactive in order to be capable of preventing the transmission of the highly diverse and generally neutralization resistant (Tier-2)

  8. Trofile HIV co-receptor usage assay.

    Science.gov (United States)

    Low, Andrew J; McGovern, Rachel A; Harrigan, P Richard

    2009-03-01

    The introduction of CCR5 antagonists increases the options available for constructing therapeutic drug regimens for HIV-positive patients. However, as these drugs do not inhibit HIV variants that use the CXCR4 co-receptor, a pretreatment test is required to determine accurately HIV co-receptor usage (tropism) before initiating CCR5 antagonist-based therapy. To discuss the Monogram Trofile assay as a diagnostic tool for determining HIV tropism by critically reviewing reported literature and available data. Monogram Trofile has become, largely by default, the de facto standard for HIV tropism assay. However, there is significant room for improvement in the speed, cost and availability of the test. Furthermore, the test is not quantitative, requires high-input HIV RNA viral loads, and produces results that are less biologically stable than expected. These technical considerations may limit the use of CCR5 antagonists in therapy. Nevertheless, this test is likely to remain the most widely used tropism diagnostic for the short term. We expect that a more practical and possibly more accurate method for measuring HIV tropism can be developed.

  9. Natural controlled HIV infection: Preserved HIV-specific immunity despite undetectable replication competent virus

    International Nuclear Information System (INIS)

    Kloosterboer, Nico; Groeneveld, Paul H.P.; Jansen, Christine A.; Vorst, Teun J.K. van der; Koning, Fransje; Winkel, Carel N.; Duits, Ashley J.; Miedema, Frank; Baarle, Debbie van; Rij, Ronald P. van; Brinkman, Kees; Schuitemaker, Hanneke

    2005-01-01

    Long-term non-progressive HIV infection, characterized by low but detectable viral load and stable CD4 counts in the absence of antiviral therapy, is observed in about 5% of HIV-infected patients. Here we identified four therapy naive individuals who are strongly seropositive for HIV-1 but who lack evidence of detectable HIV p24 antigen, plasma RNA, and proviral DNA in routine diagnostic testing. With an ultrasensitive PCR, we established that frequencies of pol proviral DNA sequences were as low as 0.2-0.5 copies/10 6 PBMC. HIV could not be isolated using up to 30 x 10 6 patient PBMC. One individual was heterozygous for CCR5 Δ32, but CCR5 expression on CD4 + T cells was normal to high in all four individuals. In vitro R5 and X4 HIV-1 susceptibility of CD8-depleted PBMC of all study subjects was significantly lower than the susceptibility of CD8-depleted PBMC of healthy blood donors. All individuals expressed protective HLA-B*58s alleles and showed evidence of HIV-specific cellular immunity either by staining with HLA-B*57 tetramers folded with an HIV RT or gag peptide or after stimulation with HIV-1 p24 gag, RT, or nef peptides in ELIspot analysis. HIV-specific CD4 + T helper cells were demonstrated by proliferation of CD4 + T cells and intracellular staining for IL-2 and IFNγ after stimulation with an HIV-gag peptide pool. Sera of all individuals showed antibody-mediated neutralization of both R5 and X4 HIV-1 variants. These data implicate that very low-level antigen exposure is sufficient for sustained HIV-specific immunity and suggest the possibility of a multi-factorial control of HIV infection

  10. CCR5 delta32, matrix metalloproteinase-9 and disease activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, Finn; Madsen, Hans O; Jensen, Claus V

    2000-01-01

    Chemokines and matrix metalloproteinases (MMPs) appear to be crucial in leukocyte recruitment to the central nervous system in multiple sclerosis (MS). CCR5 delta32, a truncated allele of the CC chemokine receptor CCR5 gene encoding a non-functional receptor, did not confer protection from MS. CCR5...... delta32 was, however, associated with a lower risk of recurrent clinical disease activity. High CSF levels of MMP-9 activity were also associated with recurrent disease activity. These results directly link intrathecal inflammation to disease activity in patients with MS, suggesting that treatments...... targeting CCR5 or treatment with MMP inhibitors may attenuate disease activity in MS...

  11. HIV-1 envelope sequence-based diversity measures for identifying recent infections.

    Directory of Open Access Journals (Sweden)

    Alexis Kafando

    Full Text Available Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing public health prevention efforts. To identify recent HIV-1 infections, we evaluated and compared the performance of 4 sequence-based diversity measures including percent diversity, percent complexity, Shannon entropy and number of haplotypes targeting 13 genetic segments within the env gene of HIV-1. A total of 597 diagnostic samples obtained in 2013 and 2015 from recently and chronically HIV-1 infected individuals were selected. From the selected samples, 249 (134 from recent versus 115 from chronic infections env coding regions, including V1-C5 of gp120 and the gp41 ectodomain of HIV-1, were successfully amplified and sequenced by next generation sequencing (NGS using the Illumina MiSeq platform. The ability of the four sequence-based diversity measures to correctly identify recent HIV infections was evaluated using the frequency distribution curves, median and interquartile range and area under the curve (AUC of the receiver operating characteristic (ROC. Comparing the median and interquartile range and evaluating the frequency distribution curves associated with the 4 sequence-based diversity measures, we observed that the percent diversity, number of haplotypes and Shannon entropy demonstrated significant potential to discriminate recent from chronic infections (p<0.0001. Using the AUC of ROC analysis, only the Shannon entropy measure within three HIV-1 env segments could accurately identify recent infections at a satisfactory level. The env segments were gp120 C2_1 (AUC = 0.806, gp120 C2_3 (AUC = 0.805 and gp120 V3 (AUC = 0.812. Our results clearly indicate that the Shannon entropy measure represents a useful tool for predicting HIV-1 infection recency.

  12. The effect of Trim5 polymorphisms on the clinical course of HIV-1 infection.

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    Daniëlle van Manen

    2008-02-01

    Full Text Available The antiviral factor tripartite interaction motif 5alpha (Trim5alpha restricts a broad range of retroviruses in a species-specific manner. Although human Trim5alpha is unable to block HIV-1 infection in human cells, a modest inhibition of HIV-1 replication has been reported. Recently two polymorphisms in the Trim5 gene (H43Y and R136Q were shown to affect the antiviral activity of Trim5alpha in vitro. In this study, participants of the Amsterdam Cohort studies were screened for polymorphisms at amino acid residue 43 and 136 of the Trim5 gene, and the potential effects of these polymorphisms on the clinical course of HIV-1 infection were analyzed. In agreement with the reported decreased antiviral activity of Trim5alpha that contains a Y at amino acid residue 43 in vitro, an accelerated disease progression was observed for individuals who were homozygous for the 43Y genotype as compared to individuals who were heterozygous or homozygous for the 43H genotype. A protective effect of the 136Q genotype was observed but only after the emergence of CXCR4-using (X4 HIV-1 variants and when a viral load of 10(4.5 copies per ml plasma was used as an endpoint in survival analysis. Interestingly, naive CD4 T cells, which are selectively targeted by X4 HIV-1, revealed a significantly higher expression of Trim5alpha than memory CD4 T cells. In addition, we observed that the 136Q allele in combination with the -2GG genotype in the 5'UTR was associated with an accelerated disease progression. Thus, polymorphisms in the Trim5 gene may influence the clinical course of HIV-1 infection also underscoring the antiviral effect of Trim5alpha on HIV-1 in vivo.

  13. The Effect of Trim5 Polymorphisms on the Clinical Course of HIV-1 Infection

    Science.gov (United States)

    van Manen, Daniëlle; Rits, Maarten A. N; Beugeling, Corrine; van Dort, Karel; Schuitemaker, Hanneke; Kootstra, Neeltje A

    2008-01-01

    The antiviral factor tripartite interaction motif 5α (Trim5α) restricts a broad range of retroviruses in a species-specific manner. Although human Trim5α is unable to block HIV-1 infection in human cells, a modest inhibition of HIV-1 replication has been reported. Recently two polymorphisms in the Trim5 gene (H43Y and R136Q) were shown to affect the antiviral activity of Trim5α in vitro. In this study, participants of the Amsterdam Cohort studies were screened for polymorphisms at amino acid residue 43 and 136 of the Trim5 gene, and the potential effects of these polymorphisms on the clinical course of HIV-1 infection were analyzed. In agreement with the reported decreased antiviral activity of Trim5α that contains a Y at amino acid residue 43 in vitro, an accelerated disease progression was observed for individuals who were homozygous for the 43Y genotype as compared to individuals who were heterozygous or homozygous for the 43H genotype. A protective effect of the 136Q genotype was observed but only after the emergence of CXCR4-using (X4) HIV-1 variants and when a viral load of 104.5 copies per ml plasma was used as an endpoint in survival analysis. Interestingly, naive CD4 T cells, which are selectively targeted by X4 HIV-1, revealed a significantly higher expression of Trim5α than memory CD4 T cells. In addition, we observed that the 136Q allele in combination with the −2GG genotype in the 5′UTR was associated with an accelerated disease progression. Thus, polymorphisms in the Trim5 gene may influence the clinical course of HIV-1 infection also underscoring the antiviral effect of Trim5α on HIV-1 in vivo. PMID:18248091

  14. Functional characteristics of HIV-1 subtype C compatible with increased heterosexual transmissibility

    DEFF Research Database (Denmark)

    Walter, Brandon L; Armitage, Andrew E; Graham, Stephen C

    2009-01-01

    BACKGROUND: Despite the existence of over 50 subtypes and circulating recombinant forms of HIV-1, subtype C dominates the heterosexual pandemic causing approximately 56% of all infections. OBJECTIVE: To evaluate whether viral genetic factors may contribute to the observed subtype-C predominance. ....... CONCLUSION: As CD4-CCR5-T cells are key targets for genital HIV infection and cervical selection can favor compact V1-V2 loops and 316T, which increase viral infectivity, we propose that these conserved subtype-C motifs may contribute to transmission and spread of this subtype....

  15. Therapeutic Vaccination Using Cationic Liposome-Adjuvanted HIV Type 1 Peptides Representing HLA-Supertype-Restricted Subdominant T Cell Epitopes

    DEFF Research Database (Denmark)

    Román, Victor Raúl Gómez; Jensen, Kristoffer Jarlov; Jensen, Sanne Skov

    2013-01-01

    We have designed a therapeutic HIV-1 vaccine concept based on peptides together with the adjuvant CAF01. Peptides represented 15 HLA-supertype-restricted subdominant and conserved CD8 T cell epitopes and three CD4 T-helper cell epitopes. In this phase I clinical trial, safety and immunogenicity...... were assessed in untreated HIV-1-infected individuals in Guinea-Bissau, West Africa. Twenty-three HIV-1-infected individuals were randomized to receive placebo (n=5) or vaccine (n=18). Safety was appraised by clinical follow-up combined with monitoring of biochemistry, hematology, CD4 T cell counts......, and HIV-1 viral loads. T cell immunogenicity was monitored longitudinally by interferon (IFN)-γ ELISpot. New vaccine-specific T cell responses were induced in 6/14 vaccinees for whom ELISpot data were valid. CD4 T cell counts and viral loads were stable. The study shows that therapeutic immunization...

  16. European recommendations for the clinical use of HIV drug resistance testing: 2011 update

    DEFF Research Database (Denmark)

    Vandamme, Anne-Mieke; Camacho, Ricardo J; Ceccherini-Silberstein, Francesca

    2011-01-01

    , and other drug targets (integrase and envelope) if such drugs were part of the failing regimen; (iii) consider testing for CCR5 tropism at virologic failure or when a change of therapy has to be made in absence of detectable viral load, and in the latter case test DNA or last detectable plasma RNA; (iv...... the following recommendations concerning the indications for resistance testing: for HIV-1 (i) test earliest sample for protease and reverse transcriptase drug resistance in drug-naive patients with acute or chronic infection; (ii) test protease and reverse transcriptase drug resistance at virologic failure...... is needed after treatment failure. The Panel recommends genotyping in most situations, using updated and clinically evaluated interpretation systems. It is mandatory that laboratories performing HIV resistance tests take part regularly in external quality assurance programs, and that they consider storing...

  17. Increased frequency of CCR4+ and CCR6+ memory T-cells including CCR7+CD45RAmed very early memory cells in granulomatosis with polyangiitis (Wegener's)

    OpenAIRE

    Fagin, Ursula; Pitann, Silke; Gross, Wolfgang L; Lamprecht, Peter

    2012-01-01

    Introduction Chemokine receptors play an important role in mediating the recruitment of T cells to inflammatory sites. Previously, small proportions of circulating Th1-type CCR5+ and Th2-type CCR3+ cells have been shown in granulomatosis with polyangiitis (GPA). Wondering to what extent CCR4 and CCR6 expression could also be implicated in T cell recruitment to inflamed sites in GPA, we investigated the expression of CCR4 and CCR6 on T cells and its association with T cell diversity and polari...

  18. Reduction of cerebral glucose utilization by the HIV envelope glycoprotein Gp-120

    Energy Technology Data Exchange (ETDEWEB)

    Kimes, A.S.; London, E.D.; Szabo, G.; Raymon, L.; Tabakoff, B. (Neuropharmacology Laboratory, National Institute on Drug Abuse, Baltimore, MD (USA))

    1991-05-01

    Gp-120 is a glycoprotein constituent of the human immunodeficiency virus (HIV) envelope. The effects of gp-120 on cerebral glucose utilization in rats were studied by the quantitative 2-deoxy-D-(1-14C) glucose method. Intracerebroventricular injection of gp-120 significantly reduced glucose utilization in the lateral habenula and the suprachiasmatic nucleus and decreased the global cerebral metabolic rate for glucose. The findings suggest that gp-120 and closely related peptides can alter neuronal function, thereby contributing to the sequelae of HIV infection.

  19. Reduction of cerebral glucose utilization by the HIV envelope glycoprotein Gp-120

    International Nuclear Information System (INIS)

    Kimes, A.S.; London, E.D.; Szabo, G.; Raymon, L.; Tabakoff, B.

    1991-01-01

    Gp-120 is a glycoprotein constituent of the human immunodeficiency virus (HIV) envelope. The effects of gp-120 on cerebral glucose utilization in rats were studied by the quantitative 2-deoxy-D-[1-14C] glucose method. Intracerebroventricular injection of gp-120 significantly reduced glucose utilization in the lateral habenula and the suprachiasmatic nucleus and decreased the global cerebral metabolic rate for glucose. The findings suggest that gp-120 and closely related peptides can alter neuronal function, thereby contributing to the sequelae of HIV infection

  20. R5-SHIV induces multiple defects in T cell function during early infection of rhesus macaques including accumulation of T reg cells in lymph nodes.

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    Michael Santosuosso

    2011-04-01

    Full Text Available HIV-1 is a pathogen that T cell responses fail to control. HIV-1gp120 is the surface viral envelope glycoprotein that interacts with CD4 T cells and mediates entry. HIV-1gp120 has been implicated in immune dysregulatory functions that may limit anti-HIV antigen-specific T cell responses. We hypothesized that in the context of early SHIV infection, immune dysregulation of antigen-specific T-effector cell and regulatory functions would be detectable and that these would be associated or correlated with measurable concentrations of HIV-1gp120 in lymphoid tissues.Rhesus macaques were intravaginally inoculated with a Clade C CCR5-tropic simian-human immunodeficiency virus, SHIV-1157ipd3N4. HIV-1gp120 levels, antigen-specificity, levels of apoptosis/anergy and frequency and function of Tregs were examined in lymph node and blood derived T cells at 5 and 12 weeks post inoculation.We observed reduced responses to Gag in CD4 and gp120 in CD8 lymph node-derived T cells compared to the peripheral blood at 5 weeks post-inoculation. Reduced antigen-specific responses were associated with higher levels of PD-1 on lymph node-derived CD4 T cells as compared to peripheral blood and uninfected lymph node-derived CD4 T cells. Lymph nodes contained increased numbers of Tregs as compared to peripheral blood, which positively correlated with gp120 levels; T regulatory cell depletion restored CD8 T cell responses to Gag but not to gp120. HIV gp120 was also able to induce T regulatory cell chemotaxis in a dose-dependent, CCR5-mediated manner. These studies contribute to our broader understanding of the ways in which HIV-1 dysregulates T cell function and localization during early infection.

  1. Colorectal mucus binds DC-SIGN and inhibits HIV-1 trans-infection of CD4+ T-lymphocytes.

    Science.gov (United States)

    Stax, Martijn J; Mouser, Emily E I M; van Montfort, Thijs; Sanders, Rogier W; de Vries, Henry J C; Dekker, Henk L; Herrera, Carolina; Speijer, Dave; Pollakis, Georgios; Paxton, William A

    2015-01-01

    Bodily secretions, including breast milk and semen, contain factors that modulate HIV-1 infection. Since anal intercourse caries one of the highest risks for HIV-1 transmission, our aim was to determine whether colorectal mucus (CM) also contains factors interfering with HIV-1 infection and replication. CM from a number of individuals was collected and tested for the capacity to bind DC-SIGN and inhibit HIV-1 cis- or trans-infection of CD4+ T-lymphocytes. To this end, a DC-SIGN binding ELISA, a gp140 trimer competition ELISA and HIV-1 capture/ transfer assays were utilized. Subsequently we aimed to identify the DC-SIGN binding component through biochemical characterization and mass spectrometry analysis. CM was shown to bind DC-SIGN and competes with HIV-1 gp140 trimer for binding. Pre-incubation of Raji-DC-SIGN cells or immature dendritic cells (iDCs) with CM potently inhibits DC-SIGN mediated trans-infection of CD4+ T-lymphocytes with CCR5 and CXCR4 using HIV-1 strains, while no effect on direct infection is observed. Preliminary biochemical characterization demonstrates that the component seems to be large (>100kDa), heat and proteinase K resistant, binds in a α1-3 mannose independent manner and is highly variant between individuals. Immunoprecipitation using DC-SIGN-Fc coated agarose beads followed by mass spectrometry indicated lactoferrin (fragments) and its receptor (intelectin-1) as candidates. Using ELISA we showed that lactoferrin levels within CM correlate with DC-SIGN binding capacity. In conclusion, CM can bind the C-type lectin DC-SIGN and block HIV-1 trans-infection of both CCR5 and CXCR4 using HIV-1 strains. Furthermore, our data indicate that lactoferrin is a DC-SIGN binding component of CM. These results indicate that CM has the potential to interfere with pathogen transmission and modulate immune responses at the colorectal mucosa.

  2. Host and viral determinants for MxB restriction of HIV-1 infection.

    Science.gov (United States)

    Matreyek, Kenneth A; Wang, Weifeng; Serrao, Erik; Singh, Parmit Kumar; Levin, Henry L; Engelman, Alan

    2014-10-25

    Interferon-induced cellular proteins play important roles in the host response against viral infection. The Mx family of dynamin-like GTPases, which include MxA and MxB, target a wide variety of viruses. Despite considerable evidence demonstrating the breadth of antiviral activity of MxA, human MxB was only recently discovered to specifically inhibit lentiviruses. Here we assess both host and viral determinants that underlie MxB restriction of HIV-1 infection. Heterologous expression of MxB in human osteosarcoma cells potently inhibited HIV-1 infection (~12-fold), yet had little to no effect on divergent retroviruses. The anti-HIV effect manifested as a partial block in the formation of 2-long terminal repeat circle DNA and hence nuclear import, and we accordingly found evidence for an additional post-nuclear entry block. A large number of previously characterized capsid mutations, as well as mutations that abrogated integrase activity, counteracted MxB restriction. MxB expression suppressed integration into gene-enriched regions of chromosomes, similar to affects observed previously when cells were depleted for nuclear transport factors such as transportin 3. MxB activity did not require predicted GTPase active site residues or a series of unstructured loops within the stalk domain that confer functional oligomerization to related dynamin family proteins. In contrast, we observed an N-terminal stretch of residues in MxB to harbor key determinants. Protein localization conferred by a nuclear localization signal (NLS) within the N-terminal 25 residues, which was critical, was fully rescuable by a heterologous NLS. Consistent with this observation, a heterologous nuclear export sequence (NES) abolished full-length MxB activity. We additionally mapped sub-regions within amino acids 26-90 that contribute to MxB activity, finding sequences present within residues 27-50 particularly important. MxB inhibits HIV-1 by interfering with minimally two steps of infection

  3. CCR5 receptor antagonists: discovery and SAR study of guanylhydrazone derivatives.

    Science.gov (United States)

    Wei, Robert G; Arnaiz, Damian O; Chou, Yuo-Ling; Davey, Dave; Dunning, Laura; Lee, Wheeseong; Lu, Shou-Fu; Onuffer, James; Ye, Bin; Phillips, Gary

    2007-01-01

    High throughput screening (HTS) led to the identification of the guanylhydrazone of 2-(4-chlorobenzyloxy)-5-bromobenzaldehyde as a CCR5 receptor antagonist. Initial modifications of the guanylhydrazone series indicated that substitution of the benzyl group at the para-position was well tolerated. Substitution at the 5-position of the central phenyl ring was critical for potency. Replacement of the guanylhydrazone group led to the discovery of a novel series of CCR5 antagonists.

  4. Novel engineered HIV-1 East African Clade-A gp160 plasmid construct induces strong humoral and cell-mediated immune responses in vivo

    International Nuclear Information System (INIS)

    Muthumani, Karuppiah; Zhang Donghui; Dayes, Nathanael S.; Hwang, Daniel S.; Calarota, Sandra A.; Choo, Andrew Y.; Boyer, Jean D.; Weiner, David B.

    2003-01-01

    HIV-1 sequences are highly diverse due to the inaccuracy of the viral reverse transcriptase. This diversity has been studied and used to categorize HIV isolates into subtypes or clades, which are geographically distinct. To develop effective vaccines against HIV-1, immunogens representing different subtypes may be important for induction of cross-protective immunity, but little data exist describing and comparing the immunogenicity induced by different subtype-based vaccines. This issue is further complicated by poor expression of HIV structural antigens due to rev dependence. One costly approach is to codon optimize each subtype construct to be examined. Interestingly, cis-acting transcriptional elements (CTE) can also by pass rev restriction by a rev independent export pathway. We reasoned that rev+CTE constructs might have advantages for such expression studies. A subtype A envelope sequence from a viral isolate from east Africa was cloned into a eukaryotic expression vector under the control of the CMV-IE promoter. The utility of inclusion of the Mason-Pfizer monkey virus (MPV)-CTE with/without rev for driving envelope expression and immunogenicity was examined. Expression of envelope (gp120) was confirmed by immunoblot analysis and by pseudotype virus infectivity assays. The presence of rev and the CTE together increased envelope expression and viral infection. Furthermore the CTE+rev construct was significantly more immunogenic then CTE alone vector. Isotype analysis and cytokine profiles showed strong Th1 response in plasmid-immunized mice, which also demonstrated the superior nature of the rev+CTE construct. These responses were of similar or greater magnitude to a codon-optimized construct. The resulting cellular immune responses were highly cross-reactive with a HIV-1 envelope subtype B antigen. This study suggests a simple strategy for improving the expression and immunogenicity of HIV subtype-specific envelope antigens as plasmid or vector

  5. HIV-1 replication through hHR23A-mediated interaction of Vpr with 26S proteasome.

    Directory of Open Access Journals (Sweden)

    Ge Li

    2010-06-01

    Full Text Available HIV-1 Vpr is a virion-associated protein. Its activities link to viral pathogenesis and disease progression of HIV-infected patients. In vitro, Vpr moderately activates HIV-1 replication in proliferating T cells, but it is required for efficient viral infection and replication in vivo in non-dividing cells such as macrophages. How exactly Vpr contributes to viral replication remains elusive. We show here that Vpr stimulates HIV-1 replication at least in part through its interaction with hHR23A, a protein that binds to 19S subunit of the 26S proteasome and shuttles ubiquitinated proteins to the proteasome for degradation. The Vpr-proteasome interaction was initially discovered in fission yeast, where Vpr was shown to associate with Mts4 and Mts2, two 19S-associated proteins. The interaction of Vpr with the 19S subunit of the proteasome was further confirmed in mammalian cells where Vpr associates with the mammalian orthologues of fission yeast Mts4 and S5a. Consistently, depletion of hHR23A interrupts interaction of Vpr with proteasome in mammalian cells. Furthermore, Vpr promotes hHR23A-mediated protein-ubiquitination, and down-regulation of hHR23A using RNAi significantly reduced viral replication in non-proliferating MAGI-CCR5 cells and primary macrophages. These findings suggest that Vpr-proteasome interaction might counteract certain host restriction factor(s to stimulate viral replication in non-dividing cells.

  6. A mechanistic understanding of allosteric immune escape pathways in the HIV-1 envelope glycoprotein.

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    Anurag Sethi

    Full Text Available The HIV-1 envelope (Env spike, which consists of a compact, heterodimeric trimer of the glycoproteins gp120 and gp41, is the target of neutralizing antibodies. However, the high mutation rate of HIV-1 and plasticity of Env facilitates viral evasion from neutralizing antibodies through various mechanisms. Mutations that are distant from the antibody binding site can lead to escape, probably by changing the conformation or dynamics of Env; however, these changes are difficult to identify and define mechanistically. Here we describe a network analysis-based approach to identify potential allosteric immune evasion mechanisms using three known HIV-1 Env gp120 protein structures from two different clades, B and C. First, correlation and principal component analyses of molecular dynamics (MD simulations identified a high degree of long-distance coupled motions that exist between functionally distant regions within the intrinsic dynamics of the gp120 core, supporting the presence of long-distance communication in the protein. Then, by integrating MD simulations with network theory, we identified the optimal and suboptimal communication pathways and modules within the gp120 core. The results unveil both strain-dependent and -independent characteristics of the communication pathways in gp120. We show that within the context of three structurally homologous gp120 cores, the optimal pathway for communication is sequence sensitive, i.e. a suboptimal pathway in one strain becomes the optimal pathway in another strain. Yet the identification of conserved elements within these communication pathways, termed inter-modular hotspots, could present a new opportunity for immunogen design, as this could be an additional mechanism that HIV-1 uses to shield vulnerable antibody targets in Env that induce neutralizing antibody breadth.

  7. Modulators of the human CCR5 receptor. Part 1: Discovery and initial SAR of 1-(3,3-diphenylpropyl)-piperidinyl amides and ureas.

    Science.gov (United States)

    Burrows, Jeremy N; Cumming, John G; Fillery, Shaun M; Hamlin, Gordon A; Hudson, Julian A; Jackson, Ruth J; McLaughlin, Sharon; Shaw, John S

    2005-01-03

    Investigation of weak screening hits led to the identification of N-alkyl-N-[1-(3,3-diphenylpropyl)piperidin-4-yl]-2-phenylacetamides and N-alkyl-N-[1-(3,3-diphenylpropyl)piperidin-4-yl]-N'-benzylureas as potent, selective ligands for the human CCR5 chemokine receptor.

  8. Antifibrotic Effects of the Dual CCR2/CCR5 Antagonist Cenicriviroc in Animal Models of Liver and Kidney Fibrosis.

    Directory of Open Access Journals (Sweden)

    Eric Lefebvre

    Full Text Available Interactions between C-C chemokine receptor types 2 (CCR2 and 5 (CCR5 and their ligands, including CCL2 and CCL5, mediate fibrogenesis by promoting monocyte/macrophage recruitment and tissue infiltration, as well as hepatic stellate cell activation. Cenicriviroc (CVC is an oral, dual CCR2/CCR5 antagonist with nanomolar potency against both receptors. CVC's anti-inflammatory and antifibrotic effects were evaluated in a range of preclinical models of inflammation and fibrosis.Monocyte/macrophage recruitment was assessed in vivo in a mouse model of thioglycollate-induced peritonitis. CCL2-induced chemotaxis was evaluated ex vivo on mouse monocytes. CVC's antifibrotic effects were evaluated in a thioacetamide-induced rat model of liver fibrosis and mouse models of diet-induced non-alcoholic steatohepatitis (NASH and renal fibrosis. Study assessments included body and liver/kidney weight, liver function test, liver/kidney morphology and collagen deposition, fibrogenic gene and protein expression, and pharmacokinetic analyses.CVC significantly reduced monocyte/macrophage recruitment in vivo at doses ≥20 mg/kg/day (p < 0.05. At these doses, CVC showed antifibrotic effects, with significant reductions in collagen deposition (p < 0.05, and collagen type 1 protein and mRNA expression across the three animal models of fibrosis. In the NASH model, CVC significantly reduced the non-alcoholic fatty liver disease activity score (p < 0.05 vs. controls. CVC treatment had no notable effect on body or liver/kidney weight.CVC displayed potent anti-inflammatory and antifibrotic activity in a range of animal fibrosis models, supporting human testing for fibrotic diseases. Further experimental studies are needed to clarify the underlying mechanisms of CVC's antifibrotic effects. A Phase 2b study in adults with NASH and liver fibrosis is fully enrolled (CENTAUR Study 652-2-203; NCT02217475.

  9. Membrane topology analysis of HIV-1 envelope glycoprotein gp41

    Directory of Open Access Journals (Sweden)

    Xiao Dan

    2010-11-01

    Full Text Available Abstract Background The gp41 subunit of the HIV-1 envelope glycoprotein (Env has been widely regarded as a type I transmembrane protein with a single membrane-spanning domain (MSD. An alternative topology model suggested multiple MSDs. The major discrepancy between the two models is that the cytoplasmic Kennedy sequence in the single MSD model is assigned as the extracellular loop accessible to neutralizing antibodies in the other model. We examined the membrane topology of the gp41 subunit in both prokaryotic and mammalian systems. We attached topological markers to the C-termini of serially truncated gp41. In the prokaryotic system, we utilized a green fluorescent protein (GFP that is only active in the cytoplasm. The tag protein (HaloTag and a membrane-impermeable ligand specific to HaloTag was used in the mammalian system. Results In the absence of membrane fusion, both the prokaryotic and mammalian systems (293FT cells supported the single MSD model. In the presence of membrane fusion in mammalian cells (293CD4 cells, the data obtained seem to support the multiple MSD model. However, the region predicted to be a potential MSD is the highly hydrophilic Kennedy sequence and is least likely to become a MSD based on several algorithms. Further analysis revealed the induction of membrane permeability during membrane fusion, allowing the membrane-impermeable ligand and antibodies to cross the membrane. Therefore, we cannot completely rule out the possible artifacts. Addition of membrane fusion inhibitors or alterations of the MSD sequence decreased the induction of membrane permeability. Conclusions It is likely that a single MSD model for HIV-1 gp41 holds true even in the presence of membrane fusion. The degree of the augmentation of membrane permeability we observed was dependent on the membrane fusion and sequence of the MSD.

  10. The effect of the CCR5-delta32 deletion on global gene expression considering immune response and inflammation

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    Hütter Gero

    2011-10-01

    Full Text Available Abstract Background The natural function of the C-C chemokine receptor type 5 (CCR5 is poorly understood. A 32 base pair deletion in the CCR5 gene (CCR5-delta32 located on chromosome 3 results in a non-functional protein. It is supposed that this deletion causes an alteration in T-cell response to inflammation. For example, the presence of the CCR5-delta32 allele in recipients of allografts constitutes as an independent and protective factor associated with a decreased risk of graft-versus-host disease (GVHD and graft rejection. However, the mechanism of this beneficial effect of the deletion regarding GVHD is unknown. In this survey we searched for a CCR5-delta32 associated regulation of critical genes involved in the immune response and the development of GVHD. Methods We examined CD34+ hematopoietic progenitor cells derived from bone marrow samples from 19 healthy volunteers for the CCR5-delta32 deletion with a genomic PCR using primers flanking the site of the deletion. Results 12 individuals were found to be homozygous for CCR5 WT and 7 carried the CCR5-delta32 deletion heterozygously. Global gene expression analysis led to the identification of 11 differentially regulated genes. Six of them are connected with mechanisms of immune response and control: LRG1, CXCR2, CCRL2, CD6, CD7, WD repeat domain, and CD30L. Conclusions Our data indicate that the CCR5-delta32 mutation may be associated with differential gene expression. Some of these genes are critical for immune response, in the case of CD30L probably protective in terms of GVHD.

  11. DNA vaccines expressing soluble CD4-envelope proteins fused to C3d elicit cross-reactive neutralizing antibodies to HIV-1

    International Nuclear Information System (INIS)

    Bower, Joseph F.; Green, Thomas D.; Ross, Ted M.

    2004-01-01

    DNA vaccines expressing the envelope (Env) of the human immunodeficiency virus type 1 (HIV-1) have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, DNA vaccines were constructed to express a fusion protein of the soluble human CD4 (sCD4) and the gp120 subunit of the HIV-1 envelope. To enhance the immunogenicity of the expressed fusion protein, three copies of the murine C3d (mC3d 3 ) were added to the carboxyl terminus of the complex. Monoclonal antibodies that recognize CD4-induced epitopes on gp120 efficiently bound to sCD4-gp120 or sCD4-gp120-mC3d 3 . In addition, both sCD4-gp120 and sCD4-gp120-mC3d 3 bound to cells expressing appropriate coreceptors in the absence of cell surface hCD4. Mice (BALB/c) vaccinated with DNA vaccines expressing either gp120-mC3d 3 or sCD4-gp120-mC3d 3 elicited antibodies that neutralized homologous virus infection. However, the use of sCD4-gp120-mC3d 3 -DNA elicited the highest titers of neutralizing antibodies that persisted after depletion of anti-hCD4 antibodies. Interestingly, only mice vaccinated with DNA expressing sCD4-gp120-mC3d 3 had antibodies that elicited cross-protective neutralizing antibodies. The fusion of sCD4 to the HIV-1 envelope exposes neutralizing epitopes that elicit broad protective immunity when the fusion complex is coupled with the molecular adjuvant, C3d

  12. Cryoelectron Tomography of HIV-1 Envelope Spikes: Further Evidence for Tripod-Like Legs

    Science.gov (United States)

    Zhu, Ping; Winkler, Hanspeter; Chertova, Elena; Taylor, Kenneth A.; Roux, Kenneth H.

    2008-01-01

    A detailed understanding of the morphology of the HIV-1 envelope (Env) spike is key to understanding viral pathogenesis and for informed vaccine design. We have previously presented a cryoelectron microscopic tomogram (cryoET) of the Env spikes on SIV virions. Several structural features were noted in the gp120 head and gp41 stalk regions. Perhaps most notable was the presence of three splayed legs projecting obliquely from the base of the spike head toward the viral membrane. Subsequently, a second 3D image of SIV spikes, also obtained by cryoET, was published by another group which featured a compact vertical stalk. We now report the cryoET analysis of HIV-1 virion-associated Env spikes using enhanced analytical cryoET procedures. More than 2,000 Env spike volumes were initially selected, aligned, and sorted into structural classes using algorithms that compensate for the “missing wedge” and do not impose any symmetry. The results show varying morphologies between structural classes: some classes showed trimers in the head domains; nearly all showed two or three legs, though unambiguous three-fold symmetry was not observed either in the heads or the legs. Subsequently, clearer evidence of trimeric head domains and three splayed legs emerged when head and leg volumes were independently aligned and classified. These data show that HIV-1, like SIV, also displays the tripod-like leg configuration, and, unexpectedly, shows considerable gp41 leg flexibility/heteromorphology. The tripod-like model for gp41 is consistent with, and helps explain, many of the unique biophysical and immunological features of this region. PMID:19008954

  13. Cyclophilin A potentiates TRIM5α inhibition of HIV-1 nuclear import without promoting TRIM5α binding to the viral capsid.

