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Sample records for hiv-1 gp41 c-peptide

  1. Evaluation of sequence variability in HIV-1 gp41 C-peptide helix-grafted proteins.

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    Tennyson, Rachel L; Walker, Susanne N; Ikeda, Terumasa; Harris, Reuben S; McNaughton, Brian R

    2017-08-01

    Many therapeutically-relevant protein-protein interactions (PPIs) have been reported that feature a helix and helix-binding cleft at the interface. Given this, different approaches to disrupting such PPIs have been developed. While short peptides (<15 amino acids) typically do not fold into a stable helix, researchers have reported chemical approaches to constraining helix structure. However, these approaches rely on laborious, and often expensive, chemical synthesis and purification. Our premise is that protein-based solutions that stabilize a therapeutically-relevant helix offer a number of advantages. In contrast to chemically constrained helical peptides, or minimal/miniature proteins, which must be synthesized (at great expense and labor), a protein can be expressed in a cellular system (like all current protein therapeutics). If selected properly, the protein scaffold can stabilize the therapeutically-relevant helix. We recently reported a protein engineering strategy, which we call "helix-grafted display", and applied it to the challenge of suppressing HIV entry. We have reported helix-grafted display proteins that inhibit formation of an intramolecular PPI involving HIV gp41 C-peptide helix, and HIV gp41 N-peptide trimer, which contain C-peptide helix-binding clefts. Here, we used yeast display to screen a library of grafted C-peptide helices for N-peptide trimer recognition. Using 'hits' from yeast display library screening, we evaluated the effect helix mutations have on structure, expression, stability, function (target recognition), and suppression of HIV entry. Copyright © 2017. Published by Elsevier Ltd.

  2. Membrane topology analysis of HIV-1 envelope glycoprotein gp41

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    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.

  3. HIV-1 infection: functional competition between gp41 and interleukin-2.

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    Sanhadji, Kamel; Tardy, Jean-Claude; Touraine, Jean-Louis

    2010-08-01

    To determine whether the gp41 of HIV-1 could adhere to the interleukin (IL)-2 receptor at the surface of target cells in vitro, we analysed in vitro the possible functional competition between various forms of the HIV-1 gp41 molecule (i.e. peptides, trimeric or primary structures) and IL-2. This competition has been analysed in a test involving the proliferation of an IL-2-dependent cell line (CTLL2). The putative interaction between the IL-2 molecule and HIV-1 has also been assayed on MT4 cells (CD4(+) T lymphocytes) in culture. The gp41 trimeric molecule and an HIV-1 gp41 peptide (578-590 aminoacid sequence) dramatically inhibited CTLL2 cell proliferation, despite the presence of IL-2. The addition of serum, containing anti-gp41 antibodies, from HIV-1 patients resulted in a significant abolition of this inhibition. The concomitant incubation of IL-2 and HIV-1 with MT4 cells resulted in a strong decrease (70%) in HIV-1 p24 release. These data suggest that the gp41 of HIV-1 can use the IL-2 receptor during the process of HIV-1 infection and that there is some functional mimesis between gp41 and IL-2. Copyright 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  4. Asymmetric deactivation of HIV-1 gp41 following fusion inhibitor binding.

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    Kristen M Kahle

    2009-11-01

    Full Text Available Both equilibrium and nonequilibrium factors influence the efficacy of pharmaceutical agents that target intermediate states of biochemical reactions. We explored the intermediate state inhibition of gp41, part of the HIV-1 envelope glycoprotein complex (Env that promotes viral entry through membrane fusion. This process involves a series of gp41 conformational changes coordinated by Env interactions with cellular CD4 and a chemokine receptor. In a kinetic window between CD4 binding and membrane fusion, the N- and C-terminal regions of the gp41 ectodomain become transiently susceptible to inhibitors that disrupt Env structural transitions. In this study, we sought to identify kinetic parameters that influence the antiviral potency of two such gp41 inhibitors, C37 and 5-Helix. Employing a series of C37 and 5-Helix variants, we investigated the physical properties of gp41 inhibition, including the ability of inhibitor-bound gp41 to recover its fusion activity once inhibitor was removed from solution. Our results indicated that antiviral activity critically depended upon irreversible deactivation of inhibitor-bound gp41. For C37, which targets the N-terminal region of the gp41 ectodomain, deactivation was a slow process that depended on chemokine receptor binding to Env. For 5-Helix, which targets the C-terminal region of the gp41 ectodomain, deactivation occurred rapidly following inhibitor binding and was independent of chemokine receptor levels. Due to this kinetic disparity, C37 inhibition was largely reversible, while 5-Helix inhibition was functionally irreversible. The fundamental difference in deactivation mechanism points to an unappreciated asymmetry in gp41 following inhibitor binding and impacts the development of improved fusion inhibitors and HIV-1 vaccines. The results also demonstrate how the activities of intermediate state inhibitors critically depend upon the final disposition of inhibitor-bound states.

  5. Diversion of HIV-1 Vaccine-induced Immunity by gp41-Microbiota Cross-reactive Antibodies

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    Williams, Wilton B; Liao, Hua-Xin; Moody, M. Anthony; Kepler, Thomas B.; Alam, S Munir; Gao, Feng; Wiehe, Kevin; Trama, Ashley M.; Jones, Kathryn; Zhang, Ruijun; Song, Hongshuo; Marshall, Dawn J; Whitesides, John F; Sawatzki, Kaitlin; Hua, Axin; Liu, Pinghuang; Tay, Matthew Z; Seaton, Kelly; Shen, Xiaoying; Foulger, Andrew; Lloyd, Krissey E.; Parks, Robert; Pollara, Justin; Ferrari, Guido; Yu, Jae-Sung; Vandergrift, Nathan; Montefiori, David C.; Sobieszczyk, Magdalena E; Hammer, Scott; Karuna, Shelly; Gilbert, Peter; Grove, Doug; Grunenberg, Nicole; McElrath, Julie; Mascola, John R.; Koup, Richard A; Corey, Lawrence; Nabel, Gary J.; Morgan, Cecilia; Churchyard, Gavin; Maenza, Janine; Keefer, Michael; Graham, Barney S.; Baden, Lindsey R.; Tomaras, Georgia D.; Haynes, Barton F.

    2015-01-01

    A HIV-1 DNA prime-recombinant Adenovirus Type 5 (rAd5) boost vaccine failed to protect from HIV-1 acquisition. We studied the nature of the vaccine-induced antibody (Ab) response to HIV-1 envelope (Env). HIV-1-reactive plasma Ab titers were higher to Env gp41 than gp120, and repertoire analysis demonstrated that 93% of HIV-1-reactive Abs from memory B cells was to Env gp41. Vaccine-induced gp41-reactive monoclonal antibodies (mAbs) were non-neutralizing, and frequently polyreactive with host and environmental antigens including intestinal microbiota (IM). Next generation sequencing of an IGHV repertoire prior to vaccination revealed an Env-IM cross-reactive Ab that was clonally-related to a subsequent vaccine-induced gp41-reactive Ab. Thus, HIV-1 Env DNA-rAd5 vaccine induced a dominant IM-polyreactive, non-neutralizing gp41-reactive Ab repertoire response that was associated with no vaccine efficacy. PMID:26229114

  6. Antigenic and immunosuppressive properties of a trimeric recombinant transmembrane envelope protein gp41 of HIV-1.

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    Michael Mühle

    Full Text Available The transmembrane envelope (TM protein gp41 of the human immunodeficiency virus-1 (HIV-1 plays an important role during virus infection inducing the fusion of the viral and cellular membranes. In addition, there are indications that the TM protein plays a role in the immunopathogenesis leading to the acquired immunodeficiency syndrome (AIDS. Inactivated virus particles and recombinant gp41 have been reported to inhibit lymphocyte proliferation, as well as to alter cytokine release and gene expression. The same was shown for a peptide corresponding to a highly conserved domain of all retroviral TM proteins, the immunosuppressive domain. Due to its propensity to aggregate and to be expressed at low levels, studies comprising authentic gp41 produced in eukaryotic cells are extremely rare. Here we describe the production of a secreted, soluble recombinant gp41 in 293 cells. The antigen was purified to homogeneity and characterised thoroughly by various biochemical and immunological methods. It was shown that the protein was glycosylated and assembled into trimers. Binding studies by ELISA and surface plasmon resonance using conformation-specific monoclonal antibodies implied a six-helix bundle conformation. The low binding of broadly neutralising antibodies (bnAb directed against the membrane proximal external region (MPER suggested that this gp41 is probably not suited as vaccine to induce such bnAb. Purified gp41 bound to monocytes and to a lesser extent to lymphocytes and triggered the production of specific cytokines when added to normal peripheral blood mononuclear cells. In addition, gp41 expressed on target cells inhibited the antigen-specific response of murine CD8+ T cells by drastically impairing their IFNγ production. To our knowledge, this is the first comprehensive analysis of a gp41 produced in eukaryotic cells including its immunosuppressive properties. Our data provide another line of evidence that gp41 might be directly involved in

  7. 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.

  8. Approaches for Identification of HIV-1 Entry Inhibitors Targeting gp41 Pocket

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    Asim K. Debnath

    2013-01-01

    Full Text Available The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon, was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD, it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of production. Thus, development of small molecule compounds targeting the gp41 pocket with oral availability has been promoted. This review describes the main approaches for identification of HIV fusion/entry inhibitors targeting the gp41 pocket and summarizes the latest progress in developing these inhibitors as a new class of anti-HIV drugs.

  9. Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated

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    Chen, Xi; Munshaw, Supriya; Zhang, Ruijun; Marshall, Dawn J.; Vandergrift, Nathan; Whitesides, John F.; Lu, Xiaozhi; Yu, Jae-Sung; Hwang, Kwan-Ki; Gao, Feng; Markowitz, Martin; Heath, Sonya L.; Bar, Katharine J.; Goepfert, Paul A.; Montefiori, David C.; Shaw, George C.; Alam, S. Munir; Margolis, David M.; Denny, Thomas N.; Boyd, Scott D.; Marshal, Eleanor; Egholm, Michael; Simen, Birgitte B.; Hanczaruk, Bozena; Fire, Andrew Z.; Voss, Gerald; Kelsoe, Garnett; Tomaras, Georgia D.; Moody, M. Anthony; Kepler, Thomas B.

    2011-01-01

    The initial antibody response to HIV-1 is targeted to envelope (Env) gp41, and is nonneutralizing and ineffective in controlling viremia. To understand the origins and characteristics of gp41-binding antibodies produced shortly after HIV-1 transmission, we isolated and studied gp41-reactive plasma cells from subjects acutely infected with HIV-1. The frequencies of somatic mutations were relatively high in these gp41-reactive antibodies. Reverted unmutated ancestors of gp41-reactive antibodies derived from subjects acutely infected with HIV-1 frequently did not react with autologous HIV-1 Env; however, these antibodies were polyreactive and frequently bound to host or bacterial antigens. In one large clonal lineage of gp41-reactive antibodies, reactivity to HIV-1 Env was acquired only after somatic mutations. Polyreactive gp41-binding antibodies were also isolated from uninfected individuals. These data suggest that the majority of gp41-binding antibodies produced after acute HIV-1 infection are cross-reactive responses generated by stimulating memory B cells that have previously been activated by non–HIV-1 antigens. PMID:21987658

  10. Small-molecule HIV-1 entry inhibitors targeting gp120 and gp41: a patent review (2010-2015).

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    Li, Wen; Lu, Lu; Li, Weihua; Jiang, Shibo

    2017-06-01

    It is essential to discover and develop small-molecule HIV-1 entry inhibitors with suitable pharmaceutical properties. Areas covered: We review the development of small-molecule HIV-1 entry inhibitors as evidenced in patents, patent applications, and related research articles published between 2010 and 2015. Expert opinion: HIV-1 Env gp120 and gp41 are important targets for development of HIV-1 entry inhibitors. The Phe43 pocket in gp120 and the highly conserved hydrophobic pocket on gp41 NHR-trimer are important targets for identification of HIV-1 attachment and fusion inhibitors, respectively. Compounds that bind to Phe43 pocket can block viral gp120 binding to CD4 on T cells, thus inhibiting HIV-1 attachment. However, most compounds targeting Phe43 pocket identified so far are HIV-1 entry agonists with the ability to enhance infectivity of HIV-1 in CD4-negative cells. Therefore, it is essential to identify HIV-1 entry antagonist-based HIV-1 attachment/entry inhibitors. Compounds binding to the gp41 hydrophobic pocket may inhibit CHR binding to the gp41 NHR trimer, thus blocking six-helix bundle formation and gp41-mediated virus-cell fusion. However, most lead compounds targeting this pocket have low potency, possibly because the pocket is too big or too deep. Therefore, it is necessary to identify other pockets in gp41 for developing HIV-1 fusion/entry inhibitors.

  11. Solution Structure and Membrane Interaction of the Cytoplasmic Tail of HIV-1 gp41 Protein.

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    Murphy, R Elliot; Samal, Alexandra B; Vlach, Jiri; Saad, Jamil S

    2017-11-07

    The cytoplasmic tail of gp41 (gp41CT) remains the last HIV-1 domain with an unknown structure. It plays important roles in HIV-1 replication such as mediating envelope (Env) intracellular trafficking and incorporation into assembling virions, mechanisms of which are poorly understood. Here, we present the solution structure of gp41CT in a micellar environment and characterize its interaction with the membrane. We show that the N-terminal 45 residues are unstructured and not associated with the membrane. However, the C-terminal 105 residues form three membrane-bound amphipathic α helices with distinctive structural features such as variable degree of membrane penetration, hydrophobic and basic surfaces, clusters of aromatic residues, and a network of cation-π interactions. This work fills a major gap by providing the structure of the last segment of HIV-1 Env, which will provide insights into the mechanisms of Gag-mediated Env incorporation as well as the overall Env mobility and conformation on the virion surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Antibodies to a conformational epitope on gp41 neutralize HIV-1 by destabilizing the Env spike

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    Lee, Jeong Hyun; Leaman, Daniel P.; Kim, Arthur S.; Torrents de La Peña, Alba; Sliepen, Kwinten; Yasmeen, Anila; Derking, Ronald; Ramos, Alejandra; de Taeye, Steven W.; Ozorowski, Gabriel; Klein, Florian; Burton, Dennis R.; Nussenzweig, Michel C.; Poignard, Pascal; Moore, John P.; Klasse, Per Johan; Sanders, Rogier W.; Zwick, Michael B.; Wilson, Ian A.; Ward, Andrew B.

    2015-09-01

    The recent identification of three broadly neutralizing antibodies (bnAbs) against gp120-gp41 interface epitopes has expanded the targetable surface on the HIV-1 envelope glycoprotein (Env) trimer. By using biochemical, biophysical and computational methods, we map the previously unknown trimer epitopes of two related antibodies, 3BC315 and 3BC176. A cryo-EM reconstruction of a soluble Env trimer bound to 3BC315 Fab at 9.3 Å resolution reveals that the antibody binds between two gp41 protomers, and neutralizes the virus by accelerating trimer decay. In contrast, bnAb 35O22 binding to a partially overlapping quaternary epitope at the gp120-gp41 interface does not induce decay. A conserved gp41-proximal glycan at N88 was also shown to play a role in the binding kinetics of 3BC176 and 3BC315. Finally, our data suggest that the dynamic structure of the Env trimer influences exposure of bnAb epitopes.

  13. Evaluation of "credit card" libraries for inhibition of HIV-1 gp41 fusogenic core formation.

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    Xu, Yang; Lu, Hong; Kennedy, Jack P; Yan, Xuxia; McAllister, Laura A; Yamamoto, Noboru; Moss, Jason A; Boldt, Grant E; Jiang, Shibo; Janda, Kim D

    2006-01-01

    Protein-protein interactions are of critical importance in biological systems, and small molecule modulators of such protein recognition and intervention processes are of particular interest. To investigate this area of research, we have synthesized small-molecule libraries that can disrupt a number of biologically relevant protein-protein interactions. These library members are designed upon planar motif, appended with a variety of chemical functions, which we have termed "credit-card" structures. From two of our "credit-card" libraries, a series of molecules were uncovered which act as inhibitors against the HIV-1 gp41 fusogenic 6-helix bundle core formation, viral antigen p24 formation, and cell-cell fusion at low micromolar concentrations. From the high-throughput screening assays we utilized, a selective index (SI) value of 4.2 was uncovered for compound 2261, which bodes well for future structure activity investigations and the design of more potent gp41 inhibitors.

  14. Amino Acid Changes in the HIV-1 gp41 Membrane Proximal Region Control Virus Neutralization Sensitivity

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    Todd Bradley

    2016-10-01

    Full Text Available Most HIV-1 vaccines elicit neutralizing antibodies that are active against highly sensitive (tier-1 viruses or rare cases of vaccine-matched neutralization-resistant (tier-2 viruses, but no vaccine has induced antibodies that can broadly neutralize heterologous tier-2 viruses. In this study, we isolated antibodies from an HIV-1-infected individual that targeted the gp41 membrane-proximal external region (MPER that may have selected single-residue changes in viral variants in the MPER that resulted in neutralization sensitivity to antibodies targeting distal epitopes on the HIV-1 Env. Similarly, a single change in the MPER in a second virus from another infected-individual also conferred enhanced neutralization sensitivity. These gp41 single-residue changes thus transformed tier-2 viruses into tier-1 viruses that were sensitive to vaccine-elicited tier-1 neutralizing antibodies. These data demonstrate that Env amino acid changes within the MPER bnAb epitope of naturally-selected escape viruses can increase neutralization sensitivity to multiple types of neutralizing antibodies, and underscore the critical importance of the MPER for maintaining the integrity of the tier-2 HIV-1 trimer.

  15. Complete dissociation of the HIV-1 gp41 ectodomain and membrane proximal regions upon phospholipid binding

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    Roche, Julien; Louis, John M.; Aniana, Annie [National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Chemical Physics (United States); Ghirlando, Rodolfo [National Institutes of Health, Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Bax, Ad, E-mail: bax@nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases, Laboratory of Chemical Physics (United States)

    2015-04-15

    The envelope glycoprotein gp41 mediates the process of membrane fusion that enables entry of the HIV-1 virus into the host cell. Strong lipid affinity of the ectodomain suggests that its heptad repeat regions play an active role in destabilizing membranes by directly binding to the lipid bilayers and thereby lowering the free-energy barrier for membrane fusion. In such a model, immediately following the shedding of gp120, the N-heptad and C-heptad helices dissociate and melt into the host cell and viral membranes, respectively, pulling the destabilized membranes into juxtaposition, ready for fusion. Post-fusion, reaching the final 6-helix bundle (6HB) conformation then involves competition between intermolecular interactions needed for formation of the symmetric 6HB trimer and the membrane affinity of gp41’s ectodomain, including its membrane-proximal regions. Our solution NMR study of the structural and dynamic properties of three constructs containing the ectodomain of gp41 with and without its membrane-proximal regions suggests that these segments do not form inter-helical interactions until the very late steps of the fusion process. Interactions between the polar termini of the heptad regions, which are not associating with the lipid surface, therefore may constitute the main driving force initiating formation of the final post-fusion states. The absence of significant intermolecular ectodomain interactions in the presence of dodecyl phosphocholine highlights the importance of trimerization of gp41’s transmembrane helix to prevent complete dissociation of the trimer during the course of fusion.

  16. Antibody to gp41 MPER alters functional properties of HIV-1 Env without complete neutralization.

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    Arthur S Kim

    2014-07-01

    Full Text Available Human antibody 10E8 targets the conserved membrane proximal external region (MPER of envelope glycoprotein (Env subunit gp41 and neutralizes HIV-1 with exceptional potency. Remarkably, HIV-1 containing mutations that reportedly knockout 10E8 binding to linear MPER peptides are partially neutralized by 10E8, producing a local plateau in the dose response curve. Here, we found that virus partially neutralized by 10E8 becomes significantly less neutralization sensitive to various MPER antibodies and to soluble CD4 while becoming significantly more sensitive to antibodies and fusion inhibitors against the heptad repeats of gp41. Thus, 10E8 modulates sensitivity of Env to ligands both pre- and post-receptor engagement without complete neutralization. Partial neutralization by 10E8 was influenced at least in part by perturbing Env glycosylation. With unliganded Env, 10E8 bound with lower apparent affinity and lower subunit occupancy to MPER mutant compared to wild type trimers. However, 10E8 decreased functional stability of wild type Env while it had an opposite, stabilizing effect on MPER mutant Envs. Clade C isolates with natural MPER polymorphisms also showed partial neutralization by 10E8 with altered sensitivity to various gp41-targeted ligands. Our findings suggest a novel mechanism of virus neutralization by demonstrating how antibody binding to the base of a trimeric spike cross talks with adjacent subunits to modulate Env structure and function. The ability of an antibody to stabilize, destabilize, partially neutralize as well as alter neutralization sensitivity of a virion spike pre- and post-receptor engagement may have implications for immunotherapy and vaccine design.

  17. 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.

  18. Viroporin potential of the lentivirus lytic peptide (LLP domains of the HIV-1 gp41 protein

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    Garry Robert F

    2007-11-01

    Full Text Available Abstract Background Mechanisms by which HIV-1 mediates reductions in CD4+ cell levels in infected persons are being intensely investigated, and have broad implications for AIDS drug and vaccine development. Virally induced changes in membrane ionic permeability induced by lytic viruses of many families contribute to cytopathogenesis. HIV-1 induces disturbances in plasma membrane ion transport. The carboxyl terminus of TM (gp41 contains potential amphipathic α-helical motifs identified through their structural similarities to naturally occurring cytolytic peptides. These sequences have been dubbed lentiviral lytic peptides (LLP -1, -2, and -3. Results Peptides corresponding to the LLP domains (from a clade B virus partition into lipid membranes, fold into α-helices and disrupt model membrane permeability. A peptide corresponding to the LLP-1 domain of a clade D HIV-1 virus, LLP-1D displayed similar activity to the LLP-1 domain of the clade B virus in all assays, despite a lack of amino acid sequence identity. Conclusion These results suggest that the C-terminal domains of HIV-1 Env proteins may form an ion channel, or viroporin. Increased understanding of the function of LLP domains and their role in the viral replication cycle could allow for the development of novel HIV drugs.

  19. Residues in the gp41 Ectodomain Regulate HIV-1 Envelope Glycoprotein Conformational Transitions Induced by gp120-Directed Inhibitors.

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    Pacheco, Beatriz; Alsahafi, Nirmin; Debbeche, Olfa; Prévost, Jérémie; Ding, Shilei; Chapleau, Jean-Philippe; Herschhorn, Alon; Madani, Navid; Princiotto, Amy; Melillo, Bruno; Gu, Christopher; Zeng, Xin; Mao, Youdong; Smith, Amos B; Sodroski, Joseph; Finzi, Andrés

    2017-03-01

    Interactions between the gp120 and gp41 subunits of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer maintain the metastable unliganded form of the viral spike. Binding of gp120 to the receptor, CD4, changes the Env conformation to promote gp120 interaction with the second receptor, CCR5 or CXCR4. CD4 binding also induces the transformation of Env into the prehairpin intermediate, in which the gp41 heptad repeat 1 (HR1) coiled coil is assembled at the trimer axis. In nature, HIV-1 Envs must balance the requirements to maintain the noncovalent association of gp120 with gp41 and to evade the host antibody response with the need to respond to CD4 binding. Here we show that the gp41 HR1 region contributes to gp120 association with the unliganded Env trimer. Changes in particular amino acid residues in the gp41 HR1 region decreased the efficiency with which Env moved from the unliganded state. Thus, these gp41 changes decreased the sensitivity of HIV-1 to cold inactivation and ligands that require Env conformational changes to bind efficiently. Conversely, these gp41 changes increased HIV-1 sensitivity to small-molecule entry inhibitors that block Env conformational changes induced by CD4. Changes in particular gp41 HR1 amino acid residues can apparently affect the relative stability of the unliganded state and CD4-induced conformations. Thus, the gp41 HR1 region contributes to the association with gp120 and regulates Env transitions from the unliganded state to downstream conformations.IMPORTANCE The development of an efficient vaccine able to prevent HIV infection is a worldwide priority. Knowledge of the envelope glycoprotein structure and the conformational changes that occur after receptor engagement will help researchers to develop an immunogen able to elicit antibodies that block HIV-1 transmission. Here we identify residues in the HIV-1 transmembrane envelope glycoprotein that stabilize the unliganded state by modulating the

  20. HIV-1 Fusion Is Blocked through Binding of GB Virus C E2D Peptides to the HIV-1 gp41 Disulfide Loop

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    Eissmann, Kristin; Mueller, Sebastian; Sticht, Heinrich; Jung, Susan; Zou, Peng; Jiang, Shibo; Gross, Andrea; Eichler, Jutta; Fleckenstein, Bernhard; Reil, Heide

    2013-01-01

    A strategy for antiviral drug discovery is the elucidation and imitation of viral interference mechanisms. HIV-1 patients benefit from a coinfection with GB Virus C (GBV-C), since HIV-positive individuals with long-term GBV-C viraemia show better survival rates than HIV-1 patients without persisting GBV-C. A direct influence of GBV-C on HIV-1 replication has been shown in coinfection experiments. GBV-C is a human non-pathogenic member of the flaviviridae family that can replicate in T and B cells. Therefore, GBV-C shares partly the same ecological niche with HIV-1. In earlier work we have demonstrated that recombinant glycoprotein E2 of GBV-C and peptides derived from the E2 N-terminus interfere with HIV entry. In this study we investigated the underlying mechanism. Performing a virus-cell fusion assay and temperature-arrested HIV-infection kinetics, we provide evidence that the HIV-inhibitory E2 peptides interfere with late HIV-1 entry steps after the engagement of gp120 with CD4 receptor and coreceptor. Binding and competition experiments revealed that the N-terminal E2 peptides bind to the disulfide loop region of HIV-1 transmembrane protein gp41. In conjunction with computational analyses, we identified sequence similarities between the N-termini of GBV-C E2 and the HIV-1 glycoprotein gp120. This similarity appears to enable the GBV-C E2 N-terminus to interact with the HIV-1 gp41 disulfide loop, a crucial domain involved in the gp120-gp41 interface. Furthermore, the results of the present study provide initial proof of concept that peptides targeted to the gp41 disulfide loop are able to inhibit HIV fusion and should inspire the development of this new class of HIV-1 entry inhibitors. PMID:23349893

  1. HIV-1 fusion is blocked through binding of GB Virus C E2-derived peptides to the HIV-1 gp41 disulfide loop [corrected].