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    Mallori Burse

    Full Text Available The host immunophilin cyclophilin A (CypA binds to the capsid protein (CA of HIV-1 and regulates its infectivity. Depending on the target cell type, CypA can either promote or inhibit HIV-1 infection. The ability of CypA to promote HIV-1 infection has been extensively studied and linked to several steps in early replication including uncoating, reverse transcription and nuclear import. By contrast, the mechanism by which CypA inhibits infection is less well understood. We investigated the mechanism by which CypA potentiates restriction of HIV-1 by the tripartite motif-containing protein 5 (TRIM5α. Depletion of TRIM5α in the African green monkey cell line Vero, resulted in a loss of inhibition of infection by CypA, demonstrating that inhibition by CypA is mediated by TRIM5α. Complementary genetic and biochemical assays failed to demonstrate an ability of CypA to promote binding of TRIM5α to the viral capsid. TRIM5α inhibits HIV-1 reverse transcription in a proteasome-dependent manner; however, we observed that inhibition of proteasome activity did not reduce the ability of CypA to inhibit infection, suggesting that CypA acts at a step after reverse transcription. Accordingly, we observed a CypA-dependent reduction in the accumulation of nuclear HIV-1 DNA, indicating that CypA specifically promotes TRIM5α inhibition of HIV-1 nuclear import. We also observed that the ability of CypA to inhibit HIV-1 infection is abolished by amino acid substitutions within the conserved CPSF6-binding surface in CA. Our results indicate that CypA inhibits HIV-1 infection in Vero cells not by promoting TRIM5α binding to the capsid but by blocking nuclear import of the HIV-1 preintegration complex.

  14. Investigating the association of chemokine receptor 5 (CCR5 polymorphism with cervical cancer in human papillomavirus (HPV positive patients - DOI: 10.4025/actascihealthsci.v30i2.944 Investigating association of chemokine receptor 5 (CCR5 polymorphism with cervical cancer in human papillomavirus (HPV suggestive patients - DOI: 10.4025/actascihealthsci.v30i2.944

    Directory of Open Access Journals (Sweden)

    Sueli Donizete Borelli

    2008-12-01

    Full Text Available HPV is one of the most frequent causes for the development of cervical cancer. It is known that chemokines are important determinants of early inflammatory responses. The CC chemokine receptor 5 (CCR5 gene is involved in the chemotaxis of leukocytes toward inflammation sites. In the present study, polymerase chain reactions (PCR in genomic DNA samples, using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion, detected a 225 bp product from the normal CCR5 allele and a 193 bp product from the 32 bp deletion allele. The wild type genotype was prevalent in both group, but it was not statistically significant, with χ2 = 1.519 (2 degrees of freedom; p > 0.05. As there are a small number of 32 allele carriers, further studies are needed to clarify the role of CCR5 in the cervical cancer.HPV is the most responsible of cervical cancer. It is known that chemokines are important determinants of the early inflammatory response. The CC chemokine receptor 5 (CCR5 gene is involved in the chemotaxis of leukocytes toward inflammation sites. In the present study, polymerase chain reactions (PCR in genomic DNA samples, using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion, detected a 225bp product from the normal CCR5 allele and a 193bp product from the 32bp deletion allele. The wild type genotype was prevalent in both group, but it wasn’t statistically significant with χ² =1,519 (2 degrees of freedom; p>0.05. Once there is a small number of 32 allele carriers, further studies are needed to clarify the role of CCR5 in the cervical cancer.

  15. Tailored HIV-1 vectors for genetic modification of primary human dendritic cells and monocytes.

    Science.gov (United States)

    Durand, Stéphanie; Nguyen, Xuan-Nhi; Turpin, Jocelyn; Cordeil, Stephanie; Nazaret, Nicolas; Croze, Séverine; Mahieux, Renaud; Lachuer, Joël; Legras-Lachuer, Catherine; Cimarelli, Andrea

    2013-01-01

    Monocyte-derived dendritic cells (MDDCs) play a key role in the regulation of the immune system and are the target of numerous gene therapy applications. The genetic modification of MDDCs is possible with human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LVs) but requires high viral doses to bypass their natural resistance to viral infection, and this in turn affects their physiological properties. To date, a single viral protein is able to counter this restrictive phenotype, Vpx, a protein derived from members of the HIV-2/simian immunodeficiency virus SM lineage that counters at least two restriction factors present in myeloid cells. By tagging Vpx with a short heterologous membrane-targeting domain, we have obtained HIV-1 LVs incorporating high levels of this protein (HIV-1-Src-Vpx). These vectors efficiently transduce differentiated MDDCs and monocytes either as previously purified populations or as populations within unsorted peripheral blood mononuclear cells (PBMCs). In addition, these vectors can be efficiently pseudotyped with receptor-specific envelopes, further restricting their cellular tropism almost uniquely to MDDCs. Compared to conventional HIV-1 LVs, these novel vectors allow for an efficient genetic modification of MDDCs and, more importantly, do not cause their maturation or affect their survival, which are unwanted side effects of the transduction process. This study describes HIV-1-Src-Vpx LVs as a novel potent tool for the genetic modification of differentiated MDDCs and of circulating monocyte precursors with strong potential for a wide range of gene therapy applications.

  16. Vif of Feline Immunodeficiency Virus from Domestic Cats Protects against APOBEC3 Restriction Factors from Many Felids▿

    Science.gov (United States)

    Zielonka, Jörg; Marino, Daniela; Hofmann, Henning; Yuhki, Naoya; Löchelt, Martin; Münk, Carsten

    2010-01-01

    To get more insight into the role of APOBEC3 (A3) cytidine deaminases in the species-specific restriction of feline immunodeficiency virus (FIV) of the domestic cat, we tested the A3 proteins present in big cats (puma, lion, tiger, and lynx). These A3 proteins were analyzed for expression and sensitivity to the Vif protein of FIV. While A3Z3s and A3Z2-Z3s inhibited Δvif FIV, felid A3Z2s did not show any antiviral activity against Δvif FIV or wild-type (wt) FIV. All felid A3Z3s and A3Z2-Z3s were sensitive to Vif of the domestic cat FIV. Vif also induced depletion of felid A3Z2s. Tiger A3s showed a moderate degree of resistance against the Vif-mediated counter defense. These findings may imply that the A3 restriction system does not play a major role to prevent domestic cat FIV transmission to other Felidae. In contrast to the sensitive felid A3s, many nonfelid A3s actively restricted wt FIV replication. To test whether VifFIV can protect also the distantly related human immunodeficiency virus type 1 (HIV-1), a chimeric HIV-1.VifFIV was constructed. This HIV-1.VifFIV was replication competent in nonpermissive feline cells expressing human CD4/CCR5 that did not support the replication of wt HIV-1. We conclude that the replication of HIV-1 in some feline cells is inhibited only by feline A3 restriction factors and the absence of the appropriate receptor or coreceptor. PMID:20444897

  17. Vif of feline immunodeficiency virus from domestic cats protects against APOBEC3 restriction factors from many felids.

    Science.gov (United States)

    Zielonka, Jörg; Marino, Daniela; Hofmann, Henning; Yuhki, Naoya; Löchelt, Martin; Münk, Carsten

    2010-07-01

    To get more insight into the role of APOBEC3 (A3) cytidine deaminases in the species-specific restriction of feline immunodeficiency virus (FIV) of the domestic cat, we tested the A3 proteins present in big cats (puma, lion, tiger, and lynx). These A3 proteins were analyzed for expression and sensitivity to the Vif protein of FIV. While A3Z3s and A3Z2-Z3s inhibited Deltavif FIV, felid A3Z2s did not show any antiviral activity against Deltavif FIV or wild-type (wt) FIV. All felid A3Z3s and A3Z2-Z3s were sensitive to Vif of the domestic cat FIV. Vif also induced depletion of felid A3Z2s. Tiger A3s showed a moderate degree of resistance against the Vif-mediated counter defense. These findings may imply that the A3 restriction system does not play a major role to prevent domestic cat FIV transmission to other Felidae. In contrast to the sensitive felid A3s, many nonfelid A3s actively restricted wt FIV replication. To test whether Vif(FIV) can protect also the distantly related human immunodeficiency virus type 1 (HIV-1), a chimeric HIV-1.Vif(FIV) was constructed. This HIV-1.Vif(FIV) was replication competent in nonpermissive feline cells expressing human CD4/CCR5 that did not support the replication of wt HIV-1. We conclude that the replication of HIV-1 in some feline cells is inhibited only by feline A3 restriction factors and the absence of the appropriate receptor or coreceptor.

  18. Cell-associated HIV DNA measured early during infection has prognostic value independent of serum HIV RNA measured concomitantly

    DEFF Research Database (Denmark)

    Katzenstein, Terese L; Oliveri, Roberto S; Benfield, Thomas

    2002-01-01

    Using data from the Danish AIDS Cohort of HIV-infected homosexual men established in the 1980s, the prognostic value of early HIV DNA loads was evaluated. In addition to DNA measurements, concomitant serum HIV RNA levels, CD4 cell counts and CCR5 genotypes were determined. The patients were divided...... into 3 groups, according to whether their cell-associated HIV DNA load was or = 2,500 DNA copies/10(6) peripheral blood mononuclear cells. Clinical progression rates differed significantly between the groups (p value independent...... of serum HIV RNA (p value. Patients heterozygous for the CCR5 delta 32 allele had significantly lower HIV DNA loads than those homozygous for the normal allele (p

  19. Impact of MCP-1 and CCR-2 gene polymorphisms on coronary artery disease susceptibility.

    Science.gov (United States)

    Lin, Hsiu-Ling; Ueng, Kwo-Chang; Hsieh, Yih-Shou; Chiang, Whei-Ling; Yang, Shun-Fa; Chu, Shu-Chen

    2012-09-01

    Coronary artery disease (CAD) was the second leading cause of death during the last 3 years in Taiwan. Smooth muscle cells, monocytes/macrophages, and endothelial cells produce monocyte chemoattractant protein-1 (MCP-1) within atherosclerotic plaques following binding to the chemokine receptor-2 (CCR-2). Previous studies have well-documented the association between MCP-1 expression and susceptibility to, or clinicopathological features, of CAD. This study investigated the relationships between MCP-1-2518A/G and CCR-2-V64I genetic polymorphisms and CAD in the Taiwanese population. A total of 608 subjects, including 392 non-CAD controls and 216 patients with CAD, were recruited and subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to evaluate the effects of these two polymorphic variants on CAD. Results indicated a significant association between MCP-1 -2548 gene polymorphism and susceptibility to CAD. GG genotypes (OR = 1.629; 95 % CI = 1.003-2.644), or individuals with at least one G allele (OR = 1.511; 95 % CI = 1.006-2.270), had a higher risk of CAD as compared with AA genotypes. Results also revealed that subjects with at least one A allele of the V64I CCR2 gene polymorphism had significantly increased risk of CAD. G allele in MCP-1-2518 might contribute to higher prevalence of atrial fibrillation in CAD patients (OR = 4.254; p CCR-2 64I gene polymorphisms represent important factors in determining susceptibility to CAD, and the contribution of MCP-1-2518G could be through effects on atrial fibrillation in CAD patients.

  20. IGHV1-69 B cell chronic lymphocytic leukemia antibodies cross-react with HIV-1 and hepatitis C virus antigens as well as intestinal commensal bacteria.

    Directory of Open Access Journals (Sweden)

    Kwan-Ki Hwang

    Full Text Available B-cell chronic lymphocytic leukemia (B-CLL patients expressing unmutated immunoglobulin heavy variable regions (IGHVs use the IGHV1-69 B cell receptor (BCR in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s (≥21 aa. IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54 of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54 allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.

  1. Identification of cell surface targets for HIV-1 therapeutics using genetic screens

    International Nuclear Information System (INIS)

    Dunn, Stephen J.; Khan, Imran H.; Chan, Ursula A.; Scearce, Robin L.; Melara, Claudia L.; Paul, Amber M.; Sharma, Vikram; Bih, Fong-Yih; Holzmayer, Tanya A.; Luciw, Paul A.; Abo, Arie

    2004-01-01

    Human immunodeficiency virus (HIV) drugs designed to interfere with obligatory utilization of certain host cell factors by virus are less likely to encounter development of resistant strains than drugs directed against viral components. Several cellular genes required for productive infection by HIV were identified by the use of genetic suppressor element (GSE) technology as potential targets for anti-HIV drug development. Fragmented cDNA libraries from various pools of human peripheral blood mononuclear cells (PBMC) were expressed in vitro in human immunodeficiency virus type 1 (HIV-1)-susceptible cell lines and subjected to genetic screens to identify GSEs that interfered with viral replication. After three rounds of selection, more than 15 000 GSEs were sequenced, and the cognate genes were identified. The GSEs that inhibited the virus were derived from a diverse set of genes including cell surface receptors, cytokines, signaling proteins, transcription factors, as well as genes with unknown function. Approximately 2.5% of the identified genes were previously shown to play a role in the HIV-1 life cycle; this finding supports the biological relevance of the assay. GSEs were derived from the following 12 cell surface proteins: CXCR4, CCR4, CCR7, CD11C, CD44, CD47, CD68, CD69, CD74, CSF3R, GABBR1, and TNFR2. Requirement of some of these genes for viral infection was also investigated by using RNA interference (RNAi) technology; accordingly, 10 genes were implicated in early events of the viral life cycle, before viral DNA synthesis. Thus, these cell surface proteins represent novel targets for the development of therapeutics against HIV-1 infection and AIDS

  2. Subtle differences in selective pressures applied on the envelope gene of HIV-1 in pregnant versus non-pregnant women.

    Science.gov (United States)

    Ransy, Doris G; Lord, Etienne; Caty, Martine; Lapointe, Normand; Boucher, Marc; Diallo, Abdoulaye Baniré; Soudeyns, Hugo

    2018-04-17

    Pregnancy is associated with modulations of maternal immunity that contribute to foeto-maternal tolerance. To understand whether and how these alterations impact antiviral immunity, a detailed cross-sectional analysis of selective pressures exerted on HIV-1 envelope amino-acid sequences was performed in a group of pregnant (n = 32) and non-pregnant (n = 44) HIV-infected women in absence of treatment with antiretroviral therapy (ART). Independent of HIV-1 subtype, p-distance, dN and dS were all strongly correlated with one another but were not significantly different in pregnant as compared to non-pregnant patients. Differential levels of selective pressure applied on different Env subdomains displayed similar yet non-identical patterns between the two groups, with pressure applied on C1 being significantly lower in constant regions C1 and C2 than in V1, V2, V3 and C3. To draw a general picture of the selection applied on the envelope and compensate for inter-individual variations, we performed a binomial test on selection frequency data pooled from pregnant and non-pregnant women. This analysis uncovered 42 positions, present in both groups, exhibiting statistically-significant frequency of selection that invariably mapped to the surface of the Env protein, with the great majority located within epitopes recognized by Env-specific antibodies or sites associated with the development of cross-reactive neutralizing activity. The median frequency of occurrence of positive selection per site was significantly lower in pregnant versus non-pregnant women. Furthermore, examination of the distribution of positively selected sites using a hypergeometric test revealed that only 2 positions (D137 and S142) significantly differed between the 2 groups. Taken together, these result indicate that pregnancy is associated with subtle yet distinctive changes in selective pressures exerted on the HIV-1 Env protein that are compatible with transient modulations of maternal

  3. Effects of treatment with Maraviroc a CCR5 inhibitor on a human hepatic stellate cell line.

    Science.gov (United States)

    Coppola, Nicola; Perna, Angelica; Lucariello, Angela; Martini, Salvatore; Macera, Margherita; Carleo, Maria A; Guerra, Germano; Esposito, Vincenzo; De Luca, Antonio

    2018-08-01

    After an acute liver damage, tissue regeneration repairs lesions with degradation of deposed fibrotic material, while mechanisms of tissue restoration are persistently activated following several repeated injuries, inducing deposition of extracellular matrix. (ECM). Factors responsible for ECM remodeling have been identified in a pathway involving a family of zinc-dependent enzyme matrix metalloproteinases (MMPs), together with tissue inhibitor of metalloproteinases (TIMPs). Recent experimental models suggested a role of CCR5 receptor in the genesis of liver fibrosis. Drawing from these background we decided to evaluate the effects of the treatment with the CCR5 inhibitor Maraviroc on LX-2, a human hepatic stellate cell line (HSC). Treatment with Maraviroc resulted in a block in S phase of LX-2 cells with increased expression levels of cyclin D1 and p21 while the expression of p53 was reduced. Treatment with Maraviroc was also able to block the accumulation of fibrillar collagens and extracellular matrix proteins (ECM), as demonstrated by the decrease of specific markers as Collagen type I, α-SMA, and TGF-β1. In addition we observed a down regulation of both metalloproteins (MMP-2, MMP-9), used for the degradation of the extracellular matrix and their inhibitors (TIMP-1, TIMP-2). The identification of a compound that may modulate the dynamic of liver fibrosis could be crucial in all chronic liver diseases. Maraviroc could play an important role because, in addition to its own anti-HIV activity, it could reduce the release of pro-inflammatory citokynes implicated in liver fibrogenesis. © 2018 Wiley Periodicals, Inc.

  4. Mapping and characterization of vicriviroc resistance mutations from HIV-1 isolated from treatment-experienced subjects enrolled in a phase II study (VICTOR-E1).

    Science.gov (United States)

    McNicholas, Paul M; Mann, Paul A; Wojcik, Lisa; Qiu, Ping; Lee, Erin; McCarthy, Michael; Shen, Junwu; Black, Todd A; Strizki, Julie M

    2011-03-01

    In the phase 2 VICTOR-E1 study, treatment-experienced subjects receiving 20 mg or 30 mg of the CCR5 antagonist vicriviroc (VCV), with a boosted protease containing optimized background regimen, experienced significantly greater reductions in HIV-1 viral load compared with control subjects. Among the 79 VCV-treated subjects, 15 experienced virologic failure, and of these 5 had VCV-resistant virus. This study investigated the molecular basis for the changes in susceptibility to VCV in these subjects. Sequence analysis and phenotypic susceptibility testing was performed on envelope clones from VCV-resistant virus. For select clones, an exchange of mutations in the V3 loop was performed between phenotypically resistant clones and the corresponding susceptible clones. Phenotypic resistance was manifest by reductions in the maximum percent inhibition. Clonal analysis of envelopes from the 5 subjects identified multiple amino acid changes in gp160 that were exclusive to the resistant clones, however, none of the changes were conserved between subjects. Introduction of V3 loop substitutions from the resistant clones into the matched susceptible clones was not sufficient to reproduce the resistant phenotype. Likewise, changing the substitutions in the V3 loops from resistant clones to match susceptible clones only restored susceptibility in 1 clone. There were no clearly conserved patterns of mutations in gp160 associated with phenotypic resistance to VCV and mutations both within and outside of the V3 loop contributed to the resistance phenotype. These data suggest that genotypic tests for VCV susceptibility may require larger training sets and additional information beyond V3 sequences.

  5. Chemokines, lymphocytes, and HIV

    Directory of Open Access Journals (Sweden)

    Farber J.M.

    1998-01-01

    Full Text Available Chemokines are members of a family of more than 30 human cytokines whose best-described activities are as chemotactic factors for leukocytes and that are presumed to be important in leukocyte recruitment and trafficking. While many chemokines can act on lymphocytes, the roles of chemokines and their receptors in lymphocyte biology are poorly understood. The recent discoveries that chemokines can suppress infection by HIV-1 and that chemokine receptors serve, along with CD4, as obligate co-receptors for HIV-1 entry have lent urgency to studies on the relationships between chemokines and lymphocytes. My laboratory has characterized Mig and Crg-2/IP-10, chemokines that are induced by IFN-g and that specifically target lymphocytes, particularly activated T cells. We have demonstrated that the genes for these chemokines are widely expressed during experimental infections in mice with protozoan and viral pathogens, but that the patterns of mig and crg-2 expression differed, suggesting non-redundant roles in vivo. Our related studies to identify new chemokine receptors from activated lymphocytes resulted in the cloning of STRL22 and STRL33. We and others have shown that STRL22 is a receptor for the CC chemokine MIP-3a, and STRL22 has been re-named CCR6. Although STRL33 remains an orphan receptor, we have shown that it can function as a co-receptor for HIV-1 envelope glycoproteins, and that it is active with a broader range of HIV-1 envelope glycoproteins than the major co-receptors described to date. The ability of STRL33 to function with a wide variety of envelope glycoproteins may become particularly important if therapies are instituted to block other specific co-receptors. We presume that investigations into the roles of chemokines and their receptors in lymphocyte biology will provide information important for understanding the pathogenesis of AIDS and for manipulating immune and inflammatory responses for clinical benefit

  6. A mammalian cell based FACS-panning platform for the selection of HIV-1 envelopes for vaccine development.

    Directory of Open Access Journals (Sweden)

    Tim-Henrik Bruun

    Full Text Available An increasing number of broadly neutralizing monoclonal antibodies (bnMAb against the HIV-1 envelope (Env protein has been discovered recently. Despite this progress, vaccination efforts with the aim to re-elicit bnMAbs that provide protective immunity have failed so far. Herein, we describe the development of a mammalian cell based FACS-panning method in which bnMAbs are used as tools to select surface-exposed envelope variants according to their binding affinity. For that purpose, an HIV-1 derived lentiviral vector was developed to infect HEK293T cells at low multiplicity of infection (MOI in order to link Env phenotype and genotype. For proof of principle, a gp145 Env model-library was established in which the complete V3 domain was substituted by five strain specific V3 loop sequences with known binding affinities to nMAb 447-52D, respectively. Env genes were recovered from selected cells by PCR, subcloned into a lentiviral vector (i to determine and quantify the enrichment nMAb binders and (ii to generate a new batch of transduction competent particles. After 2 selection cycles the Env variant with highest affinity was enriched 20-fold and represented 80% of the remaining Env population. Exploiting the recently described bnMAbs, this procedure might prove useful in selecting Env proteins from large Env libraries with the potential to elicit bnMAbs when used as vaccine candidates.

  7. NF-kappaB and p53 are the dominant apoptosis-inducing transcription factors elicited by the HIV-1 envelope.

    Science.gov (United States)

    Perfettini, Jean-Luc; Roumier, Thomas; Castedo, Maria; Larochette, Nathanael; Boya, Patricia; Raynal, Brigitte; Lazar, Vladimir; Ciccosanti, Fabiola; Nardacci, Roberta; Penninger, Josef; Piacentini, Mauro; Kroemer, Guido

    2004-03-01

    The coculture of cells expressing the HIV-1 envelope glycoprotein complex (Env) with cells expressing CD4 results into cell fusion, deregulated mitosis, and subsequent cell death. Here, we show that NF-kappaB, p53, and AP1 are activated in Env-elicited apoptosis. The nuclear factor kappaB (NF-kappaB) super repressor had an antimitotic and antiapoptotic effect and prevented the Env-elicited phosphorylation of p53 on serine 15 and 46, as well as the activation of AP1. Transfection with dominant-negative p53 abolished apoptosis and AP1 activation. Signs of NF-kappaB and p53 activation were also detected in lymph node biopsies from HIV-1-infected individuals. Microarrays revealed that most (85%) of the transcriptional effects of HIV-1 Env were blocked by the p53 inhibitor pifithrin-alpha. Macroarrays led to the identification of several Env-elicited, p53-dependent proapoptotic transcripts, in particular Puma, a proapoptotic "BH3-only" protein from the Bcl-2 family known to activate Bax/Bak. Down modulation of Puma by antisense oligonucleotides, as well as RNA interference of Bax and Bak, prevented Env-induced apoptosis. HIV-1-infected primary lymphoblasts up-regulated Puma in vitro. Moreover, circulating CD4+ lymphocytes from untreated, HIV-1-infected donors contained enhanced amounts of Puma protein, and these elevated Puma levels dropped upon antiretroviral therapy. Altogether, these data indicate that NF-kappaB and p53 cooperate as the dominant proapoptotic transcription factors participating in HIV-1 infection.

  8. Residues in the membrane-spanning domain core modulate conformation and fusogenicity of the HIV-1 envelope glycoprotein

    International Nuclear Information System (INIS)

    Shang Liang; Hunter, Eric

    2010-01-01

    The membrane-spanning domain (MSD) of human immunodeficiency virus type I (HIV-1) envelope glycoprotein (Env) is critical for its biological activity. Initial studies have defined an almost invariant 'core' structure in the MSD and demonstrated that it is crucial for anchoring Env in the membrane and virus entry. We show here that amino acid substitutions in the MSD 'core' do not influence specific virus-cell attachment, nor CD4 receptor and CXCR4 coreceptor recognition by Env. However, substitutions within the MSD 'core' delayed the kinetics and reduced the efficiency of cell-cell fusion mediated by Env. Although we observed no evidence that membrane fusion mediated by the MSD core mutants was arrested at a hemifusion stage, impaired Env fusogenicity was correlated with minor conformational changes in the V2, C1, and C5 regions in gp120 and the immunodominant loop in gp41. These changes could delay initiation of the conformational changes required in the fusion process.

  9. Polymorphisms of large effect explain the majority of the host genetic contribution to variation of HIV-1 virus load

    Science.gov (United States)

    Coulonges, Cedric; Bartha, István; Lenz, Tobias L.; Deutsch, Aaron J.; Bashirova, Arman; Buchbinder, Susan; Carrington, Mary N.; Cossarizza, Andrea; Dalmau, Judith; De Luca, Andrea; Goedert, James J.; Gurdasani, Deepti; Haas, David W.; Herbeck, Joshua T.; Johnson, Eric O.; Kirk, Gregory D.; Lambotte, Olivier; Luo, Ma; Mallal, Simon; van Manen, Daniëlle; Martinez-Picado, Javier; Meyer, Laurence; Miro, José M.; Mullins, James I.; Obel, Niels; Poli, Guido; Sandhu, Manjinder S.; Schuitemaker, Hanneke; Shea, Patrick R.; Theodorou, Ioannis; Walker, Bruce D.; Weintrob, Amy C.; Winkler, Cheryl A.; Wolinsky, Steven M.; Raychaudhuri, Soumya; Goldstein, David B.; Telenti, Amalio; de Bakker, Paul I. W.; Zagury, Jean-François; Fellay, Jacques

    2015-01-01

    Previous genome-wide association studies (GWAS) of HIV-1–infected populations have been underpowered to detect common variants with moderate impact on disease outcome and have not assessed the phenotypic variance explained by genome-wide additive effects. By combining the majority of available genome-wide genotyping data in HIV-infected populations, we tested for association between ∼8 million variants and viral load (HIV RNA copies per milliliter of plasma) in 6,315 individuals of European ancestry. The strongest signal of association was observed in the HLA class I region that was fully explained by independent effects mapping to five variable amino acid positions in the peptide binding grooves of the HLA-B and HLA-A proteins. We observed a second genome-wide significant association signal in the chemokine (C-C motif) receptor (CCR) gene cluster on chromosome 3. Conditional analysis showed that this signal could not be fully attributed to the known protective CCR5Δ32 allele and the risk P1 haplotype, suggesting further causal variants in this region. Heritability analysis demonstrated that common human genetic variation—mostly in the HLA and CCR5 regions—explains 25% of the variability in viral load. This study suggests that analyses in non-European populations and of variant classes not assessed by GWAS should be priorities for the field going forward. PMID:26553974

  10. Complement-Opsonized HIV-1 Alters Cross Talk Between Dendritic Cells and Natural Killer (NK Cells to Inhibit NK Killing and to Upregulate PD-1, CXCR3, and CCR4 on T Cells

    Directory of Open Access Journals (Sweden)

    Rada Ellegård

    2018-04-01

    Full Text Available Dendritic cells (DCs, natural killer (NK cells, and T cells play critical roles during primary HIV-1 exposure at the mucosa, where the viral particles become coated with complement fragments and mucosa-associated antibodies. The microenvironment together with subsequent interactions between these cells and HIV at the mucosal site of infection will determine the quality of immune response that ensues adaptive activation. Here, we investigated how complement and immunoglobulin opsonization influences the responses triggered in DCs and NK cells, how this affects their cross talk, and what T cell phenotypes are induced to expand following the interaction. Our results showed that DCs exposed to complement-opsonized HIV (C-HIV were less mature and had a poor ability to trigger IFN-driven NK cell activation. In addition, when the DCs were exposed to C-HIV, the cytotolytic potentials of both NK cells and CD8 T cells were markedly suppressed. The expression of PD-1 as well as co-expression of negative immune checkpoints TIM-3 and LAG-3 on PD-1 positive cells were increased on both CD4 as well as CD8 T cells upon interaction with and priming by NK–DC cross talk cultures exposed to C-HIV. In addition, stimulation by NK–DC cross talk cultures exposed to C-HIV led to the upregulation of CD38, CXCR3, and CCR4 on T cells. Together, the immune modulation induced during the presence of complement on viral surfaces is likely to favor HIV establishment, dissemination, and viral pathogenesis.

  11. Biological and genetic evolution of HIV type 1 in two siblings with different patterns of disease progression.

    Science.gov (United States)

    Ripamonti, Chiara; Leitner, Thomas; Laurén, Anna; Karlsson, Ingrid; Pastore, Angela; Cavarelli, Mariangela; Antonsson, Liselotte; Plebani, Anna; Fenyö, Eva Maria; Scarlatti, Gabriella

    2007-12-01

    To investigate the immunological and virological factors that may lead to different patterns of disease progression characteristic of HIV-1-infected children, two HIV-1-infected siblings, a slow and a fast progressor, were followed prospectively before the onset of highly active antiretroviral therapy. Viral coreceptor usage, including the use of CCR5/CXCR4 chimeric receptors, macrophage tropism, and sensitivity to the CC-chemokine RANTES, has been studied. An autologous and heterologous neutralizing antibody response has been documented using peripheral blood mononuclear cells- and GHOST(3) cell line-based assays. Viral evolution was investigated by env C2-V3 region sequence analysis. Although both siblings were infected with HIV-1 of the R5 phenotype, their viruses showed important biological differences. In the fast progressor there was a higher RANTES sensitivity of the early virus, an increased trend to change the mode of CCR5 receptor use, and a larger genetic evolution. Both children developed an autologous neutralizing antibody response starting from the second year with evidence of the continuous emergence of resistant variants. A marked viral genetic and phenotypic evolution was documented in the fast progressor sibling, which is accompanied by a high viral RANTES sensitivity and persistent neutralizing antibodies.

  12. Immunization with Clinical HIV-1 Env Proteins Induces Broad Antibody Dependent Cellular Cytotoxicity-Mediating Antibodies in a Rabbit Vaccination Model.

    Science.gov (United States)

    Karlsson, Ingrid; Borggren, Marie; Jensen, Sanne Skov; Heyndrickx, Leo; Stewart-Jones, Guillaume; Scarlatti, Gabriella; Fomsgaard, Anders

    2017-11-17

    The induction of both neutralizing antibodies and non-neutralizing antibodies with effector functions, for example, antibody-dependent cellular cytotoxicity (ADCC), is desired in the search for effective vaccines against HIV-1. In the pursuit of novel immunogens capable of inducing an efficient antibody response, rabbits were immunized with selected antigens using different prime-boost strategies. We immunized 35 different groups of rabbits with Env antigens from clinical HIV-1 subtypes A and B, including immunization with DNA alone, protein alone, and DNA prime with protein boost. The rabbit sera were screened for ADCC activity using a GranToxiLux-based assay with human peripheral blood mononuclear cells as effector cells and CEM.NKR CCR5 cells coated with HIV-1 envelope as target cells. The groups with the highest ADCC activity were further characterized for cross-reactivity between HIV-1 subtypes. The immunogen inducing the most potent and broadest ADCC response was a trimeric gp140. The ADCC activity was highest against the HIV-1 subtype corresponding to the immunogen. The ADCC activity did not necessarily reflect neutralizing activity in the pseudovirus-TZMbl assay, but there was an overall correlation between the two antiviral activities. We present a rabbit vaccination model and an assay suitable for screening HIV-1 vaccine candidates for the induction of ADCC-mediating antibodies in addition to neutralizing antibodies. The antigens and/or immunization strategies capable of inducing antibodies with ADCC activity did not necessarily induce neutralizing activity and vice versa. Nevertheless, we identified vaccine candidates that were able to concurrently induce both types of responses and that had ADCC activity that was cross-reactive between different subtypes. When searching for an effective vaccine candidate, it is important to evaluate the antibody response using a model and an assay measuring the desired function.

  13. Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector

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    Bryan P Burke

    2015-01-01

    Full Text Available We described earlier a dual-combination anti-HIV type 1 (HIV-1 lentiviral vector (LVsh5/C46 that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1 vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.

  14. Colorectal mucus binds DC-SIGN and inhibits HIV-1 trans-infection of CD4+ T-lymphocytes.

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    Martijn J Stax

    Full Text Available Bodily secretions, including breast milk and semen, contain factors that modulate HIV-1 infection. Since anal intercourse caries one of the highest risks for HIV-1 transmission, our aim was to determine whether colorectal mucus (CM also contains factors interfering with HIV-1 infection and replication. CM from a number of individuals was collected and tested for the capacity to bind DC-SIGN and inhibit HIV-1 cis- or trans-infection of CD4+ T-lymphocytes. To this end, a DC-SIGN binding ELISA, a gp140 trimer competition ELISA and HIV-1 capture/ transfer assays were utilized. Subsequently we aimed to identify the DC-SIGN binding component through biochemical characterization and mass spectrometry analysis. CM was shown to bind DC-SIGN and competes with HIV-1 gp140 trimer for binding. Pre-incubation of Raji-DC-SIGN cells or immature dendritic cells (iDCs with CM potently inhibits DC-SIGN mediated trans-infection of CD4+ T-lymphocytes with CCR5 and CXCR4 using HIV-1 strains, while no effect on direct infection is observed. Preliminary biochemical characterization demonstrates that the component seems to be large (>100kDa, heat and proteinase K resistant, binds in a α1-3 mannose independent manner and is highly variant between individuals. Immunoprecipitation using DC-SIGN-Fc coated agarose beads followed by mass spectrometry indicated lactoferrin (fragments and its receptor (intelectin-1 as candidates. Using ELISA we showed that lactoferrin levels within CM correlate with DC-SIGN binding capacity. In conclusion, CM can bind the C-type lectin DC-SIGN and block HIV-1 trans-infection of both CCR5 and CXCR4 using HIV-1 strains. Furthermore, our data indicate that lactoferrin is a DC-SIGN binding component of CM. These results indicate that CM has the potential to interfere with pathogen transmission and modulate immune responses at the colorectal mucosa.