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    Kristin Eissmann

    Full Text Available A strategy for antiviral drug discovery is the elucidation and imitation of viral interference mechanisms. HIV-1 patients benefit from a coinfection with GB Virus C (GBV-C, since HIV-positive individuals with long-term GBV-C viraemia show better survival rates than HIV-1 patients without persisting GBV-C. A direct influence of GBV-C on HIV-1 replication has been shown in coinfection experiments. GBV-C is a human non-pathogenic member of the flaviviridae family that can replicate in T and B cells. Therefore, GBV-C shares partly the same ecological niche with HIV-1. In earlier work we have demonstrated that recombinant glycoprotein E2 of GBV-C and peptides derived from the E2 N-terminus interfere with HIV entry. In this study we investigated the underlying mechanism. Performing a virus-cell fusion assay and temperature-arrested HIV-infection kinetics, we provide evidence that the HIV-inhibitory E2 peptides interfere with late HIV-1 entry steps after the engagement of gp120 with CD4 receptor and coreceptor. Binding and competition experiments revealed that the N-terminal E2 peptides bind to the disulfide loop region of HIV-1 transmembrane protein gp41. In conjunction with computational analyses, we identified sequence similarities between the N-termini of GBV-C E2 and the HIV-1 glycoprotein gp120. This similarity appears to enable the GBV-C E2 N-terminus to interact with the HIV-1 gp41 disulfide loop, a crucial domain involved in the gp120-gp41 interface. Furthermore, the results of the present study provide initial proof of concept that peptides targeted to the gp41 disulfide loop are able to inhibit HIV fusion and should inspire the development of this new class of HIV-1 entry inhibitors.

  2. HIV-1 gp41-targeting fusion inhibitory peptides enhance the gp120-targeting protein-mediated inactivation of HIV-1 virions.

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    Qi, Qianqian; Wang, Qian; Chen, Weizao; Du, Lanying; Dimitrov, Dimiter S; Lu, Lu; Jiang, Shibo

    2017-06-21

    Protein- or peptide-based viral inactivators are being developed as novel antiviral drugs with improved efficacy, pharmacokinetics and toxicity profiles because they actively inactivate cell-free human immunodeficiency virus type 1 (HIV-1) virions before attachment to host cells. By contrast, most clinically used antiviral drugs must penetrate host cells to inhibit viral replication. In this study, we pre-treated HIV-1 particles with a gp120-targeting bispecific multivalent protein, 2Dm2m or 4Dm2m, in the presence or absence of the gp41-targeting HIV-1 fusion inhibitory peptides enfuvirtide (T20), T2635, or sifuvirtide (SFT). HIV-1 virions were separated from the inhibitors using PEG-6000, followed by testing of the residual infectivity of the HIV-1 virions. 2Dm2m and 4Dm2m exhibited significant inactivation activity against all HIV-1 strains tested with EC50 values at the low nanomolar level, whereas none of the gp41-targeting peptides showed inactivation activity at concentrations up to 250 nM. Notably, these three peptides significantly enhanced protein-mediated inactivation against cell-free HIV-1 virions, including HIV-1 laboratory-adapted and primary HIV-1 strains, as well as those resistant to T20 or T2635 and virions released from reactivated latently HIV-1-infected cells. These results indicate that the gp120-targeting bispecific multivalent proteins 2Dm2m and 4Dm2m have potential for further development as HIV-1 inactivator-based antiviral drugs for use in the clinic, either alone or in combination with a gp41-targeting HIV-1 fusion inhibitor such as T20, to treat patients with HIV-1 infection and AIDS.

  3. Immunization with HIV-1 gp41 subunit virosomes induces mucosal antibodies protecting nonhuman primates against vaginal SHIV challenges.

    Science.gov (United States)

    Bomsel, Morgane; Tudor, Daniela; Drillet, Anne-Sophie; Alfsen, Annette; Ganor, Yonatan; Roger, Marie-Gaëlle; Mouz, Nicolas; Amacker, Mario; Chalifour, Anick; Diomede, Lorenzo; Devillier, Gilles; Cong, Zhe; Wei, Qiang; Gao, Hong; Qin, Chuan; Yang, Gui-Bo; Zurbriggen, Rinaldo; Lopalco, Lucia; Fleury, Sylvain

    2011-02-25

    Human immunodeficiency virus (HIV)-1 is mainly transmitted mucosally during sexual intercourse. We therefore evaluated the protective efficacy of a vaccine active at mucosal sites. Macaca mulatta monkeys were immunized via both the intramuscular and intranasal routes with an HIV-1 vaccine made of gp41-subunit antigens grafted on virosomes, a safe delivery carrier approved in humans with self-adjuvant properties. Six months after 13 vaginal challenges with simian-HIV (SHIV)-SF162P3, four out of five vaccinated animals remained virus-negative, and the fifth was only transiently infected. None of the five animals seroconverted to p27gag-SIV. In contrast, all 6 placebo-vaccinated animals became infected and seroconverted. All protected animals showed gp41-specific vaginal IgAs with HIV-1 transcytosis-blocking properties and vaginal IgGs with neutralizing and/or antibody-dependent cellular-cytotoxicity activities. In contrast, plasma IgGs totally lacked virus-neutralizing activity. The protection observed challenges the paradigm whereby circulating antiviral antibodies are required for protection against HIV-1 infection and may serve in designing a human vaccine against HIV-1-AIDS. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Evaluation of “Credit Card” Libraries for Inhibition of HIV-1 gp41 Fusogenic Core Formation

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    Xu, Yang; Lu, Hong; Kennedy, Jack P.; Yan, Xuxia; McAllister, Laura; Yamamoto, Noboru; Moss, Jason A.; Boldt, Grant E.; Jiang, Shibo; Janda, Kim D.

    2008-01-01

    Protein-protein interactions are of critical importance in biological systems and small molecule modulators of such protein recognition and intervention processes are of particular interests. To investigate this area of research, we have synthesized small molecule libraries that can disrupt a number of biologically relevant protein-protein interactions. These library members are designed upon planar motifs, appended with a variety of chemical functions, which we have termed as “credit-card” structures. From two of our “credit-card” libraries, a series of molecules were uncovered which act as inhibitors against the HIV-1 gp41 fusogenic 6-helix bundle core formation, viral antigen p24 formation and cell-cell fusion at low micromolar concentrations. From the high-throughput screening assays we utilized, a selective index (SI) value of 4.2 was uncovered for compound 2261, which bodes well for future structure activity investigations and the design of more potent gp41 inhibitors. PMID:16827565

  5. Envelope deglycosylation enhances antigenicity of HIV-1 gp41 epitopes for both broad neutralizing antibodies and their unmutated ancestor antibodies.

    Directory of Open Access Journals (Sweden)

    Ben-Jiang Ma

    2011-09-01

    Full Text Available The HIV-1 gp41 envelope (Env membrane proximal external region (MPER is an important vaccine target that in rare subjects can elicit neutralizing antibodies. One mechanism proposed for rarity of MPER neutralizing antibody generation is lack of reverted unmutated ancestor (putative naive B cell receptor antibody reactivity with HIV-1 envelope. We have studied the effect of partial deglycosylation under non-denaturing (native conditions on gp140 Env antigenicity for MPER neutralizing antibodies and their reverted unmutated ancestor antibodies. We found that native deglycosylation of clade B JRFL gp140 as well as group M consensus gp140 Env CON-S selectively increased the reactivity of Env with the broad neutralizing human mAbs, 2F5 and 4E10. Whereas fully glycosylated gp140 Env either did not bind (JRFL, or weakly bound (CON-S, 2F5 and 4E10 reverted unmutated ancestors, natively deglycosylated JRFL and CON-S gp140 Envs did bind well to these putative mimics of naive B cell receptors. These data predict that partially deglycoslated Env would bind better than fully glycosylated Env to gp41-specific naïve B cells with improved immunogenicity. In this regard, immunization of rhesus macaques demonstrated enhanced immunogenicity of the 2F5 MPER epitope on deglyosylated JRFL gp140 compared to glycosylated JRFL gp140. Thus, the lack of 2F5 and 4E10 reverted unmutated ancestor binding to gp140 Env may not always be due to lack of unmutated ancestor antibody reactivity with gp41 peptide epitopes, but rather, may be due to glycan interference of binding of unmutated ancestor antibodies of broad neutralizing mAb to Env gp41.

  6. Amplification of the Gp41 gene for detection of mutations conferring resistance to HIV-1 fusion inhibitors on genotypic assay

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    Tanumihardja, J.; Bela, B.

    2017-08-01

    Fusion inhibitors have potential for future use in HIV control programs in Indonesia, so the capacity to test resistance to such drugs needs to be developed. Resistance-detection with a genotypic assay began with amplification of the target gene, gp41. Based on the sequence of the two most common HIV subtypes in Indonesia, AE and B, a primer pair was designed. Plasma samples containing both subtypes were extracted to obtain HIV RNA. Using PCR, the primer pair was used to produce the amplification product, the identity of which was checked based on length under electrophoresis. Eleven plasma samples were included in this study. One-step PCR using the primer pair was able to amplify gp41 from 54.5% of the samples, and an unspecific amplification product was seen in 1.1% of the samples. Amplification failed in 36.4% of the samples, which may be due to an inappropriate primer sequence. It was also found that the optimal annealing temperature for producing the single expected band was 57.2 °C. With one-step PCR, the designed primer pair amplified the HIV-1 gp41 gene from subtypes AE and B. However, further research should be done to determine the conditions that will increase the sensitivity and specificity of the amplification process.

  7. HIV-1 Envelope gp41 Antibodies Can Originate from Terminal Ileum B Cells that Share Cross-Reactivity with Commensal Bacteria

    Science.gov (United States)

    Trama, Ashley M.; Moody, M. Anthony; Alam, S. Munir; Jaeger, Frederick H.; Lockwood, Bradley; Parks, Robert; Lloyd, Krissey E.; Stolarchuk, Christina; Scearce, Richard; Foulger, Andrew; Marshall, Dawn J.; Whitesides, John F.; Jeffries, Thomas L.; Wiehe, Kevin; Morris, Lynn; Lambson, Bronwen; Soderberg, Kelly; Hwang, Kwan-Ki; Tomaras, Georgia D.; Vandergrift, Nathan; Jackson, Katherine J.L.; Roskin, Krishna M.; Boyd, Scott D.; Kepler, Thomas B.; Liao, Hua-Xin; Haynes, Barton F.

    2014-01-01

    SUMMARY Monoclonal antibodies derived from blood plasma cells of acute HIV-1-infected individuals are predominantly targeted to the HIV Env gp41 and cross-reactive with commensal bacteria. To understand this phenomenon, we examined anti-HIV responses in ileum B cells using recombinant antibody technology and probed their relationship to commensal bacteria. The dominant ileum B cell response was to Env gp41. Remarkably, a majority (82%) of the ileum anti-gp41 antibodies cross-reacted with commensal bacteria, and of those, 43% showed non-HIV-1 antigen polyreactivity. Pyrosequencing revealed shared HIV-1 antibody clonal lineages between ileum and blood. Mutated immunoglobulin G antibodies cross-reactive with both Env gp41 and microbiota could also be isolated from the ileum of HIV-1 uninfected individuals. Thus, the gp41 commensal bacterial antigen cross-reactive antibodies originate in the intestine, and the gp41 Env response in HIV-1 infection can be derived from a preinfection memory B cell pool triggered by commensal bacteria that cross-react with Env. PMID:25121750

  8. Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1.

    Science.gov (United States)

    Boehme, Karl W; Ikizler, Mine'; Iskarpatyoti, Jason A; Wetzel, J Denise; Willis, Jordan; Crowe, James E; LaBranche, Celia C; Montefiori, David C; Wilson, Gregory J; Dermody, Terence S

    2016-01-01

    The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1. Sequences in reovirus strain type 1 Lang (T1L) σ1 were exchanged with sequences encoding HIV-1 strain Ba-L MPER epitope 2F5 or the entire MPER. Individual 2F5 or MPER substitutions were introduced at virion-proximal or virion-distal sites in the σ1 tail. Recombinant reoviruses containing heterologous HIV-1 sequences were viable and produced progeny yields comparable to those with wild-type virus. HIV-1 sequences were retained following 10 serial passages in cell culture, indicating that the substitutions were genetically stable. Recombinant viruses engineered to display the 2F5 epitope or full-length MPER in σ1 were recognized by purified 2F5 antibody. Inoculation of mice with 2F5-containing vectors or rabbits with 2F5- or MPER-containing vectors elicited anti-reovirus antibodies, but HIV-1-specific antibodies were not detected. Together, these findings indicate that heterologous sequences that form α-helices can functionally replace native sequences in the α-helical tail domain of reovirus attachment protein σ1. However, although these vectors retain native antigenicity, they were not immunogenic, illustrating the difficulty of experimentally inducing immune responses to this essential region of HIV-1. IMPORTANCE Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use. Antibodies that

  9. Modulating immunogenic properties of HIV-1 gp41 membrane-proximal external region by destabilizing six-helix bundle structure

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    Banerjee, Saikat; Shi, Heliang; Habte, Habtom H.; Qin, Yali; Cho, Michael W., E-mail: mcho@iastate.edu

    2016-03-15

    The C-terminal alpha-helix of gp41 membrane-proximal external region (MPER; {sup 671}NWFDITNWLWYIK{sup 683}) encompassing 4E10/10E8 epitopes is an attractive target for HIV-1 vaccine development. We previously reported that gp41-HR1-54Q, a trimeric protein comprised of the MPER in the context of a stable six-helix bundle (6HB), induced strong immune responses against the helix, but antibodies were directed primarily against the non-neutralizing face of the helix. To better target 4E10/10E8 epitopes, we generated four putative fusion intermediates by introducing double point mutations or deletions in the heptad repeat region 1 (HR1) that destabilize 6HB in varying degrees. One variant, HR1-∆10-54K, elicited antibodies in rabbits that targeted W672, I675 and L679, which are critical for 4E10/10E8 recognition. Overall, the results demonstrated that altering structural parameters of 6HB can influence immunogenic properties of the MPER and antibody targeting. Further exploration of this strategy could allow development of immunogens that could lead to induction of 4E10/10E8-like antibodies. - Highlights: • Four gp41 MPER-based immunogens that resemble fusion intermediates were generated. • C-terminal region of MPER that contains 4E10/10E8 epitopes was highly immunogenic. • Altering 6HB structure can influence immunogenic properties of the MPER. • Induced antibodies targeted multiple residues critical for 4E10/10E8 binding. • Development of immunogens based on fusion intermediates is a promising strategy.

  10. Membrane mediated regulation in free peptides of HIV-1 gp41: minimal modulation of the hemifusion phase.

    Science.gov (United States)

    Cerasoli, Eleonora; Ravi, Jascindra; Gregor, Craig; Hussain, Rohanah; Siligardi, Giuliano; Martyna, Glenn; Crain, Jason; Ryadnov, Maxim G

    2012-01-21

    Membrane-mediated structural modulation in two short fragments of the human HIV-1 envelope protein gp41 is demonstrated. Derived from the C-terminal membrane proximal external (MPE) and N-terminal fusion peptide proximal (FPP) regions, these peptides are widely separated in the primary sequence but form tertiary contacts during the intermediate (hemifusion) phase of HIV infection. The structural perturbations observed at the membrane interface offer evidence of rudimentary regulatory mechanisms operating in the free peptides which may be relevant in the biological system. No such regulatory phenomena were observed for the individual peptides in a membrane environment or between the peptides in aqueous solutions. Structure determination is made using a combination of circular and linear dichroism spectroscopy (supported by calorimetric measurements) and molecular dynamics simulations. Specifically, we show that these peptides interact locally without the conformational support of helical heptad repeat regions in native gp41 and that the modulation is not mutual with the FPP peptide operating as a primary regulator of the MPE-FPP interactions in the hemifusion phase.

  11. Photoinduced Reactivity of the HIV-1 Envelope Glycoprotein with a Membrane-Embedded Probe Reveals Insertion of Portions of the HIV-1 Gp41 Cytoplasmic Tail into the Viral Membrane†

    Science.gov (United States)

    Viard, Mathias; Ablan, Sherimay D.; Zhou, Ming; Veenstra, Timothy D.; Freed, Eric O.; Raviv, Yossef; Blumenthal, Robert

    2008-01-01

    The interactions of HIV-1 Env (gp120-gp41) with CD4 and coreceptors trigger a barrage of conformational changes in Env that drive the membrane fusion process. Various regions of gp41 have profound effects on HIV entry and budding. However, the precise interactions between gp41 and the membrane have not been elucidated. To examine portions of membrane proteins that are embedded in membrane lipids, we have studied photoinduced chemical reactions in membranes using the lipid bilayer specific probe iodonaphthyl azide (INA). Here we show that in addition to the transmembrane anchor, amphipatic sequences in the cytoplasmic tail (CT) of HIV-1 gp41 are labeled by INA. INA labeling of the HIV-1 gp41 CT was similar whether wild-type or a mutant HIV-1 was used with uncleaved p55 Gag, which does not allow entry. These results shed light on the disposition of the HIV-1 gp41 CT with respect to the membrane. Moreover, our data have general implications for topology of membrane proteins and their in situ interactions with the lipid bilayer. PMID:18198900

  12. Structural Insights into the Mechanisms of Action of Short-Peptide HIV-1 Fusion Inhibitors Targeting the Gp41 Pocket

    Directory of Open Access Journals (Sweden)

    Xiujuan Zhang

    2018-02-01

    Full Text Available The deep hydrophobic pocket of HIV-1 gp41 has been considered a drug target, but short-peptides targeting this site usually lack potent antiviral activity. By applying the M-T hook structure, we previously generated highly potent short-peptide fusion inhibitors that specifically targeted the pocket site, such as MT-SC22EK, HP23L, and LP-11. Here, the crystal structures of HP23L and LP-11 bound to the target mimic peptide N36 demonstrated the critical intrahelical and interhelical interactions, especially verifying that the hook-like conformation was finely adopted while the methionine residue was replaced by the oxidation-less prone residue leucine, and that addition of an extra glutamic acid significantly enhanced the binding and inhibitory activities. The structure of HP23L bound to N36 with two mutations (E49K and L57R revealed the critical residues and motifs mediating drug resistance and provided new insights into the mechanism of action of inhibitors. Therefore, the present data help our understanding for the structure-activity relationship (SAR of HIV-1 fusion inhibitors and facilitate the development of novel antiviral drugs.

  13. Broad and potent HIV-1 neutralization by a human antibody that binds the gp41-gp120 interface

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jinghe; Kang, Byong H.; Pancera, Marie; Lee, Jeong Hyun; Tong, Tommy; Feng, Yu; Imamichi, Hiromi; Georgiev, Ivelin S.; Chuang, Gwo-Yu; Druz, Aliaksandr; Doria-Rose, Nicole A.; Laub, Leo; Sliepen, Kwinten; van Gils, Marit J.; de la Peña, Alba Torrents; Derking, Ronald; Klasse, Per-Johan; Migueles, Stephen A.; Bailer, Robert T.; Alam, Munir; Pugach, Pavel; Haynes, Barton F.; Wyatt, Richard T.; Sanders, Rogier W.; Binley, James M.; Ward, Andrew B.; Mascola, John R.; Kwong, Peter D.; Connors, Mark [NIH

    2015-10-15

    The isolation of human monoclonal antibodies is providing important insights into the specificities that underlie broad neutralization of HIV-1 (reviewed in ref. 1). Here we report a broad and extremely potent HIV-specific monoclonal antibody, termed 35O22, which binds a novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with a half-maximum inhibitory concentration (IC50) <50 μg ml-1. The median IC50 of neutralized viruses was 0.033 μg ml-1, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and a reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed that it bound to a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current monoclonal-antibody-based approaches to immunotherapies, prophylaxis and vaccine design.

  14. Identification and characterization of a broadly cross-reactive HIV-1 human monoclonal antibody that binds to both gp120 and gp41.

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    Mei-Yun Zhang

    Full Text Available Identification of broadly cross-reactive HIV-1-neutralizing antibodies (bnAbs may assist vaccine immunogen design. Here we report a novel human monoclonal antibody (mAb, designated m43, which co-targets the gp120 and gp41 subunits of the HIV-1 envelope glycoprotein (Env. M43 bound to recombinant gp140 s from various primary isolates, to membrane-associated Envs on transfected cells and HIV-1 infected cells, as well as to recombinant gp120 s and gp41 fusion intermediate structures containing N-trimer structure, but did not bind to denatured recombinant gp140 s and the CD4 binding site (CD4bs mutant, gp120 D368R, suggesting that the m43 epitope is conformational and overlaps the CD4bs on gp120 and the N-trimer structure on gp41. M43 neutralized 34% of the HIV-1 primary isolates from different clades and all the SHIVs tested in assays based on infection of peripheral blood mononuclear cells (PBMCs by replication-competent virus, but was less potent in cell line-based pseudovirus assays. In contrast to CD4, m43 did not induce Env conformational changes upon binding leading to exposure of the coreceptor binding site, enhanced binding of mAbs 2F5 and 4E10 specific for the membrane proximal external region (MPER of gp41 Envs, or increased gp120 shedding. The overall modest neutralization activity of m43 is likely due to the limited binding of m43 to functional Envs which could be increased by antibody engineering if needed. M43 may represent a new class of bnAbs targeting conformational epitopes overlapping structures on both gp120 and gp41. Its novel epitope and possibly new mechanism(s of neutralization could helpdesign improved vaccine immunogens and candidate therapeutics.

  15. Study of the inhibition capacity of an 18-mer peptide domain of GBV-C virus on gp41-FP HIV-1 activity.

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    Haro, I; Gómara, M J; Galatola, R; Domènech, O; Prat, J; Girona, V; Busquets, M A

    2011-06-01

    The peptide sequence (175-192) RFPFHRCGAGPKLTKDLE (P59) of the E2 envelope protein of GB virus C (GBV-C) has been proved to decrease cellular membrane fusion and interfere with the HIV-1 infectivity in a dose-dependent manner. Based on these previous results, the main objective of this study was to deepen in the physicochemical aspects involved in this interaction. First, we analyzed the surface activity of P59 at the air-water interface as well as its interaction with zwitterionic or negatively charged lipid monolayers. Then we performed the same experiments with mixtures of P59/gp41-FP. Studies on lipid monolayers helped us to understand the lipid-peptide interaction and the influence of phospholipids on peptide penetration into lipid media. On another hand, studies with lipid bilayers showed that P59 decreased gp41-FP binding to anionic Large Unilamellar Vesicles. Results can be attributed to the differences in morphology of the peptides, as observed by Atomic Force Microscopy. When P59 and gp41-FP were incubated together, annular structures of about 200 nm in diameter appeared on the mica surface, thus indicating a peptide-peptide interaction. All these results confirm the gp41-FP-P59 interaction and thus support the hypothesis that gp41-FP is inhibited by P59. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Biophysical Characterization of a Vaccine Candidate against HIV-1: The Transmembrane and Membrane Proximal Domains of HIV-1 gp41 as a Maltose Binding Protein Fusion

    Science.gov (United States)

    Gong, Zhen; Martin-Garcia, Jose M.; Daskalova, Sasha M.; Craciunescu, Felicia M.; Song, Lusheng; Dörner, Katerina; Hansen, Debra T.; Yang, Jay-How; LaBaer, Joshua; Hogue, Brenda G.; Mor, Tsafrir S.; Fromme, Petra

    2015-01-01

    The membrane proximal region (MPR, residues 649–683) and transmembrane domain (TMD, residues 684–705) of the gp41 subunit of HIV-1’s envelope protein are highly conserved and are important in viral mucosal transmission, virus attachment and membrane fusion with target cells. Several structures of the trimeric membrane proximal external region (residues 662–683) of MPR have been reported at the atomic level; however, the atomic structure of the TMD still remains unknown. To elucidate the structure of both MPR and TMD, we expressed the region spanning both domains, MPR-TM (residues 649–705), in Escherichia coli as a fusion protein with maltose binding protein (MBP). MPR-TM was initially fused to the C-terminus of MBP via a 42 aa-long linker containing a TEV protease recognition site (MBP-linker-MPR-TM). Biophysical characterization indicated that the purified MBP-linker-MPR-TM protein was a monodisperse and stable candidate for crystallization. However, crystals of the MBP-linker-MPR-TM protein could not be obtained in extensive crystallization screens. It is possible that the 42 residue-long linker between MBP and MPR-TM was interfering with crystal formation. To test this hypothesis, the 42 residue-long linker was replaced with three alanine residues. The fusion protein, MBP-AAA-MPR-TM, was similarly purified and characterized. Significantly, both the MBP-linker-MPR-TM and MBP-AAA-MPR-TM proteins strongly interacted with broadly neutralizing monoclonal antibodies 2F5 and 4E10. With epitopes accessible to the broadly neutralizing antibodies, these MBP/MPR-TM recombinant proteins may be in immunologically relevant conformations that mimic a pre-hairpin intermediate of gp41. PMID:26295457

  17. Effects of the I559P gp41 change on the conformation and function of the human immunodeficiency virus (HIV-1 membrane envelope glycoprotein trimer.

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    Nirmin Alsahafi

    Full Text Available The mature human immunodeficiency virus (HIV-1 envelope glycoprotein (Env trimer is produced by proteolytic cleavage of a precursor and consists of three gp120 exterior and three gp41 transmembrane subunits. The metastable Env complex is induced to undergo conformational changes required for virus entry by the binding of gp120 to the receptors, CD4 and CCR5/CXCR4. An isoleucine-to-proline change (I559P in the gp41 ectodomain has been used to stabilize soluble forms of HIV-1 Env trimers for structural characterization and for use as immunogens. In the native membrane-anchored HIV-1BG505 Env, the I559P change modestly decreased proteolytic maturation, increased the non-covalent association of gp120 with the Env trimer, and resulted in an Env conformation distinctly different from that of the wild-type HIV-1BG505 Env. Compared with the wild-type Env, the I559P Env was recognized inefficiently by polyclonal sera from HIV-1-infected individuals, by several gp41-directed antibodies, by some antibodies against the CD4-binding site of gp120, and by antibodies that preferentially recognize the CD4-bound Env. Some of the gp120-associated antigenic differences between the wild-type HIV-1BG505 Env and the I559P mutant were compensated by the SOS disulfide bond between gp120 and gp41, which has been used to stabilize cleaved soluble Env trimers. Nonetheless, regardless of the presence of the SOS changes, Envs with proline 559 were recognized less efficiently than Envs with isoleucine 559 by the VRC01 neutralizing antibody, which binds the CD4-binding site of gp120, and the PGT151 neutralizing antibody, which binds a hybrid gp120-gp41 epitope. The I559P change completely eliminated the ability of the HIV-1BG505 Env to mediate cell-cell fusion and virus entry, and abolished the capacity of the SOS Env to support virus infection in the presence of a reducing agent. These results suggest that differences exist between the quaternary structures of functional Env

  18. Monoclonal Antibodies Specific for the V2, V3, CD4-Binding Site, and gp41 of HIV-1 Mediate Phagocytosis in a Dose-Dependent Manner.

    Science.gov (United States)

    Musich, Thomas; Li, Liuzhe; Liu, Lily; Zolla-Pazner, Susan; Robert-Guroff, Marjorie; Gorny, Miroslaw K

    2017-04-15

    In light of the weak or absent neutralizing activity mediated by anti-V2 monoclonal antibodies (MAbs), we tested whether they can mediate Ab-dependent cellular phagocytosis (ADCP), which is an important element of anti-HIV-1 immunity. We tested six anti-V2 MAbs and compared them with 21 MAbs specific for V3, the CD4-binding site (CD4bs), and gp41 derived from chronically HIV-1-infected individuals and produced by hybridoma cells. ADCP activity was measured by flow cytometry using uptake by THP-1 monocytic cells of fluorescent beads coated with gp120, gp41, BG505 SOSIP.664, or BG505 DS-SOSIP.664 complexed with MAbs. The measurement of ADCP activity by the area under the curve showed significantly higher activity of anti-gp41 MAbs than of the members of the three other groups of MAbs tested using beads coated with monomeric gp41 or gp120; anti-V2 MAbs were dominant compared to anti-V3 and anti-CD4bs MAbs against clade C gp120 ZM109 ADCP activity mediated by V2 and V3 MAbs was positive against stabilized DS-SOSIP.664 trimer but negligible against SOSIP.664 targets, suggesting that a closed envelope conformation better exposes the variable loops. Two IgG3 MAbs against the V2 and V3 regions displayed dominant ADCP activity compared to a panel of IgG1 MAbs. This superior ADCP activity was confirmed when two of three recombinant IgG3 anti-V2 MAbs were compared to their IgG1 counterparts. The study demonstrated dominant ADCP activity of anti-gp41 against monomers but not trimers, with some higher activity of anti-V2 MAbs than of anti-V3 and anti-CD4bs MAbs. The ability to mediate ADCP suggests a mechanism by which anti-HIV-1 envelope Abs can contribute to protective efficacy. IMPORTANCE Anti-V2 antibodies (Abs) correlated with reduced risk of HIV-1 infection in recipients of the RV144 vaccine, suggesting that they play a protective role, but a mechanism providing such protection remains to be determined. The rare and weak neutralizing activities of anti-V2 MAbs prompted us

  19. The cholesterol-binding motif of the HIV-1 glycoprotein gp41 regulates lateral sorting and oligomerization.

    Science.gov (United States)

    Schwarzer, Roland; Levental, Ilya; Gramatica, Andrea; Scolari, Silvia; Buschmann, Volker; Veit, Michael; Herrmann, Andreas

    2014-10-01

    Enveloped viruses often use membrane lipid rafts to assemble and bud, augment infection and spread efficiently. However, the molecular bases and functional consequences of the partitioning of viral glycoproteins into microdomains remain intriguing questions in virus biology. Here, we measured Foerster resonance energy transfer by fluorescence lifetime imaging microscopy (FLIM-FRET) to study the role of distinct membrane proximal regions of the human immunodeficiency virus glycoprotein gp41 for lipid raft partitioning in living Chinese hamster ovary cells (CHO-K1). Gp41 was labelled with a fluorescent protein at the exoplasmic face of the membrane, preventing any interference of the fluorophore with the proposed role of the transmembrane and cytoplasmic domains in lateral organization of gp41. Raft localization was deduced from interaction with an established raft marker, a fluorescently tagged glycophosphatidylinositol anchor and the cholesterol recognition amino acid consensus (CRAC) was identified as the crucial lateral sorting determinant in CHO-K1 cells. Interestingly, the raft association of gp41 indicates a substantial cell-to-cell heterogeneity of the plasma membrane microdomains. In complementary fluorescence polarization microscopy, a distinct CRAC requirement was found for the oligomerization of the gp41 variants. Our data provide further insight into the molecular basis and biological implications of the cholesterol dependent lateral sorting of viral glycoproteins for virus assembly at cellular membranes. © 2014 John Wiley & Sons Ltd.

  20. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape

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    Wibmer, Constantinos Kurt; Gorman, Jason; Ozorowski, Gabriel; Bhiman, Jinal N.; Sheward, Daniel J.; Elliott, Debra H.; Rouelle, Julie; Smira, Ashley; Joyce, M. Gordon; Ndabambi, Nonkululeko; Druz, Aliaksandr; Asokan, Mangai; Burton, Dennis R.; Connors, Mark; Abdool Karim, Salim S.; Mascola, John R.; Robinson, James E.; Ward, Andrew B.; Williamson, Carolyn; Kwong, Peter D.; Morris, Lynn; Moore, Penny L.; Desrosiers, Ronald C.

    2017-01-11

    A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing

  1. The conserved residue Arg46 in the N-terminal heptad repeat domain of HIV-1 gp41 is critical for viral fusion and entry.

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    Xiaoyi Wang

    Full Text Available During the process of HIV-1 fusion with the target cell, the N-terminal heptad repeat (NHR of gp41 interacts with the C-terminal heptad repeat (CHR to form fusogenic six-helix bundle (6-HB core. We previously identified a crucial residue for 6-HB formation and virus entry--Lys63 (K63 in the C-terminal region of NHR (aa 54-70, which forms a hydrophobic cavity. It can form an important salt bridge with Asp121 (D121 in gp41 CHR. Here, we found another important conserved residue for virus fusion and entry, Arg46 (R46, in the N-terminal region of NHR (aa 35-53, which forms a hydrogen bond with a polar residue, Asn43 (N43, in NHR, as a part of the hydrogen-bond network. R46 can also form a salt bridge with a negatively charged residue, Glu137 (E137, in gp41 CHR. Substitution of R46 with the hydrophobic residue Ala (R46A or the negatively charged residue Glu (R46E resulted in disruption of the hydrogen bond network, breakage of the salt bridge and reduction of 6-HB's stability, leading to impairment of viral fusion and decreased inhibition of N36, an NHR peptide. Similarly, CHR peptide C34 with substitution of E137 for Ala (E137A or Arg (E137R also exhibited reduced inhibitory activity against HIV-1 infection and HIV-1-mediated cell-to-cell fusion. These results suggest that the positively charged residue R46 and its hydrogen bond network, together with the salt bridge between R46 and E137, are important for viral fusion and entry and may therefore serve as a target for designing novel HIV fusion/entry inhibitors.

  2. Randomized Phase I: Safety, Immunogenicity and Mucosal Antiviral Activity in Young Healthy Women Vaccinated with HIV-1 Gp41 P1 Peptide on Virosomes.

    Science.gov (United States)

    Leroux-Roels, Geert; Maes, Cathy; Clement, Frédéric; van Engelenburg, Frank; van den Dobbelsteen, Marieke; Adler, Michael; Amacker, Mario; Lopalco, Lucia; Bomsel, Morgane; Chalifour, Anick; Fleury, Sylvain

    2013-01-01

    Mucosal antibodies harboring various antiviral activities may best protect mucosal surfaces against early HIV-1 entry at mucosal sites and they should be ideally induced by prophylactic HIV-1 vaccines for optimal prevention of sexually transmitted HIV-1. A phase I, double-blind, randomized, placebo-controlled trial was conducted in twenty-four healthy HIV-uninfected young women. The study objectives were to assess the safety, tolerability and immunogenicity of virosomes harboring surface HIV-1 gp41-derived P1 lipidated peptides (MYM-V101). Participants received placebo or MYM-V101 vaccine at 10 μg/dose or 50 μg/dose intramuscularly at week 0 and 8, and intranasally at week 16 and 24. MYM-V101 was safe and well-tolerated at both doses administered by the intramuscular and intranasal routes, with the majority of subjects remaining free of local and general symptoms. P1-specific serum IgGs and IgAs were induced in all high dose recipients after the first injection. After the last vaccination, vaginal and rectal P1-specific IgGs could be detected in all high dose recipients. Approximately 63% and 43% of the low and high dose recipients were respectively tested positive for vaginal P1-IgAs, while 29% of the subjects from the high dose group tested positive for rectal IgAs. Serum samples had total specific IgG and IgA antibody concentrations ≥ 0.4 μg/mL, while mucosal samples were usually below 0.01 μg/mL. Vaginal secretions from MYM-V101 vaccinated subjects were inhibiting HIV-1 transcytosis but had no detectable neutralizing activity. P1-specific Th1 responses could not be detected on PBMC. This study demonstrates the excellent safety and tolerability of MYM-V101, eliciting systemic and mucosal antibodies in the majority of subjects. Vaccine-induced mucosal anti-gp41 antibodies toward conserved gp41 motifs were harboring HIV-1 transcytosis inhibition activity and may contribute to reduce sexually-transmitted HIV-1. ClinicalTrials.gov NCT01084343.

  3. Randomized Phase I: Safety, Immunogenicity and Mucosal Antiviral Activity in Young Healthy Women Vaccinated with HIV-1 Gp41 P1 Peptide on Virosomes.

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    Geert Leroux-Roels

    Full Text Available Mucosal antibodies harboring various antiviral activities may best protect mucosal surfaces against early HIV-1 entry at mucosal sites and they should be ideally induced by prophylactic HIV-1 vaccines for optimal prevention of sexually transmitted HIV-1. A phase I, double-blind, randomized, placebo-controlled trial was conducted in twenty-four healthy HIV-uninfected young women. The study objectives were to assess the safety, tolerability and immunogenicity of virosomes harboring surface HIV-1 gp41-derived P1 lipidated peptides (MYM-V101. Participants received placebo or MYM-V101 vaccine at 10 μg/dose or 50 μg/dose intramuscularly at week 0 and 8, and intranasally at week 16 and 24. MYM-V101 was safe and well-tolerated at both doses administered by the intramuscular and intranasal routes, with the majority of subjects remaining free of local and general symptoms. P1-specific serum IgGs and IgAs were induced in all high dose recipients after the first injection. After the last vaccination, vaginal and rectal P1-specific IgGs could be detected in all high dose recipients. Approximately 63% and 43% of the low and high dose recipients were respectively tested positive for vaginal P1-IgAs, while 29% of the subjects from the high dose group tested positive for rectal IgAs. Serum samples had total specific IgG and IgA antibody concentrations ≥ 0.4 μg/mL, while mucosal samples were usually below 0.01 μg/mL. Vaginal secretions from MYM-V101 vaccinated subjects were inhibiting HIV-1 transcytosis but had no detectable neutralizing activity. P1-specific Th1 responses could not be detected on PBMC. This study demonstrates the excellent safety and tolerability of MYM-V101, eliciting systemic and mucosal antibodies in the majority of subjects. Vaccine-induced mucosal anti-gp41 antibodies toward conserved gp41 motifs were harboring HIV-1 transcytosis inhibition activity and may contribute to reduce sexually-transmitted HIV-1.ClinicalTrials.gov NCT01084343.

  4. Structure-Based Design of a Protein Immunogen that Displays an HIV-1 gp41 Neutralizing Epitope

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    Stanfield, Robyn L.; Julien, Jean-Philippe; Pejchal, Robert; Gach, Johannes S.; Zwick, Michael B.; Wilson, Ian A. (Scripps)

    2012-06-27

    Antibody Z13e1 is a relatively broadly neutralizing anti-human immunodeficiency virus type 1 antibody that recognizes the membrane-proximal external region (MPER) of the human immunodeficiency virus type 1 envelope glycoprotein gp41. Based on the crystal structure of an MPER epitope peptide in complex with Z13e1 Fab, we identified an unrelated protein, interleukin (IL)-22, with a surface-exposed region that is structurally homologous in its backbone to the gp41 Z13e1 epitope. By grafting the gp41 Z13e1 epitope sequence onto the structurally homologous region in IL-22, we engineered a novel protein (Z13-IL22-2) that contains the MPER epitope sequence for use as a potential immunogen and as a reagent for the detection of Z13e1-like antibodies. The Z13-IL22-2 protein binds Fab Z13e1 with a K{sub d} of 73 nM. The crystal structure of Z13-IL22-2 in complex with Fab Z13e1 shows that the epitope region is faithfully replicated in the Fab-bound scaffold protein; however, isothermal calorimetry studies indicate that Fab binding to Z13-IL22-2 is not a lock-and-key event, leaving open the question of whether conformational changes upon binding occur in the Fab, in Z13-IL-22, or in both.

  5. HIV-1 gp41-specific monoclonal mucosal IgAs derived from highly exposed but IgG-seronegative individuals block HIV-1 epithelial transcytosis and neutralize CD4(+) cell infection: an IgA gene and functional analysis.

    Science.gov (United States)

    Tudor, D; Derrien, M; Diomede, L; Drillet, A-S; Houimel, M; Moog, C; Reynes, J-M; Lopalco, L; Bomsel, M

    2009-09-01

    AIDS is mainly a sexually transmitted disease, and accordingly, mucosal tissues are the primary sites of natural human immunodeficiency virus type-1 (HIV-1) transmission. Mucosal immunoglobulin A (IgA) antibody specific for HIV-1 envelope gp41 subunit is one correlate of protection in individuals who are highly sexually exposed to HIV-1 but remain persistently IgG seronegative (HEPS). Understanding these peculiar IgAs at the gene and functional level is possible only with monoclonal IgAs. We have constructed a mucosal Fab IgA library from HEPS and have characterized a series of HIV-1 IgAs specific for gp41 that, in vitro, are transcytosis-blocking and infection-neutralizing. Characterization of their IgA genes shows that Fab specific for the gp41 membrane-proximal region harbors a long heavy-chain CDR3 loop (CDRH3) similar to the two broadly neutralizing IgG monoclonal antibodies, 2F5 and 4E10. Furthermore, the selected Fab IgA shows extensive somatic mutations that cluster in the CDR regions, indicating that affinity maturation due to an antigen-driven process had occurred in HEPS individuals, presumably upon multiple exposures to HIV. This analysis of HEPS monoclonal IgA gives a unique opportunity to correlate an antibody function (resistance to a pathogen in vivo) with an antibody gene. Such neutralizing monoclonal IgAs could be used in microbicide formulation.

  6. Complexes of neutralizing and non-neutralizing affinity matured Fabs with a mimetic of the internal trimeric coiled-coil of HIV-1 gp41.

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    Elena Gustchina

    Full Text Available A series of mini-antibodies (monovalent and bivalent Fabs targeting the conserved internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41 has been previously constructed and reported. Crystal structures of two closely related monovalent Fabs, one (Fab 8066 broadly neutralizing across a wide panel of HIV-1 subtype B and C viruses, and the other (Fab 8062 non-neutralizing, representing the extremes of this series, were previously solved as complexes with 5-Helix, a gp41 pre-hairpin intermediate mimetic. Binding of these Fabs to covalently stabilized chimeric trimers of N-peptides of HIV-1 gp41 (named (CCIZN363 or 3-H has now been investigated using X-ray crystallography, cryo-electron microscopy, and a variety of biophysical methods. Crystal structures of the complexes between 3-H and Fab 8066 and Fab 8062 were determined at 2.8 and 3.0 Å resolution, respectively. Although the structures of the complexes with the neutralizing Fab 8066 and its non-neutralizing counterpart Fab 8062 were generally similar, small differences between them could be correlated with the biological properties of these antibodies. The conformations of the corresponding CDRs of each antibody in the complexes with 3-H and 5-Helix are very similar. The adaptation to a different target upon complex formation is predominantly achieved by changes in the structure of the trimer of N-HR helices, as well as by adjustment of the orientation of the Fab molecule relative to the N-HR in the complex, via rigid-body movement. The structural data presented here indicate that binding of three Fabs 8062 with high affinity requires more significant changes in the structure of the N-HR trimer compared to binding of Fab 8066. A comparative analysis of the structures of Fabs complexed to different gp41 intermediate mimetics allows further evaluation of biological relevance for generation of neutralizing antibodies, as well as provides novel structural insights into immunogen

  7. Topology of the C-terminal tail of HIV-1 gp41: differential exposure of the Kennedy epitope on cell and viral membranes.

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    Jonathan D Steckbeck

    2010-12-01

    Full Text Available The C-terminal tail (CTT of the HIV-1 gp41 envelope (Env protein is increasingly recognized as an important determinant of Env structure and functional properties, including fusogenicity and antigenicity. While the CTT has been commonly referred to as the "intracytoplasmic domain" based on the assumption of an exclusive localization inside the membrane lipid bilayer, early antigenicity studies and recent biochemical analyses have produced a credible case for surface exposure of specific CTT sequences, including the classical "Kennedy epitope" (KE of gp41, leading to an alternative model of gp41 topology with multiple membrane-spanning domains. The current study was designed to test these conflicting models of CTT topology by characterizing the exposure of native CTT sequences and substituted VSV-G epitope tags in cell- and virion-associated Env to reference monoclonal antibodies (MAbs. Surface staining and FACS analysis of intact, Env-expressing cells demonstrated that the KE is accessible to binding by MAbs directed to both an inserted VSV-G epitope tag and the native KE sequence. Importantly, the VSV-G tag was only reactive when inserted into the KE; no reactivity was observed in cells expressing Env with the VSV-G tag inserted into the LLP2 domain. In contrast to cell-surface expressed Env, no binding of KE-directed MAbs was observed to Env on the surface of intact virions using either immune precipitation or surface plasmon resonance spectroscopy. These data indicate apparently distinct CTT topologies for virion- and cell-associated Env species and add to the case for a reconsideration of CTT topology that is more complex than currently envisioned.

  8. Transcytosis-blocking abs elicited by an oligomeric immunogen based on the membrane proximal region of HIV-1 gp41 target non-neutralizing epitopes.

    Science.gov (United States)

    Matoba, Nobuyuki; Griffin, Tagan A; Mittman, Michele; Doran, Jeffrey D; Alfsen, Annette; Montefiori, David C; Hanson, Carl V; Bomsel, Morgane; Mor, Tsafrir S

    2008-05-01

    CTB-MPR(649-684), a translational fusion protein consisting of cholera toxin B subunit (CTB) and residues 649 684 of gp41 membrane proximal region (MPR), is a candidate vaccine aimed at blocking early steps of HIV-1 mucosal transmission. Bacterially produced CTB MPR(649-684) was purified to homogeneity by two affinity chromatography steps. Similar to gp41 and derivatives thereof, the MPR domain can specifically and reversibly self-associate. The affinities of the broadly-neutralizing monoclonal Abs 4E10 and 2F5 to CTB MPR(649-684) were equivalent to their nanomolar affinities toward an MPR peptide. The fusion protein's affinity to GM1 ganglioside was comparable to that of native CTB. Rabbits immunized with CTB-MPR(649-684) raised only a modest level of anti-MPR(649-684) Abs. However, a prime-boost immunization with CTB-MPR(649-684) and a second MPR(649-684)-based immunogen elicited a more productive anti-MPR(649-684) antibody response. These Abs strongly blocked the epithelial transcytosis of a primary subtype B HIV-1 isolate in a human tight epithelial model, expanding our previously reported results using a clade D virus. The Abs recognized epitopes at the N-terminal portion of the MPR peptide, away from the 2F5 and 4E10 epitopes and were not effective in neutralizing infection of CD4+ cells. These results indicate distinct vulnerabilities of two separate interactions of HIV-1 with human cells - Abs against the C-terminal portion of the MPR can neutralize CD4+-dependent infection, while Abs targeting the MPR's N-terminal portion can effectively block galactosyl ceramide dependent transcytosis. We propose that Abs induced by MPR(649-684)-based immunogens may provide broad protective value independent of infection neutralization.

  9. A bivalent recombinant protein inactivates HIV-1 by targeting the gp41 prehairpin fusion intermediate induced by CD4 D1D2 domains

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    Lu Lu

    2012-12-01

    Full Text Available Abstract Background Most currently approved anti-HIV drugs (e.g., reverse transcriptase inhibitors, protease inhibitors and fusion/entry inhibitors must act inside or on surface of the target cell to inhibit HIV infection, but none can directly inactivate virions away from cells. Although soluble CD4 (sCD4 can inactivate laboratory-adapted HIV-1 strains, it fails to reduce the viral loads in clinical trials because of its low potency against primary isolates and tendency to enhance HIV-1 infection at low concentration. Thus, it is essential to design a better HIV inactivator with improved potency for developing new anti-HIV therapeutics that can actively attack the virus in the circulation before it attaches to and enter into the target cell. Results We engineered a bivalent HIV-1 inactivator, designated 2DLT, by linking the D1D2 domain of CD4 to T1144, the next generation HIV fusion inhibitor, with a 35-mer linker. The D1D2 domain in this soluble 2DLT protein could bind to the CD4-binding site and induce the formation of the gp41 prehairpin fusion-intermediate (PFI, but showed no sCD4-mediated enhancement of HIV-1 infection. The T1144 domain in 2DLT then bound to the exposed PFI, resulting in rapid inactivation of HIV-1 virions in the absence of the target cell. Beside, 2DLT could also inhibit fusion of the virus with the target cell if the virion escapes the first attack of 2DLT. Conclusion This bivalent molecule can serve as a dual barrier against HIV infection by first inactivating HIV-1 virions away from cells and then blocking HIV-1 entry on the target cell surface, indicating its potential for development as a new class of anti-HIV drug.