  15. Study of Patterns and Markers of Human Immune Deficiency Virus -1 (HIV-1) Progression and Unemployment Rate among Patients from Alexandria, Egypt.

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    Ghoneim, Faika M; Raouf, May M; Elshaer, Noha S; Abdelhamid, Sarah M; Noor Eldeen, Reem A

    2017-12-04

    Middle East and North Africa (MENA) new HIV cases show the highest increase among all regions in the world. Even though Egypt has a low prevalence among the general population (< 0.02%), a national HIV epidemic occurs in certain population risk groups. The current study was conducted to asses clinical and immunological disease progression; following up viral load (VL) and detecting delta-32 CCR5 genotype polymorphism in selected cases, determining unemployment rate and identify predictors of employment for HIV-cases. A cross sectional design was adopted. HIV infected cases attending Alexandria Fever Hospital (AFH) for one year. Interview questionnaire and four CD+4 counts were done for all patients, HIV VL and delta-32 CCR5 polymorphism were done for selected cases. Sexual transmission and drug abuse are the most important risk factors. Infectious comorbidity increases the rate of HIV progression. CD4+ count at the end of the study; CD+4 (4), count was significantly higher than all other CD4+ readings among the whole cohort and among the treated group. Also, VL at the end of the study; VL(2), was significantly higher than VL(1) among the untreated group. Unemployment rate was 40%. Male gender and obtaining vocational training were significant predictors of employment. It can be concluded that having a family member living with HIV and drug abusers are high risk groups for HIV acquisition. Factors responsible for progression of HIV should be further investigated. Antiretroviral therapy is very effective in checking HIV replication rate, delaying the progression of HIV, reconstituting the immune response and should be available for all cases detected.

  16. Human CNS cultures exposed to HIV-1 gp120 reproduce dendritic injuries of HIV-1-associated dementia

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    Hammond Robert R

    2004-05-01

    Full Text Available Abstract HIV-1-associated dementia remains a common subacute to chronic central nervous system degeneration in adult and pediatric HIV-1 infected populations. A number of viral and host factors have been implicated including the HIV-1 120 kDa envelope glycoprotein (gp120. In human post-mortem studies using confocal scanning laser microscopy for microtubule-associated protein 2 and synaptophysin, neuronal dendritic pathology correlated with dementia. In the present study, primary human CNS cultures exposed to HIV-1 gp120 at 4 weeks in vitro suffered gliosis and dendritic damage analogous to that described in association with HIV-1-associated dementia.

  17. Fluctuations in Blood Marginal Zone B-Cell Frequencies May Reflect Migratory Patterns Associated with HIV-1 Disease Progression Status.

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    Gauvin, Julie; Chagnon-Choquet, Josiane; Poudrier, Johanne; Roger, Michel

    2016-01-01

    We have previously shown that overexpression of BLyS/BAFF was associated with increased relative frequencies of innate "precursor" marginal zone (MZ)-like B-cells in the blood of HIV-1-infected rapid and classic progressors. However, along with relatively normal BLyS/BAFF expression levels, these cells remain unaltered in elite-controllers (EC), rather, percentages of more mature MZ-like B-cells are decreased in the blood of these individuals. Fluctuations in frequencies of blood MZ-like B-cell populations may reflect migratory patterns associated with disease progression status, suggesting an important role for these cells in HIV-1 pathogenesis. We have therefore longitudinally measured plasma levels of B-tropic chemokines by ELISA-based technology as well as their ligands by flow-cytometry on blood B-cell populations of HIV-1-infected individuals with different rates of disease progression and uninfected controls. Migration potential of B-cell populations from these individuals were determined by chemotaxis assays. We found important modulations of CXCL13-CXCR5, CXCL12-CXCR4/CXCR7, CCL20-CCR6 and CCL25-CCR9 chemokine-axes and increased cell migration patterns in HIV progressors. Interestingly, frequencies of CCR6 expressing cells were significantly elevated within the precursor MZ-like population, consistent with increased migration in response to CCL20. Although we found little modulation of chemokine-axes in EC, cell migration was greater than that observed for uninfected controls, especially for MZ-like B-cells. Overall the immune response against HIV-1 may involve recruitment of MZ-like B-cells to peripheral sites. Moreover, our findings suggest that "regulated" attraction of these cells in a preserved BLyS/BAFF non-inflammatory environment, such as encountered in EC could be beneficial to the battle and even control of HIV.

  18. Immunogenicity of NYVAC Prime-Protein Boost Human Immunodeficiency Virus Type 1 Envelope Vaccination and Simian-Human Immunodeficiency Virus Challenge of Nonhuman Primates.

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    Saunders, Kevin O; Santra, Sampa; Parks, Robert; Yates, Nicole L; Sutherland, Laura L; Scearce, Richard M; Balachandran, Harikrishnan; Bradley, Todd; Goodman, Derrick; Eaton, Amanda; Stanfield-Oakley, Sherry A; Tartaglia, James; Phogat, Sanjay; Pantaleo, Giuseppe; Esteban, Mariano; Gomez, Carmen E; Perdiguero, Beatriz; Jacobs, Bertram; Kibler, Karen; Korber, Bette; Montefiori, David C; Ferrari, Guido; Vandergrift, Nathan; Liao, Hua-Xin; Tomaras, Georgia D; Haynes, Barton F

    2018-04-15

    A preventive human immunodeficiency virus type 1 (HIV-1) vaccine is an essential part of the strategy to eradicate AIDS. A critical question is whether antibodies that do not neutralize primary isolate (tier 2) HIV-1 strains can protect from infection. In this study, we investigated the ability of an attenuated poxvirus vector (NYVAC) prime-envelope gp120 boost to elicit potentially protective antibody responses in a rhesus macaque model of mucosal simian-human immunodeficiency virus (SHIV) infection. NYVAC vector delivery of a group M consensus envelope, trivalent mosaic envelopes, or a natural clade B isolate B.1059 envelope elicited antibodies that mediated neutralization of tier 1 viruses, cellular cytotoxicity, and phagocytosis. None of the macaques made neutralizing antibodies against the tier 2 SHIV SF162P3 used for mucosal challenge. Significant protection from infection was not observed for the three groups of vaccinated macaques compared to unvaccinated macaques, although binding antibody to HIV-1 Env correlated with decreased viremia after challenge. Thus, NYVAC Env prime-gp120 boost vaccination elicited polyfunctional, nonneutralizing antibody responses with minimal protective activity against tier 2 SHIV mucosal challenge. IMPORTANCE The antibody responses that confer protection against HIV-1 infection remain unknown. Polyfunctional antibody responses correlated with time to infection in previous macaque studies. Determining the ability of vaccines to induce these types of responses is critical for understanding how to improve upon the one efficacious human HIV-1 vaccine trial completed thus far. We characterized the antibody responses induced by a NYVAC-protein vaccine and determined the protective capacity of polyfunctional antibody responses in an R5, tier 2 mucosal SHIV infection model. Copyright © 2018 American Society for Microbiology.

  19. Complexity and dynamics of HIV-1 chemokine receptor usage in a multidrug-resistant adolescent.

    Science.gov (United States)

    Cavarelli, Mariangela; Mainetti, Lara; Pignataro, Angela Rosa; Bigoloni, Alba; Tolazzi, Monica; Galli, Andrea; Nozza, Silvia; Castagna, Antonella; Sampaolo, Michela; Boeri, Enzo; Scarlatti, Gabriella

    2014-12-01

    Maraviroc (MVC) is licensed in clinical practice for patients with R5 virus and virological failure; however, in anecdotal reports, dual/mixed viruses were also inhibited. We retrospectively evaluated the evolution of HIV-1 coreceptor tropism in plasma and peripheral blood mononuclear cells (PBMCs) of an infected adolescent with a CCR5/CXCR4 Trofile profile who experienced an important but temporary immunological and virological response during a 16-month period of MVC-based therapy. Coreceptor usage of biological viral clones isolated from PBMCs was investigated in U87.CD4 cells expressing wild-type or chimeric CCR5 and CXCR4. Plasma and PBMC-derived viral clones were sequenced to predict coreceptor tropism using the geno2pheno algorithm from the V3 envelope sequence and pol gene-resistant mutations. From start to 8.5 months of MVC treatment only R5X4 viral clones were observed, whereas at 16 months the phenotype enlarged to also include R5 and X4 clones. Chimeric receptor usage suggested the preferential usage of the CXCR4 coreceptor by the R5X4 biological clones. According to phenotypic data, R5 viruses were susceptible, whereas R5X4 and X4 viruses were resistant to RANTES and MVC in vitro. Clones at 16 months, but not at baseline, showed an amino acidic resistance pattern in protease and reverse transcription genes, which, however, did not drive their tropisms. The geno2pheno algorithm predicted at baseline R5 viruses in plasma, and from 5.5 months throughout follow-up only CXCR4-using viruses. An extended methodological approach is needed to unravel the complexity of the phenotype and variation of viruses resident in the different compartments of an infected individual. The accurate evaluation of the proportion of residual R5 viruses may guide therapeutic intervention in highly experienced patients with limited therapeutic options.

  20. Increased levels of CCR7(lo)PD-1(hi) CXCR5+ CD4+ T cells, and associated factors Bcl-6, CXCR5, IL-21 and IL-6 contribute to repeated implantation failure.

    Science.gov (United States)

    Gong, Qiaoqiao; Zhu, Yuejie; Pang, Nannan; Ai, Haiquan; Gong, Xiaoyun; La, Xiaolin; Ding, Jianbing

    2017-12-01

    In vitro fertilization-embryo transfer (IVF-ET) can be used by infertile couples to assist with reproduction; however, failure of the embryo to implant into the endometrial lining results in failure of the IVF treatment. The present study investigated the expression of chemokine receptor 7 (CCR7)(lo) programmed death-1(PD-1)(hi) chemokine receptor type 5 (CXCR5) + cluster of differentiation 4 (CD4) + T cells and associated factors in patients with repeated implantation failure (RIF). A total of 30 females with RIF and 30 healthy females were enrolled in the current study. Flow cytometry was used to detect the proportion of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells in the peripheral blood. Cytokine bead arrays were performed to detect the levels of interleukin (IL)-6, -4 and -2 in the serum. ELISAs were used to detect the level of IL-21 in the serum. Quantitative real time polymerase chain reaction analysis and immunohistochemistry were used to investigate the expression of B-cell lymphoma 6 (Bcl-6), chemokine receptor type 5 (CXCR5) and IL-21 in the endometrium. The results revealed that the percentage of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells was increased in the RIF group compared with the control group during the mid luteal phase. The mRNA and protein levels of Bcl-6, IL-21 and CXCR5 in the endometrium and the concentrations of IL-21 and IL-6 in the serum were significantly increased in the RIF group; however, no significant difference was observed between the two groups in regards to the expression of IL-4 and IL-2. Furthermore, a significant positive correlation was identified between the percentage of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells and IL-21 and IL-6 levels. The expression of IL-21 also had a positive correlation with Bcl-6 and CXCR5 expression in the RIF group. These results suggest that increased levels of CCR7(lo)PD-1(hi) CXCR5 + CD4 + T cells and associated factors contribute to RIF and could therefore be a potential therapeutic target.

  1. Appraising the performance of genotyping tools in the prediction of coreceptor tropism in HIV-1 subtype C viruses

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    Crous Saleema

    2012-09-01

    Full Text Available Abstract Background In human immunodeficiency virus type 1 (HIV-1 infection, transmitted viruses generally use the CCR5 chemokine receptor as a coreceptor for host cell entry. In more than 50% of subtype B infections, a switch in coreceptor tropism from CCR5- to CXCR4-use occurs during disease progression. Phenotypic or genotypic approaches can be used to test for the presence of CXCR4-using viral variants in an individual’s viral population that would result in resistance to treatment with CCR5-antagonists. While genotyping approaches for coreceptor-tropism prediction in subtype B are well established and verified, they are less so for subtype C. Methods Here, using a dataset comprising V3 loop sequences from 349 CCR5-using and 56 CXCR4-using HIV-1 subtype C viruses we perform a comparative analysis of the predictive ability of 11 genotypic algorithms in their prediction of coreceptor tropism in subtype C. We calculate the sensitivity and specificity of each of the approaches as well as determining their overall accuracy. By separating the CXCR4-using viruses into CXCR4-exclusive (25 sequences and dual-tropic (31 sequences we evaluate the effect of the possible conflicting signal from dual-tropic viruses on the ability of a of the approaches to correctly predict coreceptor phenotype. Results We determined that geno2pheno with a false positive rate of 5% is the best approach for predicting CXCR4-usage in subtype C sequences with an accuracy of 94% (89% sensitivity and 99% specificity. Contrary to what has been reported for subtype B, the optimal approaches for prediction of CXCR4-usage in sequence from viruses that use CXCR4 exclusively, also perform best at predicting CXCR4-use in dual-tropic viral variants. Conclusions The accuracy of genotyping approaches at correctly predicting the coreceptor usage of V3 sequences from subtype C viruses is very high. We suggest that genotyping approaches can be used to test for coreceptor tropism in HIV-1

  2. Targeting TRIM5α in HIV Cure Strategies for the CRISPR-Cas9 Era

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    Daryl Anne Victoria Weatherley

    2017-11-01

    Full Text Available In the past decade, studies of innate immune activity against HIV-1 and other retroviruses have revealed a powerful array of host factors that can attack the virus at various stages of its life cycle in human and primate cells, raising the prospect that these antiviral factors could be manipulated in immunotherapeutic strategies for HIV infection. This has not proved straightforward: while HIV accessory genes encode proteins that subvert or destroy many of these restriction factors, others, such as human TRIM5α show limited potency against HIV-1. However, HIV-1 is much more susceptible to simian versions of TRIM5α: could this information be translated into the development of an effective gene therapy for HIV infection? Reigniting research into the restriction factor TRIM5α in the era of superior gene editing technology such as CRISPR-Cas9 presents an exciting opportunity to revisit this prospect.

  3. Identification of a human protein-derived HIV-1 fusion inhibitor targeting the gp41 fusion core structure.

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    Lijun Chao

    Full Text Available The HIV-1 envelope glycoprotein (Env gp41 plays a crucial role in the viral fusion process. The peptides derived from the C-terminal heptad repeat (CHR of gp41 are potent HIV fusion inhibitors. However, the activity of these anti-HIV-1 peptides in vivo may be attenuated by their induction of anti-gp41 antibodies. Thus, it is essential to identify antiviral peptides or proteins with low, or no, immunogenicity to humans. Here, we found that the C-terminal fragment (aa 462-521 of the human POB1 (the partner of RalBP1, designated C60, is an HIV-1 fusion inhibitor. It bound to N36, the peptide derived from the N-terminal heptad repeat (NHR of gp41, and to the six-helix bundle (6-HB formed by N36 and C34, a CHR-peptide, but it did not bind to C34. Unlike the CHR-peptides, C60 did not block gp41 6-HB formation. Rather, results suggest that C60 inhibits HIV-1 fusion by binding to the 6-HB, in particular, the residues in the gp41 NHR domain that are exposed on the surface of 6-HB. Since 6-HB plays a crucial role in the late stage of fusion between the viral envelope and endosomal membrane during the endocytic process of HIV-1, C60 may serve as a host restriction factor to suppress HIV-1 entry into CD4+ T lymphocytes. Taken together, it can be concluded from these results that C60 can be used as a lead for the development of anti-HIV-1 therapeutics or microbicides for the treatment and prevention of HIV-1 infection, as well as a molecular probe to study the fusogenic mechanism of HIV-1.

  4. Association between the CCR5 32-bp deletion allele and late onset of schizophrenia

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Timm, Sally; Wang, August G

    2006-01-01

    OBJECTIVE: The 32-bp deletion allele in chemokine receptor CCR5 has been associated with several immune-mediated diseases and might be implicated in schizophrenia as well. METHOD: The authors genotyped DNA samples from 268 schizophrenia patients and 323 healthy subjects. Age at first admission...... of the deletion allele in the latter subgroup of patients. CONCLUSIONS: These findings suggest that the CCR5 32-bp deletion allele is a susceptibility factor for schizophrenia with late onset. Alternatively, the CCR5 32-bp deletion allele may act as a modifier by delaying the onset of schizophrenia without...

  5. CCR5 gene polymorphism is a genetic risk factor for radiographic severity of rheumatoid arthritis.

    Science.gov (United States)

    Han, S W; Sa, K H; Kim, S I; Lee, S I; Park, Y W; Lee, S S; Yoo, W H; Soe, J S; Nam, E J; Lee, J; Park, J Y; Kang, Y M

    2012-11-01

    The chemokine receptor [C-C chemokine receptor 5 (CCR5)] is expressed on diverse immune effecter cells and has been implicated in the pathogenesis of rheumatoid arthritis (RA). This study sought to determine whether single-nucleotide polymorphisms (SNPs) in the CCR5 gene and their haplotypes were associated with susceptibility to and severity of RA. Three hundred fifty-seven patients with RA and 383 healthy unrelated controls were recruited. Using a pyrosequencing assay, we examined four polymorphisms -1118 CTAT(ins) (/del) (rs10577983), 303 A>G (rs1799987), 927 C>T (rs1800024), and 4838 G>T (rs1800874) of the CCR5 gene, which were distributed over the promoter region as well as the 5' and 3' untranslated regions. No significant difference in the genotype, allele, and haplotype frequencies of the four selected SNPs was observed between RA patients and controls. CCR5 polymorphisms of -1118 CTAT(del) (P = 0.012; corrected P = 0.048) and 303 A>G (P = 0.012; corrected P = 0.048) showed a significant association with radiographic severity in a recessive model, and, as a result of multivariate logistic regression analysis, were found to be an independent predictor of radiographic severity. When we separated the erosion score from the total Sharp score, the statistical significance of CCR5 polymorphisms showed an increase; -1118 CTAT(ins) (/del) (P = 0.007; corrected P = 0.028) and 303 A>G (P = 0.007; corrected P = 0.028). Neither SNPs nor haplotypes of the CCR5 gene showed a significant association with joint space narrowing score. These results indicate that genetic polymorphisms of CCR5 are an independent risk factor for radiographic severity denoted by modified Sharp score, particularly joint erosion in RA. © 2012 John Wiley & Sons A/S.

  6. Coreceptor use in nonhuman primate models of HIV infection.

    Science.gov (United States)

    Sina, Silvana Tasca; Ren, Wuze; Cheng-Mayer, Cecilia

    2011-01-27

    SIV or SHIV infection of nonhuman primates (NHP) has been used to investigate the impact of coreceptor usage on the composition and dynamics of the CD4+ T cell compartment, mechanisms of disease induction and development of clinical syndrome. As the entire course of infection can be followed, with frequent access to tissue compartments, infection of rhesus macaques with CCR5-tropic SHIVs further allows for study of HIV-1 coreceptor switch after intravenous and mucosal inoculation, with longitudinal and systemic analysis to determine the timing, anatomical sites and cause for the change in envelope glycoprotein and coreceptor preference. Here, we review our current understanding of coreceptor use in NHPs and their impact on the pathobiological characteristics of the infection, and discuss recent advances in NHP studies to uncover the underlying selective pressures for the change in coreceptor preference in vivo.

  7. The HIV-1 envelope transmembrane domain binds TLR2 through a distinct dimerization motif and inhibits TLR2-mediated responses.

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    Eliran Moshe Reuven

    2014-08-01

    Full Text Available HIV-1 uses a number of means to manipulate the immune system, to avoid recognition and to highjack signaling pathways. HIV-1 infected cells show limited Toll-Like Receptor (TLR responsiveness via as yet unknown mechanisms. Using biochemical and biophysical approaches, we demonstrate that the trans-membrane domain (TMD of the HIV-1 envelope (ENV directly interacts with TLR2 TMD within the membrane milieu. This interaction attenuates TNFα, IL-6 and MCP-1 secretion in macrophages, induced by natural ligands of TLR2 both in in vitro and in vivo models. This was associated with decreased levels of ERK phosphorylation. Furthermore, mutagenesis demonstrated the importance of a conserved GxxxG motif in driving this interaction within the membrane milieu. The administration of the ENV TMD in vivo to lipotechoic acid (LTA/Galactosamine-mediated septic mice resulted in a significant decrease in mortality and in tissue damage, due to the weakening of systemic macrophage activation. Our findings suggest that the TMD of ENV is involved in modulation of the innate immune response during HIV infection. Furthermore, due to the high functional homology of viral ENV proteins this function may be a general character of viral-induced immune modulation.

  8. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1

    Science.gov (United States)

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H.; Michael, Nelson L.; Alving, Carl R.; Casares, Sofia; Rao, Mangala

    2015-01-01

    CD4+ T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5+PD-1++) and precursor-TFH (CXCR5+PD-1+) cells. The majority of TFH-cells expressed CCR5 and CXCR3 and are the most permissive to HIV-1 infection. A single low-dose intravaginal HIV-1 challenge of humanized DRAG mice results in 100% infectivity with accumulation of TFH-cells mainly in the Peyer’s patches and FRT. The novel finding of TFH-cells in the FRT may contribute to the high susceptibility of DRAG mice to HIV-1 infection. This mouse model thus provides new opportunities to study TFH-cells and to evaluate HIV-1 vaccines. PMID:26034905

  9. Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes

    DEFF Research Database (Denmark)

    Pfleger, C; Kaas, A; Hansen, L

    2008-01-01

    Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated lo...

  10. Saturation Mutagenesis of the HIV-1 Envelope CD4 Binding Loop Reveals Residues Controlling Distinct Trimer Conformations.

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    Maria Duenas-Decamp

    2016-11-01

    Full Text Available The conformation of HIV-1 envelope (Env glycoprotein trimers is key in ensuring protection against waves of neutralizing antibodies generated during infection, while maintaining sufficient exposure of the CD4 binding site (CD4bs for viral entry. The CD4 binding loop on Env is an early contact site for CD4 while penetration of a proximal cavity by CD4 triggers Env conformational changes for entry. The role of residues in the CD4 binding loop in regulating the conformation of the trimer and trimer association domain (TAD was investigated using a novel saturation mutagenesis approach. Single mutations identified, resulted in distinct trimer conformations affecting CD4bs exposure, the glycan shield and the TAD across diverse HIV-1 clades. Importantly, mutations that improve access to the CD4bs without exposing the immunodominant V3 loop were identified. The different trimer conformations identified will affect the specificity and breadth of nabs elicited in vivo and are important to consider in design of Env immunogens for vaccines.

  11. A novel CCR-2/TLR-2 triggered signaling in murine peritoneal macrophages intensifies bacterial (Staphylococcus aureus) killing by reactive oxygen species through TNF-R1.

    Science.gov (United States)

    Nandi, Ajeya; Bishayi, Biswadev

    2017-10-01

    Macrophages are remarkably versatile in their ability to recognize and respond to a wide range of stimuli by expressing a variety of surface and intracellular receptors and triggering multiple signal transduction pathways. The onset of microbial infection is primarily determined by the initial contacts made by the microbes with the host macrophages. Although there prevail a relationship between the chemokine receptor and Toll like receptors during disease, particularly TLR-2 and CCR-2 signaling interdependence on each other has not been yet investigated during acute staphylococcal infection. Thus, the present study was aimed to trace possible interaction between CCR-2 and TLR-2 in peritoneal macrophages during acute Staphylococcus aureus infection. We found that neutralization of CCR-2 attenuates TLR-2 expression and restricts S. aureus burden but TLR-2 neutralization augments CCR-2 expression in macrophages, along with compromised host-derived reactive oxygen species production. S. aureus infection to CCR-2 intact but TLR-2 neutralized macrophages triggered production of IL-1β, TNF-α, IL-6, IFN-γ, MCP-1 and expression of iNOS, TNFR-1 and GPx with concomitant decrease in IL-10 production. Further, study with NG-monomethyl-l-arginine (L-NMMA) [iNOS blocker] and buthionine sulfoximine (BSO) [GPx blocker] revealed that S. aureus infection enhanced TLR-2 expression in CCR-2 intact and TLR-2 neutralized macrophages possibly via iNOS and TNFR-1 up regulation and GPx down regulation. Overall, our data indicate that targeting CCR-2 with neutralizing antibody in the early phase of S. aureus infection could restrict excessive inflammation with less compromised bacterial killing. It certainly would be a therapeutic strategy in S. aureus induced inflammatory and infective diseases. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  12. Organization of cellular receptors into a nanoscale junction during HIV-1 adhesion.

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    Terrence M Dobrowsky

    2010-07-01

    Full Text Available The fusion of the human immunodeficiency virus type 1 (HIV-1 with its host cell is the target for new antiretroviral therapies. Viral particles interact with the flexible plasma membrane via viral surface protein gp120 which binds its primary cellular receptor CD4 and subsequently the coreceptor CCR5. However, whether and how these receptors become organized at the adhesive junction between cell and virion are unknown. Here, stochastic modeling predicts that, regarding binding to gp120, cellular receptors CD4 and CCR5 form an organized, ring-like, nanoscale structure beneath the virion, which locally deforms the plasma membrane. This organized adhesive junction between cell and virion, which we name the viral junction, is reminiscent of the well-characterized immunological synapse, albeit at much smaller length scales. The formation of an organized viral junction under multiple physiopathologically relevant conditions may represent a novel intermediate step in productive infection.

  13. The impact of CCR5-Δ32 deletion on C-reactive protein levels and cardiovascular disease

    DEFF Research Database (Denmark)

    Dinh, Khoa Manh; Pedersen, Ole B; Petersen, Mikkel S

    2015-01-01

    BACKGROUND AND PURPOSE: The C-C chemokine receptor 5-Δ32 deletion (CCR5-Δ32) has been associated with lower levels of C-reactive protein (CRP), but the effect on cardiovascular diseases is uncertain. This study addresses the impact of CCR5-Δ32 on the risk of low-grade inflammation...... and hospitalization with cardiovascular diseases in a large cohort of blood donors. METHODS: Genotyping of 15,206 healthy participants from The Danish Blood Donor Study for CCR5-Δ32 was performed and combined with CRP measurements and questionnaire data. Cardiovascular disease diagnoses were identified by ICD-10......: In this cohort, carriers of the CCR5-Δ32 deletion had normal CRP levels but a borderline significant increased risk of cardiovascular diseases....

  14. HIV-1 vaccines

    Science.gov (United States)

    Excler, Jean-Louis; Robb, Merlin L; Kim, Jerome H

    2014-01-01

    The development of a safe and effective preventive HIV-1 vaccine remains a public health priority. Despite scientific difficulties and disappointing results, HIV-1 vaccine clinical development has, for the first time, established proof-of-concept efficacy against HIV-1 acquisition and identified vaccine-associated immune correlates of risk. The correlate of risk analysis showed that IgG antibodies against the gp120 V2 loop correlated with decreased risk of HIV infection, while Env-specific IgA directly correlated with increased risk. The development of vaccine strategies such as improved envelope proteins formulated with potent adjuvants and DNA and vectors expressing mosaics, or conserved sequences, capable of eliciting greater breadth and depth of potentially relevant immune responses including neutralizing and non-neutralizing antibodies, CD4+ and CD8+ cell-mediated immune responses, mucosal immune responses, and immunological memory, is now proceeding quickly. Additional human efficacy trials combined with other prevention modalities along with sustained funding and international collaboration remain key to bring an HIV-1 vaccine to licensure. PMID:24637946

  15. Expression of affordable microbicides to combat the spread of HIV pandemic

    CSIR Research Space (South Africa)

    Mawela, K

    2010-09-01

    Full Text Available activation, normal T expressed and secreted) show anti-HIV activity through their ability to block the HIV coreceptor CCR5 (Figure 1), and a number of N-terminally modified analogues of these proteins with much higher antiviral potency have been developed...

  16. Genetic signatures in the envelope glycoproteins of HIV-1 that associate with broadly neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    S Gnanakaran

    Full Text Available A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an

  17. Accurate and efficient gp120 V3 loop structure based models for the determination of HIV-1 co-receptor usage

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    Vaisman Iosif I

    2010-10-01

    Full Text Available Abstract Background HIV-1 targets human cells expressing both the CD4 receptor, which binds the viral envelope glycoprotein gp120, as well as either the CCR5 (R5 or CXCR4 (X4 co-receptors, which interact primarily with the third hypervariable loop (V3 loop of gp120. Determination of HIV-1 affinity for either the R5 or X4 co-receptor on host cells facilitates the inclusion of co-receptor antagonists as a part of patient treatment strategies. A dataset of 1193 distinct gp120 V3 loop peptide sequences (989 R5-utilizing, 204 X4-capable is utilized to train predictive classifiers based on implementations of random forest, support vector machine, boosted decision tree, and neural network machine learning algorithms. An in silico mutagenesis procedure employing multibody statistical potentials, computational geometry, and threading of variant V3 sequences onto an experimental structure, is used to generate a feature vector representation for each variant whose components measure environmental perturbations at corresponding structural positions. Results Classifier performance is evaluated based on stratified 10-fold cross-validation, stratified dataset splits (2/3 training, 1/3 validation, and leave-one-out cross-validation. Best reported values of sensitivity (85%, specificity (100%, and precision (98% for predicting X4-capable HIV-1 virus, overall accuracy (97%, Matthew's correlation coefficient (89%, balanced error rate (0.08, and ROC area (0.97 all reach critical thresholds, suggesting that the models outperform six other state-of-the-art methods and come closer to competing with phenotype assays. Conclusions The trained classifiers provide instantaneous and reliable predictions regarding HIV-1 co-receptor usage, requiring only translated V3 loop genotypes as input. Furthermore, the novelty of these computational mutagenesis based predictor attributes distinguishes the models as orthogonal and complementary to previous methods that utilize sequence

  18. Lymphotropic Virions Affect Chemokine Receptor-Mediated Neural Signaling and Apoptosis: Implications for Human Immunodeficiency Virus Type 1-Associated Dementia

    Science.gov (United States)

    Zheng, Jialin; Ghorpade, Anuja; Niemann, Douglas; Cotter, Robin L.; Thylin, Michael R.; Epstein, Leon; Swartz, Jennifer M.; Shepard, Robin B.; Liu, Xiaojuan; Nukuna, Adeline; Gendelman, Howard E.

    1999-01-01

    Chemokine receptors pivotal for human immunodeficiency virus type 1 (HIV-1) infection in lymphocytes and macrophages (CCR3, CCR5, and CXCR4) are expressed on neural cells (microglia, astrocytes, and/or neurons). It is these cells which are damaged during progressive HIV-1 infection of the central nervous system. We theorize that viral coreceptors could effect neural cell damage during HIV-1-associated dementia (HAD) without simultaneously affecting viral replication. To these ends, we studied the ability of diverse viral strains to affect intracellular signaling and apoptosis of neurons, astrocytes, and monocyte-derived macrophages. Inhibition of cyclic AMP, activation of inositol 1,4,5-trisphosphate, and apoptosis were induced by diverse HIV-1 strains, principally in neurons. Virions from T-cell-tropic (T-tropic) strains (MN, IIIB, and Lai) produced the most significant alterations in signaling of neurons and astrocytes. The HIV-1 envelope glycoprotein, gp120, induced markedly less neural damage than purified virions. Macrophage-tropic (M-tropic) strains (ADA, JR-FL, Bal, MS-CSF, and DJV) produced the least neural damage, while 89.6, a dual-tropic HIV-1 strain, elicited intermediate neural cell damage. All T-tropic strain-mediated neuronal impairments were blocked by the CXCR4 antibody, 12G5. In contrast, the M-tropic strains were only partially blocked by 12G5. CXCR4-mediated neuronal apoptosis was confirmed in pure populations of rat cerebellar granule neurons and was blocked by HA1004, an inhibitor of calcium/calmodulin-dependent protein kinase II, protein kinase A, and protein kinase C. Taken together, these results suggest that progeny HIV-1 virions can influence neuronal signal transduction and apoptosis. This process occurs, in part, through CXCR4 and is independent of CD4 binding. T-tropic viruses that traffic in and out of the brain during progressive HIV-1 disease may play an important role in HAD neuropathogenesis. PMID:10482576

  19. Molecular Mechanism of Action for Allosteric Modulators and Agonists in CC-chemokine Receptor 5 (CCR5).

    Science.gov (United States)

    Karlshøj, Stefanie; Amarandi, Roxana Maria; Larsen, Olav; Daugvilaite, Viktorija; Steen, Anne; Brvar, Matjaž; Pui, Aurel; Frimurer, Thomas Michael; Ulven, Trond; Rosenkilde, Mette Marie

    2016-12-23

    The small molecule metal ion chelators bipyridine and terpyridine complexed with Zn 2+ (ZnBip and ZnTerp) act as CCR5 agonists and strong positive allosteric modulators of CCL3 binding to CCR5, weak modulators of CCL4 binding, and competitors for CCL5 binding. Here we describe their binding site using computational modeling, binding, and functional studies on WT and mutated CCR5. The metal ion Zn 2+ is anchored to the chemokine receptor-conserved Glu-283 VII:06/7.39 Both chelators interact with aromatic residues in the transmembrane receptor domain. The additional pyridine ring of ZnTerp binds deeply in the major binding pocket and, in contrast to ZnBip, interacts directly with the Trp-248 VI:13/6.48 microswitch, contributing to its 8-fold higher potency. The impact of Trp-248 was further confirmed by ZnClTerp, a chloro-substituted version of ZnTerp that showed no inherent agonism but maintained positive allosteric modulation of CCL3 binding. Despite a similar overall binding mode of all three metal ion chelator complexes, the pyridine ring of ZnClTerp blocks the conformational switch of Trp-248 required for receptor activation, thereby explaining its lack of activity. Importantly, ZnClTerp becomes agonist to the same extent as ZnTerp upon Ala mutation of Ile-116 III:16/3.40 , a residue that constrains the Trp-248 microswitch in its inactive conformation. Binding studies with 125 I-CCL3 revealed an allosteric interface between the chemokine and the small molecule binding site, including residues Tyr-37 I:07/1.39 , Trp-86 II:20/2.60 , and Phe-109 III:09/3.33 The small molecules and CCL3 approach this interface from opposite directions, with some residues being mutually exploited. This study provides new insight into the molecular mechanism of CCR5 activation and paves the way for future allosteric drugs for chemokine receptors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Conformational preferences of a chimeric peptide HIV-1 immunogen from the C4-V3 domains of gp120 envelope protein of HIV-1 CAN0A based on solution NMR: comparison to a related immunogenic peptide from HIV-1 RF.