  10. HIV-1 gp41-targeting fusion inhibitory peptides enhance the gp120-targeting protein-mediated inactivation of HIV-1 virions

    OpenAIRE

    Qi, Qianqian; Wang, Qian; Chen, Weizao; Du, Lanying; Dimitrov, Dimiter S; Lu, Lu; Jiang, Shibo

    2017-01-01

    Protein- or peptide-based viral inactivators are being developed as novel antiviral drugs with improved efficacy, pharmacokinetics and toxicity profiles because they actively inactivate cell-free human immunodeficiency virus type 1 (HIV-1) virions before attachment to host cells. By contrast, most clinically used antiviral drugs must penetrate host cells to inhibit viral replication. In this study, we pre-treated HIV-1 particles with a gp120-targeting bispecific multivalent protein, 2Dm2m or ...

  11. Common tolerance mechanisms, but distinct cross-reactivities associated with gp41 and lipids, limit production of HIV-1 broad neutralizing antibodies 2F5 and 4E10.

    Science.gov (United States)

    Chen, Yao; Zhang, Jinsong; Hwang, Kwan-Ki; Bouton-Verville, Hilary; Xia, Shi-Mao; Newman, Amanda; Ouyang, Ying-Bin; Haynes, Barton F; Verkoczy, Laurent

    2013-08-01

    Developing an HIV-1 vaccine has been hampered by the inability of immunogens to induce broadly neutralizing Abs (BnAbs) that protect against infection. Previously, we used knockin (KI) mice expressing a prototypical gp41-specific BnAb, 2F5, to demonstrate that immunological tolerance triggered by self-reactivity of the 2F5 H chain impedes BnAb induction. In this study, we generate KI models expressing H chains from two other HIV-1 Abs, 4E10 (another self-/polyreactive, anti-gp41 BnAb) and 48d (an anti-CD4 inducible, nonpolyreactive Ab), and find a similar developmental blockade consistent with central B cell deletion in 4E10, but not in 48d VH KI mice. Furthermore, in KI strains expressing the complete 2F5 and 4E10 Abs as BCRs, we find that residual splenic B cells arrest at distinct developmental stages, yet exhibit uniformly low BCR densities, elevated basal activation, and profoundly muted responses to BCR ligation and, when captured as hybridoma mAb lines, maintain their dual (gp41/lipid) affinities and capacities to neutralize HIV-1, establishing a key role for anergy in suppressing residual 2F5- or 4E10-expressing B cells. Importantly, serum IgGs from naive 2F5 and 4E10 KI strains selectively eliminate gp41 and lipid binding, respectively, suggesting B cells expressing 2F5 or 4E10 as BCRs exhibit specificity for a distinct spectrum of host Ags, including selective interactions by 2F5 BCR(+) B cells (i.e., and not 4E10 BCR(+) B cells) with those mimicked by its gp41 neutralization epitope.

  12. HIV-1 variants with a single-point mutation in the gp41 pocket region exhibiting different susceptibility to HIV fusion inhibitors with pocket- or membrane-binding domain.

    Science.gov (United States)

    Lu, Lu; Tong, Pei; Yu, Xiaowen; Pan, Chungen; Zou, Peng; Chen, Ying-Hua; Jiang, Shibo

    2012-12-01

    Enfuvirtide (T20), the first FDA-approved peptide HIV fusion/entry inhibitor derived from the HIV-1 gp41 C-terminal heptad-repeat (CHR) domain, is believed to share a target with C34, another well-characterized CHR-peptide, by interacting with the gp41 N-terminal heptad-repeat (NHR) to form six-helix bundle core. However, our previous studies showed that T20 mainly interacts with the N-terminal region of the NHR (N-NHR) and lipid membranes, while C34 mainly binds to the NHR C-terminal pocket region. But so far, no one has shown that C34 can induce drug-resistance mutation in the gp41 pocket region. In this study, we constructed pseudoviruses in which the Ala at the position of 67 in the gp41 pocket region was substituted with Asp, Gly or Ser, respectively, and found that these mutations rendered the viruses highly resistant to C34, but sensitive to T20. The NHR-peptide N36 with mutations of A67 exhibited reduced anti-HIV-1 activity and decreased α-helicity. The stability of six-helix bundle formed by C34 and N36 with A67 mutations was significantly lower than that formed by C34 and N36 with wild-type sequence. The combination of C34 and T20 resulted in potent synergistic anti-HIV-1 effect against the viruses with mutations in either N- or C-terminal region in NHR. These results suggest that C34 with a pocket-binding domain and T20 containing the N-NHR- and membrane-binding domains inhibit HIV-1 fusion by interacting with different target sites and the combinatorial use of C34 and T20 is expected to be effective against HIV-1 variants resistant to HIV fusion inhibitors. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Binding of HIV-1 gp41-directed neutralizing and non-neutralizing fragment antibody binding domain (Fab and single chain variable fragment (ScFv antibodies to the ectodomain of gp41 in the pre-hairpin and six-helix bundle conformations.

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    John M Louis

    Full Text Available We previously reported a series of antibodies, in fragment antigen binding domain (Fab formats, selected from a human non-immune phage library, directed against the internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41. Broadly neutralizing antibodies from that series bind to both the fully exposed N-HR trimer, representing the pre-hairpin intermediate state of gp41, and to partially-exposed N-HR helices within the context of the gp41 six-helix bundle. While the affinities of the Fabs for pre-hairpin intermediate mimetics vary by only 2 to 20-fold between neutralizing and non-neutralizing antibodies, differences in inhibition of viral entry exceed three orders of magnitude. Here we compare the binding of neutralizing (8066 and non-neutralizing (8062 antibodies, differing in only four positions within the CDR-H2 binding loop, in Fab and single chain variable fragment (ScFv formats, to several pre-hairpin intermediate and six-helix bundle constructs of gp41. Residues 56 and 58 of the mini-antibodies are shown to be crucial for neutralization activity. There is a large differential (≥ 150-fold in binding affinity between neutralizing and non-neutralizing antibodies to the six-helix bundle of gp41 and binding to the six-helix bundle does not involve displacement of the outer C-terminal helices of the bundle. The binding stoichiometry is one six-helix bundle to one Fab or three ScFvs. We postulate that neutralization by the 8066 antibody is achieved by binding to a continuum of states along the fusion pathway from the pre-hairpin intermediate all the way to the formation of the six-helix bundle, but prior to irreversible fusion between viral and cellular membranes.

  14. Evaluation of a novel multi-immunogen vaccine strategy for targeting 4E10/10E8 neutralizing epitopes on HIV-1 gp41 membrane proximal external region.

    Science.gov (United States)

    Banerjee, Saikat; Shi, Heliang; Banasik, Marisa; Moon, Hojin; Lees, William; Qin, Yali; Harley, Andrew; Shepherd, Adrian; Cho, Michael W

    2017-05-01

    The membrane proximal external region (MPER) of HIV-1 gp41 is targeted by broadly neutralizing antibodies (bnAbs) 4E10 and 10E8. In this proof-of-concept study, we evaluated a novel multi-immunogen vaccine strategy referred to as Incremental, Phased Antigenic Stimulation for Rapid Antibody Maturation (IPAS-RAM) to induce 4E10/10E8-like bnAbs. Rabbits were immunized sequentially, but in a phased manner, with three immunogens that are progressively more native (gp41-28×3, gp41-54CT, and rVV-gp160DH12). Although nAbs were not induced, epitope-mapping analyses indicated that IPAS-RAM vaccination was better able to target antibodies towards the 4E10/10E8 epitopes than homologous prime-boost immunization using gp41-28×3 alone. MPER-specific rabbit monoclonal antibodies were generated, including 9F6. Although it lacked neutralizing activity, the target epitope profile of 9F6 closely resembled those of 4E10 and 10E8 ((671)NWFDITNWLWYIK(683)). B-cell repertoire analyses suggested the importance of co-immunizations for maturation of 9F6, which warrants further evaluation of our IPAS-RAM vaccine strategy using an improved priming immunogen. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. HIV-1 gp41 and TCRalpha trans-membrane domains share a motif exploited by the HIV virus to modulate T-cell proliferation.

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    Tomer Cohen

    Full Text Available Viruses have evolved several strategies to modify cellular processes and evade the immune response in order to successfully infect, replicate, and persist in the host. By utilizing in-silico testing of a transmembrane sequence library derived from virus protein sequences, we have pin-pointed a nine amino-acid motif shared by a group of different viruses; this motif resembles the transmembrane domain of the alpha-subunit of the T-cell receptor (TCRalpha. The most striking similarity was found within the immunodeficiency virus (SIV and HIV glycoprotein 41 TMD (gp41 TMD. Previous studies have shown that stable interactions between TCRalpha and CD3 are localized to this nine amino acid motif within TCRalpha, and a peptide derived from it (TCRalpha TMD, GLRILLLKV interfered and intervened in the TCR function when added exogenously. We now report that the gp41 TMD peptide co-localizes with CD3 within the TCR complex and inhibits T cell proliferation in vitro. However, the inhibitory mechanism of gp41 TMD differs from that of the TCRalpha TMD and also from the other two known immunosuppressive regions within gp41.

  16. Differences in serum IgA responses to HIV-1 gp41 in elite controllers compared to viral suppressors on highly active antiretroviral therapy.

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    Rafiq Nabi

    Full Text Available Mechanisms responsible for natural control of human immunodeficiency type 1 (HIV replication in elite controllers (EC remain incompletely defined. To determine if EC generate high quality HIV-specific IgA responses, we used Western blotting to compare the specificities and frequencies of IgA to HIV antigens in serum of gender-, age- and race-matched EC and aviremic controllers (HC and viremic noncontrollers (HN on highly active antiretroviral therapy (HAART. Concentrations and avidity of IgA to HIV antigens were measured using ELISA or multiplex assays. Measurements for IgG were performed in parallel. EC were found to have stronger p24- and V1V2-specific IgG responses than HN, but there were no IgG differences for EC and HC. In contrast, IgA in EC serum bound more frequently to gp160 and gag proteins than IgA in HC or HN. The avidity of anti-gp41 IgA was also greater in EC, and these subjects had stronger IgA responses to the gp41 heptad repeat region 1 (HR1, a reported target of anti-bacterial RNA polymerase antibodies that cross react with gp41. However, EC did not demonstrate greater IgA responses to E. coli RNA polymerase or to peptides containing the shared LRAI sequence, suggesting that most of their HR1-specific IgA antibodies were not induced by intestinal microbiota. In both EC and HAART recipients, the concentrations of HIV-specific IgG were greater than HIV-specific IgA, but their avidities were comparable, implying that they could compete for antigen. Exceptions were C1 peptides and V1V2 loops. IgG and IgA responses to these antigens were discordant, with IgG reacting to V1V2, and IgA reacting to C1, especially in EC. Interestingly, EC with IgG hypergammaglobulinemia had greater HIV-specific IgA and IgG responses than EC with normal total IgG levels. Heterogeneity in EC antibody responses may therefore be due to a more focused HIV-specific B cell response in some of these individuals. Overall, these data suggest that development of

  17. The initial antibody response to HIV-1: induction of ineffective early B cell responses against GP41 by the transmitted/founder virus

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Leslie L [Los Alamos National Laboratory; Perelson, Alan [Los Alamos National Laboratory

    2008-01-01

    A window of opportunity for immune responses to extinguish HIV -1 exists from the moment of transmission through establishment of the latent pool of HIV -I-infected cells. A critical time to study the initial immune responses to the transmitted/founder virus is the eclipse phase of HIV-1 infection (time from transmission to the first appearance of plasma virus) but, to date, this period has been logistically difficult to analyze. Studies in non-human primates challenged with chimeric simianhuman immunodeficiency virus have shown that neutralizing antibodies, when present at the time of infection, can prevent virus infection.

  18. Functional characterization of two scFv-Fc antibodies from an HIV controller selected on soluble HIV-1 Env complexes: a neutralizing V3- and a trimer-specific gp41 antibody.

    Science.gov (United States)

    Trott, Maria; Weiβ, Svenja; Antoni, Sascha; Koch, Joachim; von Briesen, Hagen; Hust, Michael; Dietrich, Ursula

    2014-01-01

    HIV neutralizing antibodies (nAbs) represent an important tool in view of prophylactic and therapeutic applications for HIV-1 infection. Patients chronically infected by HIV-1 represent a valuable source for nAbs. HIV controllers, including long-term non-progressors (LTNP) and elite controllers (EC), represent an interesting subgroup in this regard, as here nAbs can develop over time in a rather healthy immune system and in the absence of any therapeutic selection pressure. In this study, we characterized two particular antibodies that were selected as scFv antibody fragments from a phage immune library generated from an LTNP with HIV neutralizing antibodies in his plasma. The phage library was screened on recombinant soluble gp140 envelope (Env) proteins. Sequencing the selected peptide inserts revealed two major classes of antibody sequences. Binding analysis of the corresponding scFv-Fc derivatives to various trimeric and monomeric Env constructs as well as to peptide arrays showed that one class, represented by monoclonal antibody (mAb) A2, specifically recognizes an epitope localized in the pocket binding domain of the C heptad repeat (CHR) in the ectodomain of gp41, but only in the trimeric context. Thus, this antibody represents an interesting tool for trimer identification. MAb A7, representing the second class, binds to structural elements of the third variable loop V3 and neutralizes tier 1 and tier 2 HIV-1 isolates of different subtypes with matching critical amino acids in the linear epitope sequence. In conclusion, HIV controllers are a valuable source for the selection of functionally interesting antibodies that can be selected on soluble gp140 proteins with properties from the native envelope spike.

  19. The convertases furin and PC1 can both cleave the human immunodeficiency virus (HIV)-1 envelope glycoprotein gp160 into gp120 (HIV-1 SU) and gp41 (HIV-I TM).

    Science.gov (United States)

    Decroly, E; Vandenbranden, M; Ruysschaert, J M; Cogniaux, J; Jacob, G S; Howard, S C; Marshall, G; Kompelli, A; Basak, A; Jean, F

    1994-04-22

    Intracellular proteolytic processing of human immunodeficiency virus envelope glycoprotein precursor (gp160) is an essential step for virus infectivity. Northern blot analysis provided evidence that furin and PC1, but not PC2, are expressed in the CD4+ human lymphoblastoid H9 cell line, suggesting the possible participation of these convertases in human immunodeficiency virus (HIV) gp160 proteolytic processing. Purified PC1 and furin cleaved specifically in vitro gp160 into gp120 (HIV-I SU) and gp41 (HIV-I TM). NH2-terminal sequence analysis of the produced gp41 (HIV-I TM) demonstrated that the cleavage occurred within the sequence Arg-Glu-Lys-Arg decreases Ala-Val-Gly-Ile, which is identical to the bond cleaved in vivo. Transition state analog peptides were designed and tested in vitro for their ability to inhibit the PC1- or furin-mediated gp160 cleavage. The best inhibitor was decanoyl-Arg-Lys-Arg-Arg-psi [CH2NH]-Phe-Leu-Gly-Phe-NH2.

  20. HIV DNA-Adenovirus Multiclade Envelope Vaccine Induces gp41 Antibody Immunodominance in Rhesus Macaques.

    Science.gov (United States)

    Han, Qifeng; Williams, Wilton B; Saunders, Kevin O; Seaton, Kelly E; Wiehe, Kevin J; Vandergrift, Nathan; Von Holle, Tarra A; Trama, Ashley M; Parks, Robert J; Luo, Kan; Gurley, Thaddeus C; Kepler, Thomas B; Marshall, Dawn J; Montefiori, David C; Sutherland, Laura L; Alam, Munir S; Whitesides, John F; Bowman, Cindy M; Permar, Sallie R; Graham, Barney S; Mascola, John R; Seed, Patrick C; Van Rompay, Koen K A; Tomaras, Georgia D; Moody, M Anthony; Haynes, Barton F

    2017-11-01

    Dominant antibody responses in vaccinees who received the HIV-1 multiclade (A, B, and C) envelope (Env) DNA/recombinant adenovirus virus type 5 (rAd5) vaccine studied in HIV-1 Vaccine Trials Network (HVTN) efficacy trial 505 (HVTN 505) targeted Env gp41 and cross-reacted with microbial antigens. In this study, we asked if the DNA/rAd5 vaccine induced a similar antibody response in rhesus macaques (RMs), which are commonly used as an animal model for human HIV-1 infections and for testing candidate HIV-1 vaccines. We also asked if gp41 immunodominance could be avoided by immunization of neonatal RMs during the early stages of microbial colonization. We found that the DNA/rAd5 vaccine elicited a higher frequency of gp41-reactive memory B cells than gp120-memory B cells in adult and neonatal RMs. Analysis of the vaccine-induced Env-reactive B cell repertoire revealed that the majority of HIV-1 Env-reactive antibodies in both adult and neonatal RMs were targeted to gp41. Interestingly, a subset of gp41-reactive antibodies isolated from RMs cross-reacted with host antigens, including autologous intestinal microbiota. Thus, gp41-containing DNA/rAd5 vaccine induced dominant gp41-microbiota cross-reactive antibodies derived from blood memory B cells in RMs as observed in the HVTN 505 vaccine efficacy trial. These data demonstrated that RMs can be used to investigate gp41 immunodominance in candidate HIV-1 vaccines. Moreover, colonization of neonatal RMs occurred within the first week of life, and immunization of neonatal RMs during this time also induced a dominant gp41-reactive antibody response.IMPORTANCE Our results are critical to current work in the HIV-1 vaccine field evaluating the phenomenon of gp41 immunodominance induced by HIV-1 Env gp140 in RMs and humans. Our data demonstrate that RMs are an appropriate animal model to study this phenomenon and to determine the immunogenicity in new HIV-1 Env trimer vaccine designs. The demonstration of gp41 immunodominance in

  1. Antiviral properties of two trimeric recombinant gp41 proteins

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    Nisole Sébastien

    2006-03-01

    Full Text Available Abstract Background As it is the very first step of the HIV replication cycle, HIV entry represents an attractive target for the development of new antiviral drugs. In this context, fusion inhibitors are the third class of anti-HIV drugs to be used for treatment, in combination with nucleoside analogues and antiproteases. But the precise mechanism of HIV fusion mechanism is still unclear. Gp41 ectodomain-derived synthetic peptides represent ideal tools for clarifying this mechanism, in order to design more potent anti-HIV drugs. Results Two soluble trimeric recombinant gp41 proteins, termed Rgp41B and Rgp41A were designed. Both comprise the N- and C-terminal heptad repeat regions of the ectodomain of HIV-1 gp41, connected by a 7-residue hydrophilic linker, in order to mimic the trimeric fusogenic state of the transmembrane glycoprotein. Both recombinant proteins were found to inhibit HIV-1 entry into target cells in a dose-dependent manner. Rgp41A, the most potent inhibitor, was able to inhibit both X4 and R5 isolates into HeLa cells and primary T lymphocytes. X4 viruses were found to be more susceptible than R5 isolates to inhibition by Rgp41A. In order to elucidate how the trimeric recombinant gp41 protein can interfere with HIV-1 entry into target cells, we further investigated its mode of action. Rgp41A was able to bind gp120 but did not induce gp120-gp41 dissociation. Furthermore, this inhibitor could also interfere with a late step of the fusion process, following the mixing of lipids. Conclusion Taken together, our results suggest that Rgp41A can bind to gp120 and also interfere with a late event of the fusion process. Interestingly, Rgp41A can block membrane fusion without preventing lipid mixing. Although further work will be required to fully understand its mode of action, our results already suggest that Rgp41A can interfere with multiple steps of the HIV entry process.

  2. Early steps of HIV-1 fusion define the sensitivity to inhibitory peptides that block 6-helix bundle formation.

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    Kosuke Miyauchi

    2009-09-01

    Full Text Available The HIV envelope (Env glycoprotein mediates membrane fusion through sequential interactions with CD4 and coreceptors, followed by the refolding of the transmembrane gp41 subunit into the stable 6-helix bundle (6HB conformation. Synthetic peptides derived from the gp41 C-terminal heptad repeat domain (C-peptides potently inhibit fusion by binding to the gp41 pre-bundle intermediates and blocking their conversion into the 6HB. Our recent work revealed that HIV-1 enters cells by fusing with endosomes, but not with the plasma membrane. These studies also showed that, for the large part, gp41 pre-bundles progress toward 6HBs in endosomal compartments and are thus protected from external fusion inhibitors. Here, we examined the consequences of endocytic entry on the gp41 pre-bundle exposure and on the virus' sensitivity to C-peptides. The rates of CD4 and coreceptor binding, as well as the rate of productive receptor-mediated endocytosis, were measured by adding specific inhibitors of these steps at varied times of virus-cell incubation. Following the CD4 binding, CCR5-tropic viruses recruited a requisite number of coreceptors much faster than CXCR4-tropic viruses. The rate of subsequent uptake of ternary Env-CD4-coreceptor complexes did not correlate with the kinetics of coreceptor engagement. These measurements combined with kinetic analyses enabled the determination of the lifetime of pre-bundle intermediates on the cell surface. Overall, these lifetimes correlated with the inhibitory potency of C-peptides. On the other hand, the basal sensitivity to peptides varied considerably among diverse HIV-1 isolates and ranked similarly with their susceptibility to inactivation by soluble CD4. We conclude that both the longevity of gp41 intermediates and the extent of irreversible conformational changes in Env upon CD4 binding determine the antiviral potency of C-peptides.

  3. Design and application of GB virus C (GBV-C) peptide microarrays for diagnosis of GBV-C/HIV-1 co-infection.

    Science.gov (United States)

    Fernández, Leticia; Bleda, M José; Gómara, M José; Haro, Isabel

    2013-05-01

    The main objectives of the design of GB virus C (GBV-C) peptide microarrays are the miniaturisation of antigen-antibody interaction assays, the simultaneous analysis of several peptide sequences and the reduction in the volume of serum required from patients since this always represents a limiting factor in studies to develop new systems for diagnosing human diseases. We herein report the design of a microarray immunoassay based on synthetic peptides derived from the GBV-C E2 protein to evaluate their diagnostic value in detecting anti-E2 antibodies in HIV-1 patients. To this end, peptide microarrays were initially prepared to identify the most relevant epitopes in the GBV-C E2 protein. Thus, 124 peptides composed of 18 amino acids covering the whole E2-protein sequence, with 15 residue overlaps, were spotted in triplicate onto γ-aminopropyl silane-functionalised adsorbent binding slides. The procedure to select the E2 protein epitopes was carried out using serum samples from HIV-1-infected patients. The samples had previously been tested for the presence or absence of GBV-C anti-E2 antibodies by means of the Abbott test. Thus, 11 specific epitopes in the GBV-C E2 protein were identified. Subsequently, peptide antigen microarrays were constructed using the E2 epitopes identified to detect GBV-C anti-E2 antibodies in the serum of HIV-1-infected patients with no known GBV-C co-infection. The 11 peptides selected identified anti-E2 GBV-C antibodies among HIV-1-infected patients, and a reactivity of 47 % was established. The potential antigenic peptides selected could be considered a useful tool for designing a new diagnostic system based on peptide microarrays to determine anti-GBV-C E2 antibodies in the serum of HIV-1-infected patients.

  4. Immunogenicity of a chimeric hepatitis A virus (HAV) carrying the HIV gp41 epitope 2F5.

    Science.gov (United States)

    Kusov, Yuri Y; Zamjatina, Natalja A; Poleschuk, Valentina F; Michailov, Michail I; Morace, Graziella; Eberle, Josef; Gauss-Müller, Verena

    2007-02-01

    Its stable particle structure combined with its high immunogenicity makes the hepatitis A virus (HAV) a perfect carrier to expose foreign epitopes to the host immune system. In an earlier report [Beneduce, F., Kusov, Y., Klinger, M., Gauss-Müller, V., Morace, G., 2002. Chimeric hepatitis A virus particles presenting a foreign epitope (HIV gp41) at their surface. Antiviral Res. 55, 369-377] chimeric virus-like particles (HAV-gp41) were described that carried at their surface the dominant gp41 epitope 2F5 (2F5e) of the human immunodeficiency virus HIV-1. Extending this work, we now report that chimeric virus HAV-gp41 replicates in HAV-susceptible cells as well as in non-human primates. Infected marmosets developed both an anti-HAV and anti-2F5 epitope immune response. Furthermore, an HIV-neutralizing antibody response was elicited in guinea pigs immunized with HAV-gp41 chimeric particles. The results demonstrate that the replication-competent chimeric HAV-gp41 can serve as either a live or a subunit vaccine for eliciting of antibodies directed against a foreign antigenic epitope.

  5. A gp41 MPER-specific llama VHH requires a hydrophobic CDR3 for neutralization but not for antigen recognition.

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    David Lutje Hulsik

    2013-03-01

    Full Text Available The membrane proximal external region (MPER of the HIV-1 glycoprotein gp41 is targeted by the broadly neutralizing antibodies 2F5 and 4E10. To date, no immunization regimen in animals or humans has produced HIV-1 neutralizing MPER-specific antibodies. We immunized llamas with gp41-MPER proteoliposomes and selected a MPER-specific single chain antibody (VHH, 2H10, whose epitope overlaps with that of mAb 2F5. Bi-2H10, a bivalent form of 2H10, which displayed an approximately 20-fold increased affinity compared to the monovalent 2H10, neutralized various sensitive and resistant HIV-1 strains, as well as SHIV strains in TZM-bl cells. X-ray and NMR analyses combined with mutagenesis and modeling revealed that 2H10 recognizes its gp41 epitope in a helical conformation. Notably, tryptophan 100 at the tip of the long CDR3 is not required for gp41 interaction but essential for neutralization. Thus bi-2H10 is an anti-MPER antibody generated by immunization that requires hydrophobic CDR3 determinants in addition to epitope recognition for neutralization similar to the mode of neutralization employed by mAbs 2F5 and 4E10.

  6. Isolation of a human anti-HIV gp41 membrane proximal region neutralizing antibody by antigen-specific single B cell sorting.

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    Lynn Morris

    Full Text Available Broadly neutralizing antibodies are not commonly produced in HIV-1 infected individuals nor by experimental HIV-1 vaccines. When these antibodies do occur, it is important to be able to isolate and characterize them to provide clues for vaccine design. CAP206 is a South African subtype C HIV-1-infected individual previously shown to have broadly neutralizing plasma antibodies targeting the envelope gp41 distal membrane proximal external region (MPER. We have now used a fluoresceinated peptide tetramer antigen with specific cell sorting to isolate a human neutralizing monoclonal antibody (mAb against the HIV-1 envelope gp41 MPER. The isolated recombinant mAb, CAP206-CH12, utilized a portion of the distal MPER (HXB2 amino acid residues, 673-680 and neutralized a subset of HIV-1 pseudoviruses sensitive to CAP206 plasma antibodies. Interestingly, this mAb was polyreactive and used the same germ-line variable heavy (V(H1-69 and variable kappa light chain (V(K3-20 gene families as the prototype broadly neutralizing anti-MPER mAb, 4E10 (residues 672-680. These data indicate that there are multiple immunogenic targets in the C-terminus of the MPER of HIV-1 gp41 envelope and suggests that gp41 neutralizing epitopes may interact with a restricted set of naive B cells during HIV-1 infection.

  7. Isolation of a Human Anti-HIV gp41 Membrane Proximal Region Neutralizing Antibody by Antigen-Specific Single B Cell Sorting

    Science.gov (United States)

    Morris, Lynn; Chen, Xi; Alam, Munir; Tomaras, Georgia; Zhang, Ruijun; Marshall, Dawn J.; Chen, Bing; Parks, Robert; Foulger, Andrew; Jaeger, Frederick; Donathan, Michele; Bilska, Mira; Gray, Elin S.; Abdool Karim, Salim S.; Kepler, Thomas B.; Whitesides, John; Montefiori, David; Moody, M. Anthony; Liao, Hua-Xin; Haynes, Barton F.

    2011-01-01

    Broadly neutralizing antibodies are not commonly produced in HIV-1 infected individuals nor by experimental HIV-1 vaccines. When these antibodies do occur, it is important to be able to isolate and characterize them to provide clues for vaccine design. CAP206 is a South African subtype C HIV-1-infected individual previously shown to have broadly neutralizing plasma antibodies targeting the envelope gp41 distal membrane proximal external region (MPER). We have now used a fluoresceinated peptide tetramer antigen with specific cell sorting to isolate a human neutralizing monoclonal antibody (mAb) against the HIV-1 envelope gp41 MPER. The isolated recombinant mAb, CAP206-CH12, utilized a portion of the distal MPER (HXB2 amino acid residues, 673–680) and neutralized a subset of HIV-1 pseudoviruses sensitive to CAP206 plasma antibodies. Interestingly, this mAb was polyreactive and used the same germ-line variable heavy (VH1-69) and variable kappa light chain (VK3-20) gene families as the prototype broadly neutralizing anti-MPER mAb, 4E10 (residues 672–680). These data indicate that there are multiple immunogenic targets in the C-terminus of the MPER of HIV-1 gp41 envelope and suggests that gp41 neutralizing epitopes may interact with a restricted set of naive B cells during HIV-1 infection. PMID:21980336

  8. Antibody neutralization escape mediated by point mutations in the intracytoplasmic tail of human immunodeficiency virus type 1 gp41.

    Science.gov (United States)

    Kalia, Vandana; Sarkar, Surojit; Gupta, Phalguni; Montelaro, Ronald C

    2005-02-01

    The persistence of human immunodeficiency virus type 1 (HIV-1) infection in the presence of robust host immunity has been associated in part with variation in viral envelope proteins leading to antigenic variation and escape from neutralizing antibodies. Previous studies of natural neutralization escape mutants have predominantly focused on gp120 and gp41 ectodomain sequence variations that alter antibody binding via changes in conformation or glycosylation pattern of the Env, likely due to the immune pressure exerted on the exposed ectodomain component of the glycoprotein. Here, we show for the first time a novel mechanism by which point mutations in the intracytoplasmic tail of the transmembrane component (gp41) of envelope can render the virus resistant to neutralization by monoclonal antibodies and broadly neutralizing polyclonal serum antibodies. Point mutations in a highly conserved structural motif within the intracytoplasmic tail resulted in decreased binding of neutralizing antibodies to the Env ectodomain, evidently due to allosteric changes both in the gp41 ectodomain and in gp120. While receptor binding and infectivity of the mutant virus remained unaltered, the changes in Env antigenicity were associated with an increase in neutralization resistance of the mutant virus. These studies demonstrate the structurally integrated nature of gp120 and gp41 and underscore a previously unrecognized potentially critical role for even minor sequence variation of the intracytoplasmic tail in modulating the antigenicity of the ectodomain of HIV-1 envelope glycoprotein complex.

  9. Virus like particle based strategy to elicit HIV-protective antibodies to the alpha-helic regions of gp41.

    Science.gov (United States)

    Pastori, C; Tudor, D; Diomede, L; Drillet, A S; Jegerlehner, A; Röhn, T A; Bomsel, M; Lopalco, L

    Natural antibodies to gp41 inhibit HIV-1 replication through the recognition of two different regions, corresponding to the leucine zipper motif in the HR1 alpha-helix and to another motif within HR2 region, hosting 2F5 and 4E10 epitope. This study aimed at reproducing such protective responses through VLP vaccination. Six regions covering the alpha-helical regions of gp41 were conjugated to the surface of AP205 phage-based VLPs. Once administered in mice via systemic or mucosal route, these immunogens elicited high titers of gp41-specific IgG. Immunogenicity and HIV infectivity reduction were obtained either with HR2 regions or with peptides where aminoacid strings were added to either the C-terminus or N-terminus of core epitope in HR1 region. Antibody-dependent cell cytotoxicity (ADCC) activity was induced by one of the HR2 epitopes only. These results may have relevant implications for the development of new vaccinal approaches against HIV infection. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Designing a Soluble Near Full-Length HIV-1 GP41 Trimer

    Science.gov (United States)

    2012-11-26

    dilutions starting at 50 µg/ml in the growth medium [DMEM with 100 U/ml penicillin , 100 μg/ml streptomycin, 2 mM L-glutamine (Quality Biologics...This work was partly supported by a grant from The National Institute of Allergy and Infectious Diseases (R01AI02725). 1To whom correspondence may be

  11. Estimating the probability of polyreactive antibodies 4E10 and 2F5 disabling a gp41 trimer after T cell-HIV adhesion.

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    Bin Hu

    2014-01-01

    Full Text Available A few broadly neutralizing antibodies, isolated from HIV-1 infected individuals, recognize epitopes in the membrane proximal external region (MPER of gp41 that are transiently exposed during viral entry. The best characterized, 4E10 and 2F5, are polyreactive, binding to the viral membrane and their epitopes in the MPER. We present a model to calculate, for any antibody concentration, the probability that during the pre-hairpin intermediate, the transient period when the epitopes are first exposed, a bound antibody will disable a trivalent gp41 before fusion is complete. When 4E10 or 2F5 bind to the MPER, a conformational change is induced that results in a stably bound complex. The model predicts that for these antibodies to be effective at neutralization, the time to disable an epitope must be shorter than the time the antibody remains bound in this conformation, about five minutes or less for 4E10 and 2F5. We investigate the role of avidity in neutralization and show that 2F5 IgG, but not 4E10, is much more effective at neutralization than its Fab fragment. We attribute this to 2F5 interacting more stably than 4E10 with the viral membrane. We use the model to elucidate the parameters that determine the ability of these antibodies to disable epitopes and propose an extension of the model to analyze neutralization data. The extended model predicts the dependencies of IC50 for neutralization on the rate constants that characterize antibody binding, the rate of fusion of gp41, and the number of gp41 bridging the virus and target cell at the start of the pre-hairpin intermediate. Analysis of neutralization experiments indicate that only a small number of gp41 bridges must be disabled to prevent fusion. However, the model cannot determine the exact number from neutralization experiments alone.

  12. The current status and challenges in the development of fusion inhibitors as therapeutics for HIV-1 infection.

    Science.gov (United States)

    Tan, Jian Jun; Ma, Xue Ting; Liu, Chang; Zhang, Xiao Yi; Wang, Cun Xin

    2013-01-01

    HIV-1 membrane fusion as a part of the process of viral entry in the target cells is facilitated by gp41 and gp120, which are encoded by Env gene of HIV-1. Based on the structure and the mechanism researches, new treatment options targeting HIV-1 entry process have been proposed. Enfuvirtide, which mimics amino acid sequences of viral envelope glycoprotein gp41, is the first HIV-1 fusion inhibitor approved by FDA. Although it fulfills vital functions by binding to gp41 and abolishing the membrane fusion reaction when used in combination, it could induce drug resistant virus variants. Currently, a number of design and modification schemes have been presented, a large number of prospective fusion peptides have emerged. For these fusion inhibitors, multiple mutations in gp41 have been associated with the loss of susceptibility to agents. This review reported the current developments and innovative designs of HIV-1 membrane fusion inhibitors.

  13. C-Peptide Test

    Science.gov (United States)

    ... Weisenberger, J. (2013 March) Why Does a C-Peptide Test Matter? Diabetes Forecast [On-line information]. Available online at http:// ... Updated). What is c-peptide? What do c-peptide levels mean? Misc.health.diabetes, diabetes FAQ [On-line information from newsgroup]. Available ...

  14. Maturation-induced cloaking of neutralization epitopes on HIV-1 particles.

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    Amanda S Joyner

    2011-09-01

    Full Text Available To become infectious, HIV-1 particles undergo a maturation process involving proteolytic cleavage of the Gag and Gag-Pol polyproteins. Immature particles contain a highly stable spherical Gag lattice and are impaired for fusion with target cells. The fusion impairment is relieved by truncation of the gp41 cytoplasmic tail (CT, indicating that an interaction between the immature viral core and gp41 within the particle represses HIV-1 fusion by an unknown mechanism. We hypothesized that the conformation of Env on the viral surface is regulated allosterically by interactions with the HIV-1 core during particle maturation. To test this, we quantified the binding of a panel of monoclonal antibodies to mature and immature HIV-1 particles by immunofluorescence imaging. Surprisingly, immature particles exhibited markedly enhanced binding of several gp41-specific antibodies, including two that recognize the membrane proximal external region (MPER and neutralize diverse HIV-1 strains. Several of the differences in epitope exposure on mature and immature particles were abolished by truncation of the gp41 CT, thus linking the immature HIV-1 fusion defect with altered Env conformation. Our results suggest that perturbation of fusion-dependent Env conformational changes contributes to the impaired fusion of immature particles. Masking of neutralization-sensitive epitopes during particle maturation may contribute to HIV-1 immune evasion and has practical implications for vaccine strategies targeting the gp41 MPER.

  15. Insulin C-peptide

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003701.htm Insulin C-peptide test To use the sharing features ... a product that is created when the hormone insulin is produced and released into the body. The ...

  16. Map of sequential B cell epitopes of the HIV-1 transmembrane protein using human antibodies as probe

    NARCIS (Netherlands)

    Goudsmit, J.; Meloen, R. H.; Brasseur, R.

    1990-01-01

    Antibodies of individuals infected with the human immunodeficiency virus type 1 (HIV-1) were used to probe the antigenicity of the HIV-1 transmembrane protein of 41 kD (gp41) by antibody-reactive peptide scanning (Pepscan). Eleven distinct sequential antibody-binding sites were defined by testing

  17. Adding an Artificial Tail—Anchor to a Peptide-Based HIV-1 Fusion Inhibitor for Improvement of Its Potency and Resistance Profile

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    Shan Su

    2017-11-01

    Full Text Available Peptides derived from the C-terminal heptad repeat (CHR of human immunodeficiency virus type 1 (HIV-1 envelope protein transmembrane subunit gp41, such as T20 (enfuvirtide, can bind to the N-terminal heptad repeat (NHR of gp41 and block six-helix bundle (6-HB formation, thus inhibiting HIV-1 fusion with the target cell. However, clinical application of T20 is limited because of its low potency and genetic barrier to resistance. HP23, the shortest CHR peptide, exhibits better anti-HIV-1 activity than T20, but the HIV-1 strains with E49K mutations in gp41 will become resistant to it. Here, we modified HP23 by extending its C-terminal sequence using six amino acid residues (E6 and adding IDL (Ile-Asp-Leu to the C-terminus of E6, which is expected to bind to the shallow pocket in the gp41 NHR N-terminal region. The newly designed peptide, designated HP23-E6-IDL, was about 2- to 16-fold more potent than HP23 against a broad spectrum of HIV-1 strains and more than 12-fold more effective against HIV-1 mutants resistant to HP23. These findings suggest that addition of an anchor–tail to the C-terminus of a CHR peptide will allow binding with the pocket in the gp41 NHR that may increase the peptide’s antiviral efficacy and its genetic barrier to resistance.

  18. 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.

  19. Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV

    Science.gov (United States)

    Lim, K.; Ho, J. X.; Keeling, K.; Gilliland, G. L.; Ji, X.; Ruker, F.; Carter, D. C.

    1994-01-01

    The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.

  20. A monocyte chemotaxis inhibiting factor in serum of HIV infected men shares epitopes with the HIV transmembrane protein gp41

    NARCIS (Netherlands)

    Tas, M.; Drexhage, H. A.; Goudsmit, J.

    1988-01-01

    This report describes that gp41, the transmembranous envelope protein of HIV, is able to inhibit monocyte chemotaxis (measured as FMLP-induced polarization). To study the presence of such immunosuppressive HIV env proteins in the circulation of HIV-infected men, fractions were prepared from serum

  1. Solid-state nuclear magnetic resonance (NMR) spectroscopy of human immunodeficiency virus gp41 protein that includes the fusion peptide: NMR detection of recombinant Fgp41 in inclusion bodies in whole bacterial cells and structural characterization of purified and membrane-associated Fgp41.

    Science.gov (United States)

    Vogel, Erica P; Curtis-Fisk, Jaime; Young, Kaitlin M; Weliky, David P

    2011-11-22

    Human immunodeficiency virus (HIV) infection of a host cell begins with fusion of the HIV and host cell membranes and is mediated by the gp41 protein, a single-pass integral membrane protein of HIV. The 175 N-terminal residues make up the ectodomain that lies outside the virus. This work describes the production and characterization of an ectodomain construct containing the 154 N-terminal gp41 residues, including the fusion peptide (FP) that binds to target cell membranes. The Fgp41 sequence was derived from one of the African clade A strains of HIV-1 that have been less studied than European/North American clade B strains. Fgp41 expression at a level of ~100 mg/L of culture was evidenced by an approach that included amino acid type (13)CO and (15)N labeling of recombinant protein and solid-state NMR (SSNMR) spectroscopy of lyophilized whole cells. The approach did not require any protein solubilization or purification and may be a general approach for detection of recombinant protein. The purified Fgp41 yield was ~5 mg/L of culture. SSNMR spectra of membrane-associated Fgp41 showed high helicity for the residues C-terminal of the FP. This was consistent with a "six-helix bundle" (SHB) structure that is the final gp41 state during membrane fusion. This observation and negligible Fgp41-induced vesicle fusion supported a function for SHB gp41 of membrane stabilization and fusion arrest. SSNMR spectra of residues in the membrane-associated FP provided evidence of a mixture of molecular populations with either helical or β-sheet FP conformation. These and earlier SSNMR data strongly support the existence of these populations in the SHB state of membrane-associated gp41. © 2011 American Chemical Society

  2. HIV gp41 engages gC1qR on CD4+ T cells to induce the expression of an NK ligand through the PIP3/H2O2 pathway.

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    Hugues Fausther-Bovendo

    Full Text Available CD4(+ T cell loss is central to HIV pathogenesis. In the initial weeks post-infection, the great majority of dying cells are uninfected CD4(+ T cells. We previously showed that the 3S motif of HIV-1 gp41 induces surface expression of NKp44L, a cellular ligand for an activating NK receptor, on uninfected bystander CD4(+ T cells, rendering them susceptible to autologous NK killing. However, the mechanism of the 3S mediated NKp44L surface expression on CD4(+ T cells remains unknown. Here, using immunoprecipitation, ELISA and blocking antibodies, we demonstrate that the 3S motif of HIV-1 gp41 binds to gC1qR on CD4(+ T cells. We also show that the 3S peptide and two endogenous gC1qR ligands, C1q and HK, each trigger the translocation of pre-existing NKp44L molecules through a signaling cascade that involves sequential activation of PI3K, NADPH oxidase and p190 RhoGAP, and TC10 inactivation. The involvement of PI3K and NADPH oxidase derives from 2D PAGE experiments and the use of PIP3 and H2O2 as well as small molecule inhibitors to respectively induce and inhibit NKp44L surface expression. Using plasmid encoding wild type or mutated form of p190 RhoGAP, we show that 3S mediated NKp44L surface expression on CD4(+ T cells is dependent on p190 RhoGAP. Finally, the role of TC10 in NKp44L surface induction was demonstrated by measuring Rho protein activity following 3S stimulation and using RNA interference. Thus, our results identify gC1qR as a new receptor of HIV-gp41 and demonstrate the signaling cascade it triggers. These findings identify potential mechanisms that new therapeutic strategies could use to prevent the CD4(+ T cell depletion during HIV infection and provide further evidence of a detrimental role played by NK cells in CD4(+ T cell depletion during HIV-1 infection.

  3. Evidence against Extracellular Exposure of a Highly Immunogenic Region in the C-Terminal Domain of the Simian Immunodeficiency Virus gp41 Transmembrane Protein

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    Postler, Thomas S.; Martinez-Navio, José M.; Yuste, Eloísa

    2012-01-01

    The generally accepted model for human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein topology includes a single membrane-spanning domain. An alternate model has been proposed which features multiple membrane-spanning domains. Consistent with the alternate model, a high percentage of HIV-1-infected individuals produce unusually robust antibody responses to a region of envelope, the so-called “Kennedy epitope,” that in the conventional model should be in the cytoplasm. Here we show analogous, robust antibody responses in simian immunodeficiency virus SIVmac239-infected rhesus macaques to a region of SIVmac239 envelope located in the C-terminal domain, which in the conventional model should be inside the cell. Sera from SIV-infected rhesus macaques consistently reacted with overlapping oligopeptides corresponding to a region located within the cytoplasmic domain of gp41 by the generally accepted model, at intensities comparable to those observed for immunodominant areas of the surface component gp120. Rabbit serum raised against this highly immunogenic region (HIR) reacted with SIV envelope in cell surface-staining experiments, as did monoclonal anti-HIR antibodies isolated from an SIVmac239-infected rhesus macaque. However, control experiments demonstrated that this surface staining could be explained in whole or in part by the release of envelope protein from expressing cells into the supernatant and the subsequent attachment to the surfaces of cells in the culture. Serum and monoclonal antibodies directed against the HIR failed to neutralize even the highly neutralization-sensitive strain SIVmac316. Furthermore, a potential N-linked glycosylation site located close to the HIR and postulated to be outside the cell in the alternate model was not glycosylated. An artificially introduced glycosylation site within the HIR was also not utilized for glycosylation. Together, these data support the conventional model of SIV envelope as a type Ia

  4. Induction of HIV neutralizing antibodies against the MPER of the HIV envelope protein by HA/gp41 chimeric protein-based DNA and VLP vaccines.

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    Ye, Ling; Wen, Zhiyuan; Dong, Ke; Wang, Xi; Bu, Zhigao; Zhang, Huizhong; Compans, Richard W; Yang, Chinglai

    2011-01-01

    Several conserved neutralizing epitopes have been identified in the HIV Env protein and among these, the MPER of gp41 has received great attention and is widely recognized as a promising target. However, little success has been achieved in eliciting MPER-specific HIV neutralizing antibodies by a number of different vaccine strategies. We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies. In characterization of the HA/gp41 chimeric protein, we found that by mutating an unpaired Cys residue (Cys-14) in its HA1 subunit to a Ser residue, the modified chimeric protein HA-C14S/gp41 showed increased reactivity to a conformation-sensitive monoclonal antibody against HA and formed more stable trimers in VLPs. On the other hand, HA-C14S/gp41 and HA/gp41 chimeric proteins expressed on the cell surfaces exhibited similar reactivity to monoclonal antibodies 2F5 and 4E10. Immunization of guinea pigs using the HA-C14S/gp41 DNA or VLP vaccines induced antibodies against the HIV gp41 as well as to a peptide corresponding to a segment of MPER at higher levels than immunization by standard HIV VLPs. Further, sera from vaccinated guinea pigs were found to exhibit HIV neutralizing activities. Moreover, sera from guinea pigs vaccinated by HA-C14S/gp41 DNA and VLP vaccines but not the standard HIV VLPs, were found to neutralize HIV pseudovirions containing a SIV-4E10 chimeric Env protein. The virus neutralization could be blocked by a MPER-specific peptide, thus demonstrating induction of MPER-specific HIV neutralizing antibodies by this novel vaccine strategy. These results show that induction of MPER-specific HIV neutralizing antibodies can be achieved through a rationally designed vaccine strategy.

  5. 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.

  6. Immunogenicity of HIV-1LAI gp160 and env peptides in squirrel monkey Saimiri sciureus using alumine and experimental adjuvants.

    Science.gov (United States)

    Perraut, R; Chouteau, P; Moog, C; Bonnemains, B; Kieny, M P

    1996-12-01

    Since the identification of the HIV virus, important advances have been achieved in the definition of potential subunit vaccines. We investigated the immunogenicity of a recombinant gp160 antigen and of two gp41 peptides from HIV-1LAI associated with seven different adjuvant formulations in squirrel monkeys. All animals were immunized twice with gp160 and then with a gp41 peptide using the same formulation. All adjuvants used led to a subsequent antibody response against gp160, and 55% of the animals immunized developed anti-gp160 antibodies that could neutralize the virus in vitro. Specific anti-gp41 antibody response was also observed. Results obtained underlined the key role of the adjuvant formulation in the antibody response against a given part of the immunogen, and indicate that such immunogenicity-related investigation can be carried out conveniently in the squirrel monkey Saimiri sciureus.

  7. Recombinant envelope protein of HIV-1 subtype E as antigen in HIV-1 antibody detection enzyme immunoassay.

    Science.gov (United States)

    Sutthent, Ruengpung; Kanoksinsombat, Chinda; Horthongkham, Navin; Louisirirotchanakul, Suda; Auewarakul, Prasert; Kantakamalakul, Wannee

    2002-06-01

    In order to develop a reliable and inexpensive serodiagnostic method to be used for anti-HIV antibody detection in Thailand, recombinant envelope (TM or gp41 subunit) protein of HIV-1 subtype E was produced from prokaryotic cell (Escherichia coli) as the source of antigen in enzyme immunoassay (TE diagnostic EIA kit). HIV-1 gp41 subunit of subtype E was successfully expressed in E. coli in the form of polyhistidine-tagged proteins, comprising of rgp41A (601 bases N-terminal half of TM or 25kDa) and rgp41B (560 bases C-terminal half of TM or 24 kDa) by using an expression vector, pBAD/His C. The amount of protein, dilution of sera, and anti-human IgG labeled HRP used in the EIA test optimized by a checker board titration of the protein and seropositive or seronegative sera, were 5.0 microg/ml, 1:300, and 1:4,000, respectively. The blinded test evaluation of TE-diagnostic EIA in 500 seropositive and 500 seronegative sera which have been simultaneously tested by two available commercial kits and compared with our TE diagnostic EIA, gave 99.6% sensitivity and specificity. The other known genetic subtypes sera such as subtype A (n=5), B (n=9), C (n=4) and D (n=5) were also positive with this EIA. The estimated manufacturer cost per test of rgp41 based anti-HIV antibody detection EIA or TE-diagnostic EIA was about 15 baht. This recombinant envelope (gp41 or TM) protein from HIV-1, which can be produced in large quantities without any hazards from growing the virus and has lower cost to produce anti-HIV antibody serological diagnostic kit, should be considered as an HIV screening test in Thailand.