    Science.gov (United States)

    Vu, H M; de Lorimier, R; Moody, M A; Haynes, B F; Spicer, L D

    1996-04-23

    A critical problem to overcome on HIV vaccine design is the variability among HIV strains. One strategy to solve this problem is the construction of multicomponent immunogens reflective of common HIV motifs. Currently, it is not known if these motifs should be based primarily on amino acid sequence or higher-order structure of the viral proteins of a combination of the two. In this paper, we report NMR-derived solution conformations for a sympathetic peptide taken from the C4 and V3 domains of HIV-1 CAN0A gp120 envelope protein. This peptide, designated T1-SP10CAN0(A), is compared to a recently reported C4-V3 peptide. T1-SP10RF(A) from the HIV-1 RF strain [de Lorimier et al. (1994) Biochemistry 33, 2055-2062], in terms of conformational features and immune responses in mice [Haynes et al. (1995) AIDS Res. Hum. Retroviruses 11, 211-221]. The T1 segment of 16 amino acids from the gp120 C4 domain is identical in both peptides and exhibits nascent helical character. The SP10 region, taken from the gp120 V3 loop, differs from that of T1-SP10RF(A) in both sequence and conformations. A reverse turn is observed at the conserved GPGX sequence. The rest of the Sp10 domain is extended with the exception of the last three residues which show evidence for a helical arrangement. Modeling of the turn region of the T1-SP10CAN0(A) peptide shows exposure of a continuous apolar stretch of side chains similar to that reported in the crystal structure of a V3 peptide from HIV-1 MN complexed with a monoclonal antibody [Rini et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 6325-6329]. this hydrophobic patch is interrupted by a charged Lys residue in the T1-SP10RF(A) peptide. This observation suggests that the HIV-1 CAN0A and HIV-1 RF C4-V3 peptides can induce widely different anti-HIV antibodies. consistent with immunogenic results.

  1. HIV-1-Specific IgA Monoclonal Antibodies from an HIV-1 Vaccinee Mediate Galactosylceramide Blocking and Phagocytosis

    Science.gov (United States)

    2018-01-01

    ABSTRACT Vaccine-elicited humoral immune responses comprise an array of antibody forms and specificities, with only a fraction contributing to protective host immunity. Elucidation of antibody effector functions responsible for protective immunity against human immunodeficiency virus type 1 (HIV-1) acquisition is a major goal for the HIV-1 vaccine field. Immunoglobulin A (IgA) is an important part of the host defense against pathogens; however, little is known about the role of vaccine-elicited IgA and its capacity to mediate antiviral functions. To identify the antiviral functions of HIV-1-specific IgA elicited by vaccination, we cloned HIV-1 envelope-specific IgA monoclonal antibodies (MAbs) by memory B cell cultures from peripheral blood mononuclear cells from an RV144 vaccinee and produced two IgA clonal cell lines (HG129 and HG130) producing native, nonrecombinant IgA MAbs. The HG129 and HG130 MAbs mediated phagocytosis by monocytes, and HG129 blocked HIV-1 Env glycoprotein binding to galactosylceramide, an alternative HIV-1 receptor. These findings elucidate potential antiviral functions of vaccine-elicited HIV-1 envelope-specific IgA that may act to block HIV-1 acquisition at the portal of entry by preventing HIV-1 binding to galactosylceramide and mediating antibody Fc receptor-mediated virion phagocytosis. Furthermore, these findings highlight the complex and diverse interactions of vaccine-elicited IgA with pathogens that depend on IgA fine specificity and form (e.g., multimeric or monomeric) in the systemic circulation and mucosal compartments. IMPORTANCE Host-pathogen interactions in vivo involve numerous immune mechanisms that can lead to pathogen clearance. Understanding the nature of antiviral immune mechanisms can inform the design of efficacious HIV-1 vaccine strategies. Evidence suggests that both neutralizing and nonneutralizing antibodies can mediate some protection against HIV in animal models. Although numerous studies have characterized the

  2. A Single HIV-1 Cluster and a Skewed Immune Homeostasis Drive the Early Spread of HIV among Resting CD4+ Cell Subsets within One Month Post-Infection

    Science.gov (United States)

    Avettand-Fenoël, Véronique; Nembot, Georges; Mélard, Adeline; Blanc, Catherine; Lascoux-Combe, Caroline; Slama, Laurence; Allegre, Thierry; Allavena, Clotilde; Yazdanpanah, Yazdan; Duvivier, Claudine; Katlama, Christine; Goujard, Cécile; Seksik, Bao Chau Phung; Leplatois, Anne; Molina, Jean-Michel; Meyer, Laurence; Autran, Brigitte; Rouzioux, Christine

    2013-01-01

    Optimizing therapeutic strategies for an HIV cure requires better understanding the characteristics of early HIV-1 spread among resting CD4+ cells within the first month of primary HIV-1 infection (PHI). We studied the immune distribution, diversity, and inducibility of total HIV-DNA among the following cell subsets: monocytes, peripheral blood activated and resting CD4 T cells, long-lived (naive [TN] and central-memory [TCM]) and short-lived (transitional-memory [TTM] and effector-memory cells [TEM]) resting CD4+T cells from 12 acutely-infected individuals recruited at a median 36 days from infection. Cells were sorted for total HIV-DNA quantification, phylogenetic analysis and inducibility, all studied in relation to activation status and cell signaling. One month post-infection, a single CCR5-restricted viral cluster was massively distributed in all resting CD4+ subsets from 88% subjects, while one subject showed a slight diversity. High levels of total HIV-DNA were measured among TN (median 3.4 log copies/million cells), although 10-fold less (p = 0.0005) than in equally infected TCM (4.5), TTM (4.7) and TEM (4.6) cells. CD3−CD4+ monocytes harbored a low viral burden (median 2.3 log copies/million cells), unlike equally infected resting and activated CD4+ T cells (4.5 log copies/million cells). The skewed repartition of resting CD4 subsets influenced their contribution to the pool of resting infected CD4+T cells, two thirds of which consisted of short-lived TTM and TEM subsets, whereas long-lived TN and TCM subsets contributed the balance. Each resting CD4 subset produced HIV in vitro after stimulation with anti-CD3/anti-CD28+IL-2 with kinetics and magnitude varying according to subset differentiation, while IL-7 preferentially induced virus production from long-lived resting TN cells. In conclusion, within a month of infection, a clonal HIV-1 cluster is massively distributed among resting CD4 T-cell subsets with a flexible inducibility, suggesting that

  3. A single HIV-1 cluster and a skewed immune homeostasis drive the early spread of HIV among resting CD4+ cell subsets within one month post-infection.

    Directory of Open Access Journals (Sweden)

    Charline Bacchus

    Full Text Available Optimizing therapeutic strategies for an HIV cure requires better understanding the characteristics of early HIV-1 spread among resting CD4+ cells within the first month of primary HIV-1 infection (PHI. We studied the immune distribution, diversity, and inducibility of total HIV-DNA among the following cell subsets: monocytes, peripheral blood activated and resting CD4 T cells, long-lived (naive [TN] and central-memory [TCM] and short-lived (transitional-memory [TTM] and effector-memory cells [TEM] resting CD4+T cells from 12 acutely-infected individuals recruited at a median 36 days from infection. Cells were sorted for total HIV-DNA quantification, phylogenetic analysis and inducibility, all studied in relation to activation status and cell signaling. One month post-infection, a single CCR5-restricted viral cluster was massively distributed in all resting CD4+ subsets from 88% subjects, while one subject showed a slight diversity. High levels of total HIV-DNA were measured among TN (median 3.4 log copies/million cells, although 10-fold less (p = 0.0005 than in equally infected TCM (4.5, TTM (4.7 and TEM (4.6 cells. CD3-CD4+ monocytes harbored a low viral burden (median 2.3 log copies/million cells, unlike equally infected resting and activated CD4+ T cells (4.5 log copies/million cells. The skewed repartition of resting CD4 subsets influenced their contribution to the pool of resting infected CD4+T cells, two thirds of which consisted of short-lived TTM and TEM subsets, whereas long-lived TN and TCM subsets contributed the balance. Each resting CD4 subset produced HIV in vitro after stimulation with anti-CD3/anti-CD28+IL-2 with kinetics and magnitude varying according to subset differentiation, while IL-7 preferentially induced virus production from long-lived resting TN cells. In conclusion, within a month of infection, a clonal HIV-1 cluster is massively distributed among resting CD4 T-cell subsets with a flexible inducibility

  4. Chimeric HIV-1 envelope glycoproteins with potent intrinsic granulocyte-macrophage colony-stimulating factor (GM-CSF activity.

    Directory of Open Access Journals (Sweden)

    Gözde Isik

    Full Text Available HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs that target the envelope glycoprotein complex (Env. An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env makes the elicitation of such BrNAbs challenging. Co-stimulatory molecules can increase the immunogenicity of Env and we have engineered a soluble chimeric Env trimer with an embedded granulocyte-macrophage colony-stimulating factor (GM-CSF domain. This chimeric molecule induced enhanced B and helper T cell responses in mice compared to Env without GM-CSF. We studied whether we could optimize the activity of the embedded GM-CSF as well as the antigenic structure of the Env component of the chimeric molecule. We assessed the effect of truncating GM-CSF, removing glycosylation-sites in GM-CSF, and adjusting the linker length between GM-CSF and Env. One of our designed Env(GM-CSF chimeras improved GM-CSF-dependent cell proliferation by 6-fold, reaching the same activity as soluble recombinant GM-CSF. In addition, we incorporated GM-CSF into a cleavable Env trimer and found that insertion of GM-CSF did not compromise Env cleavage, while Env cleavage did not compromise GM-CSF activity. Importantly, these optimized Env(GM-CSF proteins were able to differentiate human monocytes into cells with a macrophage-like phenotype. Chimeric Env(GM-CSF should be useful for improving humoral immunity against HIV-1 and these studies should inform the design of other chimeric proteins.

  5. Chimeric HIV-1 Envelope Glycoproteins with Potent Intrinsic Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) Activity*

    Science.gov (United States)

    Boot, Maikel; Cobos Jiménez, Viviana; Kootstra, Neeltje A.; Sanders, Rogier W.

    2013-01-01

    HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs) that target the envelope glycoprotein complex (Env). An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env makes the elicitation of such BrNAbs challenging. Co-stimulatory molecules can increase the immunogenicity of Env and we have engineered a soluble chimeric Env trimer with an embedded granulocyte-macrophage colony-stimulating factor (GM-CSF) domain. This chimeric molecule induced enhanced B and helper T cell responses in mice compared to Env without GM-CSF. We studied whether we could optimize the activity of the embedded GM-CSF as well as the antigenic structure of the Env component of the chimeric molecule. We assessed the effect of truncating GM-CSF, removing glycosylation-sites in GM-CSF, and adjusting the linker length between GM-CSF and Env. One of our designed EnvGM-CSF chimeras improved GM-CSF-dependent cell proliferation by 6-fold, reaching the same activity as soluble recombinant GM-CSF. In addition, we incorporated GM-CSF into a cleavable Env trimer and found that insertion of GM-CSF did not compromise Env cleavage, while Env cleavage did not compromise GM-CSF activity. Importantly, these optimized EnvGM-CSF proteins were able to differentiate human monocytes into cells with a macrophage-like phenotype. Chimeric EnvGM-CSF should be useful for improving humoral immunity against HIV-1 and these studies should inform the design of other chimeric proteins. PMID:23565193

  6. Association Study of Common Genetic Variants and HIV-1 Acquisition in 6,300 Infected Cases and 7,200 Controls

    Science.gov (United States)

    Ripke, Stephan; van den Berg, Leonard; Buchbinder, Susan; Carrington, Mary; Cossarizza, Andrea; Dalmau, Judith; Deeks, Steven G.; Delaneau, Olivier; De Luca, Andrea; Goedert, James J.; Haas, David; Herbeck, Joshua T.; Kathiresan, Sekar; Kirk, Gregory D.; Lambotte, Olivier; Luo, Ma; Mallal, Simon; van Manen, Daniëlle; Martinez-Picado, Javier; Meyer, Laurence; Miro, José M.; Mullins, James I.; Obel, Niels; O'Brien, Stephen J.; Pereyra, Florencia; Plummer, Francis A.; Poli, Guido; Qi, Ying; Rucart, Pierre; Sandhu, Manj S.; Shea, Patrick R.; Schuitemaker, Hanneke; Theodorou, Ioannis; Vannberg, Fredrik; Veldink, Jan; Walker, Bruce D.; Weintrob, Amy; Winkler, Cheryl A.; Wolinsky, Steven; Telenti, Amalio; Goldstein, David B.; de Bakker, Paul I. W.; Zagury, Jean-François; Fellay, Jacques

    2013-01-01

    Multiple genome-wide association studies (GWAS) have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although in generally small samples. Under the auspices of the International Collaboration for the Genomics of HIV, we have combined the genome-wide single nucleotide polymorphism (SNP) data collected by 25 cohorts, studies, or institutions on HIV-1 infected individuals and compared them to carefully matched population-level data sets (a list of all collaborators appears in Note S1 in Text S1). After imputation using the 1,000 Genomes Project reference panel, we tested approximately 8 million common DNA variants (SNPs and indels) for association with HIV-1 acquisition in 6,334 infected patients and 7,247 population samples of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6×10−11). However, restricting analysis to individuals with a known date of seroconversion suggested that this association was due to the frailty bias in studies of lethal diseases. Further analyses including testing recessive genetic models, testing for bulk effects of non-genome-wide significant variants, stratifying by sexual or parenteral transmission risk and testing previously reported associations showed no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity). Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size. PMID:23935489

  7. Association study of common genetic variants and HIV-1 acquisition in 6,300 infected cases and 7,200 controls.

    Directory of Open Access Journals (Sweden)

    Paul J McLaren

    Full Text Available Multiple genome-wide association studies (GWAS have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although in generally small samples. Under the auspices of the International Collaboration for the Genomics of HIV, we have combined the genome-wide single nucleotide polymorphism (SNP data collected by 25 cohorts, studies, or institutions on HIV-1 infected individuals and compared them to carefully matched population-level data sets (a list of all collaborators appears in Note S1 in Text S1. After imputation using the 1,000 Genomes Project reference panel, we tested approximately 8 million common DNA variants (SNPs and indels for association with HIV-1 acquisition in 6,334 infected patients and 7,247 population samples of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6 × 10⁻¹¹. However, restricting analysis to individuals with a known date of seroconversion suggested that this association was due to the frailty bias in studies of lethal diseases. Further analyses including testing recessive genetic models, testing for bulk effects of non-genome-wide significant variants, stratifying by sexual or parenteral transmission risk and testing previously reported associations showed no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity. Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size.

  8. HIV tropism and decreased risk of breast cancer.

    Directory of Open Access Journals (Sweden)

    Nancy A Hessol

    2010-12-01

    Full Text Available During the first two decades of the U.S. AIDS epidemic, and unlike some malignancies, breast cancer risk was significantly lower for women with human immunodeficiency virus (HIV infection compared to the general population. This deficit in HIV-associated breast cancer could not be attributed to differences in survival, immune deficiency, childbearing or other breast cancer risk factors. HIV infects mononuclear immune cells by binding to the CD4 molecule and to CCR5 or CXCR4 chemokine coreceptors. Neoplastic breast cells commonly express CXCR4 but not CCR5. In vitro, binding HIV envelope protein to CXCR4 has been shown to induce apoptosis of neoplastic breast cells. Based on these observations, we hypothesized that breast cancer risk would be lower among women with CXCR4-tropic HIV infection.We conducted a breast cancer nested case-control study among women who participated in the WIHS and HERS HIV cohort studies with longitudinally collected risk factor data and plasma. Cases were HIV-infected women (mean age 46 years who had stored plasma collected within 24 months of breast cancer diagnosis and an HIV viral load≥500 copies/mL. Three HIV-infected control women, without breast cancer, were matched to each case based on age and plasma collection date. CXCR4-tropism was determined by a phenotypic tropism assay. Odds ratios (OR and 95% confidence intervals (CI for breast cancer were estimated by exact conditional logistic regression. Two (9% of 23 breast cancer cases had CXCR4-tropic HIV, compared to 19 (28% of 69 matched controls. Breast cancer risk was significantly and independently reduced with CXCR4 tropism (adjusted odds ratio, 0.10, 95% CI 0.002-0.84 and with menopause (adjusted odds ratio, 0.08, 95% CI 0.001-0.83. Adjustment for CD4+ cell count, HIV viral load, and use of antiretroviral therapy did not attenuate the association between infection with CXCR4-tropic HIV and breast cancer.Low breast cancer risk with HIV is specifically linked

  9. eCD4-Ig variants that more potently neutralize HIV-1.

    Science.gov (United States)

    Fetzer, Ina; Gardner, Matthew R; Davis-Gardner, Meredith E; Prasad, Neha R; Alfant, Barnett; Weber, Jesse A; Farzan, Michael

    2018-03-28

    The HIV-1 entry inhibitor eCD4-Ig is a fusion of CD4-Ig and a coreceptor-mimetic peptide. eCD4-Ig is markedly more potent than CD4-Ig, with neutralization efficiencies approaching those of HIV-1 broadly neutralizing antibodies (bNAbs). However, unlike bNAbs, eCD4-Ig neutralizes all HIV-1, HIV-2 and SIV isolates that it has been tested against, suggesting that it may be useful in clinical settings where antibody escape is a concern. Here we characterize three new eCD4-Ig variants, each with different architectures and each utilizing D1.22, a stabilized form of CD4 domain 1. These variants were 10- to 20-fold more potent than our original eCD4-Ig variant, with a construct bearing four D1.22 domains (eD1.22-HL-Ig) exhibiting the greatest potency. However, this variant mediated less efficient antibody-dependent cell-mediated cytotoxicity (ADCC) activity than eCD4-Ig itself or several other eCD4-Ig variants, including the smallest variant (eD1.22-Ig). A variant with the same architecture as original eCD4-Ig (eD1.22-D2-Ig) showed modestly higher thermal stability and best prevented promotion of infection of CCR5-positive, CD4-negative cells. All three variants, and eCD4-Ig itself, mediated more efficient shedding of the HIV-1 envelope glycoprotein gp120 than did CD4-Ig. Finally, we show that only three D1.22 mutations contributed to the potency of eD1.22-D2-Ig, and that introduction of these changes into eCD4-Ig resulted in a variant 9-fold more potent than eCD4-Ig and 2-fold more potent than eD1.22-D2-Ig. These studies will assist in developing eCD4-Ig variants with properties optimized for prophylaxis, therapy, and cure applications. IMPORTANCE HIV-1 bNAbs have properties different from antiretroviral compounds. Specifically, antibodies can enlist immune effector cells to eliminate infected cells, whereas antiretroviral compounds simply interfere with various steps in the viral lifecycle. Unfortunately, HIV-1 is adept at evading antibody recognition, limiting the

  10. Phenotype Variation in Human Immunodeficiency virus Type 1 Transmission and Disease Progression

    Directory of Open Access Journals (Sweden)

    Mariangela Cavarelli

    2009-01-01

    Full Text Available Human immunodeficiency virus type I (HIV-1 infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly CCR5 and CXCR4. Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. Thus, R5 and X4 virus use respectively CCR5 and CXCR4, whereas R5X4 virus can use either CCR5 or CXCR4. This review describes the central role played by co-receptor expression and usage for HIV-1 cell tropism, transmission and pathogenesis. We discuss various hypotheses proposed to explain the preferential transmission of R5 viruses and the mechanisms driving the change of HIV-1 co-receptor usage in the course of infection. Recent insights in the intrinsic variability of R5 viruses and their role in influencing disease progression in both adults and children are also discussed.

  11. Phenotype variation in human immunodeficiency virus type 1 transmission and disease progression.

    Science.gov (United States)

    Cavarelli, Mariangela; Scarlatti, Gabriella

    2009-01-01

    Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly CCR5 and CXCR4. Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. Thus, R5 and X4 virus use respectively CCR5 and CXCR4, whereas R5X4 virus can use either CCR5 or CXCR4. This review describes the central role played by co-receptor expression and usage for HIV-1 cell tropism, transmission and pathogenesis. We discuss various hypotheses proposed to explain the preferential transmission of R5 viruses and the mechanisms driving the change of HIV-1 co-receptor usage in the course of infection. Recent insights in the intrinsic variability of R5 viruses and their role in influencing disease progression in both adults and children are also discussed.

  12. Genetic modification of mesenchymal stem cells overexpressing CCR1 increases cell viability, migration, engraftment, and capillary density in the injured myocardium.

    Science.gov (United States)

    Huang, Jing; Zhang, Zhiping; Guo, Jian; Ni, Aiguo; Deb, Arjun; Zhang, Lunan; Mirotsou, Maria; Pratt, Richard E; Dzau, Victor J

    2010-06-11

    Although mesenchymal stem cell (MSC) transplantation has been shown to promote cardiac repair in acute myocardial injury in vivo, its overall restorative capacity appears to be restricted mainly because of poor cell viability and low engraftment in the ischemic myocardium. Specific chemokines are upregulated in the infarcted myocardium. However the expression levels of the corresponding chemokine receptors (eg, CCR1, CXCR2) in MSCs are very low. We hypothesized that this discordance may account for the poor MSC engraftment and survival. To determine whether overexpression of CCR1 or CXCR2 chemokine receptors in MSCs augments their cell survival, migration and engraftment after injection in the infarcted myocardium. Overexpression of CCR1, but not CXCR2, dramatically increased chemokine-induced murine MSC migration and protected MSC from apoptosis in vitro. Moreover, when MSCs were injected intramyocardially one hour after coronary artery ligation, CCR1-MSCs accumulated in the infarcted myocardium at significantly higher levels than control-MSCs or CXCR2-MSCs 3 days postmyocardial infarction (MI). CCR1-MSC-injected hearts exhibited a significant reduction in infarct size, reduced cardiomyocytes apoptosis and increased capillary density in injured myocardium 3 days after MI. Furthermore, intramyocardial injection of CCR1-MSCs prevented cardiac remodeling and restored cardiac function 4 weeks after MI. Our results demonstrate the in vitro and in vivo salutary effects of genetic modification of stem cells. Specifically, overexpression of chemokine receptor enhances the migration, survival and engraftment of MSCs, and may provide a new therapeutic strategy for the injured myocardium.

  13. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation....

  14. Molecular Mechanism of Action for Allosteric Modulators and Agonists in CC-chemokine Receptor 5 (CCR5)

    DEFF Research Database (Denmark)

    Karlshøj, Stefanie; Amarandi, Roxana Maria; Larsen, Olav

    2016-01-01

    The small molecule metal ion chelators bipyridine and terpyridine complexed with Zn(2+) (ZnBip and ZnTerp) act as CCR5 agonists and strong positive allosteric modulators of CCL3 binding to CCR5, weak modulators of CCL4 binding, and competitors for CCL5 binding. Here we describe their binding site......Terp binds deeply in the major binding pocket and, in contrast to ZnBip, interacts directly with the Trp-248(VI:13/6.48) microswitch, contributing to its 8-fold higher potency. The impact of Trp-248 was further confirmed by ZnClTerp, a chloro-substituted version of ZnTerp that showed no inherent agonism...

  15. Maturation Pathways of Cross-Reactive HIV-1 Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Dimiter S. Dimitrov

    2009-11-01

    Full Text Available Several human monoclonal antibodies (hmAbs and antibody fragments, including the best characterized in terms of structure-function b12 and Fab X5, exhibit relatively potent and broad HIV-1 neutralizing activity. However, the elicitation of b12 or b12-like antibodies in vivo by vaccine immunogens based on the HIV-1 envelope glycoprotein (Env has not been successful. B12 is highly divergent from the closest corresponding germline antibody while X5 is less divergent. We have hypothesized that the relatively high degree of specific somatic hypermutations may preclude binding of the HIV-1 envelope glycoprotein (Env to closest germline antibodies, and that identifying antibodies that are intermediates in the pathways to maturation could help design novel vaccine immunogens to guide the immune system for their enhanced elicitation. In support of this hypothesis we have previously found that a germline-like b12 (monovalent and bivalent scFv as an Fc fusion protein or IgG lacks measurable binding to an Env as measured by ELISA with a sensitivity in the μM range [1]; here we present evidence confirming and expanding these findings for a panel of Envs. In contrast, a germline-like scFv X5 bound Env with high (nM affinity. To begin to explore the maturation pathways of these antibodies we identified several possible b12 intermediate antibodies and tested their neutralizing activity. These intermediate antibodies neutralized only some HIV-1 isolates and with relatively weak potency. In contrast, germline-like scFv X5 neutralized a subset of the tested HIV-1 isolates with comparable efficiencies to that of the mature X5. These results could help explain the relatively high immunogenicity of the coreceptor binding site on gp120 and the abundance of CD4-induced (CD4i antibodies in HIV-1-infected patients (X5 is a CD4i antibody as well as the maturation pathway of X5. They also can help identify antigens that can bind specifically to b12 germline and

  16. On relativistic irreducible quantum fields fulfilling CCR

    International Nuclear Information System (INIS)

    Baumann, K.

    1987-01-01

    Let phi be a relativistic scalar field fulfilling canonical commutation relations (CCR). Furthermore it is assumed that the time zero fields and momenta form an irreducible set. Based on estimates given by Herbst [I. W. Herbst, J. Math. Phys. 17, 1210 (1976)], and by methods developed by Powers [R. T. Powers, Commun. Math. Phys. 4, 145 (1967)], it is shown that phi has to be a free field in n>3 space dimensions. For n = 3 (resp. n = 2) restrictions that look similar to the restriction in a formal :phi 4 : 3 /sub +/ 1 (resp. :phi 6 : 2 /sub +/ 1 ) theory are obtained

  17. Moderate restriction of macrophage-tropic human immunodeficiency virus type 1 by SAMHD1 in monocyte-derived macrophages.

    Science.gov (United States)

    Taya, Kahoru; Nakayama, Emi E; Shioda, Tatsuo

    2014-01-01

    Macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains are able to grow to high titers in human monocyte-derived macrophages. However, it was recently reported that cellular protein SAMHD1 restricts HIV-1 replication in human cells of the myeloid lineage, including monocyte-derived macrophages. Here we show that degradation of SAMHD1 in monocyte-derived macrophages was associated with moderately enhanced growth of the macrophage-tropic HIV-1 strain. SAMHD1 degradation was induced by treating target macrophages with vesicular stomatitis virus glycoprotein-pseudotyped human immunodeficiency virus type 2 (HIV-2) particles containing viral protein X. For undifferentiated monocytes, HIV-2 particle treatment allowed undifferentiated monocytes to be fully permissive for productive infection by the macrophage-tropic HIV-1 strain. In contrast, untreated monocytes were totally resistant to HIV-1 replication. These results indicated that SAMHD1 moderately restricts even a macrophage-tropic HIV-1 strain in monocyte-derived macrophages, whereas the protein potently restricts HIV-1 replication in undifferentiated monocytes.

  18. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation.

    Science.gov (United States)

    Morrison, James H; Guevara, Rebekah B; Marcano, Adriana C; Saenz, Dyana T; Fadel, Hind J; Rogstad, Daniel K; Poeschla, Eric M

    2014-03-01

    BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env(-) particles do not. HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV tetherin antagonist is

  19. Increased chemokine signaling in a model of HIV1-associated peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Buchanan David J

    2009-08-01

    Full Text Available Abstract Painful distal sensory polyneuropathy (DSP is the most common neurological complication of HIV1 infection. Although infection with the virus itself is associated with an incidence of DSP, patients are more likely to become symptomatic following initiation of nucleoside reverse transcriptase inhibitor (NRTI treatment. The chemokines monocyte chemoattractant protein-1 (MCP1/CCL2 and stromal derived factor-1 (SDF1/CXCL12 and their respective receptors, CCR2 and CXCR4, have been implicated in HIV1 related neuropathic pain mechanisms including NRTI treatment in rodents. Utilizing a rodent model that incorporates the viral coat protein, gp120, and the NRTI, 2'3'-dideoxycytidine (ddC, we examined the degree to which chemokine receptor signaling via CCR2 and CXCR4 potentially influences the resultant chronic hypernociceptive behavior. We observed that following unilateral gp120 sciatic nerve administration, rats developed profound tactile hypernociception in the hindpaw ipsilateral to gp120 treatment. Behavioral changes were also present in the hindpaw contralateral to the injury, albeit delayed and less robust. Using immunohistochemical studies, we demonstrated that MCP1 and CCR2 were upregulated by primary sensory neurons in lumbar ganglia by post-operative day (POD 14. The functional nature of these observations was confirmed using calcium imaging in acutely dissociated lumbar dorsal root ganglion (DRG derived from gp120 injured rats at POD 14. Tactile hypernociception in gp120 treated animals was reversed following treatment with a CCR2 receptor antagonist at POD 14. Some groups of animals were subjected to gp120 sciatic nerve injury in combination with an injection of ddC at POD 14. This injury paradigm produced pronounced bilateral tactile hypernociception from POD 14–48. More importantly, functional MCP1/CCR2 and SDF1/CXCR4 signaling was present in sensory neurons. In contrast to gp120 treatment alone, the hypernociceptive behavior

  20. Use of four next-generation sequencing platforms to determine HIV-1 coreceptor tropism.

    Science.gov (United States)

    Archer, John; Weber, Jan; Henry, Kenneth; Winner, Dane; Gibson, Richard; Lee, Lawrence; Paxinos, Ellen; Arts, Eric J; Robertson, David L; Mimms, Larry; Quiñones-Mateu, Miguel E

    2012-01-01

    HIV-1 coreceptor tropism assays are required to rule out the presence of CXCR4-tropic (non-R5) viruses prior treatment with CCR5 antagonists. Phenotypic (e.g., Trofile™, Monogram Biosciences) and genotypic (e.g., population sequencing linked to bioinformatic algorithms) assays are the most widely used. Although several next-generation sequencing (NGS) platforms are available, to date all published deep sequencing HIV-1 tropism studies have used the 454™ Life Sciences/Roche platform. In this study, HIV-1 co-receptor usage was predicted for twelve patients scheduled to start a maraviroc-based antiretroviral regimen. The V3 region of the HIV-1 env gene was sequenced using four NGS platforms: 454™, PacBio® RS (Pacific Biosciences), Illumina®, and Ion Torrent™ (Life Technologies). Cross-platform variation was evaluated, including number of reads, read length and error rates. HIV-1 tropism was inferred using Geno2Pheno, Web PSSM, and the 11/24/25 rule and compared with Trofile™ and virologic response to antiretroviral therapy. Error rates related to insertions/deletions (indels) and nucleotide substitutions introduced by the four NGS platforms were low compared to the actual HIV-1 sequence variation. Each platform detected all major virus variants within the HIV-1 population with similar frequencies. Identification of non-R5 viruses was comparable among the four platforms, with minor differences attributable to the algorithms used to infer HIV-1 tropism. All NGS platforms showed similar concordance with virologic response to the maraviroc-based regimen (75% to 80% range depending on the algorithm used), compared to Trofile (80%) and population sequencing (70%). In conclusion, all four NGS platforms were able to detect minority non-R5 variants at comparable levels suggesting that any NGS-based method can be used to predict HIV-1 coreceptor usage.

  1. Use of four next-generation sequencing platforms to determine HIV-1 coreceptor tropism.

    Directory of Open Access Journals (Sweden)

    John Archer

    Full Text Available HIV-1 coreceptor tropism assays are required to rule out the presence of CXCR4-tropic (non-R5 viruses prior treatment with CCR5 antagonists. Phenotypic (e.g., Trofile™, Monogram Biosciences and genotypic (e.g., population sequencing linked to bioinformatic algorithms assays are the most widely used. Although several next-generation sequencing (NGS platforms are available, to date all published deep sequencing HIV-1 tropism studies have used the 454™ Life Sciences/Roche platform. In this study, HIV-1 co-receptor usage was predicted for twelve patients scheduled to start a maraviroc-based antiretroviral regimen. The V3 region of the HIV-1 env gene was sequenced using four NGS platforms: 454™, PacBio® RS (Pacific Biosciences, Illumina®, and Ion Torrent™ (Life Technologies. Cross-platform variation was evaluated, including number of reads, read length and error rates. HIV-1 tropism was inferred using Geno2Pheno, Web PSSM, and the 11/24/25 rule and compared with Trofile™ and virologic response to antiretroviral therapy. Error rates related to insertions/deletions (indels and nucleotide substitutions introduced by the four NGS platforms were low compared to the actual HIV-1 sequence variation. Each platform detected all major virus variants within the HIV-1 population with similar frequencies. Identification of non-R5 viruses was comparable among the four platforms, with minor differences attributable to the algorithms used to infer HIV-1 tropism. All NGS platforms showed similar concordance with virologic response to the maraviroc-based regimen (75% to 80% range depending on the algorithm used, compared to Trofile (80% and population sequencing (70%. In conclusion, all four NGS platforms were able to detect minority non-R5 variants at comparable levels suggesting that any NGS-based method can be used to predict HIV-1 coreceptor usage.

  2. Impairments, activity limitations and participation restrictions: Prevalence and associations among persons living with HIV/AIDS in British Columbia

    Directory of Open Access Journals (Sweden)

    Braitstein Paula

    2004-09-01

    Full Text Available Abstract Background To measure the prevalence of and associations among impairments, activity limitations and participation restrictions in persons living with HIV in British Columbia to inform support and care programs, policy and research. Methods A cross-sectional population-based sample of persons living with HIV in British Columbia was obtained through an anonymous survey sent to members of the British Columbia Persons With AIDS Society. The survey addressed the experience of physical and mental impairments, and the experience and level of activity limitations and participation restrictions. Associations were measured in three ways: 1 impact of types of impairment on social restriction; 2 impact of specific limitations on social restriction; and 3 independent association of overall impairments and limitations on restriction levels. Logistic regression was used to measure associations with social restriction, while ordinal logistic regression was used to measure associations with a three-category measure of restriction level. Results The survey was returned by 762 (50.5% of the BCPWA participants. Over ninety percent of the population experienced one or more impairments, with one-third reporting over ten. Prevalence of activity limitations and participation restrictions was 80.4% and 93.2%, respectively. The presence of social restrictions was most closely associated with mental function impairments (OR: 7.0 for impairment vs. no impairment; 95% CI: 4.7 – 10.4. All limitations were associated with social restriction. Among those with ≤ 200 CD4 cells/mm3, odds of being at a higher restriction level were lower among those on antiretrovirals (OR: 0.3 for antiretrovirals vs. no antiretrovirals; 95% CI: 0.1–0.9, while odds of higher restriction were increased with higher limitation (OR: 3.6 for limitation score of 15 vs. no limitation, 95%CI: 0.9–14.2; OR: 24.7 for limitation score > 5 vs. no limitation, 95%CI: 4.9–125.0. Among those

  3. Entry inhibitor-based microbicides are active in vitro against HIV-1 isolates from multiple genetic subtypes

    International Nuclear Information System (INIS)

    Ketas, Thomas J.; Schader, Susan M.; Zurita, Juan; Teo, Esther; Polonis, Victoria; Lu Min; Klasse, Per Johan; Moore, John P.