  8. Cloaked similarity between HIV-1 and SARS-CoV suggests an anti-SARS strategy

    Directory of Open Access Journals (Sweden)

    Kliger Yossef

    2003-09-01

    Full Text Available Abstract Background Severe acute respiratory syndrome (SARS is a febrile respiratory illness. The disease has been etiologically linked to a novel coronavirus that has been named the SARS-associated coronavirus (SARS-CoV, whose genome was recently sequenced. Since it is a member of the Coronaviridae, its spike protein (S2 is believed to play a central role in viral entry by facilitating fusion between the viral and host cell membranes. The protein responsible for viral-induced membrane fusion of HIV-1 (gp41 differs in length, and has no sequence homology with S2. Results Sequence analysis reveals that the two viral proteins share the sequence motifs that construct their active conformation. These include (1 an N-terminal leucine/isoleucine zipper-like sequence, and (2 a C-terminal heptad repeat located upstream of (3 an aromatic residue-rich region juxtaposed to the (4 transmembrane segment. Conclusions This study points to a similar mode of action for the two viral proteins, suggesting that anti-viral strategy that targets the viral-induced membrane fusion step can be adopted from HIV-1 to SARS-CoV. Recently the FDA approved Enfuvirtide, a synthetic peptide corresponding to the C-terminal heptad repeat of HIV-1 gp41, as an anti-AIDS agent. Enfuvirtide and C34, another anti HIV-1 peptide, exert their inhibitory activity by binding to a leucine/isoleucine zipper-like sequence in gp41, thus inhibiting a conformational change of gp41 required for its activation. We suggest that peptides corresponding to the C-terminal heptad repeat of the S2 protein may serve as inhibitors for SARS-CoV entry.

  9. Induction of HIV neutralizing antibodies against the MPER of the HIV envelope protein by HA/gp41 chimeric protein-based DNA and VLP vaccines

    National Research Council Canada - National Science Library

    Ye, Ling; Wen, Zhiyuan; Dong, Ke; Wang, Xi; Bu, Zhigao; Zhang, Huizhong; Compans, Richard W; Yang, Chinglai

    2011-01-01

    .... We investigated the ability of HA/gp41 chimeric protein-based vaccines, which were designed to enhance the exposure of the MPER in its native conformation, to induce MPER-specific HIV neutralizing antibodies...

  10. Isotype modulates epitope specificity, affinity, and antiviral activities of anti-HIV-1 human broadly neutralizing 2F5 antibody.

    Science.gov (United States)

    Tudor, Daniela; Yu, Huifeng; Maupetit, Julien; Drillet, Anne-Sophie; Bouceba, Tahar; Schwartz-Cornil, Isabelle; Lopalco, Lucia; Tuffery, Pierre; Bomsel, Morgane

    2012-07-31

    The constant heavy chain (CH1) domain affects antibody affinity and fine specificity, challenging the paradigm that only variable regions contribute to antigen binding. To investigate the role of the CH1 domain, we constructed IgA2 from the broadly neutralizing anti-HIV-1 2F5 IgG1, and compared 2F5 IgA2 and IgG binding affinity and functional activities. We found that 2F5 IgA2 bound to the gp41 membrane proximal external region with higher affinity than IgG1. Functionally, compared with IgG1, 2F5 IgA2 more efficiently blocked HIV-1 transcytosis across epithelial cells and CD4(+) cell infection by R5 HIV-1. The 2F5 IgG1 and IgA2 acted synergistically to fully block HIV-1 transfer from Langerhans to autologous CD4(+) T cells and to inhibit CD4(+) T-cell infection. Epitope mapping performed by screening a random peptide library and in silico docking modeling suggested that along with the 2F5 IgG canonical ELDKWA epitope on gp41, the IgG1 recognized an additional 3D-conformational epitope on the gp41 C-helix. In contrast, the IgA2 epitope included a unique conformational motif on the gp41 N-helix. Overall, the CH1 region of 2F5 contributes to shape its epitope specificity, antibody affinity, and functional activities. In the context of sexually transmitted infections such as HIV-1/AIDS, raising a mucosal IgA-based vaccine response should complement an IgG-based vaccine response in blocking HIV-1 transmission.

  11. Isotype modulates epitope specificity, affinity, and antiviral activities of anti–HIV-1 human broadly neutralizing 2F5 antibody

    Science.gov (United States)

    Tudor, Daniela; Yu, Huifeng; Maupetit, Julien; Drillet, Anne-Sophie; Bouceba, Tahar; Schwartz-Cornil, Isabelle; Lopalco, Lucia; Tuffery, Pierre; Bomsel, Morgane

    2012-01-01

    The constant heavy chain (CH1) domain affects antibody affinity and fine specificity, challenging the paradigm that only variable regions contribute to antigen binding. To investigate the role of the CH1 domain, we constructed IgA2 from the broadly neutralizing anti–HIV-1 2F5 IgG1, and compared 2F5 IgA2 and IgG binding affinity and functional activities. We found that 2F5 IgA2 bound to the gp41 membrane proximal external region with higher affinity than IgG1. Functionally, compared with IgG1, 2F5 IgA2 more efficiently blocked HIV-1 transcytosis across epithelial cells and CD4+ cell infection by R5 HIV-1. The 2F5 IgG1 and IgA2 acted synergistically to fully block HIV-1 transfer from Langerhans to autologous CD4+ T cells and to inhibit CD4+ T-cell infection. Epitope mapping performed by screening a random peptide library and in silico docking modeling suggested that along with the 2F5 IgG canonical ELDKWA epitope on gp41, the IgG1 recognized an additional 3D-conformational epitope on the gp41 C-helix. In contrast, the IgA2 epitope included a unique conformational motif on the gp41 N-helix. Overall, the CH1 region of 2F5 contributes to shape its epitope specificity, antibody affinity, and functional activities. In the context of sexually transmitted infections such as HIV-1/AIDS, raising a mucosal IgA-based vaccine response should complement an IgG-based vaccine response in blocking HIV-1 transmission. PMID:22723360

  12. Fertilization competence of the egg-coating envelope is regulated by direct interaction of dicalcin and gp41, the Xenopus laevis ZP3.

    Science.gov (United States)

    Miwa, Naofumi; Ogawa, Motoyuki; Hanaue, Mayu; Takamatsu, Ken

    2015-08-05

    Fertilization begins with species-restricted interaction of sperm and the egg-coating envelope, which includes a three-dimensional meshwork of filaments composed of glycoproteins (called ZP proteins). Growing evidence has unveiled the molecular nature of ZP proteins; however, the structural property conferring fertilization competence to the egg-coating envelope remains unknown. Here, we show the molecular mechanism that mediates direct interaction between dicalcin, a novel fertilization-suppressive ZP protein-associated protein, and gp41, a Xenopus laevis ortholog of mammalian ZP3, and subsequently demonstrate the structural basis of the envelope for fertilization competence. The interactive regions between dicalcin and gp41 comprised five and nine amino acid residues within dicalcin and twenty-three within gp41 [corrected]. Synthetic peptides corresponding to these regions dramatically affected fertilization: treatment with dicalcin- or gp41-derived peptides decreased or increased fertilization rates, respectively. Prior application of these peptides caused distinct alterations in the in vivo lectin-staining pattern of the envelope as well. Transmission electron microscopy analysis revealed that the dicalcin-derived peptide induced the formation of a well-organized meshwork, whereas the gp41-derived peptide caused the formation of a significantly disorganized meshwork. These findings indicated that the fertilization competence of the egg-coating envelope is crucially regulated by the direct interaction between dicalcin and gp41.

  13. The crystal structure of HIV CRF07 B′/C gp41 reveals a hyper-mutant site in the middle of HR2 heptad repeat

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jiansen; Xue, Hailing; Ma, Jing; Liu, Fang [State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China); Zhou, Jianhua [Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001 (China); Shao, Yiming [State Key Laboratory for Infectious Disease Prevention and Control, and National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206 (China); Qiao, Wentao, E-mail: wentaoqiao@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China); Liu, Xinqi, E-mail: liu2008@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2013-11-15

    HIV CRF07 B′/C is a strain circulating mainly in northwest region of China. The gp41 region of CRF07 is derived from a clade C virus. In order to compare the difference of CRF07 gp41 with that of typical clade B virus, we solved the crystal structure of the core region of CRF07 gp41. Compared with clade B gp41, CRF07 gp41 evolved more basic and hydrophilic residues on its helix bundle surface. Based on sequence alignment, a hyper-mutant cluster located in the middle of HR2 heptads repeat was identified. The mutational study of these residues revealed that this site is important in HIV mediated cell–cell fusion and plays critical roles in conformational changes during viral invasion. - Highlights: • We solved the crystal structure of HIV CRF07 gp41 core region. • A hyper-mutant cluster in the middle of HR2 heptads repeat was identified. • The hyper-mutant site is important in HIV-cell fusion. • The model will help to understand the HIV fusion process.

  14. Exploring the membrane fusion mechanism through force-induced disassembly of HIV-1 six-helix bundle

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Kai [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yong [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Lou, Jizhong, E-mail: jlou@ibp.ac.cn [Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Beijing Key Laboratory of Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-05-13

    Enveloped virus, such as HIV-1, employs membrane fusion mechanism to invade into host cell. HIV-1 gp41 ectodomain uses six-helix bundle configuration to accomplish this process. Using molecular dynamic simulations, we confirmed the stability of this six-helix bundle by showing high occupancy of hydrogen bonds and hydrophobic interactions. Key residues and interactions important for the bundle integration were characterized by force-induced unfolding simulations of six-helix bundle, exhibiting the collapse order of these groups of interactions. Moreover, our results in some way concerted with a previous theory that the formation of coiled-coil choose a route which involved cooperative interactions between the N-terminal and C-terminal helix. -- Highlights: •Unfolding of HIV-1 gp41 six-helix bundle is studied by molecular dynamics simulations. •Specific interactions responsible for the stability of HIV-1 envelope post-fusion conformation were identified. •The gp41 six-helix bundle transition inducing membrane fusion might be a cooperative process of the three subunits.

  15. GB Virus Type C Envelope Protein E2 Elicits Antibodies That React with a Cellular Antigen on HIV-1 Particles and Neutralize Diverse HIV-1 Isolates

    Science.gov (United States)

    Mohr, Emma L.; Xiang, Jinhua; McLinden, James H.; Kaufman, Thomas M.; Chang, Qing; Montefiori, David C.; Klinzman, Donna; Stapleton, Jack T.

    2012-01-01

    Broadly neutralizing Abs to HIV-1 are well described; however, identification of Ags that elicit these Abs has proven difficult. Persistent infection with GB virus type C (GBV-C) is associated with prolonged survival in HIV-1–infected individuals, and among those without HIV-1 viremia, the presence of Ab to GBV-C glycoprotein E2 is also associated with survival. GBV-C E2 protein inhibits HIV-1 entry, and an antigenic peptide within E2 interferes with gp41-induced membrane perturbations in vitro, suggesting the possibility of structural mimicry between GBV-C E2 protein and HIV-1 particles. Naturally occurring human and experimentally induced GBV-C E2 Abs were examined for their ability to neutralize infectious HIV-1 particles and HIV-1–enveloped pseudovirus particles. All GBV-C E2 Abs neutralized diverse isolates of HIV-1 with the exception of rabbit anti-peptide Abs raised against a synthetic GBV-C E2 peptide. Rabbit anti–GBV-C E2 Abs neutralized HIV-1–pseudotyped retrovirus particles but not HIV-1–pseudotyped vesicular stomatitis virus particles, and E2 Abs immune-precipitated HIV-1 gag particles containing the vesicular stomatitis virus type G envelope, HIV-1 envelope, GBV-C envelope, or no viral envelope. The Abs did not neutralize or immune-precipitate mumps or yellow fever viruses. Rabbit GBV-C E2 Abs inhibited HIV attachment to cells but did not inhibit entry following attachment. Taken together, these data indicate that the GBV-C E2 protein has a structural motif that elicits Abs that cross-react with a cellular Ag present on retrovirus particles, independent of HIV-1 envelope glycoproteins. The data provide evidence that a heterologous viral protein can induce HIV-1–neutralizing Abs. PMID:20826757

  16. Anti-HIV double variable domain immunoglobulins binding both gp41 and gp120 for targeted delivery of immunoconjugates.

    Directory of Open Access Journals (Sweden)

    Ryan B Craig

    Full Text Available BACKGROUND: Anti-HIV immunoconjugates targeted to the HIV envelope protein may be used to eradicate the latent reservoir of HIV infection using activate-and-purge protocols. Previous studies have identified the two target epitopes most effective for the delivery of cytotoxic immunoconjugates the CD4-binding site of gp120, and the hairpin loop of gp41. Here we construct and test tetravalent double variable domain immunoglobulin molecules (DVD-Igs that bind to both epitopes. METHODS: Synthetic genes that encode DVD-Igs utilizing V-domains derived from human anti-gp120 and anti-gp41 Abs were designed and expressed in 293F cells. A series of constructs tested different inter-V-linker domains and orientations of the two V domains. Antibodies were tested for binding to recombinant Ag and native Env expressed on infected cells, for neutralization of infectious HIV, and for their ability to deliver cytotoxic immunoconjugates to infected cells. FINDINGS: The outer V-domain was the major determinant of binding and functional activity of the DVD-Ig. Function of the inner V-domain and bifunctional binding required at least 15 AA in the inter-V-domain linker. A molecular model showing the spatial orientation of the two epitopes is consistent with this observation. Linkers that incorporated helical domains (A[EAAAK](nA resulted in more effective DVD-Igs than those based solely on flexible domains ([GGGGS](n. In general, the DVD-Igs outperformed the less effective parental antibody and equaled the activity of the more effective. The ability of the DVD-Igs to deliver cytotoxic immunoconjugates in the absence of soluble CD4 was improved over that of either parent. CONCLUSIONS: DVD-Igs can be designed that bind to both gp120 and gp41 on the HIV envelope. DVD-Igs are effective in delivering cytotoxic immunoconjugates. The optimal design of these DVD-Igs, in which both domains are fully functional, has not yet been achieved.

  17. HIV-1 Structural Proteins Serve as PAMPs for TLR2 Heterodimers Significantly Increasing Infection and Innate Immune Activation.

    Science.gov (United States)

    Henrick, Bethany M; Yao, Xiao-Dan; Rosenthal, Kenneth Lee

    2015-01-01

    Immune activation is critical to HIV infection and pathogenesis; however, our understanding of HIV innate immune activation remains incomplete. Recently we demonstrated that soluble TLR2 (sTLR2) physically inhibited HIV-induced NFκB activation and inflammation, as well as HIV-1 infection. In light of these findings, we hypothesized that HIV-1 structural proteins may serve as pathogen-associated molecular patterns (PAMPs) for cellular TLR2 heterodimers. These studies made use of primary human T cells and TZMbl cells stably transformed to express TLR2 (TZMbl-2). Our results demonstrated that cells expressing TLR2 showed significantly increased proviral DNA compared to cells lacking TLR2, and mechanistically this may be due to a TLR2-mediated increased CCR5 expression. Importantly, we show that HIV-1 structural proteins, p17, p24, and gp41, act as viral PAMPs signaling through TLR2 and its heterodimers leading to significantly increased immune activation via the NFκB signaling pathway. Using co-immunoprecipitation and a dot blot method, we demonstrated direct protein interactions between these viral PAMPs and TLR2, while only p17 and gp41 bound to TLR1. Specifically, TLR2/1 heterodimer recognized p17 and gp41, while p24 lead to immune activation through TLR2/6. These results were confirmed using TLR2/1 siRNA knock down assays which ablated p17 and gp41-induced cellular activation and through studies of HEK293 cells expressing selected TLRs. Interestingly, our results show in the absence of TLR6, p24 bound to TLR2 and blocked p17 and gp41-induced activation, thus providing a novel mechanism by which HIV-1 can manipulate innate sensing. Taken together, our results identified, for the first time, novel HIV-1 PAMPs that play a role in TLR2-mediated cellular activation and increased proviral DNA. These findings have important implications for our fundamental understanding of HIV-1 immune activation and pathogenesis, as well as HIV-1 vaccine development.

  18. Glycosylation of gp41 of simian immunodeficiency virus shields epitopes that can be targets for neutralizing antibodies.

    Science.gov (United States)

    Yuste, Eloìsa; Bixby, Jacqueline; Lifson, Jeffrey; Sato, Shuji; Johnson, Welkin; Desrosiers, Ronald

    2008-12-01

    Human immunodeficiency virus type 1 and simian immunodeficiency virus possess three closely spaced, highly conserved sites for N-linked carbohydrate attachment in the extracellular domain of the transmembrane protein gp41. We infected rhesus monkeys with a variant of cloned SIVmac239 lacking the second and third sites or with a variant strain lacking all three of SIVmac239's glycosylation sites in gp41. For each mutation, asparagine (N) in the canonical N-X-S/T recognition sequence for carbohydrate attachment was changed to the structurally similar glutamine such that two nucleotide changes would be required for a reversion of the mutated codon. By 16 weeks, experimentally infected monkeys made antibodies that neutralized the mutant viruses to high titers. Such antibodies were not observed in monkeys infected with the parental virus. Thus, new specificities were revealed as a result of the carbohydrate attachment mutations, and antibodies of these specificities had neutralizing activity. Unlike monkeys infected with the parental virus, monkeys infected with the mutant viruses made antibodies that reacted with peptides corresponding to the sequences in this region. Furthermore, there was strong selective pressure for the emergence of variant sequences in this region during the course of infection. By analyzing the neutralization profiles of sequence variants, we were able to define three mutations (Q625R, K631N, and Q634H) in the region of the glycosylation site mutations that conferred resistance to neutralization by plasma from the monkeys infected with mutant virus. Based on the reactivity of antibodies to peptides in this region and the colocalization of neutralization escape mutations, we conclude that N-linked carbohydrates in the ectodomain of the transmembrane protein shield underlying epitopes that would otherwise be the direct targets of neutralizing antibodies.

  19. Efficient Fusion at Neutral pH by Human Immunodeficiency Virus gp41 Trimers containing the Fusion Peptide and Transmembrane Domain.

    Science.gov (United States)

    Liang, Shuang; Ratnayake, Punsisi; Keinath, Craig; Jia, Lihui; Wolfe, Robert; Ranaweera, Ahinsa; Weliky, David P

    2018-01-18

    Human immunodeficiency virus (HIV) is membrane-enveloped and an initial infection step is joining/fusion of viral and cell membranes. This step is catalyzed by gp41 which is a single-pass integral viral membrane protein. The protein contains a ~170-residue ectodomain located outside the virus that is important for fusion, and includes the fusion peptide (FP), N-helix, loop, C-helix, and viral membrane-proximal external region (MPER). The virion initially has non-covalent complexes between three gp41 ectodomains and three gp120 proteins. A gp120 contains ~500-residues and functions to identify target T-cells and macrophages via binding to specific protein receptors of the target cell membrane. Gp120 moves away from the gp41 ectodomain, and the ectodomain is thought to bind to the target cell membrane and mediate membrane fusion. The secondary and tertiary structures of the ectodomain are different in the initial complex with gp120 and the final state without gp120. There isn't yet imaging of gp41 during fusion, so the temporal relationship between the gp41 and membrane structures isn't known. The present study describes biophysical and functional characterization of large gp41 constructs that include the ectodomain and transmembrane domain (TM). Significant fusion is observed of both neutral and anionic vesicles at neutral pH which reflects the expected conditions of HIV/cell fusion. Fusion is enhanced by the FP, which in HIV/cell fusion likely contacts the host membrane, and the MPER and TM, which respectively interfacially contact and traverse the HIV membrane. Initial contact with vesicles is made by protein trimers which are in a native oligomeric state that reflects the initial complex with gp120, and also is commonly observed for the ectodomain without gp120. Circular dichroism data support helical structure for the N-helix, C-helix, and MPER, and non-helical structure for the FP and loop. Distributions of monomer, trimer, and hexamer states are observed by

  20. Identification of autoantigens recognized by the 2F5 and 4E10 broadly neutralizing HIV-1 antibodies

    Science.gov (United States)

    Yang, Guang; Holl, T. Matt; Liu, Yang; Li, Yi; Lu, Xiaozhi; Nicely, Nathan I.; Kepler, Thomas B.; Alam, S. Munir; Liao, Hua-Xin; Cain, Derek W.; Spicer, Leonard; VandeBerg, John L.; Haynes, Barton F.

    2013-01-01

    Many human monoclonal antibodies that neutralize multiple clades of HIV-1 are polyreactive and bind avidly to mammalian autoantigens. Indeed, the generation of neutralizing antibodies to the 2F5 and 4E10 epitopes of HIV-1 gp41 in man may be proscribed by immune tolerance because mice expressing the VH and VL regions of 2F5 have a block in B cell development that is characteristic of central tolerance. This developmental blockade implies the presence of tolerizing autoantigens that are mimicked by the membrane-proximal external region of HIV-1 gp41. We identify human kynureninase (KYNU) and splicing factor 3b subunit 3 (SF3B3) as the primary conserved, vertebrate self-antigens recognized by the 2F5 and 4E10 antibodies, respectively. 2F5 binds the H4 domain of KYNU which contains the complete 2F5 linear epitope (ELDKWA). 4E10 recognizes an epitope of SF3B3 that is strongly dependent on hydrophobic interactions. Opossums carry a rare KYNU H4 domain that abolishes 2F5 binding, but they retain the SF3B3 4E10 epitope. Immunization of opossums with HIV-1 gp140 induced extraordinary titers of serum antibody to the 2F5 ELDKWA epitope but little or nothing to the 4E10 determinant. Identification of structural motifs shared by vertebrates and HIV-1 provides direct evidence that immunological tolerance can impair humoral responses to HIV-1. PMID:23359068

  1. Transplanting supersites of HIV-1 vulnerability.

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    Tongqing Zhou

    Full Text Available One strategy for isolating or eliciting antibodies against a specific target region on the envelope glycoprotein trimer (Env of the human immunodeficiency virus type 1 (HIV-1 involves the creation of site transplants, which present the target region on a heterologous protein scaffold with preserved antibody-binding properties. If the target region is a supersite of HIV-1 vulnerability, recognized by a collection of broadly neutralizing antibodies, this strategy affords the creation of "supersite transplants", capable of binding (and potentially eliciting antibodies similar to the template collection of effective antibodies. Here we transplant three supersites of HIV-1 vulnerability, each targeted by effective neutralizing antibodies from multiple donors. To implement our strategy, we chose a single representative antibody against each of the target supersites: antibody 10E8, which recognizes the membrane-proximal external region (MPER on the HIV-1 gp41 glycoprotein; antibody PG9, which recognizes variable regions one and two (V1V2 on the HIV-1 gp120 glycoprotein; and antibody PGT128 which recognizes a glycopeptide supersite in variable region 3 (glycan V3 on gp120. We used a structural alignment algorithm to identify suitable acceptor proteins, and then designed, expressed, and tested antigenically over 100-supersite transplants in a 96-well microtiter-plate format. The majority of the supersite transplants failed to maintain the antigenic properties of their respective template supersite. However, seven of the glycan V3-supersite transplants exhibited nanomolar affinity to effective neutralizing antibodies from at least three donors and recapitulated the mannose9-N-linked glycan requirement of the template supersite. The binding of these transplants could be further enhanced by placement into self-assembling nanoparticles. Essential elements of the glycan V3 supersite, embodied by as few as 3 N-linked glycans and ∼ 25 Env residues, can be

  2. HLA-C increases HIV-1 infectivity and is associated with gp120

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    Beretta Alberto

    2008-08-01

    Full Text Available Abstract Background A recently identified genetic polymorphism located in the 5' region of the HLA-C gene is associated with individual variations in HIV-1 viral load and with differences in HLA-C expression levels. HLA-C has the potential to restrict HIV-1 by presenting epitopes to cytotoxic T cells but it is also a potent inhibitor of NK cells. In addition, HLA-C molecules incorporated within the HIV-1 envelope have been shown to bind to the envelope glycoprotein gp120 and enhance viral infectivity. We investigated this last property in cell fusion assays where the expression of HLA-C was silenced by small interfering RNA sequences. Syncytia formation was analyzed by co-cultivating cell lines expressing HIV-1 gp120/gp41 from different laboratory and primary isolates with target cells expressing different HIV-1 co-receptors. Virus infectivity was analyzed using pseudoviruses. Molecular complexes generated during cell fusion (fusion complexes were purified and analyzed for their HLA-C content. Results HLA-C positive cells co-expressing HIV-1 gp120/gp41 fused more rapidly and produced larger syncytia than HLA-C negative cells. Transient transfection of gp120/gp41 from different primary isolates in HLA-C positive cells resulted in a significant cell fusion increase. Fusion efficiency was reduced in HLA-C silenced cells compared to non-silenced cells when co-cultivated with different target cell lines expressing HIV-1 co-receptors. Similarly, pseudoviruses produced from HLA-C silenced cells were significantly less infectious. HLA-C was co-purified with gp120 from cells before and after fusion and was associated with the fusion complex. Conclusion Virionic HLA-C molecules associate to Env and increase the infectivity of both R5 and X4 viruses. Genetic polymorphisms associated to variations in HLA-C expression levels may therefore influence the individual viral set point not only by means of a regulation of the virus-specific immune response but also

  3. Gp120 on HIV-1 Virions Lacks O-Linked Carbohydrate.

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    Elizabeth Stansell

    Full Text Available As HIV-1-encoded envelope protein traverses the secretory pathway, it may be modified with N- and O-linked carbohydrate. When the gp120s of HIV-1 NL4-3, HIV-1 YU2, HIV-1 Bal, HIV-1 JRFL, and HIV-1 JRCSF were expressed as secreted proteins, the threonine at consensus position 499 was found to be O-glycosylated. For SIVmac239, the corresponding threonine was also glycosylated when gp120 was recombinantly expressed. Similarly-positioned, highly-conserved threonines in the influenza A virus H1N1 HA1 and H5N1 HA1 envelope proteins were also found to carry O-glycans when expressed as secreted proteins. In all cases, the threonines were modified predominantly with disialylated core 1 glycans, together with related core 1 and core 2 structures. Secreted HIV-1 gp140 was modified to a lesser extent with mainly monosialylated core 1 O-glycans, suggesting that the ectodomain of the gp41 transmembrane component may limit the accessibility of Thr499 to glycosyltransferases. In striking contrast to these findings, gp120 on purified virions of HIV-1 Bal and SIV CP-MAC lacked any detectable O-glycosylation of the C-terminal threonine. Our results indicate the absence of O-linked carbohydrates on Thr499 as it exists on the surface of virions and suggest caution in the interpretation of analyses of post-translational modifications that utilize recombinant forms of envelope protein.

  4. Kinetics of interaction of HIV fusion protein (gp41) with lipid membranes studied by real-time AFM imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bitler, Arkady, E-mail: arkady.bitler@weizmann.ac.il [Department of Chemical Research Support (Israel); Lev, Naama; Fridmann-Sirkis, Yael; Blank, Lior [Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel); Cohen, Sidney R. [Department of Chemical Research Support (Israel); Shai, Yechiel [Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel)

    2010-05-15

    One of the most important steps in the process of viral infection is a fusion between cell membrane and virus, which is mediated by the viral envelope glycoprotein. The study of activity of the glycoprotein in the post-fusion state is important for understanding the progression of infection. Here we present a first real-time kinetic study of the activity of gp41 (the viral envelope glycoprotein of human immunodeficiency virus-HIV) and its two mutants in the post-fusion state with nanometer resolution by atomic force microscopy (AFM). Tracking the changes in the phosphatidylcholine (PC) and phosphatidylcholine-phosphatidylserine (PC:PS) membrane integrity over one hour by a set of AFM images revealed differences in the interaction of the three types of protein with zwitterionic and negatively charged membranes. A quantitative analysis of the slow kinetics of hole formation in the negatively charged lipid bilayer is presented. Specifically, analysis of the rate of roughness change for the three types of proteins suggests that they exhibit different types of kinetic behavior.

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

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    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

  6. Chimeric Cyanovirin-MPER Recombinantly Engineered Proteins Cause Cell-Free Virolysis of HIV-1

    OpenAIRE

    Contarino, Mark; Bastian, Arangassery R.; Kalyana Sundaram, Ramalingam Venkat; McFadden, Karyn; Duffy, Caitlin; Gangupomu, Vamshi; Baker, Michelle; Abrams, Cameron; Chaiken, Irwin

    2013-01-01

    Human immunodeficiency virus (HIV) is the primary etiologic agent responsible for the AIDS pandemic. In this work, we used a chimeric recombinant protein strategy to test the possibility of irreversibly destroying the HIV-1 virion using an agent that simultaneously binds the Env protein and viral membrane. We constructed a fusion of the lectin cyanovirin-N (CVN) and the gp41 membrane-proximal external region (MPER) peptide with a variable-length (Gly4Ser)x linker (where x is 4 or 8) between t...

  7. 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.

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    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.

  8. Resistance of Human Immunodeficiency Virus Type 1 to a Third-Generation Fusion Inhibitor Requires Multiple Mutations in gp41 and Is Accompanied by a Dramatic Loss of gp41 Function

    NARCIS (Netherlands)

    Eggink, Dirk; Bontjer, Ilja; Langedijk, Johannes P. M.; Berkhout, Ben; Sanders, Rogier W.

    2011-01-01

    HIV-1 entry into target cells requires the fusion of viral and cellular membranes. This process is an attractive target for therapeutic intervention, and a first-generation fusion inhibitor, T20 (Enfuvirtide; Fuzeon), was approved for clinical use in 2003. Second-generation (T1249) and

  9. Psychoneuroimmunology and HIV-1.

    Science.gov (United States)

    Antoni, Michael H.; And Others

    1990-01-01

    Presents evidence describing benefits of behavioral interventions such as aerobic exercise training on both psychological and immunological functioning among high risk human immunodeficiency virus-Type 1 (HIV-1) seronegative and very early stage seropositive homosexual men. HIV-1 infection is cast as chronic disease for which early…

  10. HIV-1 envelope glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Serotyping and genotyping of HIV-1 infection in residents of Khayelitsha, Cape Town, South Africa.

    Science.gov (United States)

    Jacobs, G B; de Beer, C; Fincham, J E; Adams, V; Dhansay, M A; van Rensburg, E Janse; Engelbrecht, S

    2006-12-01

    It is estimated that between 5.5 and 6.1 million people are infected with HIV/acquired immunodeficiency syndrome (AIDS) in South Africa, with subtype C responsible for the majority of these infections. The Khayelitsha suburb of Cape Town has one of the highest HIV prevalence rates in South Africa. Overcrowding combined with unemployment and crime in parts of the area perpetuates high-risk sexual behavior, which increases exposure to infection by HIV. Against this background, the objective of this study was to characterize HIV-1 in residents confirmed to be seropositive. Serotyping was performed through a competitive enzyme-linked immunosorbent assay (cPEIA). Genotyping methods included RNA isolation followed by RT-PCR and sequencing of the gag p24, env gp41 immunodominant region (IDR), and env gp120 V3 genome regions of HIV-1. With the exception of a possible C/D recombinant strain, all HIV-1 strains were characterized as HIV-1 group M subtype C. One individual was shown to harbor multiple strains of HIV-1 subtype C. In Southern Africa, the focus has been to develop a subtype C candidate vaccine, as this is the major subtype found in this geographical area. Therefore, the spread of HIV-1 and its recombinant strains needs to be monitored closely. (c) 2006 Wiley-Liss, Inc.

  12. Immunising with the transmembrane envelope proteins of different retroviruses including HIV-1

    Science.gov (United States)

    Denner, Joachim

    2013-01-01

    The induction of neutralizing antibodies is a promising way to prevent retrovirus infections. Neutralizing antibodies are mainly directed against the envelope proteins, which consist of two molecules, the surface envelope (SU) protein and the transmembrane envelope (TM) protein. Antibodies broadly neutralizing the human immunodeficiencvy virus-1 (HIV-1) and binding to the TM protein gp41 of the virus have been isolated from infected individuals. Their epitopes are located in the membrane proximal external region (MPER). Since there are difficulties to induce such neutralizing antibodies as basis for an effective AIDS vaccine, we performed a comparative analysis immunising with the TM proteins of different viruses from the family Retroviridae. Both subfamilies, the Orthoretrovirinae and the Spumaretrovirinae were included. In this study, the TM proteins of three gammaretroviruses including (1) the porcine endogenous retrovirus (PERV), (2) the Koala retrovirus (KoRV), (3) the feline leukemia virus (FeLV), of two lentiviruses, HIV-1, HIV-2, and of two spumaviruses, the feline foamy virus (FFV) and the primate foamy virus (PFV) were used for immunisation. Whereas in all immunisation studies binding antibodies were induced, neutralizing antibodies were only found in the case of the gammaretroviruses. The induced antibodies were directed against the MPER and the fusion peptide proximal region (FPPR) of their TM proteins; however only the antibodies against the MPER were neutralizing. Most importantly, the epitopes in the MPER were localized in the same position as the epitopes of the antibodies broadly neutralizing HIV-1 in the TM protein gp41 of HIV-1, indicating that the MPER is an effective target for the neutralization of retroviruses. PMID:23249763

  13. Different pattern of immunoglobulin gene usage by HIV-1 compared to non-HIV-1 antibodies derived from the same infected subject.

    Science.gov (United States)

    Li, Liuzhe; Wang, Xiao-Hong; Banerjee, Sagarika; Volsky, Barbara; Williams, Constance; Virland, Diana; Nadas, Arthur; Seaman, Michael S; Chen, Xuemin; Spearman, Paul; Zolla-Pazner, Susan; Gorny, Miroslaw K

    2012-01-01

    A biased usage of immunoglobulin (Ig) genes is observed in human anti-HIV-1 monoclonal antibodies (mAbs) resulting probably from compensation to reduced usage of the VH3 family genes, while the other alternative suggests that this bias usage is due to antigen requirements. If the antigen structure is responsible for the preferential usage of particular Ig genes, it may have certain implications for HIV vaccine development by the targeting of particular Ig gene-encoded B cell receptors to induce neutralizing anti-HIV-1 antibodies. To address this issue, we have produced HIV-1 specific and non-HIV-1 mAbs from an infected individual and analyzed the Ig gene usage. Green-fluorescence labeled virus-like particles (VLP) expressing HIV-1 envelope (Env) proteins of JRFL and BaL and control VLPs (without Env) were used to select single B cells for the production of 68 recombinant mAbs. Ten of these mAbs were HIV-1 Env specific with neutralizing activity against V3 and the CD4 binding site, as well as non-neutralizing mAbs to gp41. The remaining 58 mAbs were non-HIV-1 Env mAbs with undefined specificities. Analysis revealed that biased usage of Ig genes was restricted only to anti-HIV-1 but not to non-HIV-1 mAbs. The VH1 family genes were dominantly used, followed by VH3, VH4, and VH5 among anti-HIV-1 mAbs, while non-HIV-1 specific mAbs preferentially used VH3 family genes, followed by VH4, VH1 and VH5 families in a pattern identical to Abs derived from healthy individuals. This observation suggests that the biased usage of Ig genes by anti-HIV-1 mAbs is driven by structural requirements of the virus antigens rather than by compensation to any depletion of VH3 B cells due to autoreactive mechanisms, according to the gp120 superantigen hypothesis.

  14. Different pattern of immunoglobulin gene usage by HIV-1 compared to non-HIV-1 antibodies derived from the same infected subject.

    Directory of Open Access Journals (Sweden)

    Liuzhe Li

    Full Text Available A biased usage of immunoglobulin (Ig genes is observed in human anti-HIV-1 monoclonal antibodies (mAbs resulting probably from compensation to reduced usage of the VH3 family genes, while the other alternative suggests that this bias usage is due to antigen requirements. If the antigen structure is responsible for the preferential usage of particular Ig genes, it may have certain implications for HIV vaccine development by the targeting of particular Ig gene-encoded B cell receptors to induce neutralizing anti-HIV-1 antibodies. To address this issue, we have produced HIV-1 specific and non-HIV-1 mAbs from an infected individual and analyzed the Ig gene usage. Green-fluorescence labeled virus-like particles (VLP expressing HIV-1 envelope (Env proteins of JRFL and BaL and control VLPs (without Env were used to select single B cells for the production of 68 recombinant mAbs. Ten of these mAbs were HIV-1 Env specific with neutralizing activity against V3 and the CD4 binding site, as well as non-neutralizing mAbs to gp41. The remaining 58 mAbs were non-HIV-1 Env mAbs with undefined specificities. Analysis revealed that biased usage of Ig genes was restricted only to anti-HIV-1 but not to non-HIV-1 mAbs. The VH1 family genes were dominantly used, followed by VH3, VH4, and VH5 among anti-HIV-1 mAbs, while non-HIV-1 specific mAbs preferentially used VH3 family genes, followed by VH4, VH1 and VH5 families in a pattern identical to Abs derived from healthy individuals. This observation suggests that the biased usage of Ig genes by anti-HIV-1 mAbs is driven by structural requirements of the virus antigens rather than by compensation to any depletion of VH3 B cells due to autoreactive mechanisms, according to the gp120 superantigen hypothesis.

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

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    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.

  16. Fasting plasma C-peptide, glucagon stimulated plasma C-peptide, and urinary C-peptide in relation to clinical type of diabetes

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Faber, O K

    1989-01-01

    Many patients with Type 2 (non-insulin-dependent) diabetes mellitus are treated with insulin in order to control hyperglycaemia. We studied fasting plasma C-peptide, glucagon stimulated plasma C-peptide, and 24 h urinary C-peptide in relation to clinical type of diabetes in 132 insulin treated......) weight below 110% of ideal weight of the same age and sex. Eighty patients were classified as Type 1 and 52 as Type 2 diabetic subjects. A second classification of patients into 6 C-peptide classes was then performed. Class I consisted of patients without islet B-cell function. Class II-VI had preserved...... islet B-cell function and were separated according to the 20%, 40%, 60% and 80% C-peptide percentiles. The two classifications of patients were compared by calculating the prevalence of clinical Type 1 and Type 2 diabetes in each of the C-peptide classes. This analysis showed that patients...

  17. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses

    Science.gov (United States)

    McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T.; Dennison, S. Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S. Munir; Haynes, Barton F.; Tomaras, Georgia D.

    2016-01-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  18. 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

  19. HIV reverse transcriptase inhibiting antibodies detected by a new technique: relation to p24 and gp41 antibodies, HIV antigenemia and clinical variables.

    Science.gov (United States)

    Neumüller, M; Karlsson, A; Lennerstrand, J; Källander, C F; Holmberg, V; Långström-Persson, U; Thorstensson, R; Sandström, E; Gronowitz, J S

    1991-05-01

    A new assay for HIV reverse transcriptase activity inhibiting antibodies (RTI-ab) was used for the analysis of a large collection of sera sampled before and after confirmation of HIV infection. In this assay HIV-RT was preincubated with diluted serum, after which residual RT activity was determined by a technique using a template coupled to macrobeads and 125I-lodo-deoxyuridine-triphosphate as the tracer-substrate. Of the 936 sera analysed, 818 were found positive for RTI-ab, and 824 were positive in Western blot (Wb). The prevalence of RTI-ab compared to Wb was therefore 99.3%. The corresponding figure for 930 sera analysed for envelope-ab, i.e., gp41-ab, was 823 positive, and of these 930 sera 815 were Wb positive, giving a comparative prevalence of 101%. In contrast, only 678 samples of 993 analyzed for core ab, i.e., p24, were positive, giving a prevalence of 77.0% as 880 of these samples were Wb positive. Thus, RTI-ab was as prevalent as gp41-ab, and although the analyses of RTI-ab amounts in different stages showed decreasing levels in stage IV compared to stages II or III, all of the sera except 1 were found positive in stages III and IV. Further, it was found that both the few RTI-ab negative samples in stage II and the few RTI-ab positive samples among Wb negative sera were sampled in connection with seroconversion. The specificity of the RTI-ab assay was 100% in a test of 200 serum samples from HIV negative blood donors. It was concluded that RTI-ab analyses can be made highly sensitive and specific and useful for studies of HIV infection.

  20. CD4-gp120 interaction interface - a gateway for HIV-1 infection in human: molecular network, modeling and docking studies.

    Science.gov (United States)

    Pandey, Deeksha; Podder, Avijit; Pandit, Mansi; Latha, Narayanan

    2017-09-01

    The major causative agent for Acquired Immune Deficiency Syndrome (AIDS) is Human Immunodeficiency Virus-1 (HIV-1). HIV-1 is a predominant subtype of HIV which counts on human cellular mechanism virtually in every aspect of its life cycle. Binding of viral envelope glycoprotein-gp120 with human cell surface CD4 receptor triggers the early infection stage of HIV-1. This study focuses on the interaction interface between these two proteins that play a crucial role for viral infectivity. The CD4-gp120 interaction interface has been studied through a comprehensive protein-protein interaction network (PPIN) analysis and highlighted as a useful step towards identifying potential therapeutic drug targets against HIV-1 infection. We prioritized gp41, Nef and Tat proteins of HIV-1 as valuable drug targets at early stage of viral infection. Lack of crystal structure has made it difficult to understand the biological implication of these proteins during disease progression. Here, computational protein modeling techniques and molecular dynamics simulations were performed to generate three-dimensional models of these targets. Besides, molecular docking was initiated to determine the desirability of these target proteins for already available HIV-1 specific drugs which indicates the usefulness of these protein structures to identify an effective drug combination therapy against AIDS.

  1. Recombinant viruses initiated the early HIV-1 epidemic in Burkina Faso.

    Directory of Open Access Journals (Sweden)

    Peter N Fonjungo

    Full Text Available We analyzed genetic diversity and phylogenetic relationships among 124 HIV-1 and 19 HIV-2 strains in sera collected in 1986 from patients of the state hospital in Ouagadougou, Burkina Faso. Phylogenetic analysis of the HIV-1 env gp41 region of 65 sequences characterized 37 (56.9% as CRF06_cpx strains, 25 (38.5% as CRF02_AG, 2 (3.1% as CRF09_cpx, and 1 (1.5% as subtype A. Similarly, phylogenetic analysis of the protease (PR gene region of 73 sequences identified 52 (71.2% as CRF06_cpx, 15 (20.5% as CRF02_AG, 5 (6.8% as subtype A, and 1 (1.4% was a unique strain that clustered along the B/D lineage but basal to the node connecting the two lineages. HIV-2 PR or integrase (INT groups A (n = 17 [89.5%] and B (n = 2 [10.5%] were found in both monotypic (n = 11 and heterotypic HIV-1/HIV-2 (n = 8 infections, with few HIV-2 group B infections. Based on limited available sampling, evidence suggests two recombinant viruses, CRF06_cpx and CRF02_AG, appear to have driven the beginning of the mid-1980s HIV-1 epidemic in Burkina Faso.

  2. Bifunctional recombinant fusion proteins for rapid detection of antibodies to both HIV-1 and HIV-2 in whole blood

    Directory of Open Access Journals (Sweden)

    Chaudhary Vijay K

    2006-09-01

    Full Text Available Abstract Background Availability of accurate diagnostic tests has been helpful in curtailing the spread of HIV infection. Among these, simple, point of care, inexpensive tests which require only a drop of blood from finger-prick and give reliable results within minutes are a must for expansion of testing services and for reaching mobile and marginalised populations. Such tests will not only be a boon for the infrastructure-starved developing and underdeveloped countries but will also be extremely useful in developed countries where post-testing compliance is a major problem. Our laboratory has been involved in developing reagents for heamagglutination-based rapid detection of antibodies to HIV in whole blood using recombinant molecules specific for either HIV-1 or HIV-2. Since it is not required of a screening test to differentially detect HIV and HIV-2, it would useful to create a single molecule capable of simultaneous detection of both HIV-1 and HIV-2 in a drop of blood. Results The present paper describes designing, high-level expression and large-scale purification of new molecules comprising recombinant anti-RBC Fab fused to immunodominant regions of envelope sequences from both gp41 of HIV-1 and gp36 of HIV-2. These immunodominant regions of HIV envelope contain cysteine residues, which make disulfide bond and can interfere with the assembly of light chain and heavy chain fragment to make Fab molecule in vitro. To circumvent this problem, a series of fusion proteins having different combinations of native and mutant envelope sequences were constructed, purified and evaluated for their efficacy in detecting antibodies to HIV-1 and HIV-2. A chimeric molecule comprising native envelope sequence of gp41 of HIV-1 and modified envelope sequence of gp36 of HIV-2 gave good production yield and also detected both HIV-1 and HIV-2 samples with high sensitivity and specificity. Conclusion The new bifunctional antibody fusion protein identified in

  3. Mechanisms of HIV-1 Control.

    Science.gov (United States)

    Soliman, Mary; Srikrishna, Geetha; Balagopal, Ashwin

    2017-06-01

    HIV-1 infection is of global importance, and still incurs substantial morbidity and mortality. Although major pharmacologic advances over the past two decades have resulted in remarkable HIV-1 control, a cure is still forthcoming. One approach to a cure is to exploit natural mechanisms by which the host restricts HIV-1. Herein, we review past and recent discoveries of HIV-1 restriction factors, a diverse set of host proteins that limit HIV-1 replication at multiple levels, including entry, reverse transcription, integration, translation of viral proteins, and packaging and release of virions. Recent studies of intracellular HIV-1 restriction have offered unique molecular insights into HIV-1 replication and biology. Studies have revealed insights of how restriction factors drive HIV-1 evolution. Although HIV-1 restriction factors only partially control the virus, their importance is underscored by their effect on HIV-1 evolution and adaptation. The list of host restriction factors that control HIV-1 infection is likely to expand with future discoveries. A deeper understanding of the molecular mechanisms of regulation by these factors will uncover new targets for therapeutic control of HIV-1 infection.

  4. 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.

  5. HIV-1 diversity in an antiretroviral treatment naïve cohort from Bushbuckridge, Mpumalanga Province, South Africa.

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    Msimanga, Patrick Wela; Vardas, Efthyia; Engelbrecht, Susan

    2015-02-13

    South Africa has a generalized and explosive HIV/AIDS epidemic with the largest number of people infected with HIV-1 in the world. Molecular investigations of HIV-1 diversity can help enhance interventions to contain and combat the HIV/AIDS epidemic. However, many studies of HIV-1 diversity in South Africa tend to be limited to the major metropolitan centers and their surrounding provinces. Hardly any studies of HIV diversity have been undertaken in Mpumalanga Province, and this study sought to investigate the HIV-1 diversity in this province, as well as establish the occurrence and extent of transmitted antiretroviral drug resistance mutations. HIV-1 gag p24, pol p10 and p66/p51, pol p31 and env gp41 gene fragments from 43 participants were amplified and sequenced. Quality control on the sequences was carried out using the LANL QC online tool. HIV-1 subtype was preliminary assigned using the REGA 3.0 and jpHMM online tools. Subtype for the pol gene fragment was further designated using the SCUEAL online tool. Phylogenetic analysis was inferred using the Maximum Likelihood methods in MEGA version 6. HIV-1 antiretroviral drug resistance mutations were determined using the Stanford database. Phylogenetic analysis using Maximum Likelihood methods indicated that all sequences in the study clustered with HIV-1 subtype C. The exception was one putative subtype BC unique recombinant form. Antiretroviral drug resistance mutations K103N and E138A were also detected, indicating possible transmission of anti-retroviral drug resistance mutations. The phylogenetic analysis of the HIV sequences revealed that, by 2009, patients in the Bushbuckridge, Mpumalanga were predominantly infected with HIV-1 subtype C. However, the generalized, explosive nature of the HIV/AIDS epidemic in South Africa, in the context of extensive mobility by South Africans who inhabit rural areas, renders the continued molecular monitoring and surveillance of the epidemic imperative.

  6. Humoral Immunogenicity of an HIV-1 Envelope Residue 649-684 Membrane-proximal Region Peptide Fused to the Plague Antigen F1-V

    OpenAIRE

    Matoba, Nobuyuki; Shah, Namrata Rahul; Tsafrir S. Mor

    2011-01-01

    The membrane-proximal region spanning residues 649-684 of the HIV-1 envelope protein gp41 (MPR649-684) is an attractive vaccine target for humoral immunity that blocks viral transcytosis across the mucosal epithelia. However, induction of high-titer MPR649-684-specific antibodies remains a challenging task. To explore potential solutions for this challenge, we tested a new translational fusion protein comprising the plague F1-V antigen and MPR649-684 (F1-V-MPR649-684). We employed systemic im...