    2007-01-01

    Inhibitors of viral entry are under consideration as topical microbicides to prevent HIV-1 sexual transmission. Small molecules targeting HIV-1 gp120 (BMS-378806) or CCR5 (CMPD167), and a peptide fusion inhibitor (C52L), each blocks vaginal infection of macaques by a SHIV. A microbicide, however, must be active against multiple HIV-1 variants. We therefore tested BMS-C (a BMS-378806 derivative), CMPD167, C52L and the CXCR4 ligand AMD3465, alone and in combination, against 25 primary R5, 12 X4 and 7 R5X4 isolates from subtypes A-G. At high concentrations (0.1-1 μM), the replication of most R5 isolates in human donor lymphocytes was inhibited by > 90%. At lower concentrations, double and triple combinations were more effective than individual inhibitors. Similar results were obtained with X4 viruses when AMD3465 was substituted for CMPD167. The R5X4 viruses were inhibited by combining AMD3465 with CMPD167, or by the coreceptor-independent compounds. Thus, combining entry inhibitors may improve microbicide effectiveness

  4. Chemokine receptor Ccr1 drives neutrophil-mediated kidney immunopathology and mortality in invasive candidiasis.

    Directory of Open Access Journals (Sweden)

    Michail S Lionakis

    Full Text Available Invasive candidiasis is the 4(th leading cause of nosocomial bloodstream infection in the US with mortality that exceeds 40% despite administration of antifungal therapy; neutropenia is a major risk factor for poor outcome after invasive candidiasis. In a fatal mouse model of invasive candidiasis that mimics human bloodstream-derived invasive candidiasis, the most highly infected organ is the kidney and neutrophils are the major cellular mediators of host defense; however, factors regulating neutrophil recruitment have not been previously defined. Here we show that mice lacking chemokine receptor Ccr1, which is widely expressed on leukocytes, had selectively impaired accumulation of neutrophils in the kidney limited to the late phase of the time course of the model; surprisingly, this was associated with improved renal function and survival without affecting tissue fungal burden. Consistent with this, neutrophils from wild-type mice in blood and kidney switched from Ccr1(lo to Ccr1(high at late time-points post-infection, when Ccr1 ligands were produced at high levels in the kidney and were chemotactic for kidney neutrophils ex vivo. Further, when a 11 mixture of Ccr1(+/+ and Ccr1(-/- donor neutrophils was adoptively transferred intravenously into Candida-infected Ccr1(+/+ recipient mice, neutrophil trafficking into the kidney was significantly skewed toward Ccr1(+/+ cells. Thus, neutrophil Ccr1 amplifies late renal immunopathology and increases mortality in invasive candidiasis by mediating excessive recruitment of neutrophils from the blood to the target organ.

  5. MCP-1/CCR-2-double-deficiency severely impairs the migration of hematogenous inflammatory cells following transient cerebral ischemia in mice.

    Science.gov (United States)

    Schuette-Nuetgen, Katharina; Strecker, Jan-Kolja; Minnerup, Jens; Ringelstein, E Bernd; Schilling, Matthias

    2012-02-01

    Monocyte chemoattractant protein-1 (MCP-1) and its receptor CCR-2 are known to play a major role in inflammatory responses after cerebral ischemia. Mice deficient in either MCP-1 or CCR-2 have been reported to develop smaller infarct sizes and show decreased numbers of infiltrating inflammatory cells. In the present study we used green fluorescent protein (GFP) transgenic mice to investigate the effect of MCP-1/CCR-2-double deficiency on the recruitment of inflammatory cells in a model of both, mild and severe cerebral ischemia. We show that MCP-1/CCR-2-double deficiency virtually entirely abrogates the recruitment of hematogenous macrophages and significantly reduces neutrophil migration to the ischemic brain 4 and 7 days following focal cerebral ischemia. This argues for a predominant role of the MCP-1/CCR-2 axis in chemotaxis of monocytes despite a wide redundancy in the chemokine-receptor-system. Chemokine analysis revealed that even candidates known to be involved in monocyte and neutrophil recruitment like MIP-1α, CXCL-1, C5a, G-CSF and GM-CSF showed a reduced and delayed or even a lack of relevant compensatory response in MCP-1(-/-)/CCR-2(-/-)-mice. Solely, chemokine receptor 5 (CCR-5) increased early in both, but rose above wildtype levels at day 7 in MCP-1(-/-)/CCR-2(-/-)-animals, which might explain the higher number of activated microglial cells compared to control mice. Our study was, however, not powered to investigate infarct volumes. Further studies are needed to clarify whether these mechanisms of inflammatory cell recruitment might be essential for early infarct development and final infarct size and to evaluate potential therapeutic implications. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Transcriptional Reprogramming during Effector-to-Memory Transition Renders CD4+ T Cells Permissive for Latent HIV-1 Infection.

    Science.gov (United States)

    Shan, Liang; Deng, Kai; Gao, Hongbo; Xing, Sifei; Capoferri, Adam A; Durand, Christine M; Rabi, S Alireza; Laird, Gregory M; Kim, Michelle; Hosmane, Nina N; Yang, Hung-Chih; Zhang, Hao; Margolick, Joseph B; Li, Linghua; Cai, Weiping; Ke, Ruian; Flavell, Richard A; Siliciano, Janet D; Siliciano, Robert F

    2017-10-17

    The latent reservoir for HIV-1 in resting memory CD4 + T cells is the major barrier to curing HIV-1 infection. Studies of HIV-1 latency have focused on regulation of viral gene expression in cells in which latent infection is established. However, it remains unclear how infection initially becomes latent. Here we described a unique set of properties of CD4 + T cells undergoing effector-to-memory transition including temporary upregulation of CCR5 expression and rapid downregulation of cellular gene transcription. These cells allowed completion of steps in the HIV-1 life cycle through integration but suppressed HIV-1 gene transcription, thus allowing the establishment of latency. CD4 + T cells in this stage were substantially more permissive for HIV-1 latent infection than other CD4 + T cells. Establishment of latent HIV-1 infection in CD4 + T could be inhibited by viral-specific CD8 + T cells, a result with implications for elimination of latent HIV-1 infection by T cell-based vaccines. Copyright © 2017. Published by Elsevier Inc.

  7. Frequency and site mapping of HIV-1/SIVcpz, HIV- 2/SIVsmm and ...

    African Journals Online (AJOL)

    out to analyze the effects of various restriction enzymes on the HIV genome. A computer simulated model using Web cutter Version 2.0, and cytogenetic analysis. 339 restriction enzymes from Promega database, 10 HIV-1/SIVcpz genes, 10 HIV-2/SIVsmm genes and 10 other SIV genes. Gene sequences were fed into Web ...

  8. 38 CFR 1.462 - Confidentiality restrictions.

    Science.gov (United States)

    2010-07-01

    ... Sickle Cell Anemia § 1.462 Confidentiality restrictions. (a) General. The patient records to which §§ 1..., infection with the HIV, or sickle cell anemia may be acknowledged only if the patient's written consent is... with the HIV, or sickle cell anemia. (2) Any answer to a request for a disclosure of patient records...

  9. Evidence that Vpu modulates HIV-1 Gag-envelope interaction towards envelope incorporation and infectivity in a cell type dependent manner.

    Directory of Open Access Journals (Sweden)

    Archana Gautam

    Full Text Available The HIV-1 Vpu is required for efficient virus particle release from the plasma membrane and intracellular CD4 degradation in infected cells. In the present study, we found that the loss of virus infectivity as a result of envelope (Env incorporation defect caused by a Gag matrix (MA mutation (L30E was significantly alleviated by introducing a start codon mutation in vpu. Inactivation of Vpu partially restored the Env incorporation defect imposed by L30E substitution in MA. This effect was found to be comparable in cell types such as 293T, HeLa, NP2 and GHOST as well as in peripheral blood mononuclear cells (PBMC and monocyte-derived macrophages (MDM. However, in HeLa cells BST-2 knockdown was found to further alleviate the effect of Vpu inactivation on infectivity of L30E mutant. Our data demonstrated that the impaired infectivity of virus particles due to Env incorporation defect caused by MA mutation was modulated by start codon mutation in Vpu.

  10. Maturation of the viral core enhances the fusion of HIV-1 particles with primary human T cells and monocyte-derived macrophages

    International Nuclear Information System (INIS)

    Jiang Jiyang; Aiken, Christopher

    2006-01-01

    HIV-1 infection requires fusion of viral and cellular membranes in a reaction catalyzed by the viral envelope proteins gp120 and gp41. We recently reported that efficient HIV-1 particle fusion with target cells is linked to maturation of the viral core by an activity of the gp41 cytoplasmic domain. Here, we show that maturation enhances the fusion of a variety of recombinant viruses bearing primary and laboratory-adapted Env proteins with primary human CD4 + T cells. Overall, HIV-1 fusion was more dependent on maturation for viruses bearing X4-tropic envelope proteins than for R5-tropic viruses. Fusion of HIV-1 with monocyte-derived macrophages was also dependent on particle maturation. We conclude that the ability to couple fusion to particle maturation is a common feature of HIV-1 Env proteins and may play an important role during HIV-1 replication in vivo

  11. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells.

    Science.gov (United States)

    Oufir, Mouhssin; Bisset, Leslie R; Hoffmann, Stefan R K; Xue, Gongda; Klauser, Stephan; Bergamaschi, Bianca; Gervaix, Alain; Böni, Jürg; Schüpbach, Jörg; Gutte, Bernd

    2011-01-01

    An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  12. Chemokine Ligand 5 (CCL5 and chemokine receptor (CCR5 genetic variants and prostate cancer risk among men of African Descent: a case-control study

    Directory of Open Access Journals (Sweden)

    Kidd LaCreis R

    2012-11-01

    Full Text Available Abstract Background Chemokine and chemokine receptors play an essential role in tumorigenesis. Although chemokine-associated single nucleotide polymorphisms (SNPs are associated with various cancers, their impact on prostate cancer (PCA among men of African descent is unknown. Consequently, this study evaluated 43 chemokine-associated SNPs in relation to PCA risk. We hypothesized inheritance of variant chemokine-associated alleles may lead to alterations in PCA susceptibility, presumably due to variations in antitumor immune responses. Methods Sequence variants were evaluated in germ-line DNA samples from 814 African-American and Jamaican men (279 PCA cases and 535 controls using Illumina’s Goldengate genotyping system. Results Inheritance of CCL5 rs2107538 (AA, GA+AA and rs3817655 (AA, AG, AG+AA genotypes were linked with a 34-48% reduction in PCA risk. Additionally, the recessive and dominant models for CCR5 rs1799988 and CCR7 rs3136685 were associated with a 1.52-1.73 fold increase in PCA risk. Upon stratification, only CCL5 rs3817655 and CCR7 rs3136685 remained significant for the Jamaican and U.S. subgroups, respectively. Conclusions In summary, CCL5 (rs2107538, rs3817655 and CCR5 (rs1799988 sequence variants significantly modified PCA susceptibility among men of African descent, even after adjusting for age and multiple comparisons. Our findings are only suggestive and require further evaluation and validation in relation to prostate cancer risk and ultimately disease progression, biochemical/disease recurrence and mortality in larger high-risk subgroups. Such efforts will help to identify genetic markers capable of explaining disproportionately high prostate cancer incidence, mortality, and morbidity rates among men of African descent.

  13. Effectiveness and cost of treatment with maraviroc in HIV infection

    Directory of Open Access Journals (Sweden)

    Viola Sacchi

    2009-12-01

    Full Text Available Since 1995, life expectancy and quality of life of HIV patients improved significantly due to the use of Highly Active Anti-Retroviral Therapy (HAART, consisting of different combinations of three classes of antiretroviral agents, nucleoside and non-nucleoside reverse transcriptase inhibitors, and protease inhibitors. Recently, new treatment options for individuals developing resistance to these drugs have become available, with the appearance of new drug classes like integrase inhibitors, fusion inhibitors and CCR5 antagonists. Maraviroc is the first antiretroviral agent belonging to the latter drug class approved for clinical use. CCR5 receptor antagonists act by blocking the interaction of the HIV virus with the CCR5 chemokine receptor, a co-receptor essential to the entry process of R5-tropic viruses. The drug is indicated, in combination with other antiretroviral products, for treatment-experienced adult patients infected with only CCR5-tropic HIV-1 detectable virus strains. Results of main phase III clinical trials indicate that maraviroc, in combination with optimized background therapy (OBT, causes significantly greater reductions in viral load and increases in CD4+ cell count, as compared to OBT alone in this kind of patients. In Italy, the monthly cost of maraviroc therapy is about € 780. A number of economic evaluations, performed for different settings, demonstrate that the therapy including maraviroc is cost-effective if compared to OBT alone, determining an ICER generally below the threshold of three times the GDP per capita. In the Italian context, the ICER determined by OBT + maraviroc vs OBT alone is approximately 45,000 €/LYG.

  14. Cell-associated HIV DNA measured early during infection has prognostic value independent of serum HIV RNA measured concomitantly

    DEFF Research Database (Denmark)

    Katzenstein, Terese L; Oliveri, Roberto S; Benfield, Thomas

    2002-01-01

    Using data from the Danish AIDS Cohort of HIV-infected homosexual men established in the 1980s, the prognostic value of early HIV DNA loads was evaluated. In addition to DNA measurements, concomitant serum HIV RNA levels, CD4 cell counts and CCR5 genotypes were determined. The patients were divided...... of serum HIV RNA (p normal allele (p

  15. Chemokine Receptor Ccr1 Drives Neutrophil-Mediated Kidney Immunopathology and Mortality in Invasive Candidiasis

    Science.gov (United States)

    Lionakis, Michail S.; Swamydas, Muthulekha; Wan, Wuzhou; Richard Lee, Chyi-Chia; Cohen, Jeffrey I.; Scheinberg, Phillip; Gao, Ji-Liang; Murphy, Philip M.

    2012-01-01

    Invasive candidiasis is the 4th leading cause of nosocomial bloodstream infection in the US with mortality that exceeds 40% despite administration of antifungal therapy; neutropenia is a major risk factor for poor outcome after invasive candidiasis. In a fatal mouse model of invasive candidiasis that mimics human bloodstream-derived invasive candidiasis, the most highly infected organ is the kidney and neutrophils are the major cellular mediators of host defense; however, factors regulating neutrophil recruitment have not been previously defined. Here we show that mice lacking chemokine receptor Ccr1, which is widely expressed on leukocytes, had selectively impaired accumulation of neutrophils in the kidney limited to the late phase of the time course of the model; surprisingly, this was associated with improved renal function and survival without affecting tissue fungal burden. Consistent with this, neutrophils from wild-type mice in blood and kidney switched from Ccr1lo to Ccr1high at late time-points post-infection, when Ccr1 ligands were produced at high levels in the kidney and were chemotactic for kidney neutrophils ex vivo. Further, when a 11 mixture of Ccr1+/+ and Ccr1−/− donor neutrophils was adoptively transferred intravenously into Candida-infected Ccr1+/+ recipient mice, neutrophil trafficking into the kidney was significantly skewed toward Ccr1+/+ cells. Thus, neutrophil Ccr1 amplifies late renal immunopathology and increases mortality in invasive candidiasis by mediating excessive recruitment of neutrophils from the blood to the target organ. PMID:22916017

  16. Production and characterization of human anti-V3 monoclonal antibodies from the cells of HIV-1 infected Indian donors

    Directory of Open Access Journals (Sweden)

    Andrabi Raiees

    2012-09-01

    Full Text Available Abstract Background Analysis of human monoclonal antibodies (mAbs developed from HIV-1 infected donors have enormously contributed to the identification of neutralization sensitive epitopes on the HIV-1 envelope glycoprotein. The third variable region (V3 is a crucial target on gp120, primarily due to its involvement in co-receptor (CXCR4 or CCR5 binding and presence of epitopes recognized by broadly neutralizing antibodies. Methods Thirty-three HIV-1 seropositive drug naive patients (18 males and 15 females within the age range of 20–57 years (median = 33 years were recruited in this study for mAb production. The mAbs were selected from EBV transformed cultures with conformationally constrained Cholera-toxin-B containing V3C (V3C-CTB fusion protein. We tested the mAbs for their binding with HIV-1 derived proteins and peptides by ELISA and for neutralization against HIV-1 viruses by TZM-bl assays. Results We isolated three anti-V3 mAbs, 277, 903 and 904 from the cells of different individuals. The ELISA binding revealed a subtype-C and subtype-A specific binding of antibody 277 and 903 while mAb 904 exhibited cross reactivity also with subtype-B V3. Epitope mapping of mAbs with overlapping V3 peptides showed exclusive binding to V3 crown. The antibodies displayed high and low neutralizing activity against 2/5 tier 1 and 1/6 tier 2 viruses respectively. Overall, we observed a resistance of the tier 2 viruses to neutralization by the anti-V3 mAbs, despite the exposure of the epitopes recognized by these antibodies on two representative native viruses (Du156.12 and JRFL, suggesting that the affinity of mAb might equally be crucial for neutralization, as the epitope recognition. Conclusions Our study suggests that the anti-V3 antibodies derived from subtype-C infected Indian patients display neutralization potential against tier 1 viruses while such activity may be limited against more resistant tier 2 viruses. Defining the fine epitope

  17. The Era of HIV Cure Research | Michael | Annals of Ibadan ...

    African Journals Online (AJOL)

    Timothy Ray Brown is widely referred to as the first HIV patient to be cured of the disease. He received a CCR5 deficient bone marrow transplant as a treatment for Acute Myeloid Leukemia, with HAART controlled HIV-1 infection at the background. Seven years after the transplant, and discontinuation of HAART, he has been ...

  18. Langerhans Cells: the 'Yin and Yang' of HIV Restriction and Transmission.

    Science.gov (United States)

    Mayr, Luzia; Su, Bin; Moog, Christiane

    2017-03-01

    Langerhans cells are specialized sentinels present in the epidermis expressing Langerin, a specific C-type lectin receptor involved in HIV capture and destruction. Recently, the specific mechanism leading to this HIV restriction was discovered. Nevertheless, Langerhans cells can be infected and the way HIV escapes this restriction needs to be unraveled. Copyright © 2017. Published by Elsevier Ltd.

  19. HMGB1 Is Involved in IFN-α Production and TRAIL Expression by HIV-1-Exposed Plasmacytoid Dendritic Cells: Impact of the Crosstalk with NK Cells.

    Directory of Open Access Journals (Sweden)

    Héla Saïdi

    2016-02-01

    Full Text Available Plasmacytoid dendritic cells (pDCs are innate sensors of viral infections and important mediators of antiviral innate immunity through their ability to produce large amounts of IFN-α. Moreover, Toll-like receptor 7 (TLR7 and 9 (TLR9 ligands, such as HIV and CpG respectively, turn pDCs into TRAIL-expressing killer pDCs able to lyse HIV-infected CD4+ T cells. NK cells can regulate antiviral immunity by modulating pDC functions, and pDC production of IFN-α as well as cell-cell contact is required to promote NK cell functions. Impaired pDC-NK cell crosstalk was reported in the setting of HIV-1 infection, but the impact of HIV-1 on TRAIL expression and innate antiviral immunity during this crosstalk is unknown. Here, we report that low concentrations of CCR5-tropic HIV-1Ba-L promote the release of pro-inflammatory cytokines such as IFN-α, TNF-α, IFN-γ and IL-12, and CCR5-interacting chemokines (MIP-1α and MIP-1β in NK-pDCs co-cultures. At high HIV-1BaL concentrations, the addition of NK cells did not promote the release of these mediators, suggesting that once efficiently triggered by the virus, pDCs could not integrate new activating signals delivered by NK cells. However, high HIV-1BaL concentrations were required to trigger IFN-α-mediated TRAIL expression at the surface of both pDCs and NK cells during their crosstalk. Interestingly, we identified the alarmin HMGB1, released at pDC-NK cell synapse, as an essential trigger for the secretion of IFN-α and IFN-related soluble mediators during the interplay of HIV-1 exposed pDCs with NK cells. Moreover, HMGB1 was found crucial for mTRAIL translocation to the plasma membrane of both pDCs and NK cells during their crosstalk following pDC exposure to HIV-1. Data from serum analyses of circulating HMGB1, HMGB1-specific antibodies, sTRAIL and IP-10 in a cohort of 67 HIV-1+ patients argue for the in vivo relevance of these observations. Altogether, these findings identify HMGB1 as a trigger for IFN

  20. HMGB1 Is Involved in IFN-α Production and TRAIL Expression by HIV-1-Exposed Plasmacytoid Dendritic Cells: Impact of the Crosstalk with NK Cells.

    Science.gov (United States)

    Saïdi, Héla; Bras, Marlène; Formaglio, Pauline; Melki, Marie-Thérèse; Charbit, Bruno; Herbeuval, Jean-Philippe; Gougeon, Marie-Lise

    2016-02-01

    Plasmacytoid dendritic cells (pDCs) are innate sensors of viral infections and important mediators of antiviral innate immunity through their ability to produce large amounts of IFN-α. Moreover, Toll-like receptor 7 (TLR7) and 9 (TLR9) ligands, such as HIV and CpG respectively, turn pDCs into TRAIL-expressing killer pDCs able to lyse HIV-infected CD4+ T cells. NK cells can regulate antiviral immunity by modulating pDC functions, and pDC production of IFN-α as well as cell-cell contact is required to promote NK cell functions. Impaired pDC-NK cell crosstalk was reported in the setting of HIV-1 infection, but the impact of HIV-1 on TRAIL expression and innate antiviral immunity during this crosstalk is unknown. Here, we report that low concentrations of CCR5-tropic HIV-1Ba-L promote the release of pro-inflammatory cytokines such as IFN-α, TNF-α, IFN-γ and IL-12, and CCR5-interacting chemokines (MIP-1α and MIP-1β) in NK-pDCs co-cultures. At high HIV-1BaL concentrations, the addition of NK cells did not promote the release of these mediators, suggesting that once efficiently triggered by the virus, pDCs could not integrate new activating signals delivered by NK cells. However, high HIV-1BaL concentrations were required to trigger IFN-α-mediated TRAIL expression at the surface of both pDCs and NK cells during their crosstalk. Interestingly, we identified the alarmin HMGB1, released at pDC-NK cell synapse, as an essential trigger for the secretion of IFN-α and IFN-related soluble mediators during the interplay of HIV-1 exposed pDCs with NK cells. Moreover, HMGB1 was found crucial for mTRAIL translocation to the plasma membrane of both pDCs and NK cells during their crosstalk following pDC exposure to HIV-1. Data from serum analyses of circulating HMGB1, HMGB1-specific antibodies, sTRAIL and IP-10 in a cohort of 67 HIV-1+ patients argue for the in vivo relevance of these observations. Altogether, these findings identify HMGB1 as a trigger for IFN

  1. DMPD: Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited signalingpathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12960231 Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited sign...82. Epub 2003 Jul 22. (.png) (.svg) (.html) (.csml) Show Macrophage activation through CCR5- and CXCR4-media...on through CCR5- and CXCR4-mediated gp120-elicited signalingpathways. Authors Lee C, Liu QH, Tomkowicz B, Yi

  2. A predominance of R5-like HIV genotypes in vaginal secretions is associated with elevated plasma HIV-1 RNA levels and the absence of anti-retroviral therapy

    Directory of Open Access Journals (Sweden)

    Lacour Nedra

    2008-07-01

    Full Text Available Abstract HIV expressed in genital secretions provides the inoculum from which transmitting variants are selected, both in sexual transmission and mother-to-infant transmission during partuition. Characterization of HIV levels and genotypes found in vaginal secretions and the impact of anti-retroviral therapy (ART on this virus can provide valuable insight for the prevention of HIV transmission. Vaginal HIV was evaluated in a cohort of 43 women attending a New Orleans HIV outpatient clinic. Predominant vaginal genotypes were characterized as R5- or X4-like by heteroduplex tracking analyses of the envelope V3 region. Most women (67.4% shed R5-like genotypes in vaginal secretions which was associated with elevated plasma HIV levels (≥ 10,000 copies HIV-RNA/mL and absence of ART. Because R5-like genotypes are more frequently associated with transmission, these observations suggest that the majority of women shedding HIV in genital secretions present a transmission risk. The levels of vaginal virus were similar between both groups, but shedding of X4-like genotypes was associated with lower plasma viral loads and the use of ART, suggesting that ART use may impact the genotypes of virus found in the female genital compartment.

  3. Reanalysis of Coreceptor Tropism in HIV-1–Infected Adults Using a Phenotypic Assay with Enhanced Sensitivity

    Science.gov (United States)

    Goetz, Mathew Bidwell; Leduc, Robert; Skowron, Gail; Su, Zhaohui; Chan, Ellen S.; Heera, Jayyant; Chapman, Doug; Spritzler, John; Reeves, Jacqueline D.; Gulick, Roy M.; Coakley, Eoin

    2011-01-01

    The enhanced-sensitivity Trofile assay (TF-ES; Monogram Biosciences) was used to retest coreceptor tropism samples from 4 different cohorts of HIV-1–infected patients. Nine percent to 26% of patients with CCR5-tropic virus by the original Trofile assay had CXCR4-using virus by TF-ES. Lower CD4 cell counts were associated with CXCR4-using virus in all cohorts. PMID:21427401

  4. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells

    Directory of Open Access Journals (Sweden)

    Mouhssin Oufir

    2011-01-01

    Full Text Available An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  5. Comparison of chemokines (CCL-5 and SDF-1), chemokine receptors (CCR-5 and CXCR-4) and IL-6 levels in patients with different severities of depression.

    Science.gov (United States)

    Ogłodek, Ewa A; Szota, Anna; Just, Marek J; Moś, Danuta; Araszkiewicz, Aleksander

    2014-10-01

    Depression can be perceived as a psychoneuroimmunological disorder in which cytokines affecting the body's neurochemical and neuroendocrine functions play an important role. Among cytokines, chemokines participating in activation of the inflammatory response are considered to be crucial. 160 men and women were enrolled in the study. 120 of them were diagnosed with various types of depression. The mean age was 45.2 ± 4.5 years (range: 19-47 years). The control group consisted of 40 healthy individuals. The average age in this group was 42.4 ± 4.1 years. Plasma levels of chemokines and their receptors (CCL-5 - RANTES and CXCR-5, SDF-1 and CXCR-4), as well as of IL-6, were assessed by ELISA. There was an increase in SDF-1 and CCL-5 levels in women and men with different severities of depression, versus the control group. Also, an increase in the IL-6 levels, CXCR4 and CCR-5 receptors was observed in both women and men with all types of depression. Levels of SDF-1 and CCL-5 chemokines, as well as of CCR-5 and CXCR4 chemokine receptors, were higher in women than in men. The results of this study indicate the need for assessment of CCL-5 and SDF-1 chemokines levels, as they are likely markers of developing depression. Early measurement of these chemokines levels may be helpful in choosing the best pharmacotherapy. Copyright © 2014 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  6. TLR-4 engagement of dendritic cells confers a BST-2/tetherin-mediated restriction of HIV-1 infection to CD4+ T cells across the virological synapse

    Directory of Open Access Journals (Sweden)

    Blanchet Fabien P

    2013-01-01

    Full Text Available Abstract Background Dendritic cells and their subsets, located at mucosal surfaces, are among the first immune cells to encounter disseminating pathogens. The cellular restriction factor BST-2/tetherin (also known as CD317 or HM1.24 potently restricts HIV-1 release by retaining viral particles at the cell surface in many cell types, including primary cells such as macrophages. However, BST-2/tetherin does not efficiently restrict HIV-1 infection in immature dendritic cells. Results We now report that BST-2/tetherin expression in myeloid (myDC and monocyte-derived dendritic cells (DC can be significantly up-regulated by IFN-α treatment and TLR-4 engagement with LPS. In contrast to HeLa or 293T cells, infectious HIV-1 release in immature DC and IFN-α–matured DC was only modestly affected in the absence of Vpu compared to wild-type viruses. Strikingly, immunofluorescence analysis revealed that BST-2/tetherin was excluded from HIV containing tetraspanin-enriched microdomains (TEMs in both immature DC and IFN-α–matured DC. In contrast, in LPS-mediated mature DC, BST-2/tetherin exerted a significant restriction in transfer of HIV-1 infection to CD4+ T cells. Additionally, LPS, but not IFN-α stimulation of immature DC, leads to a dramatic redistribution of cellular restriction factors to the TEM as well as at the virological synapse between DC and CD4+ T cells. Conclusions In conclusion, we demonstrate that TLR-4 engagement in immature DC significantly up-regulates the intrinsic antiviral activity of BST-2/tetherin, during cis-infection of CD4+ T cells across the DC/T cell virological synapse. Manipulating the function and potency of cellular restriction factors such as BST-2/tetherin to HIV-1 infection, has implications in the design of antiviral therapeutic strategies.

  7. Expression pattern of Ccr2 and Cx3cr1 in inherited retinal degeneration.

    Science.gov (United States)

    Kohno, Hideo; Koso, Hideto; Okano, Kiichiro; Sundermeier, Thomas R; Saito, Saburo; Watanabe, Sumiko; Tsuneoka, Hiroshi; Sakai, Tsutomu

    2015-10-12

    Though accumulating evidence suggests that microglia, resident macrophages in the retina, and bone marrow-derived macrophages can cause retinal inflammation which accelerates photoreceptor cell death, the details of how these cells are activated during retinal degeneration (RD) remain uncertain. Therefore, it is important to clarify which cells play a dominant role in fueling retinal inflammation. However, distinguishing between microglia and macrophages is difficult using conventional techniques such as cell markers (e.g., Iba-1). Recently, two mouse models for visualizing chemokine receptors were established, Cx3cr1 (GFP/GFP) and Ccr2 (RFP/RFP) mice. As Cx3cr1 is expressed in microglia and Ccr2 is reportedly expressed in activated macrophages, these mice have the potential to distinguish microglia and macrophages, yielding novel information about the activation of these inflammatory cells and their individual roles in retinal inflammation. In this study, c-mer proto-oncogene tyrosine kinase (Mertk) (-/-) mice, which show photoreceptor cell death due to defective retinal pigment epithelium phagocytosis, were employed as an animal model of RD. Mertk (-/-) Cx3cr1 (GFP/+) Ccr2 (RFP/+) mice were established by breeding Mertk (-/-) , Cx3cr1 (GFP/GFP) , and Ccr2 (RFP/RFP) mice. The retinal morphology and pattern of inflammatory cell activation and invasion of Mertk (-/-) Cx3cr1 (GFP/+) Ccr2 (RFP/+) mice were evaluated using retina and retinal pigment epithelium (RPE) flat mounts, retinal sections, and flow cytometry. Four-week-old Mertk (-/-) Cx3cr1 (GFP/+) Ccr2 (RFP/+) mice showed Cx3cr1-GFP-positive microglia in the inner retina. Cx3cr1-GFP and Ccr2-RFP dual positive activated microglia were observed in the outer retina and subretinal space of 6- and 8-week-old animals. Ccr2-RFP single positive bone marrow-derived macrophages were observed to migrate into the retina of Mertk (-/-) Cx3cr1 (GFP/+) Ccr2 (RFP/+) mice. These invading cells were still observed in the

  8. HIV coreceptor phenotyping in the clinical setting.

    Science.gov (United States)

    Low, Andrew J; Swenson, Luke C; Harrigan, P Richard

    2008-01-01

    The introduction of CCR5 antagonists increases the options available for constructing antiretroviral regimens. However, this option is coupled with the caveat that patients should be tested for HIV coreceptor tropism prior to initiating CCR5 antagonist-based therapy. Failure to screen for CXCR4 usage increases the risk of using an ineffective drug, thus reducing the likelihood of viral suppression and increasing their risk for developing antiretroviral resistance. This review discusses current and future methods of determining HIV tropism, with a focus on their utility in the clinical setting for screening purposes. Some of these methods include recombinant phenotypic tests, such as the Monogram Trofile assay, as well as genotype-based predictors, heteroduplex tracking assays, and flow cytometry based methods. Currently, the best evidence supports the use of phenotypic methods, although other methods of screening for HIV coreceptor usage prior to the administration of CCR5 antagonists may reduce costs and increase turnaround time over phenotypic methods. The presence of low levels of X4 virus is a challenge to all assay methods, resulting in reduced sensitivity in clinical, patient-derived samples when compared to clonally derived samples. Gaining a better understanding of the output of these assays and correlating them with clinical progression and therapy response will provide some indication on how both genotype-based, and phenotypic assays for determining HIV coreceptor usage can be improved. In addition, leveraging new technologies capable of detecting low-level minority species may provide the most significant advances in ensuring that individuals with low levels of dual/mixed tropic virus are not inadvertently prescribed CCR5 antagonists.

  9. Impact of Multi-Targeted Antiretroviral Treatment on Gut T Cell Depletion and HIV Reservoir Seeding during Acute HIV Infection

    Science.gov (United States)

    Ananworanich, Jintanat; Schuetz, Alexandra; Vandergeeten, Claire; Sereti, Irini; de Souza, Mark; Rerknimitr, Rungsun; Dewar, Robin; Marovich, Mary; van Griensven, Frits; Sekaly, Rafick; Pinyakorn, Suteeraporn; Phanuphak, Nittaya; Trichavaroj, Rapee; Rutvisuttinunt, Wiriya; Chomchey, Nitiya; Paris, Robert; Peel, Sheila; Valcour, Victor; Maldarelli, Frank; Chomont, Nicolas; Michael, Nelson; Phanuphak, Praphan; Kim, Jerome H.

    2012-01-01

    Background Limited knowledge exists on early HIV events that may inform preventive and therapeutic strategies. This study aims to characterize the earliest immunologic and virologic HIV events following infection and investigates the usage of a novel therapeutic strategy. Methods and Findings We prospectively screened 24,430 subjects in Bangkok and identified 40 AHI individuals. Thirty Thais were enrolled (8 Fiebig I, 5 Fiebig II, 15 Fiebig III, 2 Fiebig IV) of whom 15 completed 24 weeks of megaHAART (tenofovir/emtricitabine/efavirenz/raltegravir/maraviroc). Sigmoid biopsies were completed in 24/30 at baseline and 13/15 at week 24. At baseline, the median age was 29 years and 83% were MSM. Most were symptomatic (87%), and were infected with R5-tropic (77%) CRF01_AE (70%). Median CD4 was 406 cells/mm3. HIV RNA was 5.5 log10 copies/ml. Median total blood HIV DNA was higher in Fiebig III (550 copy/106 PBMC) vs. Fiebig I (8 copy/106 PBMC) (p = 0.01) while the median %CD4+CCR5+ gut T cells was lower in Fiebig III (19%) vs. Fiebig I (59%) (p = 0.0008). After 24 weeks of megaHAART, HIV RNA levels of HIV DNA at week 0 predicted reservoir size at week 24 (pHIV DNA declined significantly and was undetectable in 3 of 15 in blood and 3 of 7 in gut. Frequency of CD4+CCR5+ gut T cells increased from 41% at baseline to 64% at week 24 (p>0.050); subjects with less than 40% at baseline had a significant increase in CD4+CCR5+ T cells from baseline to week 24 (14% vs. 71%, p = 0.02). Conclusions Gut T cell depletion and HIV reservoir seeding increases with progression of AHI. MegaHAART was associated with immune restoration and reduced reservoir size. Our findings could inform research on strategies to achieve HIV drug-free remission. PMID:22479485

  10. A genome-wide association study of resistance to HIV infection in highly exposed uninfected individuals with hemophilia A

    Science.gov (United States)

    Lane, Jérôme; McLaren, Paul J.; Dorrell, Lucy; Shianna, Kevin V.; Stemke, Amanda; Pelak, Kimberly; Moore, Stephen; Oldenburg, Johannes; Alvarez-Roman, Maria Teresa; Angelillo-Scherrer, Anne; Boehlen, Francoise; Bolton-Maggs, Paula H.B.; Brand, Brigit; Brown, Deborah; Chiang, Elaine; Cid-Haro, Ana Rosa; Clotet, Bonaventura; Collins, Peter; Colombo, Sara; Dalmau, Judith; Fogarty, Patrick; Giangrande, Paul; Gringeri, Alessandro; Iyer, Rathi; Katsarou, Olga; Kempton, Christine; Kuriakose, Philip; Lin, Judith; Makris, Mike; Manco-Johnson, Marilyn; Tsakiris, Dimitrios A.; Martinez-Picado, Javier; Mauser-Bunschoten, Evelien; Neff, Anne; Oka, Shinichi; Oyesiku, Lara; Parra, Rafael; Peter-Salonen, Kristiina; Powell, Jerry; Recht, Michael; Shapiro, Amy; Stine, Kimo; Talks, Katherine; Telenti, Amalio; Wilde, Jonathan; Yee, Thynn Thynn; Wolinsky, Steven M.; Martinson, Jeremy; Hussain, Shehnaz K.; Bream, Jay H.; Jacobson, Lisa P.; Carrington, Mary; Goedert, James J.; Haynes, Barton F.; McMichael, Andrew J.; Goldstein, David B.; Fellay, Jacques

    2013-01-01

    Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979–1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this population. PMID:23372042

  11. TFH cells accumulate in mucosal tissues of humanized-DRAG mice and are highly permissive to HIV-1

    OpenAIRE

    Allam, Atef; Majji, Sai; Peachman, Kristina; Jagodzinski, Linda; Kim, Jiae; Ratto-Kim, Silvia; Wijayalath, Wathsala; Merbah, Melanie; Kim, Jerome H.; Michael, Nelson L.; Alving, Carl R.; Casares, Sofia; Rao, Mangala

    2015-01-01

    CD4+ T follicular helper cells (TFH) in germinal centers are required for maturation of B-cells. While the role of TFH-cells has been studied in blood and lymph nodes of HIV-1 infected individuals, its role in the mucosal tissues has not been investigated. We show that the gut and female reproductive tract (FRT) of humanized DRAG mice have a high level of human lymphocytes and a high frequency of TFH (CXCR5+PD-1++) and precursor-TFH (CXCR5+PD-1+) cells. The majority of TFH-cells expressed CCR...

  12. Binding kinetics of aptamers to gp120 derived from HIV-1 subtype C

    CSIR Research Space (South Africa)

    Millroy, L

    2011-02-01

    Full Text Available aptamers with specific and strong affinity to the HIV-1 envelope glycoprotein gp120 and act as novel HIV-1 entry inhibitor drugs or as targeted drug delivery systems to HIV-1 infected cells. Prior to any downstream applications, novel gp120 aptamers need...

  13. HIVBrainSeqDB: a database of annotated HIV envelope sequences from brain and other anatomical sites

    Directory of Open Access Journals (Sweden)

    O'Connor Niall

    2010-12-01

    Full Text Available Abstract Background The population of HIV replicating within a host consists of independently evolving and interacting sub-populations that can be genetically distinct within anatomical compartments. HIV replicating within the brain causes neurocognitive disorders in up to 20-30% of infected individuals and is a viral sanctuary site for the development of drug resistance. The primary determinant of HIV neurotropism is macrophage tropism, which is primarily determined by the viral envelope (env gene. However, studies of genetic aspects of HIV replicating in the brain are hindered because existing repositories of HIV sequences are not focused on neurotropic virus nor annotated with neurocognitive and neuropathological status. To address this need, we constructed the HIV Brain Sequence Database. Results The HIV Brain Sequence Database is a public database of HIV envelope sequences, directly sequenced from brain and other tissues from the same patients. Sequences are annotated with clinical data including viral load, CD4 count, antiretroviral status, neurocognitive impairment, and neuropathological diagnosis, all curated from the original publication. Tissue source is coded using an anatomical ontology, the Foundational Model of Anatomy, to capture the maximum level of detail available, while maintaining ontological relationships between tissues and their subparts. 44 tissue types are represented within the database, grouped into 4 categories: (i brain, brainstem, and spinal cord; (ii meninges, choroid plexus, and CSF; (iii blood and lymphoid; and (iv other (bone marrow, colon, lung, liver, etc. Patient coding is correlated across studies, allowing sequences from the same patient to be grouped to increase statistical power. Using Cytoscape, we visualized relationships between studies, patients and sequences, illustrating interconnections between studies and the varying depth of sequencing, patient number, and tissue representation across studies

  14. Composition and Antigenic Effects of Individual Glycan Sites of a Trimeric HIV-1 Envelope Glycoprotein

    Directory of Open Access Journals (Sweden)

    Anna-Janina Behrens

    2016-03-01

    Full Text Available The HIV-1 envelope glycoprotein trimer is covered by an array of N-linked glycans that shield it from immune surveillance. The high density of glycans on the trimer surface imposes steric constraints limiting the actions of glycan-processing enzymes, so that multiple under-processed structures remain on specific areas. These oligomannose glycans are recognized by broadly neutralizing antibodies (bNAbs that are not thwarted by the glycan shield but, paradoxically, target it. Our site-specific glycosylation analysis of a soluble, recombinant trimer (BG505 SOSIP.664 maps the extremes of simplicity and diversity of glycan processing at individual sites and reveals a mosaic of dense clusters of oligomannose glycans on the outer domain. Although individual sites usually minimally affect the global integrity of the glycan shield, we identify examples of how deleting some glycans can subtly influence neutralization by bNAbs that bind at distant sites. The network of bNAb-targeted glycans should be preserved on vaccine antigens.

  15. Clustering of HIV-1 Subtypes Based on gp120 V3 Loop electrostatic properties

    International Nuclear Information System (INIS)

    López de Victoria, Aliana; Kieslich, Chris A; Rizos, Apostolos K; Krambovitis, Elias; Morikis, Dimitrios

    2012-01-01

    The V3 loop of the glycoprotein gp120 of HIV-1 plays an important role in viral entry into cells by utilizing as coreceptor CCR5 or CXCR4, and is implicated in the phenotypic tropisms of HIV viruses. It has been hypothesized that the interaction between the V3 loop and CCR5 or CXCR4 is mediated by electrostatics. We have performed hierarchical clustering analysis of the spatial distributions of electrostatic potentials and charges of V3 loop structures containing consensus sequences of HIV-1 subtypes. Although the majority of consensus sequences have a net charge of +3, the spatial distribution of their electrostatic potentials and charges may be a discriminating factor for binding and infectivity. This is demonstrated by the formation of several small subclusters, within major clusters, which indicates common origin but distinct spatial details of electrostatic properties. Some of this information may be present, in a coarse manner, in clustering of sequences, but the spatial details are largely lost. We show the effect of ionic strength on clustering of electrostatic potentials, information that is not present in clustering of charges or sequences. We also make correlations between clustering of electrostatic potentials and net charge, coreceptor selectivity, global prevalence, and geographic distribution. Finally, we interpret coreceptor selectivity based on the N 6 X 7 T 8 |S 8 X 9 sequence glycosylation motif, the specific positive charge location according to the 11/24/25 rule, and the overall charge and electrostatic potential distribution. We propose that in addition to the sequence and the net charge of the V3 loop of each subtype, the spatial distributions of electrostatic potentials and charges may also be important factors for receptor recognition and binding and subsequent viral entry into cells. This implies that the overall electrostatic potential is responsible for long-range recognition of the V3 loop with coreceptors CCR5/CXCR4, whereas the charge

  16. Clustering of HIV-1 Subtypes Based on gp120 V3 Loop electrostatic properties

    Directory of Open Access Journals (Sweden)

    López de Victoria Aliana

    2012-02-01

    Full Text Available Abstract Background The V3 loop of the glycoprotein gp120 of HIV-1 plays an important role in viral entry into cells by utilizing as coreceptor CCR5 or CXCR4, and is implicated in the phenotypic tropisms of HIV viruses. It has been hypothesized that the interaction between the V3 loop and CCR5 or CXCR4 is mediated by electrostatics. We have performed hierarchical clustering analysis of the spatial distributions of electrostatic potentials and charges of V3 loop structures containing consensus sequences of HIV-1 subtypes. Results Although the majority of consensus sequences have a net charge of +3, the spatial distribution of their electrostatic potentials and charges may be a discriminating factor for binding and infectivity. This is demonstrated by the formation of several small subclusters, within major clusters, which indicates common origin but distinct spatial details of electrostatic properties. Some of this information may be present, in a coarse manner, in clustering of sequences, but the spatial details are largely lost. We show the effect of ionic strength on clustering of electrostatic potentials, information that is not present in clustering of charges or sequences. We also make correlations between clustering of electrostatic potentials and net charge, coreceptor selectivity, global prevalence, and geographic distribution. Finally, we interpret coreceptor selectivity based on the N6X7T8|S8X9 sequence glycosylation motif, the specific positive charge location according to the 11/24/25 rule, and the overall charge and electrostatic potential distribution. Conclusions We propose that in addition to the sequence and the net charge of the V3 loop of each subtype, the spatial distributions of electrostatic potentials and charges may also be important factors for receptor recognition and binding and subsequent viral entry into cells. This implies that the overall electrostatic potential is responsible for long-range recognition of the V3

  17. Psoralen/UV inactivation of HIV-1-infected cells for use in cytologic and immunologic procedures

    International Nuclear Information System (INIS)

    Watson, A.J.; Klaniecki, J.; Hanson, C.V.

    1990-01-01

    A rapid procedure for the inactivation of HIV-1-infected cells using psoralen and ultraviolet (UV) light is described. Exposure of HIV-1-infected cells to 5 micrograms/ml psoralen followed by UV irradiation (320-380 nm) for 5 minutes yields cells that are noninfectious as assessed by extended infectivity assays. The psoralen/UV inactivation procedure described is effective with cells chronically or acutely infected with HIV-1 and is unaffected by cell densities up to 12 x 10(6)/ml. At 5 micrograms/ml psoralen does little damage to cellular permeability as shown by the ability of treated cells to exclude trypan blue and propidium iodide. Psoralen/UV treatment of HIV-1-infected cells does not cause a significant decrease in the reactivity of HIV-1 core and envelope antigens or cellular antigens to monoclonal antibodies. Experiments are presented demonstrating the use of these cells for flow cytometry studies and for cell surface labeling using the lactoperoxidase 125 I iodination procedure

  18. Development of an inflammation imaging tracer, 111In-DOTA-DAPTA, targeting chemokine receptor CCR5 and preliminary evaluation in an ApoE-/- atherosclerosis mouse model.

    Science.gov (United States)

    Wei, Lihui; Petryk, Julia; Gaudet, Chantal; Kamkar, Maryam; Gan, Wei; Duan, Yin; Ruddy, Terrence D

    2018-02-07

    Chemokine receptor 5 (CCR5) plays an important role in atherosclerosis. Our objective was to develop a SPECT tracer targeting CCR5 for imaging plaque inflammation by radiolabeling D-Ala-peptide T-amide (DAPTA), a CCR5 antagonist, with 111 In. 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) conjugated DAPTA (DOTA-DAPTA) was labeled with 111 In. Cell uptake studies were conducted in U87-CD4-CCR5 and U87-MG cells. Biodistribution was determined in C57BL/6 mice. Autoradiography, en face and Oil Red O (ORO) imaging studies were performed in ApoE -/- mice. DOTA-DAPTA was radiolabeled with 111 In with high radiochemical purity (> 98%) and specific activity (70 MBq·nmol). 111 In-DOTA-DAPTA exhibited fast blood and renal clearance and high spleen uptake. The U87-CD4-CCR5 cells had significantly higher uptake in comparison to the U87-MG cells. The cell uptake was reduced by three times with DAPTA, indicating the receptor specificity of the uptake. Autoradiographic images showed significantly higher lesion uptake of 111 In-DOTA-DAPTA in ApoE -/- mice than that in C57BL/6 mice. The tracer uptake in 4 month old ApoE -/- high fat diet (HFD) mice with blocking agent was twofold lower than the same mice without the blocking agent, demonstrating the specificity of the tracer for the CCR5 receptor. 111 In-DOTA-DAPTA, specifically targeting chemokine receptor CCR5, is a potential SPECT agent for imaging inflammation in atherosclerosis.

  19. Escape from Human Immunodeficiency Virus Type 1 (HIV-1 Entry Inhibitors

    Directory of Open Access Journals (Sweden)

    Carol D. Weiss

    2012-12-01

    Full Text Available The human immunodeficiency virus (HIV enters cells through a series of molecular interactions between the HIV envelope protein and cellular receptors, thus providing many opportunities to block infection. Entry inhibitors are currently being used in the clinic, and many more are under development. Unfortunately, as is the case for other classes of antiretroviral drugs that target later steps in the viral life cycle, HIV can become resistant to entry inhibitors. In contrast to inhibitors that block viral enzymes in intracellular compartments, entry inhibitors interfere with the function of the highly variable envelope glycoprotein as it continuously adapts to changing immune pressure and available target cells in the extracellular environment. Consequently, pathways and mechanisms of resistance for entry inhibitors are varied and often involve mutations across the envelope gene. This review provides a broad overview of entry inhibitor resistance mechanisms that inform our understanding of HIV entry and the design of new inhibitors and vaccines.

  20. Cellular specificity of HIV-1 replication can be controlled by LTR sequences

    International Nuclear Information System (INIS)

    Reed-Inderbitzin, Edward; Maury, Wendy

    2003-01-01

    Two well-established determinants of retroviral tropism are envelope sequences that regulate entry and LTR sequences that can regulate viral expression in a cell-specific manner. Studies with human immunodeficiency virus-1 (HIV-1) have demonstrated that tropism of this virus maps primarily to variable envelope sequences. Studies have demonstrated that T cell and macrophage-specific transcription factor binding motifs exist in the upstream region of the LTR U3; however, the ability of the core enhancer/promoter proximal elements (two NF-κB and three Sp1 sites) to function well in macrophages and T cells have led many to conclude that HIV LTR sequences are not primary determinants of HIV tropism. To determine if cellular specificity could be imparted to HIV by the core enhancer elements, the enhancer/promoter proximal region of the HIV LTR was substituted with motifs that control gene expression in a myeloid-specific manner. The enhancer region from equine infectious anemia virus (EIAV) when substituted for the HIV enhancer/promoter proximal region was found to drive expression in a macrophage-specific manner and was responsive to HIV Tat. The addition of a 5' methylation-dependent binding site (MDBP) and a promoter proximal Sp1 motif increased expression without altering cellular specificity. Spacing between the promoter proximal region and the TATA box was also found to influence LTR activity. Infectivity studies using chimeric LTRs within the context of a dual-tropic infectious molecular clone established that these LTRs directed HIV replication and production of infectious virions in macrophages but not primary T cells or T cell lines. This investigation demonstrates that cellular specificity can be imparted onto HIV-1 replication at the level of viral transcription and not entry

  1. CCR presentations at AACR | Center for Cancer Research

    Science.gov (United States)

    CCR presentations at AACR Several CCR scientists will present their research at the AACR Annual Meeting in Washington, D.C., between April 1-5, 2017. Selected oral presentations are listed below. A full list of abstracts can be found on the AACR website.

  2. Feline tetherin is characterized by a short N-terminal region and is counteracted by the feline immunodeficiency virus envelope glycoprotein.

    Science.gov (United States)

    Celestino, Michele; Calistri, Arianna; Del Vecchio, Claudia; Salata, Cristiano; Chiuppesi, Flavia; Pistello, Mauro; Borsetti, Alessandra; Palù, Giorgio; Parolin, Cristina

    2012-06-01

    Tetherin (BST2) is the host cell factor that blocks the particle release of some enveloped viruses. Two putative feline tetherin proteins differing at the level of the N-terminal coding region have recently been described and tested for their antiviral activity. By cloning and comparing the two reported feline tetherins (called here cBST2(504) and cBST2*) and generating specific derivative mutants, this study provides evidence that feline tetherin has a shorter intracytoplasmic domain than those of other known homologues. The minimal tetherin promoter was identified and assayed for its ability to drive tetherin expression in an alpha interferon-inducible manner. We also demonstrated that cBST2(504) is able to dimerize, is localized at the cellular membrane, and impairs human immunodeficiency virus type 1 (HIV-1) particle release, regardless of the presence of the Vpu antagonist accessory protein. While cBST2(504) failed to restrict wild-type feline immunodeficiency virus (FIV) egress, FIV mutants, bearing a frameshift at the level of the envelope-encoding region, were potently blocked. The transient expression of the FIV envelope glycoprotein was able to rescue mutant particle release from feline tetherin-positive cells but did not antagonize human BST2 activity. Moreover, cBST2(504) was capable of specifically immunoprecipitating the FIV envelope glycoprotein. Finally, cBST2(504) also exerted its function on HIV-2 ROD10 and on the simian immunodeficiency virus SIVmac239. Taken together, these results show that feline tetherin does indeed have a short N-terminal region and that the FIV envelope glycoprotein is the predominant factor counteracting tetherin restriction.

  3. Analysis of Staphylococcal cassette chromosome mec in Staphylococcus haemolyticus and Staphylococcus sciuri: identification of a novel ccr gene complex with a newly identified ccrA allotype (ccrA7).

    Science.gov (United States)

    Urushibara, Noriko; Paul, Shyamal Kumar; Hossain, Mohammad Akram; Kawaguchiya, Mitsuyo; Kobayashi, Nobumichi

    2011-06-01

    Methicillin resistance in staphylococci is conferred by the acquisition in its chromosome of the mecA gene, which is located on a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec). Genetic type of SCCmec is defined by combination of mec gene complex class and cassette chromosome recombinase gene (ccr) allotype. In this study, we analyzed genetic diversity of the SCCmec in 11 Staphylococcus haemolyticus strains and a Staphylococcus sciuri strain, which were recently isolated from clinical specimens in Bangladesh. Among these strains, only two S. haemolyticus strains were proved to have the known types of SCCmec, that is, SCCmec V (class C2 mec-ccrC) and VII (class C1 mec-ccrC). Five S. haemolyticus strains were assigned two unique mec-ccr gene complexes combination; that is, class C1 mec-ccrA4B4 (four isolates) and class A mec-ccrC (one isolate). In the remaining four S. haemolyticus strains with class C1 mec, no known ccr allotypes could be detected. A single S. sciuri strain with class A mec complex carried a ccrA gene belonging to a novel allotype designated ccrA7, together with ccrB3. The ccrA7 gene in the S. sciuri strain showed 61.7%-82.7% sequence identity to the ccrA gene sequences published so far, and 75.3% identity to ccrA3, which is a component of the type 3 ccr complex (ccrA3-ccrB3) in methicillin-resistant Staphylococcus aureus. The results of the present study indicated that mec gene complex and ccr genes in coagulase-negative staphylococci are highly divergent, and distinct from those of common methicillin-resistant S. aureus. Identification of the novel ccrA7 allotype combined with ccrB3 suggested an occurrence of recombination between different ccr complexes in nature.

  4. Genetic architecture of HIV-1 genes circulating in north India & their functional implications.

    Science.gov (United States)

    Neogi, Ujjwal; Sood, Vikas; Ronsard, Larence; Singh, Jyotsna; Lata, Sneh; Ramachandran, V G; Das, S; Wanchu, Ajay; Banerjea, Akhil C

    2011-12-01

    This review presents data on genetic and functional analysis of some of the HIV-1 genes derived from HIV-1 infected individuals from north India (Delhi, Punjab and Chandigarh). We found evidence of novel B/C recombinants in HIV-1 LTR region showing relatedness to China/Myanmar with 3 copies of Nfκb sites; B/C/D mosaic genomes for HIV-1 Vpr and novel B/C Tat. We reported appearance of a complex recombinant form CRF_02AG of HIV-1 envelope sequences which is predominantly found in Central/Western Africa. Also one Indian HIV-1 envelope subtype C sequence suggested exclusive CXCR4 co-receptor usage. This extensive recombination, which is observed in about 10 per cent HIV-1 infected individuals in the Vpr genes, resulted in remarkably altered functions when compared with prototype subtype B Vpr. The Vpu C was found to be more potent in causing apoptosis when compared with Vpu B when analyzed for subG1 DNA content. The functional implications of these changes as well as in other genes of HIV-1 are discussed in detail with possible implications for subtype-specific pathogenesis highlighted.

  5. The mitochondrial translocator protein, TSPO, inhibits HIV-1 envelope glycoprotein biosynthesis via the endoplasmic reticulum-associated protein degradation pathway.

    Science.gov (United States)

    Zhou, Tao; Dang, Ying; Zheng, Yong-Hui

    2014-03-01

    The HIV-1 Env glycoprotein is folded in the endoplasmic reticulum (ER), which is necessary for viral entry and replication. Currently, it is still unclear how this process is regulated. The glycoprotein folding in the ER is controlled by the ER-associated protein degradation (ERAD) pathway, which specifically targets misfolded proteins for degradation. Previously, we reported that HIV-1 replication is restricted in the human CD4(+) T cell line CEM.NKR (NKR). To understand this mechanism, we first analyzed cellular protein expression in NKR cells and discovered that levels of the mitochondrial translocator protein TSPO were upregulated by ∼64-fold. Notably, when NKR cells were treated with TSPO antagonist PK-11195, Ro5-4864, or diazepam, HIV restriction was completely disrupted, and TSPO knockdown by short hairpin RNAs (shRNAs) achieved a similar effect. We next analyzed viral protein expression, and, interestingly, we discovered that Env expression was specifically inhibited. Both TSPO knockdown and treatment with TSPO antagonist could restore Env expression in NKR cells. We further discovered that Env proteins were rapidly degraded and that kifunensine, an ERAD pathway inhibitor, could restore Env expression and viral replication, indicating that Env proteins were misfolded and degraded through the ERAD pathway in NKR cells. We also knocked out the TSPO gene in 293T cells using CRISPR/Cas9 (clustered, regularly interspaced, short palindromic repeat [CRISPR]/CRISPR-associated-9) technology and found that TSPO could similarly inhibit Env expression in these cells. Taken together, these results demonstrate that TSPO inhibits Env protein expression through the ERAD pathway and suggest that mitochondria play an important role in regulating the Env folding process. The HIV-1 Env glycoprotein is absolutely required for viral infection, and an understanding of its expression pathway in infected cells will identify new targets for antiretroviral therapies. Env proteins

  6. Two selective novel triterpene glycosides from sea cucumber, Telenata ananas: Inhibitors of chemokine receptor-5

    Digital Repository Service at National Institute of Oceanography (India)

    Hegde, V.R.; Chan, T.-M.; Pu, H.; Gullo, V.P.; Patel, M.G.; Das, P.; Wagner, N.; Parameswaran, P.S.; Naik, C.G.

    mostclinicallyrelevantsince all HIV-1 isolates can utilize one or both of these receptors to gain entry into cells. Recently, much atten- tion has been focused on targeting these receptors for antiviral therapy. The CCR5 receptor has been particu- larly attractive since... and that blockade of these receptors by a specific antagonist will not severely affect normal immune function. Several small molecule antagonists of CCR5 are being developed for HIV therapy, one of which, SCH-C, 3 is currently in clinical trials. As part of our...

  7. Single Nucleotide Polymorphism in Gene Encoding Transcription Factor Prep1 Is Associated with HIV-1-Associated Dementia

    Science.gov (United States)

    van Manen, Daniëlle; Bunnik, Evelien M.; van Sighem, Ard I.; Sieberer, Margit; Boeser-Nunnink, Brigitte; de Wolf, Frank; Schuitemaker, Hanneke; Portegies, Peter; Kootstra, Neeltje A.; van 't Wout, Angélique B.

    2012-01-01

    Background Infection with HIV-1 may result in severe cognitive and motor impairment, referred to as HIV-1-associated dementia (HAD). While its prevalence has dropped significantly in the era of combination antiretroviral therapy, milder neurocognitive disorders persist with a high prevalence. To identify additional therapeutic targets for treating HIV-associated neurocognitive disorders, several candidate gene polymorphisms have been evaluated, but few have been replicated across multiple studies. Methods We here tested 7 candidate gene polymorphisms for association with HAD in a case-control study consisting of 86 HAD cases and 246 non-HAD AIDS patients as controls. Since infected monocytes and macrophages are thought to play an important role in the infection of the brain, 5 recently identified single nucleotide polymorphisms (SNPs) affecting HIV-1 replication in macrophages in vitro were also tested. Results The CCR5 wt/Δ32 genotype was only associated with HAD in individuals who developed AIDS prior to 1991, in agreement with the observed fading effect of this genotype on viral load set point. A significant difference in genotype distribution among all cases and controls irrespective of year of AIDS diagnosis was found only for a SNP in candidate gene PREP1 (p = 1.2×10−5). Prep1 has recently been identified as a transcription factor preferentially binding the −2,518 G allele in the promoter of the gene encoding MCP-1, a protein with a well established role in the etiology of HAD. Conclusion These results support previous findings suggesting an important role for MCP-1 in the onset of HIV-1-associated neurocognitive disorders. PMID:22347417

  8. Single nucleotide polymorphism in gene encoding transcription factor Prep1 is associated with HIV-1-associated dementia.

    Directory of Open Access Journals (Sweden)

    Sebastiaan M Bol

    Full Text Available BACKGROUND: Infection with HIV-1 may result in severe cognitive and motor impairment, referred to as HIV-1-associated dementia (HAD. While its prevalence has dropped significantly in the era of combination antiretroviral therapy, milder neurocognitive disorders persist with a high prevalence. To identify additional therapeutic targets for treating HIV-associated neurocognitive disorders, several candidate gene polymorphisms have been evaluated, but few have been replicated across multiple studies. METHODS: We here tested 7 candidate gene polymorphisms for association with HAD in a case-control study consisting of 86 HAD cases and 246 non-HAD AIDS patients as controls. Since infected monocytes and macrophages are thought to play an important role in the infection of the brain, 5 recently identified single nucleotide polymorphisms (SNPs affecting HIV-1 replication in macrophages in vitro were also tested. RESULTS: The CCR5 wt/Δ32 genotype was only associated with HAD in individuals who developed AIDS prior to 1991, in agreement with the observed fading effect of this genotype on viral load set point. A significant difference in genotype distribution among all cases and controls irrespective of year of AIDS diagnosis was found only for a SNP in candidate gene PREP1 (p = 1.2 × 10(-5. Prep1 has recently been identified as a transcription factor preferentially binding the -2,518 G allele in the promoter of the gene encoding MCP-1, a protein with a well established role in the etiology of HAD. CONCLUSION: These results support previous findings suggesting an important role for MCP-1 in the onset of HIV-1-associated neurocognitive disorders.

  9. Pathogenic infection of Macaca nemestrina with a CCR5-tropic subtype-C simian-human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Song Ruijiang

    2009-07-01

    Full Text Available Abstract Background Although pig-tailed macaques (Macaca nemestrina have been used in AIDS research for years, less is known about the early immunopathogenic events in this species, as compared to rhesus macaques (Macaca mulatta. Similarly, the events in early infection are well-characterized for simian immunodeficiency viruses (SIV, but less so for chimeric simian-human immunodeficiency viruses (SHIV, although the latter have been widely used in HIV vaccine studies. Here, we report the consequences of intrarectal infection with a CCR5-tropic clade C SHIV-1157ipd3N4 in pig-tailed macaques. Results Plasma and cell-associated virus was detectable in peripheral blood and intestinal tissues of all four pig-tailed macaques following intrarectal inoculation with SHIV-1157ipd3N4. We also observed a rapid and irreversible loss of CD4+ T cells at multiple mucosal sites, resulting in a marked decrease of CD4:CD8 T cell ratios 0.5–4 weeks after inoculation. This depletion targeted subsets of CD4+ T cells expressing the CCR5 coreceptor and having a CD28-CD95+ effector memory phenotype, consistent with the R5-tropism of SHIV-1157ipd3N4. All three animals that were studied beyond the acute phase seroconverted as early as week 4, with two developing cross-clade neutralizing antibody responses by week 24. These two animals also demonstrated persistent plasma viremia for >48 weeks. One of these animals developed AIDS, as shown by peripheral blood CD4+ T-cell depletion starting at 20 weeks post inoculation. Conclusion These findings indicate that SHIV-1157ipd3N4-induced pathogenesis in pig-tailed macaques followed a similar course as SIV-infected rhesus macaques. Thus, R5 SHIV-C-infection of pig-tailed macaques could provide a useful and relevant model for AIDS vaccine and pathogenesis research.

  10. Sodium Lauryl Sulfate Abrogates Human Immunodeficiency Virus Infectivity by Affecting Viral Attachment

    Science.gov (United States)

    Bestman-Smith, Julie; Piret, Jocelyne; Désormeaux, André; Tremblay, Michel J.; Omar, Rabeea F.; Bergeron, Michel G.

    2001-01-01

    The microbicidal activity of sodium lauryl sulfate (SLS) against human immunodeficiency virus type 1 (HIV-1) was studied in cultured cells. Pretreatment of HIV-1NL4-3 with SLS decreased, in a concentration-dependent manner, its infectivity when using 1G5 as target cells. In the absence of a viral pretreatment period or when 1G5 cells were pretreated with SLS, the surfactant-induced inactivation of viral infectivity was less pronounced, especially at concentrations between 375 and 550 μM. SLS had no effect on HIV-1 when the virus was adsorbed to 1G5 cells by a 2-h incubation period. SLS almost completely inhibited the fusion process by decreasing the attachment of HIV-1 to target cells. SLS also inhibited the infectivity of HIV-1-based luciferase reporter viruses pseudotyped with the amphotropic murine leukemia virus envelope (which enters cells in a CD4-, CCR5-, and CXCR4-independent manner), indicating that SLS may inactivate other envelope viruses. In contrast, no effect was seen with vesicular stomatitis virus envelope glycoprotein G (which enters cells through receptor-mediated endocytosis) pretreated with up to 700 μM SLS. SLS also decreased, in a dose-dependent manner, the HIV-1-dependent syncytium formation between 1G5 and J1.1 cells after a 24-h incubation. The reduction of luciferase activity was more pronounced when J1.1 cells (which express HIV-1 proteins on their surface) were pretreated with SLS rather than 1G5 cells. Taken together, our results suggest that SLS could represent a candidate of choice for use in vaginal microbicides to prevent the sexual transmission of HIV and possibly other pathogens causing sexually transmitted diseases. PMID:11451679

  11. The HIV-1 Rev/RRE system is required for HIV-1 5' UTR cis elements to augment encapsidation of heterologous RNA into HIV-1 viral particles

    Directory of Open Access Journals (Sweden)

    Ma Hong

    2011-06-01

    Full Text Available Abstract Background The process of HIV-1 genomic RNA (gRNA encapsidation is governed by a number of viral encoded components, most notably the Gag protein and gRNA cis elements in the canonical packaging signal (ψ. Also implicated in encapsidation are cis determinants in the R, U5, and PBS (primer binding site from the 5' untranslated region (UTR. Although conventionally associated with nuclear export of HIV-1 RNA, there is a burgeoning role for the Rev/RRE in the encapsidation process. Pleiotropic effects exhibited by these cis and trans viral components may confound the ability to examine their independent, and combined, impact on encapsidation of RNA into HIV-1 viral particles in their innate viral context. We systematically reconstructed the HIV-1 packaging system in the context of a heterologous murine leukemia virus (MLV vector RNA to elucidate a mechanism in which the Rev/RRE system is central to achieving efficient and specific encapsidation into HIV-1 viral particles. Results We show for the first time that the Rev/RRE system can augment RNA encapsidation independent of all cis elements from the 5' UTR (R, U5, PBS, and ψ. Incorporation of all the 5' UTR cis elements did not enhance RNA encapsidation in the absence of the Rev/RRE system. In fact, we demonstrate that the Rev/RRE system is required for specific and efficient encapsidation commonly associated with the canonical packaging signal. The mechanism of Rev/RRE-mediated encapsidation is not a general phenomenon, since the combination of the Rev/RRE system and 5' UTR cis elements did not enhance encapsidation into MLV-derived viral particles. Lastly, we show that heterologous MLV RNAs conform to transduction properties commonly associated with HIV-1 viral particles, including in vivo transduction of non-dividing cells (i.e. mouse neurons; however, the cDNA forms are episomes predominantly in the 1-LTR circle form. Conclusions Premised on encapsidation of a heterologous RNA into

  12. Broadly neutralizing antibodies for treatment and prevention of HIV-1 infection.

    Science.gov (United States)

    Cohen, Yehuda Z; Caskey, Marina

    2018-04-24

    Several anti-HIV-1 broadly neutralizing antibodies (bNAbs) with exceptional breadth and potency that target different HIV-1 envelope epitopes have been identified. bNAbs are an attractive new strategy for HIV-1 prevention and therapy, and potentially, for long-term remission or cure. Here, we discuss findings from early clinical studies that have evaluated these novel bNAbs. Phase 1 studies of bNAbs targeting two distinct HIV-1 envelope epitopes have demonstrated their favorable safety and pharmacokinetic profile. Single bNAb infusions led to significant, but transient, decline in viremia with selection of escape variants. A single bNAb also delayed viral rebound in ART-treated participants who discontinued ART. Importantly, in-vivo efficacy was related to antibody potency and to the level of preexisting resistance. Studies in animal models showed that bNAbs can clear HIV-infected cells and modulate host immune responses. These findings suggest that bNAbs may target the latent HIV reservoir in humans and could contribute to long-term remission of HIV-1 infection. bNAbs may offer advantages over traditional ART for both the prevention and treatment of HIV-1 infection. In addition, bNAbs may target the latent viral reservoir. bNAb combinations and bNAbs engineered for prolonged half-life and increased potency are currently undergoing clinical evaluation.

  13. Study of Patterns and Markers of Human Immune Deficiency Virus -1 (HIV-1) Progression and Unemployment Rate among Patients from Alexandria, Egypt

    OpenAIRE

    GHONEIM, FAIKA M.; RAOUF, MAY M.; ELSHAER, NOHA S.; ABDELHAMID, SARAH M.; NOOR ELDEEN, REEM A.

    2017-01-01

    Middle East and North Africa (MENA) new HIV cases show the highest increase among all regions in the world. Even though Egypt has a low prevalence among the general population (< 0.02%), a national HIV epidemic occurs in certain population risk groups. The current study was conducted to asses clinical and immunological disease progression; following up viral load (VL) and detecting delta-32 CCR5 genotype polymorphism in selected cases, determining unemployment rate and identify predictors of ...

  14. Surfactant protein D binds to human immunodeficiency virus (HIV) envelope protein gp120 and inhibits HIV replication

    DEFF Research Database (Denmark)

    Meschi, Joseph; Crouch, Erika C; Skolnik, Paul

    2005-01-01

    The envelope protein (gp120) of human immunodeficiency virus (HIV) contains highly conserved mannosylated oligosaccharides. These glycoconjugates contribute to resistance to antibody neutralization, and binding to cell surface lectins on macrophages and dendritic cells. Mannose-binding lectin (MBL......) binds to gp120 and plays a role in defence against the virus. In this study it is demonstrated that surfactant protein D (SP-D) binds to gp120 and inhibits HIV infectivity at significantly lower concentrations than MBL. The binding of SP-D was mediated by its calcium-dependent carbohydrate......-binding activity and was dependent on glycosylation of gp120. Native dodecameric SP-D bound to HIV gp120 more strongly than native trimeric SP-D. Since one common polymorphic form of SP-D is predominantly expressed as trimers and associated with lower blood levels, these individuals may have less effective innate...

  15. Alterations in cholesterol metabolism restrict HIV-1 trans infection in nonprogressors.

    Science.gov (United States)

    Rappocciolo, Giovanna; Jais, Mariel; Piazza, Paolo; Reinhart, Todd A; Berendam, Stella J; Garcia-Exposito, Laura; Gupta, Phalguni; Rinaldo, Charles R

    2014-04-29

    ABSTRACT HIV-1-infected nonprogressors (NP) inhibit disease progression for years without antiretroviral therapy. Defining the mechanisms for this resistance to disease progression could be important in determining strategies for controlling HIV-1 infection. Here we show that two types of professional antigen-presenting cells (APC), i.e., dendritic cells (DC) and B lymphocytes, from NP lacked the ability to mediate HIV-1 trans infection of CD4(+) T cells. In contrast, APC from HIV-1-infected progressors (PR) and HIV-1-seronegative donors (SN) were highly effective in mediating HIV-1 trans infection. Direct cis infection of T cells with HIV-1 was comparably efficient among NP, PR, and SN. Lack of HIV-1 trans infection in NP was linked to lower cholesterol levels and an increase in the levels of the reverse cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) in APC but not in T cells. Moreover, trans infection mediated by APC from NP could be restored by reconstitution of cholesterol and by inhibiting ABCA1 by mRNA interference. Importantly, this appears to be an inherited trait, as it was evident in APC obtained from NP prior to their primary HIV-1 infection. The present study demonstrates a new mechanism wherein enhanced lipid metabolism in APC results in remarkable control of HIV-1 trans infection that directly relates to lack of HIV-1 disease progression. IMPORTANCE HIV-1 can be captured by antigen-presenting cells (APC) such as dendritic cells and transferred to CD4 helper T cells, which results in greatly enhanced viral replication by a mechanism termed trans infection. A small percentage of HIV-1-infected persons are able to control disease progression for many years without antiretroviral therapy. In our study, we linked this lack of disease progression to a profound inability of APC from these individuals to trans infect T cells. This effect was due to altered lipid metabolism in their APC, which appears to be an inherited trait. These

  16. Control of Both Myeloid Cell Infiltration and Angiogenesis by CCR1 Promotes Liver Cancer Metastasis Development in Mice

    Directory of Open Access Journals (Sweden)

    Mathieu Paul Rodero

    2013-06-01

    Full Text Available Expression of the CC chemokine receptor 1 (CCR1 by tumor cells has been associated with protumoral activity; however, its role in nontumoral cells during tumor development remains elusive. Here, we investigated the role of CCR1 deletion on stromal and hematopoietic cells in a liver metastasis tumor model. Metastasis development was strongly impaired in CCR1-deficient mice compared to control mice and was associated with reduced liver monocyte infiltration. To decipher the role of myeloid cells, sublethally irradiated mice were reconstituted with CCR1-deficient bone marrow (BM and showed better survival rates than the control reconstituted mice. These results point toward the involvement of CCR1 myeloid cell infiltration in the promotion of tumor burden. In addition, survival rates were extended in CCR1-deficient mice receiving either control or CCR1-deficient BM, indicating that host CCR1 expression on nonhematopoietic cells also supports tumor growth. Finally, we found defective tumor-induced neoangiogenesis (in vitro and in vivo in CCR1-deficient mice. Overall, our results indicate that CCR1 expression by both hematopoietic and nonhematopoietic cells favors tumor aggressiveness. We propose CCR1 as a potential therapeutical target for liver metastasis therapy.

  17. N-terminal substitutions in HIV-1 gp41 reduce the expression of non-trimeric envelope glycoproteins on the virus

    International Nuclear Information System (INIS)

    Dey, Antu K.; David, Kathryn B.; Ray, Neelanjana; Ketas, Thomas J.; Klasse, Per J.; Doms, Robert W.; Moore, John P.

    2008-01-01

    The native, functional HIV-1 envelope glycoprotein (Env) complex is a trimer of two non-covalently associated subunits: the gp120 surface glycoprotein and the gp41 transmembrane glycoprotein. However, various non-functional forms of Env are present on virus particles and HIV-1-infected cells, some of which probably arise as the native complex decays. The aberrant forms include gp120-gp41 monomers and oligomers, as well as gp41 subunits from which gp120 has dissociated. The presence of non-functional Env creates binding sites for antibodies that do not recognize native Env complexes and that are, therefore, non-neutralizing. Non-native Env forms (monomers, dimers, tetramers and aggregates) can also arise when soluble gp140 proteins, lacking the cytoplasmic and transmembrane domains of gp41, are expressed for vaccine studies. We recently identified five amino acids in the gp41 N-terminal region (I535, Q543, S553, K567 and R588) that promote gp140 trimerization. We have now studied their influence on the function and antigenic properties of JR-FL Env expressed on the surfaces of pseudoviruses and Env-transfected cells. The 5 substitutions in gp41 reduce the expression of non-trimeric gp160s, without affecting trimer levels. Pseudovirions bearing the mutant Env are fully infectious with similar kinetics of Env-mediated fusion. Various non-neutralizing antibodies bind less strongly to the Env mutant, but neutralizing antibody binding is unaffected. Hence the gp41 substitutions do not adversely affect Env structure, supporting their use for making new Env-based vaccines. The mutant Env might also help in studies intended to correlate antibody binding to virus neutralization. Of note is that the 5 residues are much more frequent, individually or collectively, in viruses from subtypes other than B

  18. Upregulation of innate antiviral restricting factor expression in the cord blood and decidual tissue of HIV-infected mothers.

    Science.gov (United States)

    Pereira, Nátalli Zanete; Cardoso, Elaine Cristina; Oliveira, Luanda Mara da Silva; de Lima, Josenilson Feitosa; Branco, Anna Cláudia Calvielli Castelo; Ruocco, Rosa Maria de Souza Aveiro; Zugaib, Marcelo; de Oliveira Filho, João Bosco; Duarte, Alberto José da Silva; Sato, Maria Notomi

    2013-01-01

    Programs for the prevention of mother-to-child transmission of HIV have reduced the transmission rate of perinatal HIV infection and have thereby increased the number of HIV-exposed uninfected (HEU) infants. Natural immunity to HIV-1 infection in both mothers and newborns needs to be further explored. In this study, we compared the expression of antiviral restricting factors in HIV-infected pregnant mothers treated with antiretroviral therapy (ART) in pregnancy (n=23) and in cord blood (CB) (n=16), placental tissues (n=10-13) and colostrum (n=5-6) samples and compared them to expression in samples from uninfected (UN) pregnant mothers (n=21). Mononuclear cells (MNCs) were prepared from maternal and CB samples following deliveries by cesarean section. Maternal (decidua) and fetal (chorionic villus) placental tissues were obtained, and colostrum was collected 24 h after delivery. The mRNA and protein expression levels of antiviral factors were then evaluated. We observed a significant increase in the mRNA expression levels of antiviral factors in MNCs from HIV-infected mothers and CB, including the apolipoprotein B mRNA-editing enzyme 3G (A3G), A3F, tripartite motif family-5α (TRIM-5α), TRIM-22, myxovirus resistance protein A (MxA), stimulator of interferon (IFN) genes (STING) and IFN-β, compared with the levels detected in uninfected (UN) mother-CB pairs. Moreover, A3G transcript and protein levels and α-defensin transcript levels were decreased in the decidua of HIV-infected mothers. Decreased TRIM-5α protein levels in the villi and increased STING mRNA expression in both placental tissues were also observed in HIV-infected mothers compared with uninfected (UN) mothers. Additionally, colostrum cells from infected mothers showed increased tetherin and IFN-β mRNA levels and CXCL9 protein levels. The data presented here indicate that antiviral restricting factor expression can be induced in utero in HIV-infected mothers. Future studies are warranted to determine

  19. Characteristics of HIV target CD4 T cells collected using different sampling methods from the genital tract of HIV seronegative women.

    Science.gov (United States)

    Iyer, Smita S; Sabula, Michael J; Mehta, C Christina; Haddad, Lisa B; Brown, Nakita L; Amara, Rama R; Ofotokun, Igho; Sheth, Anandi N

    2017-01-01

    Understanding the immune profile of CD4 T cells, the primary targets for HIV, in the female genital tract (FGT) is critical for evaluating and developing effective biomedical HIV prevention strategies in women. However, longitudinal investigation of HIV susceptibility markers expressed by FGT CD4 T cells has been hindered by low cellular yield and risk of sampling-associated trauma. We investigated three minimally invasive FGT sampling methods to characterize and compare CD4 T cell yield and phenotype with the goal of establishing feasible sampling strategies for immune profiling of mucosal CD4 T cells. FGT samples were collected bimonthly from 12 healthy HIV negative women of reproductive age in the following order: 1) Cervicovaginal lavage (CVL), 2) two sequential endocervical flocked swabs (FS), and 3) two sequential endocervical cytobrushes (CB1, CB2). Cells were isolated and phentoyped via flow cytometry. CD4 T cell recovery was highest from each individual CB compared to either CVL or FS (p sampling method, expressed CCR5 relative to peripheral blood (p samples. Using three different mucosal sampling methods collected longitudinally we demonstrate that CD4 T cells within the FGT express CCR5 and α4β7 and are highly activated, attributes which could act in concert to facilitate HIV acquisition. FS and CB sampling methods can allow for investigation of strategies to reduce HIV target cells in the FGT and could inform the design and interpretation microbicide and vaccine studies in women.

  20. Long-term effect of depot medroxyprogesterone acetate on vaginal microbiota, epithelial thickness and HIV target cells.

    Science.gov (United States)

    Mitchell, Caroline M; McLemore, Leslie; Westerberg, Katharine; Astronomo, Rena; Smythe, Kimberly; Gardella, Carolyn; Mack, Matthias; Magaret, Amalia; Patton, Dorothy; Agnew, Kathy; McElrath, M Juliana; Hladik, Florian; Eschenbach, David

    2014-08-15

    Depot medroxyprogesterone acetate (DMPA) has been linked to human immunodeficiency virus type 1 (HIV-1) acquisition. Vaginal microbiota of women using DMPA for up to 2 years were cultured. Mucosal immune cell populations were measured by immunohistological staining. Over 12 months, the proportion with H2O2-positive lactobacilli decreased (n = 32; 53% vs 27%; P = .03). Median vaginal CD3(+) cells also decreased (n = 15; 355 vs 237 cells/mm(2); P = .03), as did CD3(+)CCR5(+) cells (195 vs 128 cells/mm(2); P = .04), HLA-DR(+) cells (130 vs 96 cells/mm(2); P = .27), and HLA-DR(+)CCR5(+) cells (18 vs 10 cells/mm(2); P = .33). DMPA contraception does not increase vaginal mucosal CCR5(+) HIV target cells but does decrease CD3(+) T lymphocytes and vaginal H2O2-producing lactobacilli. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells.

    Directory of Open Access Journals (Sweden)

    Meron Mengistu

    2015-03-01

    Full Text Available The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step

  2. HIV-1 co-receptor usage:influence on mother-to-child transmission and pediatric infection

    Directory of Open Access Journals (Sweden)

    Cavarelli Mariangela

    2010-01-01

    Full Text Available Abstract Viral CCR5 usage is not a predictive marker of mother to child transmission (MTCT of HIV-1. CXCR4-using viral variants are little represented in pregnant women, have an increased although not significant risk of transmission and can be eventually also detected in the neonates. Genetic polymorphisms are more frequently of relevance in the child than in the mother. However, specific tissues as the placenta or the intestine, which are involved in the prevalent routes of infection in MTCT, may play an important role of selective barriers. The virus phenotype of the infected children, like that of adults, can evolve from R5 to CXCR4-using phenotype or remain R5 despite clinical progression to overt immune deficiency. The refined classification of R5 viruses into R5narrow and R5broad resolves the enigma of the R5 phenotype being associated with the state of immune deficiency. Studies are needed to address more in specific the relevance of these factors in HIV-1 MTCT and pediatric infection of non-B subtypes.

  3. HIV-1 co-receptor usage: influence on mother-to-child transmission and pediatric infection.

    Science.gov (United States)

    Cavarelli, Mariangela; Scarlatti, Gabriella

    2011-01-27

    Viral CCR5 usage is not a predictive marker of mother to child transmission (MTCT) of HIV-1. CXCR4-using viral variants are little represented in pregnant women, have an increased although not significant risk of transmission and can be eventually also detected in the neonates. Genetic polymorphisms are more frequently of relevance in the child than in the mother. However, specific tissues as the placenta or the intestine, which are involved in the prevalent routes of infection in MTCT, may play an important role of selective barriers. The virus phenotype of the infected children, like that of adults, can evolve from R5 to CXCR4-using phenotype or remain R5 despite clinical progression to overt immune deficiency. The refined classification of R5 viruses into R5(narrow) and R5(broad) resolves the enigma of the R5 phenotype being associated with the state of immune deficiency. Studies are needed to address more in specific the relevance of these factors in HIV-1 MTCT and pediatric infection of non-B subtypes.

  4. Evidence favoring the involvement of CC chemokine receptor (CCR) 5 in T-lymphocyte accumulation in optic neuritis

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Ransohoff, R M; Jensen, J

    2003-01-01

    To define the relationships between levels of chemokine receptor (CCR)5+ T-cells in blood and cerebrospinal fluid (CSF) of optic neuritis (ON) and control patients (CON).......To define the relationships between levels of chemokine receptor (CCR)5+ T-cells in blood and cerebrospinal fluid (CSF) of optic neuritis (ON) and control patients (CON)....

  5. Inhibition of microtubules and dynein rescues human immunodeficiency virus type 1 from owl monkey TRIMCyp-mediated restriction in a cellular context-specific fashion.

    Science.gov (United States)

    Pawlica, Paulina; Dufour, Caroline; Berthoux, Lionel

    2015-04-01

    IFN-induced restriction factors can significantly affect the replicative capacity of retroviruses in mammals. TRIM5α (tripartite motif protein 5, isoform α) is a restriction factor that acts at early stages of the virus life cycle by intercepting and destabilizing incoming retroviral cores. Sensitivity to TRIM5α maps to the N-terminal domain of the retroviral capsid proteins. In several New World and Old World monkey species, independent events of retrotransposon-mediated insertion of the cyclophilin A (CypA)-coding sequence in the trim5 gene have given rise to TRIMCyp (also called TRIM5-CypA), a hybrid protein that is active against some lentiviruses in a species-specific fashion. In particular, TRIMCyp from the owl monkey (omkTRIMCyp) very efficiently inhibits human immunodeficiency virus type 1 (HIV-1). Previously, we showed that disrupting the integrity of microtubules (MTs) and of cytoplasmic dynein complexes partially rescued replication of retroviruses, including HIV-1, from restriction mediated by TRIM5α. Here, we showed that efficient restriction of HIV-1 by omkTRIMCyp was similarly dependent on the MT network and on dynein complexes, but in a context-dependent fashion. When omkTRIMCyp was expressed in human HeLa cells, restriction was partially counteracted by pharmacological agents targeting MTs or by small interfering RNA-mediated inhibition of dynein. The same drugs (nocodazole and paclitaxel) also rescued HIV-1 from restriction in cat CRFK cells, although to a lesser extent. Strikingly, neither nocodazole, paclitaxel nor depletion of the dynein heavy chain had a significant effect on the restriction of HIV-1 in an owl monkey cell line. These results suggested the existence of cell-specific functional interactions between MTs/dynein and TRIMCyp. © 2015 The Authors.

  6. Sequence similarity between the erythrocyte binding domain 1 of the Plasmodium vivax Duffy binding protein and the V3 loop of HIV-1 strain MN reveals binding residues for the Duffy Antigen Receptor for Chemokines

    OpenAIRE

    Bolton, Michael J; Garry, Robert F

    2011-01-01

    Abstract Background The surface glycoprotein (SU, gp120) of the human immunodeficiency virus (HIV) must bind to a chemokine receptor, CCR5 or CXCR4, to invade CD4+ cells. Plasmodium vivax uses the Duffy Binding Protein (DBP) to bind the Duffy Antigen Receptor for Chemokines (DARC) and invade reticulocytes. Results Variable loop 3 (V3) of HIV-1 SU and domain 1 of the Plasmodium vivax DBP share a sequence similarity. The site of amino acid sequence similarity was necessary, but not sufficient, ...

  7. Natural mannosylation of HIV-1 gp120 imposes no immunoregulatory effects in primary human plasmacytoid dendritic cells

    DEFF Research Database (Denmark)

    Søndergaard, Jonas Nørskov; Vinner, Lasse; Pedersen, Susanne Brix

    2014-01-01

    Plasmacytoid dendritic cells (pDCs) play a vital role in activation of anti-HIV-1 immunity, and suppression of pDCs might mitigate immune responses against HIV-1. HIV-1 gp120 high-mannose has been attributed immunosuppressive roles in human myeloid DCs, but no receptors for high-mannose have so far...... or viable HIV-1 particles with various degrees of mannosylation were cultured with pDCs. Activation of pDCs was determined by assaying secretion of IFN-alpha, viability, and upregulation of several pDC-activation markers: CD40, CD86, HLA-DR, CCR7, and PD-L1. The level of activation negatively correlated...

  8. Analysis of Social and Genetic Factors Influencing Heterosexual Transmission of HIV within Serodiscordant Couples in the Henan Cohort.

    Science.gov (United States)

    Zhu, Qian; Zhu, Peng; Zhang, Yilei; Li, Jie; Ma, Xuejun; Li, Ning; Wang, Qi; Xue, Xiujuan; Luo, Le; Li, Zizhao; Ring, Huijun Z; Ring, Brian Z; Su, Li

    2015-01-01

    There is considerable variability between individuals in susceptibility to infection by human immunodeficiency virus (HIV). Many social, clinical and genetic factors are known to contribute to the likelihood of HIV transmission, but there is little consensus on the relative importance and potential interaction of these factors. Additionally, recent studies of several variants in chemokine receptors have identified alleles that may be predictive of HIV transmission and disease progression; however the strengths and directions of the associations of these genetic markers with HIV transmission have markedly varied between studies. To better identify factors that predict HIV transmission in a Chinese population, 180 cohabiting serodiscordant couples were enrolled for study by the Henan Center for Disease Prevention and Control, and transmission and progression of HIV infection were regularly measured. We found that anti-retroviral therapy, education level, and condom use were the most significant factors in determining likelihood of HIV transmission in this study. We also assessed ten variants in three genes (CXCL12, CCR2, and CCR5) that have been shown to influence HIV transmission. We found two tightly linked variants in CCR2 and CCR5, rs1799864 and rs1800024, have a significant positive association with transmission as recessive models (OR>10, P value=0.011). Mixed effects models showed that these genetic variants both retained significance when assessed with either treatment or condom use. These markers of transmission susceptibility may therefore serve to help stratify individuals by risk for HIV transmission.

  9. Analysis of Social and Genetic Factors Influencing Heterosexual Transmission of HIV within Serodiscordant Couples in the Henan Cohort.

    Directory of Open Access Journals (Sweden)

    Qian Zhu

    Full Text Available There is considerable variability between individuals in susceptibility to infection by human immunodeficiency virus (HIV. Many social, clinical and genetic factors are known to contribute to the likelihood of HIV transmission, but there is little consensus on the relative importance and potential interaction of these factors. Additionally, recent studies of several variants in chemokine receptors have identified alleles that may be predictive of HIV transmission and disease progression; however the strengths and directions of the associations of these genetic markers with HIV transmission have markedly varied between studies. To better identify factors that predict HIV transmission in a Chinese population, 180 cohabiting serodiscordant couples were enrolled for study by the Henan Center for Disease Prevention and Control, and transmission and progression of HIV infection were regularly measured. We found that anti-retroviral therapy, education level, and condom use were the most significant factors in determining likelihood of HIV transmission in this study. We also assessed ten variants in three genes (CXCL12, CCR2, and CCR5 that have been shown to influence HIV transmission. We found two tightly linked variants in CCR2 and CCR5, rs1799864 and rs1800024, have a significant positive association with transmission as recessive models (OR>10, P value=0.011. Mixed effects models showed that these genetic variants both retained significance when assessed with either treatment or condom use. These markers of transmission susceptibility may therefore serve to help stratify individuals by risk for HIV transmission.

  10. Mucosal CCR1 gene expression as a marker of molecular activity in Crohn's disease: preliminary data.

    Science.gov (United States)

    Dobre, Maria; Mănuc, Teodora Ecaterina; Milanesi, Elena; Pleşea, Iancu Emil; Ţieranu, Eugen Nicolae; Popa, Caterina; Mănuc, Mircea; Preda, Carmen Monica; Ţieranu, Ioana; Diculescu, Mihai Mircea; Ionescu, Elena Mirela; Becheanu, Gabriel

    2017-01-01

    A series of mechanisms of immune response, inflammation and apoptosis have been demonstrated to contribute to the appearance and evolution of Crohn's disease (CD) through the overexpression of several cytokines and chemokines in a susceptible host. The aim of this study was to identify the differences in gene expression profiles analyzing a panel of candidate genes in the mucosa from patients with active CD (CD-A), patients in remission (CD-R), and normal controls. Nine individuals were enrolled in the study: six CD patients (three with active lesions, three with mucosal healing) and three controls without inflammatory bowel disease (IBD) seen on endoscopy. All the individuals underwent mucosal biopsy during colonoscopy. Gene expression levels of 84 genes previously associated with CD were evaluated by polymerase chain reaction (PCR) array. Ten genes out of 84 were found significantly differentially expressed in CD-A (CCL11, CCL25, DEFA5, GCG, IL17A, LCN2, REG1A, STAT3, MUC1, CCR1) and eight genes in CD-R (CASP1, IL23A, STAT1, STAT3, TNF, CCR1, CCL5, and HSP90B1) when compared to controls. A quantitative gene expression analysis revealed that CCR1 gene was more expressed in CD-A than in CD-R. Our data suggest that CCR1 gene may be a putative marker of molecular activity of Crohn's disease. Following these preliminary data, a confirmation in larger cohort studies could represent a useful method in order to identify new therapeutic targets.

  11. Structure-based stabilization of HIV-1 gp120 enhances humoral immune responses to the induced co-receptor binding site.

    Directory of Open Access Journals (Sweden)

    Barna Dey

    2009-05-01

    Full Text Available The human immunodeficiency virus type 1 (HIV-1 exterior envelope glycoprotein, gp120, possesses conserved binding sites for interaction with the primary virus receptor, CD4, and also for the co-receptor, generally CCR5. Although gp120 is a major target for virus-specific neutralizing antibodies, the gp120 variable elements and its malleable nature contribute to evasion of effective host-neutralizing antibodies. To understand the conformational character and immunogenicity of the gp120 receptor binding sites as potential vaccine targets, we introduced structure-based modifications to stabilize gp120 core proteins (deleted of the gp120 major variable regions into the conformation recognized by both receptors. Thermodynamic analysis of the re-engineered core with selected ligands revealed significant stabilization of the receptor-binding regions. Stabilization of the co-receptor-binding region was associated with a marked increase in on-rate of ligand binding to this site as determined by surface plasmon resonance. Rabbit immunization studies showed that the conformational stabilization of core proteins, along with increased ligand affinity, was associated with strikingly enhanced humoral immune responses against the co-receptor-binding site. These results demonstrate that structure-based approaches can be exploited to stabilize a conformational site in a large functional protein to enhance immunogenic responses specific for that region.

  12. Preclinical and clinical investigation of a CCR5 antagonist, AZD5672, in patients with rheumatoid arthritis receiving methotrexate

    NARCIS (Netherlands)

    Gerlag, Daniëlle M.; Hollis, Sally; Layton, Mark; Vencovský, Jiří; Szekanecz, Zoltán; Braddock, Martin; Tak, Paul P.; Oparanov, Boycho; Stoilov, Rumen; Yaneva, Tanya; Batalov, Anastas; Arteaga, Edgardo Tobias; Escalante, William Otero; Velez, Patricia; Restrepo, Jose Molina; Augustinova, Sevda; Blahova, Anna; Dvorak, Zdenek; Novosad, Libor; Rosa, Jan; Stehlikova, Helena; Vitek, Petr; Balazs, Tibor; Seregely, Katalin; Szombati, Istvan; Tarjan, Katalin; Csengei, Gabor; Galeazzi, Mauro; Saleniece, Sarmite; Saulite-Kandevica, Daina; Coleiro, Bernard; Badurski, Janusz; Brzosko, Marek; Chudzik, Dariusz; Gruszecka-Marczynska, Katarzyna; Hensel, Joanna; Pokrzywnicka-Gajek, Ines; Korpanty-Danda, Joanna; Sochocka-Bykowska, Malgorzata; Tlustochowicz, Witold; Stopinska-Polaszewska, Maria; Gluszko, Piotr; Nedelcovici, Corina; Radulescu, Florin; Gavrila, Mirea; Tanasescu, Coman; Korshunov, Nikolay; Matsievskaia, Galina; Damjanov, Nemanja; Dimic, Aleksandar

    2010-01-01

    To investigate both the preclinical effects of blocking the chemokine receptor CCR5 and the clinical effects of this approach on the signs and symptoms of rheumatoid arthritis (RA) in patients with active disease. Preclinical evaluations of AZD5672, a small-molecule antagonist of CCR5, were

  13. Association between HIV-1 coreceptor usage and resistance to broadly neutralizing antibodies.

    Science.gov (United States)

    Pfeifer, Nico; Walter, Hauke; Lengauer, Thomas

    2014-10-01

    Recently discovered broadly neutralizing antibodies have revitalized hopes of developing a universal vaccine against HIV-1. Mainly responsible for new infections are variants only using CCR5 for cell entry, whereas CXCR4-using variants can become dominant in later infection stages. We performed a statistical analysis on two different previously published data sets. The first data set was a panel of 199 diverse HIV-1 isolates for which IC50 neutralization titers were determined for the broadly neutralizing antibodies VRC01, VRC-PG04, PG9, and PG16. The second data set contained env sequences of viral variants extracted from HIV-1-infected humanized mice treated with the antibody PGT128 and from untreated control mice. For the panel of 199 diverse HIV-1 isolates, we found a statistically significant association between viral resistance to PG9 and PG16 and CXCR4 coreceptor usage (P = 0.0011 and P = 0.0010, respectively). Our analysis of viral variants from HIV-1-infected humanized mice under treatment with the broadly neutralizing antibody PGT128 indicated that certain antibodies might drive a viral population toward developing CXCR4 coreceptor usage capability (P = 0.0011 for the comparison between PGT128 and control measurement). These analyses highlight the importance of accounting for a possible coreceptor usage bias pertaining to the effectiveness of an HIV vaccine and to passive antibody transfer as therapeutic approach.

  14. TRPV1 and the MCP-1/CCR2 Axis Modulate Post-UTI Chronic Pain.

    Science.gov (United States)

    Rosen, John M; Yaggie, Ryan E; Woida, Patrick J; Miller, Richard J; Schaeffer, Anthony J; Klumpp, David J

    2018-05-08

    The etiology of chronic pelvic pain syndromes remains unknown. In a murine urinary tract infection (UTI) model, lipopolysaccharide of uropathogenic E. coli and its receptor TLR4 are required for post-UTI chronic pain development. However, downstream mechanisms of post-UTI chronic pelvic pain remain unclear. Because the TRPV1 and MCP-1/CCR2 pathways are implicated in chronic neuropathic pain, we explored their role in post-UTI chronic pain. Mice were infected with the E. coli strain SΦ874, known to produce chronic allodynia, and treated with the TRPV1 antagonist capsazepine. Mice treated with capsazepine at the time of SΦ874 infection failed to develop chronic allodynia, whereas capsazepine treatment of mice at two weeks following SΦ874 infection did not reduce chronic allodynia. TRPV1-deficient mice did not develop chronic allodynia either. Similar results were found using novelty-suppressed feeding (NSF) to assess depressive behavior associated with neuropathic pain. Imaging of reporter mice also revealed induction of MCP-1 and CCR2 expression in sacral dorsal root ganglia following SΦ874 infection. Treatment with a CCR2 receptor antagonist at two weeks post-infection reduced chronic allodynia. Taken together, these results suggest that TRPV1 has a role in the establishment of post-UTI chronic pain, and CCR2 has a role in maintenance of post-UTI chronic pain.

  15. Colorectal carcinoma metastases: Detection with In-111-labeled monoclonal antibody CCR 086

    International Nuclear Information System (INIS)

    Abdel-Nabi, H.H.; Levine, G.; Lamki, L.M.; Murray, J.L.; Tauxe, W.N.; Shah, A.N.; Patt, Y.Z.; Doerr, R.J.; Klein, H.A.; Gona, J.

    1990-01-01

    A phase I/II clinical trial with indium-111-labeled antimucin murine monoclonal antibody (MoAb) CCR 086 was conducted. Seventeen patients with histologically proved colorectal carcinoma and known metastatic disease underwent external scintigraphy after administration of 5.5 mCi (203.5 MBq) of In-111 CCR 086 at doses of 5 and 20 mg. Of 25 known lesions, 17 were detected (sensitivity, 68%). The smallest detected lesion in the lung was 1 cm and in the liver was 1.5 cm. The serum half-life of In-111-labeled CCR 086 MoAb was approximately 64 hours. The formation of human antimouse antibody (HAMA) was detected in the serum of four of five patients who received 20 mg of MoAb. No HAMAs were detected in four patients receiving 5 mg of MoAb. No side effects were encountered. Because of effective detection of liver and lung metastases with lower doses (5-20 mg) of CCR 086 conjugated with In-111, further investigations are warranted to assess clinical and therapeutic potentials of CCR 086 in the management of colorectal cancer

  16. Human Eosinophils Express Functional CCR7

    Science.gov (United States)

    Ueki, Shigeharu; Estanislau, Jessica; Weller, Peter F.

    2013-01-01

    Human eosinophils display directed chemotactic activity toward an array of soluble chemokines. Eosinophils have been observed to migrate to draining lymph nodes in experimental models of allergic inflammation, yet it is unknown whether eosinophils express CCR7, a key chemokine receptor in coordinating leukocyte trafficking to lymph nodes. The purpose of this study is to demonstrate expression of CCR7 by human eosinophils and functional responses to CCL19 and CCL21, the known ligands of CCR7. Human eosinophils were purified by negative selection from healthy donors. CCR7 expression of freshly purified, unstimulated eosinophils and of IL-5–primed eosinophils was determined by flow cytometry and Western blot. Chemotaxis to CCL19 and CCL21 was measured in transwell assays. Shape changes to CCL19 and CCL21 were analyzed by flow cytometry and microscopy. Calcium fluxes of fluo-4 AM–loaded eosinophils were recorded by flow cytometry after chemokine stimulation. ERK phosphorylation of CCL19- and CCL21-stimulated eosinophils was measured by Western blot and Luminex assay. Human eosinophils expressed CCR7 as demonstrated by flow cytometry and Western blots. Eosinophils exhibited detectable cell surface expression of CCR7. IL-5–primed eosinophils exhibited chemotaxis toward CCL19 and CCL21 in a dose-dependent fashion. Upon stimulation with CCL19 or CCL21, IL-5–primed eosinophils demonstrated dose-dependent shape changes with polarization of F-actin and exhibited calcium influxes. Finally, primed eosinophils stimulated with CCL19 or CCL21 exhibited increased phosphorylation of ERK in response to both CCR7 ligands. We demonstrate that human eosinophils express CCR7 and have multipotent responses to the known ligands of CCR7. PMID:23449735

  17. Potential use of rapamycin in HIV infection

    DEFF Research Database (Denmark)

    Donia, Marco; McCubrey, James A; Bendtzen, Klaus

    2010-01-01

    The strong need for the development of alternative anti-HIV agents is primarily due to the emergence of strain-resistant viruses, the need for sustained adherence to complex treatment regimens and the toxicity of currently used antiviral drugs. This review analyzes proof of concept studies...... indicating that the immunomodulatory drug rapamycin (RAPA) possesses anti-HIV properties both in vitro and in vivo that qualifies it as a potential new anti-HIV drug. It represents a literature review of published studies that evaluated the in vitro and in vivo activity of RAPA in HIV. RAPA represses HIV-1...... replication in vitro through different mechanisms including, but not limited, to down regulation of CCR5. In addition RAPA synergistically enhances the anti-HIV activity of entry inhibitors such as vicriviroc, aplaviroc and enfuvirtide in vitro. RAPA also inhibits HIV-1 infection in human peripheral blood...

  18. Induction of human immunodeficiency virus neutralizing antibodies using fusion complexes.

    Science.gov (United States)

    Zipeto, Donato; Matucci, Andrea; Ripamonti, Chiara; Scarlatti, Gabriella; Rossolillo, Paola; Turci, Marco; Sartoris, Silvia; Tridente, Giuseppe; Bertazzoni, Umberto

    2006-05-01

    Human immunodeficiency virus-1 (HIV-1) infects cells by membrane fusion that is mediated by the envelope proteins gp120/gp41 and the cellular receptors CD4 and CCR5. During this process, some conserved viral epitopes are temporarily exposed and may induce a neutralizing antibody response when fixed in the fusogenic conformation. These transient structures are conserved and may be effective antigens for use in an anti-HIV-1 vaccine. In this study we tested different conditions of preparation of fusion complexes inducing neutralizing antibodies against both R5 and X4 tropic HIV-1 strains. Cell lines expressing HIV-1 gp120/gp41 and CD4-CCR5 were prepared and conditions for producing fusion complexes were tested. Complexes produced at different temperature and fixative combinations were used to immunize mice. Results indicated that (a) fusion complexes prepared at either 21 degrees C, 30 degrees C or 37 degrees C were immunogenic and induced neutralizing antibodies against both R5 and X4 HIV-1 heterologous isolates; (b) after extensive purification of antibodies there was no cytotoxic effect; (c) complexes prepared at 37 degrees C were more immunogenic and induced higher titers of neutralizing antibodies than complexes prepared at either 21 degrees C or 30 degrees C; (d) the fixative used did not affect the titer of neutralizing antibodies except for glutaraldehyde which was ineffective; (e) the neutralizing activity was retained after CD4-CCR5 antibody removal. The production of higher titers of neutralizing antibody with fusion complexes prepared at 37 degrees C, as compared to lower temperatures, may be related to the induction of antibodies against many different conformation intermediates that subsequently act synergistically at different steps in the fusion process.

  19. Clinical benefits of using inulin clearance and cystatin C for determining glomerular filtration rate in HIV-1-infected individuals treated with dolutegravir.

    Science.gov (United States)

    Yukawa, Satomi; Watanabe, Dai; Uehira, Tomoko; Shirasaka, Takuma

    2018-03-01

    Dolutegravir may inhibit creatinine transporters in renal tubules and elevate serum creatinine levels. We investigated the usefulness of glomerular filtration rate (GFR) measured using inulin clearance (Cin), creatinine clearance (Ccr), and estimated GFR based on both serum creatinine (eGFRcre) and serum cystatin C (eGFRcys). HIV-1-infected Japanese patients with suppressed viremia and whose antiretroviral drug was switched to dolutegravir from other drugs were included (n = 108, Study 1). We compared eGFRcre and eGFRcys at the start and after 48 weeks of dolutegravir administration. For the patients providing consent, we measured Cin and Ccr (n = 15, Study 2). We assessed biases and accuracy and compared Cin with eGFRcre, eGFRcys, and Ccr. There were no differences in serum cystatin C and eGFRcys between baseline and at 48 weeks. Moreover, eGFRcre was significantly less accurate (within 30% of measured GFR) than both eGFRcys and Ccr (40% accuracy compared to 93% and 93%, respectively). eGFRcys was significantly less biased than eGFRcre and Ccr (p inulin clearance and eGFRcys. This is the first study performing inulin clearance for HIV-1-infected individuals and to show data for eGFRcys from a large cohort following a switch to dolutegravir from other antiretroviral agents. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2.

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    Bin Jia

    2009-05-01

    Full Text Available Tetherin, also known as BST2, CD317 or HM1.24, was recently identified as an interferon-inducible host-cell factor that interferes with the detachment of virus particles from infected cells. HIV-1 overcomes this restriction by expressing an accessory protein, Vpu, which counteracts tetherin. Since lentiviruses of the SIV(smm/mac/HIV-2 lineage do not have a vpu gene, this activity has likely been assumed by other viral gene products. We found that deletion of the SIV(mac239 nef gene significantly impaired virus release in cells expressing rhesus macaque tetherin. Virus release could be restored by expressing Nef in trans. However, Nef was unable to facilitate virus release in the presence of human tetherin. Conversely, Vpu enhanced virus release in the presence of human tetherin, but not in the presence of rhesus tetherin. In accordance with the species-specificity of Nef in mediating virus release, SIV Nef downregulated cell-surface expression of rhesus tetherin, but did not downregulate human tetherin. The specificity of SIV Nef for rhesus tetherin mapped to four amino acids in the cytoplasmic domain of the molecule that are missing from human tetherin, whereas the specificity of Vpu for human tetherin mapped to amino acid differences in the transmembrane domain. Nef alleles of SIV(smm, HIV-2 and HIV-1 were also able to rescue virus release in the presence of both rhesus macaque and sooty mangabey tetherin, but were generally ineffective against human tetherin. Thus, the ability of Nef to antagonize tetherin from these Old World primates appears to be conserved among the primate lentiviruses. These results identify Nef as the viral gene product of SIV that opposes restriction by tetherin in rhesus macaques and sooty mangabeys, and reveal species-specificity in the activities of both Nef and Vpu in overcoming tetherin in their respective hosts.

  1. Genetic Susceptibility to Cardiac and Digestive Clinical Forms of Chronic Chagas Disease: Involvement of the CCR5 59029 A/G Polymorphism.

    Science.gov (United States)

    de Oliveira, Amanda Priscila; Bernardo, Cássia Rubia; Camargo, Ana Vitória da Silveira; Ronchi, Luiz Sérgio; Borim, Aldenis Albaneze; de Mattos, Cinara Cássia Brandão; de Campos Júnior, Eumildo; Castiglioni, Lílian; Netinho, João Gomes; Cavasini, Carlos Eugênio; Bestetti, Reinaldo Bulgarelli; de Mattos, Luiz Carlos

    2015-01-01

    The clinical manifestations of chronic Chagas disease include the cardiac form of the disease and the digestive form. Not all the factors that act in the variable clinical course of this disease are known. This study investigated whether the CCR5Δ32 (rs333) and CCR5 59029 A/G (promoter region--rs1799987) polymorphisms of the CCR5 gene are associated with different clinical forms of chronic Chagas disease and with the severity of left ventricular systolic dysfunction in patients with chronic Chagas heart disease (CCHD). The antibodies anti-T. cruzi were identified by ELISA. PCR and PCR-RFLP were used to identify the CCR5Δ32 and CCR5 59029 A/G polymorphisms. The chi-square test was used to compare variables between groups. There was a higher frequency of the AA genotype in patients with CCHD compared with patients with the digestive form of the disease and the control group. The results also showed a high frequency of the AG genotype in patients with the digestive form of the disease compared to the other groups. The results of this study show that the CCR5Δ32 polymorphism does not seem to influence the different clinical manifestations of Chagas disease but there is involvement of the CCR5 59029 A/G polymorphism in susceptibility to the different forms of chronic Chagas disease. Besides, these polymorphisms do not influence left ventricular systolic dysfunction in patients with CCHD.

  2. Genetic Susceptibility to Cardiac and Digestive Clinical Forms of Chronic Chagas Disease: Involvement of the CCR5 59029 A/G Polymorphism.

    Directory of Open Access Journals (Sweden)

    Amanda Priscila de Oliveira

    Full Text Available The clinical manifestations of chronic Chagas disease include the cardiac form of the disease and the digestive form. Not all the factors that act in the variable clinical course of this disease are known. This study investigated whether the CCR5Δ32 (rs333 and CCR5 59029 A/G (promoter region--rs1799987 polymorphisms of the CCR5 gene are associated with different clinical forms of chronic Chagas disease and with the severity of left ventricular systolic dysfunction in patients with chronic Chagas heart disease (CCHD. The antibodies anti-T. cruzi were identified by ELISA. PCR and PCR-RFLP were used to identify the CCR5Δ32 and CCR5 59029 A/G polymorphisms. The chi-square test was used to compare variables between groups. There was a higher frequency of the AA genotype in patients with CCHD compared with patients with the digestive form of the disease and the control group. The results also showed a high frequency of the AG genotype in patients with the digestive form of the disease compared to the other groups. The results of this study show that the CCR5Δ32 polymorphism does not seem to influence the different clinical manifestations of Chagas disease but there is involvement of the CCR5 59029 A/G polymorphism in susceptibility to the different forms of chronic Chagas disease. Besides, these polymorphisms do not influence left ventricular systolic dysfunction in patients with CCHD.

  3. Preferential susceptibility of Th9 and Th2 CD4+ T cells to X4-tropic HIV-1 infection.

    Science.gov (United States)

    Orlova-Fink, Nina; Chowdhury, Fatema Z; Sun, Xiaoming; Harrington, Sean; Rosenberg, Eric S; Yu, Xu G; Lichterfeld, Mathias

    2017-10-23

    The functional polarization of CD4 T cells determines their antimicrobial effector profile, but may also impact the susceptibility to infection with HIV-1. Here, we analyzed the susceptibility of CD4 T cells with different functional polarization to infection with X4 and R5-tropic HIV-1. CD4 T cells with a Th1, Th2, Th17, and Th9 polarization were subjected to in-vitro infection assays with X4, R5, or vesicular stomatitis virus-G protein-pseudotyped HIV-1. In addition, we sorted differentially polarized CD4 T-cell subsets from individuals treated with antiretroviral therapy and analyzed the tropism of viral env sequences. Th9-polarized CD4 T cells and, to a lesser extent, Th2-polarized CD4 T cells expressed higher surface levels of CXCR4, and are more permissive to X4-tropic infection in vitro. In contrast, Th1 and Th17 CD4 T cells exhibited stronger surface expression of CCR5, and were more susceptible to infection with R5-tropic viruses. Correspondingly, the distribution of X4-tropic viral sequences in antiretroviral therapy-treated HIV-1-infected patients was biased toward Th9/Th2 cells, whereas R5-tropic sequences were more frequently observed in Th17 cells. CD4 T-cell polarization is associated with a distinct susceptibility to X4 and R5-tropic HIV-1 infection.

  4. Production of Mucosally Transmissible SHIV Challenge Stocks from HIV-1 Circulating Recombinant Form 01_AE env Sequences.

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    Lawrence J Tartaglia

    2016-02-01

    Full Text Available Simian-human immunodeficiency virus (SHIV challenge stocks are critical for preclinical testing of vaccines, antibodies, and other interventions aimed to prevent HIV-1. A major unmet need for the field has been the lack of a SHIV challenge stock expressing circulating recombinant form 01_AE (CRF01_AE env sequences. We therefore sought to develop mucosally transmissible SHIV challenge stocks containing HIV-1 CRF01_AE env derived from acutely HIV-1 infected individuals from Thailand. SHIV-AE6, SHIV-AE6RM, and SHIV-AE16 contained env sequences that were >99% identical to the original HIV-1 isolate and did not require in vivo passaging. These viruses exhibited CCR5 tropism and displayed a tier 2 neutralization phenotype. These challenge stocks efficiently infected rhesus monkeys by the intrarectal route, replicated to high levels during acute infection, and established chronic viremia in a subset of animals. SHIV-AE16 was titrated for use in single, high dose as well as repetitive, low dose intrarectal challenge studies. These SHIV challenge stocks should facilitate the preclinical evaluation of vaccines, monoclonal antibodies, and other interventions targeted at preventing HIV-1 CRF01_AE infection.

  5. Conformational alterations in the CD4 binding cavity of HIV-1 gp120 influencing gp120-CD4 interactions and fusogenicity of HIV-1 envelopes derived from brain and other tissues

    Directory of Open Access Journals (Sweden)

    Ramsland Paul A

    2011-06-01

    Full Text Available Abstract Background CD4-binding site (CD4bs alterations in gp120 contribute to HIV-1 envelope (Env mediated fusogenicity and the ability of gp120 to utilize low levels of cell-surface CD4. In a recent study, we constructed three-dimensional models of gp120 to illustrate CD4bs conformations associated with enhanced fusogenicity and enhanced CD4-usage of a modestly-sized panel of blood-derived HIV-1 Envs (n = 16. These conformations were characterized by a wider aperture of the CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop. Here, we sought to provide further validation of the utility of these models for understanding mechanisms that influence Env function, by characterizing the structure-function relationships of a larger panel of Envs derived from brain and other tissues (n = 81. Findings Three-dimensional models of gp120 were generated by our recently validated homology modelling protocol. Analysis of predicted CD4bs structures showed correlations between the aperture width of the CD4bs cavity and ability of the Envs to mediate cell-cell fusion, scavenge low-levels of cell-surface CD4, bind directly to soluble CD4, and bind to the Env mAb IgG1b12 whose epitope overlaps the gp120 CD4bs. These structural alterations in the CD4bs cavity were associated with repositioning of the V5 loop. Conclusions Using a large, independent panel of Envs, we can confirm the utility of three-dimensional gp120 structural models for illustrating CD4bs alterations that can affect Env function. Furthermore, we now provide new evidence that these CD4bs alterations augment the ability of gp120 to interact with CD4 by increasing the exposure of the CD4bs.

  6. HIV-1 impairs human retinal pigment epithelial barrier function: possible association with the pathogenesis of HIV-associated retinopathy.

    Science.gov (United States)

    Tan, Suiyi; Duan, Heng; Xun, Tianrong; Ci, Wei; Qiu, Jiayin; Yu, Fei; Zhao, Xuyan; Wu, Linxuan; Li, Lin; Lu, Lu; Jiang, Shibo; Liu, Shuwen

    2014-07-01

    The breakdown of human retinal pigment epithelial (HRPE) barrier is considered as the etiology of retinopathy, which affects the quality of life of HIV/AIDS patients. Here we demonstrate that HIV-1 could directly impair HRPE barrier function, which leads to the translocation of HIV-1 and bacteria. HRPE cells (D407) were grown to form polarized, confluent monolayers and treated with different HIV-1 infectious clones. A significant increase of monolayer permeability, as measured by trans-epithelial electrical resistance (TEER) and apical-basolateral movements of sodium fluorescein, was observed. Disrupted tightness of HRPE barrier was associated with the downregulation of several tight junction proteins in D407 cells, including ZO-1, Occludin, Claudin-1, Claudin-2, Claudin-3, Claudin-4, and Claudin-5, after exposure to HIV-1, without affecting the viability of cells. HIV-1 gp120 was shown to participate in the alteration of barrier properties, as evidenced by decreased TEER and weakened expression of tight junction proteins in D407 monolayers after exposure to pseudotyped HIV-1, UV-inactivated HIV-1, and free gp120, but not to an envelope (Env)-defective mutant of HIV. Furthermore, exposure to HIV-1 particles could induce the release of pro-inflammatory cytokines in D407, including IL-6 and MCP-1, both of which downregulated the expression of ZO-1 in the HRPE barrier. Disrupted HRPE monolayer allowed translocation of HIV-1 and bacteria across the epithelium. Overall, these findings suggest that HIV-1 may exploit its Env glycoprotein to induce an inflammatory state in HRPE cells, which could result in impairment of HRPE monolayer integrity, allowing virus and bacteria existing in ocular fluids to cross the epithelium and penetrate the HRPE barrier. Our study highlights the role of HIV-1 in the pathogenesis of HIV/AIDS-related retinopathy and suggests potential therapeutic targets for this ocular complication.

  7. Imperatorin inhibits HIV-1 replication through an Sp1-dependent pathway.

    Science.gov (United States)

    Sancho, Rocío; Márquez, Nieves; Gómez-Gonzalo, Marta; Calzado, Marco A; Bettoni, Giorgio; Coiras, Maria Teresa; Alcamí, José; López-Cabrera, Manuel; Appendino, Giovanni; Muñoz, Eduardo

    2004-09-03

    Coumarins and structurally related compounds have been recently shown to present anti-human immunodeficiency virus, type 1 (HIV-1) activity. Among them, the dietary furanocoumarin imperatorin is present in citrus fruits, in culinary herbs, and in some medicinal plants. In this study we report that imperatorin inhibits either vesicular stomatitis virus-pseudotyped or gp160-enveloped recombinant HIV-1 infection in several T cell lines and in HeLa cells. These recombinant viruses express luciferase as a marker of viral replication. Imperatorin did not inhibit the reverse transcription nor the integration steps in the viral cell cycle. Using several 5' long terminal repeat-HIV-1 constructs where critical response elements were either deleted or mutated, we found that the transcription factor Sp1 is critical for the inhibitory activity of imperatorin induced by both phorbol 12-myristate 13-acetate and HIV-1 Tat. Moreover in transient transfections imperatorin specifically inhibited phorbol 12-myristate 13-acetate-induced transcriptional activity of the Gal4-Sp1 fusion protein. Since Sp1 is also implicated in cell cycle progression we further studied the effect of imperatorin on cyclin D1 gene transcription and protein expression and in HeLa cell cycle progression. We found that imperatorin strongly inhibited cyclin D1 expression and arrested the cells at the G(1) phase of the cell cycle. These results highlight the potential of Sp1 transcription factor as a target for natural anti-HIV-1 compounds such as furanocoumarins that might have a potential therapeutic role in the management of AIDS.

  8. Reanalysis of coreceptor tropism in HIV-1-infected adults using a phenotypic assay with enhanced sensitivity.

    Science.gov (United States)

    Wilkin, Timothy J; Goetz, Mathew Bidwell; Leduc, Robert; Skowron, Gail; Su, Zhaohui; Chan, Ellen S; Heera, Jayyant; Chapman, Doug; Spritzler, John; Reeves, Jacqueline D; Gulick, Roy M; Coakley, Eoin

    2011-04-01

    The enhanced-sensitivity Trofile assay (TF-ES; Monogram Biosciences) was used to retest coreceptor tropism samples from 4 different cohorts of HIV-1-infected patients. Nine percent to 26% of patients with CCR5-tropic virus by the original Trofile assay had CXCR4-using virus by TF-ES. Lower CD4 cell counts were associated with CXCR4-using virus in all cohorts. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.

  9. HIV-1 specific IgA detected in vaginal secretions of HIV uninfected women participating in a microbicide trial in Southern Africa are primarily directed toward gp120 and gp140 specificities.

    Directory of Open Access Journals (Sweden)

    Kelly E Seaton

    Full Text Available Many participants in microbicide trials remain uninfected despite ongoing exposure to HIV-1. Determining the emergence and nature of mucosal HIV-specific immune responses in such women is important, since these responses may contribute to protection and could provide insight for the rational design of HIV-1 vaccines.We first conducted a pilot study to compare three sampling devices (Dacron swabs, flocked nylon swabs and Merocel sponges for detection of HIV-1-specific IgG and IgA antibodies in vaginal secretions. IgG antibodies from HIV-1-positive women reacted broadly across the full panel of eight HIV-1 envelope (Env antigens tested, whereas IgA antibodies only reacted to the gp41 subunit. No Env-reactive antibodies were detected in the HIV-negative women. The three sampling devices yielded equal HIV-1-specific antibody titers, as well as total IgG and IgA concentrations. We then tested vaginal Dacron swabs archived from 57 HIV seronegative women who participated in a microbicide efficacy trial in Southern Africa (HPTN 035. We detected vaginal IgA antibodies directed at HIV-1 Env gp120/gp140 in six of these women, and at gp41 in another three women, but did not detect Env-specific IgG antibodies in any women.Vaginal secretions of HIV-1 infected women contained IgG reactivity to a broad range of Env antigens and IgA reactivity to gp41. In contrast, Env-binding antibodies in the vaginal secretions of HIV-1 uninfected women participating in the microbicide trial were restricted to the IgA subtype and were mostly directed at HIV-1 gp120/gp140.

  10. ERManI (Endoplasmic Reticulum Class I α-Mannosidase) Is Required for HIV-1 Envelope Glycoprotein Degradation via Endoplasmic Reticulum-associated Protein Degradation Pathway.

    Science.gov (United States)

    Zhou, Tao; Frabutt, Dylan A; Moremen, Kelley W; Zheng, Yong-Hui

    2015-09-04

    Previously, we reported that the mitochondrial translocator protein (TSPO) induces HIV-1 envelope (Env) degradation via the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway, but the mechanism was not clear. Here we investigated how the four ER-associated glycoside hydrolase family 47 (GH47) α-mannosidases, ERManI, and ER-degradation enhancing α-mannosidase-like (EDEM) proteins 1, 2, and 3, are involved in the Env degradation process. Ectopic expression of these four α-mannosidases uncovers that only ERManI inhibits HIV-1 Env expression in a dose-dependent manner. In addition, genetic knock-out of the ERManI gene MAN1B1 using CRISPR/Cas9 technology disrupts the TSPO-mediated Env degradation. Biochemical studies show that HIV-1 Env interacts with ERManI, and between the ERManI cytoplasmic, transmembrane, lumenal stem, and lumenal catalytic domains, the catalytic domain plays a critical role in the Env-ERManI interaction. In addition, functional studies show that inactivation of the catalytic sites by site-directed mutagenesis disrupts the ERManI activity. These studies identify ERManI as a critical GH47 α-mannosidase in the ER-associated protein degradation pathway that initiates the Env degradation and suggests that its catalytic domain and enzymatic activity play an important role in this process. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. CCR6 and NK1.1 distinguish between IL-17A and IFN-gamma-producing gammadelta effector T cells.

    Science.gov (United States)

    Haas, Jan D; González, Frano H Malinarich; Schmitz, Susanne; Chennupati, Vijaykumar; Föhse, Lisa; Kremmer, Elisabeth; Förster, Reinhold; Prinz, Immo

    2009-12-01

    Gammadelta T cells are a potent source of innate IL-17A and IFN-gamma, and they acquire the capacity to produce these cytokines within the thymus. However, the precise stages and required signals that guide this differentiation are unclear. Here we show that the CD24(low) CD44(high) effector gammadelta T cells of the adult thymus are segregated into two lineages by the mutually exclusive expression of CCR6 and NK1.1. Only CCR6+ gammadelta T cells produced IL-17A, while NK1.1+ gammadelta T cells were efficient producers of IFN-gamma but not of IL-17A. Their effector phenotype correlated with loss of CCR9 expression, particularly among the NK1.1+ gammadelta T cells. Accordingly, both gammadelta T-cell subsets were rare in gut-associated lymphoid tissues, but abundant in peripheral lymphoid tissues. There, they provided IL-17A and IFN-gamma in response to TCR-specific and TCR-independent stimuli. IL-12 and IL-18 induced IFN-gamma and IL-23 induced IL-17A production by NK1.1+ or CCR6+ gammadelta T cells, respectively. Importantly, we show that CCR6+ gammadelta T cells are more responsive to TCR stimulation than their NK1.1+ counterparts. In conclusion, our findings support the hypothesis that CCR6+ IL-17A-producing gammadelta T cells derive from less TCR-dependent selection events than IFN-gamma-producing NK1.1+ gammadelta T cells.

  12. Gene polymorphisms and febrile neutropenia in acute leukemia--no association with IL-4, CCR-5, IL-1RA, but the MBL-2, ACE, and TLR-4 are associated with the disease in Turkish patients: a preliminary study.

    Science.gov (United States)

    Pehlivan, Mustafa; Sahin, Handan Haydaroğlu; Ozdilli, Kurşat; Onay, Hüseyin; Ozcan, Ali; Ozkinay, Ferda; Pehlivan, Sacide

    2014-07-01

    The aim of this study was to investigate the mannose-binding lectin 2 (MBL-2), interleukin (IL)-4, Toll-like receptor 4 (TLR-4), angiotensin converting enzyme (ACE), chemokine receptor 5 (CCR-5), and IL-1 receptor antagonist (RA) gene polymorphisms (GPs) in acute leukemias (ALs) and to evaluate their roles in febrile neutropenia (FN) resulting from chemotherapy. The study included 60 AL patients hospitalized between the period of July 2001 and August 2006. Polymorphisms for the genes ACE(I/D), CCR-5, IL-1RA, MBL-2, TLR-4, and IL-4 were typed by polymerase chain reaction (PCR) and/or PCR-restriction fragment length polymerase. Genotype frequencies for these genes were compared in the patient and control groups. The relationships between the genotypes and the body distribution of infections, pathogens, the duration of neutropenia, and febrile episodes in AL patients were evaluated. No significant differences in either the genotype distribution or the allelic frequencies of TLR-4, IL-4, CCR-5, IL-1RN GPs were observed between patients and healthy controls. The AB/BB genotype (53.3%) in the MBL-2 gene was found to be significantly higher in the AL patients compared with control groups. There were correlations between the presence of MBL-2, TLR-4, and ACE polymorphisms and clinical parameters due to FN. Overall, bacteremia was more common in MBL BB and ACE DD. Gram-positive bacteremia was more common in ACE for ID versus DD genotype. Gram-negative bacteremia was more common for both the MBL-2 AB/BB genotype and TLR-4 AG genotype. Median durations of febrile episodes were significantly shorter in ACE DD and MBL AB/BB. Although TLR-4, ACE, and MBL-2 GPs have been extensively investigated in different clinical pictures, this is the first study to evaluate the role of these polymorphisms in the genetic etiopathogenesis of FN in patients with ALs. As a conclusion, TLR-4, ACE, and MBL-2 genes might play roles in the genetic etiopathogenesis of FN in patients with ALs.

  13. Nonproductive human immunodeficiency virus type 1 infection of human fetal astrocytes: independence from CD4 and major chemokine receptors.

    Science.gov (United States)

    Sabri, F; Tresoldi, E; Di Stefano, M; Polo, S; Monaco, M C; Verani, A; Fiore, J R; Lusso, P; Major, E; Chiodi, F; Scarlatti, G

    1999-11-25

    Human immunodeficiency virus type 1 (HIV-1) infection of the brain is associated with neurological manifestations both in adults and in children. The primary target for HIV-1 infection in the brain is the microglia, but astrocytes can also be infected. We tested 26 primary HIV-1 isolates for their capacity to infect human fetal astrocytes in culture. Eight of these isolates, independent of their biological phenotype and chemokine receptor usage, were able to infect astrocytes. Although no sustained viral replication could be demonstrated, the virus was recovered by coculture with receptive cells such as macrophages or on stimulation with interleukin-1beta. To gain knowledge into the molecular events that regulate attachment and penetration of HIV-1 in astrocytes, we investigated the expression of several chemokine receptors. Fluorocytometry and calcium-mobilization assay did not provide evidence of expression of any of the major HIV-1 coreceptors, including CXCR4, CCR5, CCR3, and CCR2b, as well as the CD4 molecule on the cell surface of human fetal astrocytes. However, mRNA transcripts for CXCR4, CCR5, Bonzo/STRL33/TYMSTR, and APJ were detected by RT-PCR. Furthermore, infection of astrocytes by HIV-1 isolates with different chemokine receptor usage was not inhibited by the chemokines SDF-1beta, RANTES, MIP-1beta, or MCP-1 or by antibodies directed against the third variable region or the CD4 binding site of gp120. These data show that astrocytes can be infected by primary HIV-1 isolates via a mechanism independent of CD4 or major chemokine receptors. Furthermore, astrocytes are potential carriers of latent HIV-1 and on activation may be implicated in spreading the infection to other neighbouring cells, such as microglia or macrophages. Copyright 1999 Academic Press.

  14. Up-regulation of the Neuronal Nicotinic Receptor α7 by HIV Glycoprotein 120

    Science.gov (United States)

    Ballester, Leomar Y.; Capó-Vélez, Coral M.; García-Beltrán, Wilfredo F.; Ramos, Félix M.; Vázquez-Rosa, Edwin; Ríos, Raymond; Mercado, José R.; Meléndez, Roberto I.; Lasalde-Dominicci, José A.

    2012-01-01

    Approximately 30–50% of the >30 million HIV-infected subjects develop neurological complications ranging from mild symptoms to dementia. HIV does not infect neurons, and the molecular mechanisms behind HIV-associated neurocognitive decline are not understood. There are several hypotheses to explain the development of dementia in HIV+ individuals, including neuroinflammation mediated by infected microglia and neuronal toxicity by HIV proteins. A key protein associated with the neurological complications of HIV, gp120, forms part of the viral envelope and can be found in the CSF of infected individuals. HIV-1-gp120 interacts with several receptors including CD4, CCR5, CXCR4, and nicotinic acetylcholine receptors (nAChRs). However, the role of nAChRs in HIV-associated neurocognitive disorder has not been investigated. We studied the effects of gp120IIIB on the expression and function of the nicotinic receptor α7 (α7-nAChR). Our results show that gp120, through activation of the CXCR4 chemokine receptor, induces a functional up-regulation of α7-nAChRs. Because α7-nAChRs have a high permeability to Ca2+, we performed TUNEL staining to investigate the effects of receptor up-regulation on cell viability. Our data revealed an increase in cell death, which was blocked by the selective antagonist α-bungarotoxin. The in vitro data are supported by RT-PCR and Western blot analysis, confirming a remarkable up-regulation of the α7-nAChR in gp120-transgenic mice brains. Specifically, α7-nAChR up-regulation is observed in mouse striatum, a region severely affected in HIV+ patients. In summary, CXCR4 activation induces up-regulation of α7-nAChR, causing cell death, suggesting that α7-nAChR is a previously unrecognized contributor to the neurotoxicity associated with HIV infection. PMID:22084248

  15. HIV-related restrictions on entry, residence and stay in the WHO European Region: a survey

    DEFF Research Database (Denmark)

    Lazarus, Jeff; Curth, Nadja; Weait, Matthew

    2010-01-01

    Back in 1987, the World Health Organization (WHO) concluded that the screening of international travellers was an ineffective way to prevent the spread of HIV. However, some countries still restrict the entrance and/or residency of foreigners with an HIV infection. HIV-related travel restrictions...

  16. Differential between Protein and mRNA Expression of CCR7 and SSTR5 Receptors in Crohn's Disease Patients

    Directory of Open Access Journals (Sweden)

    Nathalie Taquet

    2009-01-01

    Full Text Available Crohn's disease (CD is a multifactorial chronic inflammatory bowel disease of unknown cause. The aim of the present study was to explore if mRNA over-expression of SSTR5 and CCR7 found in CD patients could be correlated to respective protein expression. When compared to healthy donors, SSTR5 was over-expressed 417 ± 71 times in CD peripheral blood mononuclear cells (PBMCs. Flow cytometry experiments showed no correlation between mRNA and protein expression for SSTR5 in PBMCs. In an attempt to find a reason of such a high mRNA expression, SSTR5 present on CD PBMCs were tested and found as biologically active as on healthy cells. In biopsies of CD intestinal tissue, SSTR5 was not over-expressed but CCR7, unchanged in PBMCs, was over-expressed by 10 ± 3 times in the lamina propria. Confocal microscopy showed a good correlation of CCR7 mRNA and protein expression in CD intestinal biopsies. Our data emphasize flow and image cytometry as impossible to circumvent in complement to molecular biology so to avoid false interpretation on receptor expressions. Once confirmed by further large-scale studies, our preliminary results suggest a role for SSTR5 and CCR7 in CD pathogenesis.

  17. Heme oxygenase-1 induction alters chemokine regulation and ameliorates human immunodeficiency virus-type-1 infection in lipopolysaccharide-stimulated macrophages

    International Nuclear Information System (INIS)

    Zhou, Zhao-Hua; Kumari, Namita; Nekhai, Sergei; Clouse, Kathleen A.; Wahl, Larry M.; Yamada, Kenneth M.; Dhawan, Subhash

    2013-01-01

    Highlights: •Lipopolysaccharide stimulation of heme oxygenase-1 (HO-1) ameliorated HIV-1 infection of primary human macrophages. •The partial protection by HO-1 against HIV infection was associated with induction of chemokines such as MIP1α and MIP1β. •This mechanism explains lipopolysaccharide-stimulated HO-1-mediated inhibition of HIV-1 infection of macrophages. -- Abstract: We have elucidated a putative mechanism for the host resistance against HIV-1 infection of primary human monocyte-derived macrophages (MDM) stimulated with lipopolysaccharide (LPS). We show that LPS-activated MDM both inhibited HIV-1 entry into the cells and were refractory to post-entry productive viral replication. LPS-treated cells were virtually negative for mature virions as revealed by transmission electron microscopy. LPS activation of MDM markedly enhanced the expression of heme oxygenase-1 (HO-1), a potent inducible cytoprotective enzyme. Increased HO-1 expression was accompanied by elevated production of macrophage inflammatory chemokines (MIP1α and MIP1β) by LPS-activated MDM, significantly decreased surface chemokine receptor-5 (CCR-5) expression, and substantially reduced virus replication. Treatment of cells with HO-1 inhibitor SnPP IX (tin protoporphyrin IX) attenuated the LPS-mediated responses, HIV-1 replication and secretion of MIP1α, MIP1β, and LD78β chemokines with little change in surface CCR-5 expression. These results identify a novel role for HO-1 in the modulation of host immune response against HIV infection of MDM

  18. Lack of mucosal immune reconstitution during prolonged treatment of acute and early HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Saurabh Mehandru

    2006-12-01

    Full Text Available During acute and early HIV-1 infection (AEI, up to 60% of CD4(+ T cells in the lamina propria of the lower gastrointestinal (GI tract are lost as early as 2-4 wk after infection. Reconstitution in the peripheral blood during therapy with highly active antiretroviral therapy (HAART is well established. However, the extent of immune reconstitution in the GI tract is unknown.Fifty-four AEI patients and 18 uninfected control participants underwent colonic biopsy. Forty of the 54 AEI patients were followed after initiation of antiretroviral therapy (18 were studied longitudinally with sequential biopsies over a 3-y period after beginning HAART, and 22 were studied cross sectionally after 1-7 y of uninterrupted therapy. Lymphocyte subsets, markers of immune activation and memory in the peripheral blood and GI tract were determined by flow cytometry and immunohistochemistry. In situ hybridization was performed in order to identify persistent HIV-1 RNA expression. Of the patients studied, 70% maintained, on average, a 50%-60% depletion of lamina propria lymphocytes despite 1-7 y of HAART. Lymphocytes expressing CCR5 and both CCR5 and CXCR4 were persistently and preferentially depleted. Levels of immune activation in the memory cell population, CD45RO+ HLA-DR+, returned to levels seen in the uninfected control participants in the peripheral blood, but were elevated in the GI tract of patients with persistent CD4+ T cell depletion despite therapy. Rare HIV-1 RNA-expressing cells were detected by in situ hybridization.Apparently suppressive treatment with HAART during acute and early infection does not lead to complete immune reconstitution in the GI mucosa in the majority of patients studied, despite immune reconstitution in the peripheral blood. Though the mechanism remains obscure, the data suggest that there is either viral or immune-mediated accelerated T cell destruction or, possibly, alterations in T cell homing to the GI tract. Although clinically

  19. Molecular cloning and anti-HIV-1 activities of APOBEC3s from northern pig-tailed macaques (Macaca leonina

    Directory of Open Access Journals (Sweden)

    Xiao-Liang ZHANG

    2016-07-01

    Full Text Available Northern pig-tailed macaques (NPMs, Macaca leonina are susceptible to HIV-1 infection largely due to the loss of HIV-1-restricting factor TRIM5α. However, great impediments still exist in the persistent replication of HIV-1 in vivo, suggesting some viral restriction factors are reserved in this host. The APOBEC3 proteins have demonstrated a capacity to restrict HIV-1 replication, but their inhibitory effects in NPMs remain elusive. In this study, we cloned the NPM A3A-A3H genes, and determined by BLAST searching that their coding sequences (CDSs showed 99% identity to the corresponding counterparts from rhesus and southern pig-tailed macaques. We further analyzed the anti-HIV-1 activities of the A3A-A3H genes, and found that A3G and A3F had the greatest anti-HIV-1 activity compared with that of other members. The results of this study indicate that A3G and A3F might play critical roles in limiting HIV-1 replication in NPMs in vivo. Furthermore, this research provides valuable information for the optimization of monkey models of HIV-1 infection.

  20. Rapid quantification of the latent reservoir for HIV-1 using a viral outgrowth assay.

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    Gregory M Laird

    Full Text Available HIV-1 persists in infected individuals in a stable pool of resting CD4(+ T cells as a latent but replication-competent provirus. This latent reservoir is the major barrier to the eradication of HIV-1. Clinical trials are currently underway investigating the effects of latency-disrupting compounds on the persistence of the latent reservoir in infected individuals. To accurately assess the effects of such compounds, accurate assays to measure the frequency of latently infected cells are essential. The development of a simpler assay for the latent reservoir has been identified as a major AIDS research priority. We report here the development and validation of a rapid viral outgrowth assay that quantifies the frequency of cells that can release replication-competent virus following cellular activation. This new assay utilizes bead and column-based purification of resting CD4(+ T cells from the peripheral blood of HIV-1 infected patients rather than cell sorting to obtain comparable resting CD4(+ T cell purity. This new assay also utilizes the MOLT-4/CCR5 cell line for viral expansion, producing statistically comparable measurements of the frequency of latent HIV-1 infection. Finally, this new assay employs a novel quantitative RT-PCR specific for polyadenylated HIV-1 RNA for virus detection, which we demonstrate is a more sensitive and cost-effective method to detect HIV-1 replication than expensive commercial ELISA detection methods. The reductions in both labor and cost make this assay suitable for quantifying the frequency of latently infected cells in clinical trials of HIV-1 eradication strategies.