  7. Complementation of diverse HIV-1 Env defects through cooperative subunit interactions: a general property of the functional trimer

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    Salzwedel Karl

    2009-08-01

    Full Text Available Abstract Background The HIV-1 Env glycoprotein mediates virus entry by catalyzing direct fusion between the virion membrane and the target cell plasma membrane. Env is composed of two subunits: gp120, which binds to CD4 and the coreceptor, and gp41, which is triggered upon coreceptor binding to promote the membrane fusion reaction. Env on the surface of infected cells is a trimer consisting of three gp120/gp41 homo-dimeric protomers. An emerging question concerns cooperative interactions between the protomers in the trimer, and possible implications for Env function. Results We extended studies on cooperative subunit interactions within the HIV-1 Env trimer, using analysis of functional complementation between coexpressed inactive variants harboring different functional deficiencies. In assays of Env-mediated cell fusion, complementation was observed between variants with a wide range of defects in both the gp120 and gp41 subunits. The former included gp120 subunits mutated in the CD4 binding site or incapable of coreceptor interaction due either to mismatched specificity or V3 loop mutation. Defective gp41 variants included point mutations at different residues within the fusion peptide or heptad repeat regions, as well as constructs with modifications or deletions of the membrane proximal tryptophan-rich region or the transmembrane domain. Complementation required the defective variants to be coexpressed in the same cell. The observed complementation activities were highly dependent on the assay system. The most robust activities were obtained with a vaccinia virus-based expression and reporter gene activation assay for cell fusion. In an alternative system involving Env expression from integrated provirus, complementation was detected in cell fusion assays, but not in virus particle entry assays. Conclusion Our results indicate that Env function does not require every subunit in the trimer to be competent for all essential activities. Through

  8. Proinflammatory Effects of C-Peptide in Different Tissues

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    Dusica Vasic

    2012-01-01

    Full Text Available Atherosclerosis is well known as an inflammatory disease that can lead to clinical complications such as heart attack or stroke. C-peptide as a cleavage product of proinsulin is in the last few decades known as an active peptide with a number of different effects on microvascular and macrovascular complications in type 2 diabetic patients. Patients with insulin resistance and early type 2 diabetes show elevated levels of C-peptide in blood. Several last findings demonstrated deposition of C-peptide in the vessel wall in ApoE-deficient mice and induction of local inflammation. Besides that, C-peptide has proliferative effects on human mesangial cells. This review discusses recently published proinflammatory effects of C-peptide in different tissues.

  9. Interactions between HIV-1 Neutralizing Antibodies and Model Lipid Membranes imaged with AFM

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    Zauscher, Stefan; Hardy, Gregory; Alam, Munir; Shapter, Joseph

    2012-02-01

    Lipid membrane interactions with rare, broadly neutralizing antibodies (NAbs), 2F5 and 4E10, play a critical role in HIV-1 neutralization. Our research is motivated by recent immunization studies that have shown that induction of antibodies that avidly bind the gp41-MPER antigen is not sufficient for neutralization. Rather, it is required that antigen designs induce polyreactive antibodies that recognize MPER antigens as well as the viral lipid membrane. However, the mechanistic details of how membrane properties influence NAb-lipid and NAb-antigen interactions remain unknown. Furthermore, it is well established that the native viral membrane is heterogeneous, representing a mosaic of lipid rafts and protein clustering. However, the size, physical properties, and dynamics of these regions are poorly characterized and their potential roles in HIV-1 neutralization are also unknown. To understand how membrane properties contribute to 2F5/4E10 membrane interactions, we have engineered biomimetic supported lipid bilayers (SLBs) and use atomic force microscopy to visualize membrane domains, antigen clustering, and antibody-membrane interactions at sub-nanometer z-resolution. Our results show that localized binding of HIV-1 antigens and NAbs occur preferentially with the most fluid membrane domain. This supports the theory that NAbs may interact with regions of low lateral lipid forces that allow antibody insertion into the bilayer.

  10. Sexual transmission of HIV-1.

    Science.gov (United States)

    Fox, Julie; Fidler, Sarah

    2010-01-01

    HIV-1 transmission occurs in a limited number of ways all of which are preventable. Overall, the risk of HIV-1 transmission following a single sexual exposure is low especially in comparison with other sexually transmitted infections (STIs); with estimates of the average probability of male to female HIV-1 transmission only 0.0005-0.0026 per coital act. The risk of acquiring HIV-1 from a single contact varies enormously and is dependant upon the infectiousness of the HIV-1 positive individual and the susceptibility to HIV-1 of their sexual partner. An understanding of the determinants of HIV-1 transmission is important not only to assess the infection risk to an individual when exposed to the virus (e.g. to determine the provision of post exposure prophylaxis), but also to make accurate predictions on the potential spread of HIV-1 infection in a population and to direct appropriate targeted prevention strategies. In this review article we summarise the current literature on the major worldwide source of HIV-1 acquisition, sexual transmission. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, Vol 85, issue 1, 2010. Copyright 2009 Elsevier B.V. All rights reserved.

  11. Revisiting HIV-1 uncoating

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    Arhel Nathalie

    2010-11-01

    Full Text Available Abstract HIV uncoating is defined as the loss of viral capsid that occurs within the cytoplasm of infected cells before entry of the viral genome into the nucleus. It is an obligatory step of HIV-1 early infection and accompanies the transition between reverse transcription complexes (RTCs, in which reverse transcription occurs, and pre-integration complexes (PICs, which are competent to integrate into the host genome. The study of the nature and timing of HIV-1 uncoating has been paved with difficulties, particularly as a result of the vulnerability of the capsid assembly to experimental manipulation. Nevertheless, recent studies of capsid structure, retroviral restriction and mechanisms of nuclear import, as well as the recent expansion of technical advances in genome-wide studies and cell imagery approaches, have substantially changed our understanding of HIV uncoating. Although early work suggested that uncoating occurs immediately following viral entry in the cell, thus attributing a trivial role for the capsid in infected cells, recent data suggest that uncoating occurs several hours later and that capsid has an all-important role in the cell that it infects: for transport towards the nucleus, reverse transcription and nuclear import. Knowing that uncoating occurs at a later stage suggests that the viral capsid interacts extensively with the cytoskeleton and other cytoplasmic components during its transport to the nucleus, which leads to a considerable reassessment of our efforts to identify potential therapeutic targets for HIV therapy. This review discusses our current understanding of HIV uncoating, the functional interplay between infectivity and timely uncoating, as well as exposing the appropriate methods to study uncoating and addressing the many questions that remain unanswered.

  12. HIV-1 replication in macrophages

    NARCIS (Netherlands)

    Kootstra, N.A.

    1999-01-01

    Lentiviruses such as the human immunodeficiency virus type 1 (HIV-1) are considered to be unique amongst the retroviruses due to their ability to replicate in macrophages, which are often referred to as non-dividing cells. The studies described in this thesis focus on the ability of HIV-1 to

  13. Multimeric scaffolds displaying the HIV-1 envelope MPER induce MPER-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 DNA.

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    Shelly J Krebs

    Full Text Available Developing a vaccine that overcomes the diversity of HIV-1 is likely to require a strategy that directs antibody (Ab responses toward conserved regions of the viral Envelope (Env. However, the generation of neutralizing Abs (NAbs targeting these regions through vaccination has proven to be difficult. One conserved region of particular interest is the membrane proximal external region (MPER of Env located within the gp41 ectodomain. In order to direct the immune response to this region, the MPER and gp41 ectodomain were expressed separately as N-terminal fusions to the E2 protein of Geobacillus stearothermophilus. The E2 protein acts as a scaffold by self-assembling into 60-mer particles, displaying up to 60 copies of the fused target on the surface. Rabbits were immunized with E2 particles displaying MPER and/or the gp41 ectodomain in conjunction with DNA encoding full-length gp160. Only vaccines including E2 particles displaying MPER elicited MPER-specific Ab responses. NAbs were elicited after two immunizations that largely targeted the V3 loop. To overcome V3 immunodominance in the DNA component, E2 particles displaying MPER were used in conjunction with gp160 DNA lacking hypervariable regions V2, V3, or combined V1V2V3. All rabbits had HIV binding Ab responses and NAbs following the second vaccination. Using HIV-2/HIV-1 MPER chimeric viruses as targets, NAbs were detected in 12/16 rabbits after three immunizations. Low levels of NAbs specific for Tier 1 and 2 viruses were observed in all groups. This study provides evidence that co-immunizing E2 particles displaying MPER and gp160 DNA can focus Ab responses toward conserved regions of Env.

  14. Molecular investigations into vaginal immunization with HIV gp41 antigenic construct H4A in a quick release solid dosage form.

    Science.gov (United States)

    Pattani, Aditya; McKay, Paul F; Curran, Rhonda M; McCaffrey, Joanne; Gupta, Prem N; Lowry, Deborah; Kett, Vicky L; Shattock, Robin J; McCarthy, Helen O; Malcolm, R Karl

    2012-04-05

    A robust vaginal immune response is considered essential for an effective prophylactic vaccine that prevents transmission of HIV and other sexually acquired diseases. Considerable attention has recently focused on the potential of vaginally administered vaccines as a means to induce such local immunity. However, the potential for vaccination at this site remains in doubt as the vaginal mucosa is generally considered to have low immune inductive potential. In the current study, we explored for the first time the use of a quick release, freeze-dried, solid dosage system for practical vaginal administration of a protein antigen. These solid dosage forms overcome the common problem associated with leakage and poor retention of vaginally administered antigen solutions. Mice were immunized vaginally with H4A, an HIV gp41 envelope based recombinant protein, using quick release, freeze-dried solid rods, and the immune responses compared to a control group immunized via subcutaneous H4A injection. Vaginally immunized mice failed to elicit robust immune responses. Our detailed investigations, involving cytokine analysis, the stability of H4A in mouse cervicovaginal lavage, and elucidation of the state of H4A protein in the immediate-release dosage form, revealed that antigen instability in vaginal fluid, the state of the antigen in the dosage form, and the cytokine profile induced are all likely to have contributed to the observed lack of immunogenicity. These are important factors affecting vaginal immunization and provide a rational basis for explaining the typically poor and variable elicitation of immunity at this site, despite the presence of immune responsive cells within the vaginal mucosae. In future mucosal vaccine studies, a more explicit focus on antigen stability in the dosage form and the immune potential of available antigen-responsive cells is recommended. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

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    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.

  16. The role of blood cell membrane lipids on the mode of action of HIV-1 fusion inhibitor sifuvirtide

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Pedro M.; Freitas, Teresa; Castanho, Miguel A.R.B. [Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisbon, Av. Prof. Egas Moniz, 1649-028 Lisboa (Portugal); Santos, Nuno C., E-mail: nsantos@fm.ul.pt [Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisbon, Av. Prof. Egas Moniz, 1649-028 Lisboa (Portugal)

    2010-12-17

    Research highlights: {yields} Sifuvirtide interacts with erythrocyte and lymphocyte membrane in a concentration dependent manner by decreasing its dipole potential. {yields} Dipole potential variations in lipid vesicles show sifuvirtide's lipid selectivity towards saturated phosphatidylcholines. {yields} This peptide-membrane interaction may direct the drug towards raft-like membrane domains where the receptors used by HIV are located, facilitating its inhibitory action. -- Abstract: Sifuvirtide is a gp41 based peptide that inhibits HIV-1 fusion with the host cells and is currently under clinical trials. Previous studies showed that sifuvirtide partitions preferably to saturated phosphatidylcholine lipid membranes, instead of fluid-phase lipid vesicles. We extended the study to the interaction of the peptide with circulating blood cells, by using the dipole potential sensitive probe di-8-ANEPPS. Sifuvirtide decreased the dipole potential of erythrocyte and lymphocyte membranes in a concentration dependent manner, demonstrating its interaction. Also, the lipid selectivity of the peptide towards more rigid phosphatidylcholines was confirmed based on the dipole potential variations. Overall, the interaction of the peptide with the cell membranes is a contribution of different lipid preferences that presumably directs the peptide towards raft-like domains where the receptors are located, facilitating the reach of the peptide to its molecular target, the gp41 in its pre-fusion conformation.

  17. A Lipopeptide HIV-1/2 Fusion Inhibitor with Highly Potent In Vitro, Ex Vivo, and In Vivo Antiviral Activity.

    Science.gov (United States)

    Chong, Huihui; Xue, Jing; Xiong, Shengwen; Cong, Zhe; Ding, Xiaohui; Zhu, Yuanmei; Liu, Zixuan; Chen, Ting; Feng, Yifan; He, Lei; Guo, Yan; Wei, Qiang; Zhou, Yusen; Qin, Chuan; He, Yuxian

    2017-06-01

    Peptides derived from the C-terminal heptad repeat (CHR) region of the human immunodeficiency virus type 1 (HIV-1) fusogenic protein gp41 are potent viral entry inhibitors, and currently, enfuvirtide (T-20) is the only one approved for clinical use; however, emerging drug resistance largely limits its efficacy. In this study, we generated a novel lipopeptide inhibitor, named LP-19, by integrating multiple design strategies, including an N-terminal M-T hook structure, an HIV-2 sequence, intrahelical salt bridges, and a membrane-anchoring lipid tail. LP-19 showed stable binding affinity and highly potent, broad, and long-lasting antiviral activity. In in vitro studies, LP-19 efficiently inhibited HIV-1-, HIV-2-, and simian immunodeficiency virus (SIV)-mediated cell fusion, viral entry, and infection, and it was highly active against diverse subtypes of primary HIV-1 isolates and inhibitor-resistant mutants. Ex vivo studies demonstrated that LP-19 exhibited dramatically increased anti-HIV activity and an extended half-life in rhesus macaques. In short-term monotherapy, LP-19 reduced viral loads to undetectable levels in acutely and chronically simian-human immunodeficiency virus (SHIV)-infected monkeys. Therefore, this study offers an ideal HIV-1/2 fusion inhibitor for clinical development and emphasizes the importance of the viral fusion step as a drug target.IMPORTANCE The peptide drug T-20 is the only viral fusion inhibitor in the clinic, which is used for combination therapy of HIV-1 infection; however, it requires a high dosage and easily induces drug resistance, calling for a new drug with significantly improved pharmaceutical profiles. Here, we have developed a short-lipopeptide-based fusion inhibitor, termed LP-19, which mainly targets the conserved gp41 pocket site and shows highly potent inhibitory activity against HIV-1, HIV-2, and even SIV isolates. LP-19 exhibits dramatically increased antiviral activity and an extended half-life in rhesus macaques, and

  18.  Pleiotropic action of proinsulin C-peptid

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    Michał Usarek

    2012-03-01

    Full Text Available  Proinsulin C-peptide, released in equimolar amounts with insulin by pancreatic β cells, since its discovery in 1967 has been thought to be devoid of biological functions apart from correct insulin processing and formation of disulfide bonds between A and B chains. However, in the last two decades research has brought a substantial amount of data indicating a crucial role of C-peptide in regulating various processes in different types of cells and organs. C-peptide acts presumably via either G-protein-coupled receptor or directly inside the cell, after being internalized. However, a receptor binding this peptide has not been identified yet. This peptide ameliorates pathological changes induced by type 1 diabetes mellitus, including glomerular hyperfiltration, vessel endothelium inflammation and neuron demyelinization. In diabetic patients and diabetic animal models, C-peptide substitution in physiological doses improves the functional and structural properties of peripheral neurons and protects against hyperglycemia-induced apoptosis, promoting neuronal development, regeneration and cell survival. Moreover, it affects glycogen synthesis in skeletal muscles. In vitro C-peptide promotes disaggregation of insulin oligomers, thus enhancing its bioavailability and effects on metabolism. There are controversies concerning the biological action of C-peptide, particularly with respect to its effect on Na /K -ATPase activity. Surprisingly, the excess of circulating peptide associated with diabetes type 2 contributes to atherosclerosis development. In view of these observations, long-term, large-scale clinical investigations using C-peptide physiological doses need to be conducted in order to determine safety and health outcomes of long-term administration of C-peptide to diabetic patients.

  19. Immunogenicity of a novel Clade B HIV-1 vaccine combination: Results of phase 1 randomized placebo controlled trial of an HIV-1 GM-CSF-expressing DNA prime with a modified vaccinia Ankara vaccine boost in healthy HIV-1 uninfected adults.

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    Susan P Buchbinder

    Full Text Available A phase 1 trial of a clade B HIV vaccine in HIV-uninfected adults evaluated the safety and immunogenicity of a DNA prime co-expressing GM-CSF (Dg followed by different numbers and intervals of modified vaccinia Ankara Boosts (M. Both vaccines produce virus-like particles presenting membrane-bound Env.Four US sites randomized 48 participants to receiving 1/10th the DNA dose as DgDgMMM given at 0, 2, 4, 6 and 8 months, or full dose DgDgM_M or DgDgMM_M regimens, given at 0, 2, 4, and 8 months, and 0, 2, 4, 6, and 10 months, respectively. Peak immunogenicity was measured 2 weeks post-last vaccination.All regimens were well tolerated and safe. Full dose DgDgM_M and DgDgMM_M regimens generated Env-specific IgG to HIV-1 Env in >90%, IgG3 in >80%, and IgA in <20% of participants. Responses to gp140 and gp41 targets were more common and of higher magnitude than to gp120 and V1V2. The gp41 antibody included reactivity to the conserved immunodominant region with specificities known to mediate virus capture and phagocytosis and did not cross-react with a panel of intestinal flora antigens. The 3rd dose of MVA increased the avidity of elicited antibody (7.5% to 39%, the ADCC response to Bal gp120 (14% to 64%, and the one-year durability of the IgG3 responses to gp41 by 4-fold (13% vs. 3.5% retention of peak response. The co-expressed GM-CSF did not enhance responses over those in trials testing this vaccine without GM-CSF.This DNA/MVA prime-boost regimen induced durable, functional humoral responses that included ADCC, high antibody avidity, and Env IgG1 and IgG3 binding responses to the immunodominant region of gp41. The third, spaced MVA boost improved the overall quality of the antibody response. These products without co-expressed GM-CSF but combined with protein boosts will be considered for efficacy evaluation.ClinicalTrials.gov NCT01571960.

  20. Kinetic studies of HIV-1 and HIV-2 envelope glycoprotein-mediated fusion

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    Doms Robert W

    2006-12-01

    Full Text Available Abstract Background HIV envelope glycoprotein (Env-mediated fusion is driven by the concerted coalescence of the HIV gp41 N-helical and C-helical regions, which results in the formation of 6 helix bundles. Kinetics of HIV Env-mediated fusion is an important determinant of sensitivity to entry inhibitors and antibodies. However, the parameters that govern the HIV Env fusion cascade have yet to be fully elucidated. We address this issue by comparing the kinetics HIV-1IIIB Env with those mediated by HIV-2 from two strains with different affinities for CD4 and CXCR4. Results HIV-1 and HIV-2 Env-mediated cell fusion occurred with half times of about 60 and 30 min, respectively. Binding experiments of soluble HIV gp120 proteins to CD4 and co-receptor did not correlate with the differences in kinetics of fusion mediated by the three different HIV Envs. However, escape from inhibition by reagents that block gp120-CD4 binding, CD4-induced CXCR4 binding and 6-helix bundle formation, respectively, indicated large difference between HIV-1 and HIV-2 envelope glycoproteins in their CD4-induced rates of engagement with CXCR4. Conclusion The HIV-2 Env proteins studied here exhibited a significantly reduced window of time between the engagement of gp120 with CD4 and exposure of the CXCR4 binding site on gp120 as compared with HIV-1IIIB Env. The efficiency with which HIV-2 Env undergoes this CD4-induced conformational change is the major cause of the relatively rapid rate of HIV-2 Env mediated-fusion.

  1. Enfuvirtide cerebrospinal fluid (CSF) pharmacokinetics and potential use in defining CSF HIV-1 origin.

    Science.gov (United States)

    Price, Richard W; Parham, Robin; Kroll, Jing Lu; Wring, Stephen A; Baker, Brian; Sailstad, Jeff; Hoh, Rebecca; Liegler, Teri; Spudich, Serena; Kuritzkes, Daniel R; Deeks, Steven G

    2008-01-01

    Enfuvirtide is a potent inhibitor of systemic HIV-1 replication, but its penetration into the human central nervous system (CNS) has not been analysed. Here, we define cerebrospinal fluid (CSF) enfuvirtide pharmacokinetics and present a case illustrating the use of enfuvirtide as a probe to trace the origins of CSF HIV-1 quasispecies. Enfuvirtide CSF pharmacokinetics were assessed in 18 CSF and plasma sample pairs from four HIV-1-infected individuals. Enfuvirtide levels were measured by liquid chromatography tandem mass spectrometry using known standards and controls that included spiked CSF samples from untreated, HIV-negative individuals. A segment of the gp41 coding region encompassing the heptad repeat HR-1 and HR-2 domains was amplified from selected CSF and plasma samples and independent clones sequenced to assess resistance-associated mutations. CSF and plasma samples obtained between 2 and 20 h after enfuvirtide injection showed plasma concentrations similar to previous reports (mean 3.687 SD +/- 1.828 mg/ml) with prolonged decay. By contrast, enfuvirtide in all CSF samples was below the assay detection limit of 0.025 mg/ml. In one individual, who developed a transient increase in CSF HIV-1 RNA, seven of seven CSF and plasma clones had identical enfuvirtide resistance-associated V38A mutations, suggesting that the CSF quasispecies derived from that of blood. Enfuvirtide penetration into CSF is negligible; thus, in clinical settings, where direct CNS drug exposure is crucial, this drug Is not likely to directly contribute to the local therapeutic effect. Enfuvirtide can be used as a tool to dissect the origin of the CNS virus.

  2. Developmental Pathway of the MPER-Directed HIV-1-Neutralizing Antibody 10E8.

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    Cinque Soto

    Full Text Available Antibody 10E8 targets the membrane-proximal external region (MPER of HIV-1 gp41, neutralizes >97% of HIV-1 isolates, and lacks the auto-reactivity often associated with MPER-directed antibodies. The developmental pathway of 10E8 might therefore serve as a promising template for vaccine design, but samples from time-of-infection-often used to infer the B cell record-are unavailable. In this study, we used crystallography, next-generation sequencing (NGS, and functional assessments to infer the 10E8 developmental pathway from a single time point. Mutational analysis indicated somatic hypermutation of the 2nd-heavy chain-complementarity determining region (CDR H2 to be critical for neutralization, and structures of 10E8 variants with V-gene regions reverted to genomic origin for heavy-and-light chains or heavy chain-only showed structural differences >2 Å relative to mature 10E8 in the CDR H2 and H3. To understand these developmental changes, we used bioinformatic sieving, maximum likelihood, and parsimony analyses of immunoglobulin transcripts to identify 10E8-lineage members, to infer the 10E8-unmutated common ancestor (UCA, and to calculate 10E8-developmental intermediates. We were assisted in this analysis by the preservation of a critical D-gene segment, which was unmutated in most 10E8-lineage sequences. UCA and early intermediates weakly bound a 26-residue-MPER peptide, whereas HIV-1 neutralization and epitope recognition in liposomes were only observed with late intermediates. Antibody 10E8 thus develops from a UCA with weak MPER affinity and substantial differences in CDR H2 and H3 from the mature 10E8; only after extensive somatic hypermutation do 10E8-lineage members gain recognition in the context of membrane and HIV-1 neutralization.

  3. Targeting cell surface HIV-1 Env protein to suppress infectious virus formation

    Science.gov (United States)

    Bastian, Arangassery Rosemary; Ang, Charles G.; Kamanna, Kantharaju; Shaheen, Farida; Huang, Yu-Hung; McFadden, Karyn; Duffy, Caitlin; Bailey, Lauren D.; Sundaram, Ramalingam Venkat Kalyana; Chaiken, Irwin

    2017-01-01

    HIV-1 Env protein is essential for host cell entry, and targeting Env remains an important antiretroviral strategy. We previously found that a peptide triazole thiol KR13 and its gold nanoparticle conjugate AuNP-KR13 directly and irreversibly inactivate the virus by targeting the Env protein, leading to virus gp120 shedding, membrane disruption and p24 capsid protein release. Here, we examined the consequences of targeting cell-surface Env with the virus inactivators. We found that both agents led to formation of non-infectious virus from transiently transfected 293T cells. The budded non-infectious viruses lacked Env gp120 but contained gp41. Importantly, budded virions also retained the capsid protein p24, in stark contrast to p24 leakage from viruses directly treated by these agents and arguing that the agents led to deformed viruses by transforming the cells at a stage before virus budding. We found that the Env inactivators caused gp120 shedding from the transiently transfected 293T cells as well as non-producer CHO-K1-gp160 cells. Additionally, AuNP-KR13 was cytotoxic against the virus-producing 293T and CHO-K1-gp160 cells, but not untransfected 293T or unmodified CHO-K1 cells. The results obtained reinforce the argument that cell-surface HIV-1 Env is metastable, as on virus particles, and provides a conformationally vulnerable target for virus suppression and infectious cell inactivation. PMID:28390972

  4. Development of potent and long-acting HIV-1 fusion inhibitors.

    Science.gov (United States)

    Chong, Huihui; Wu, Xiyuan; Su, Yang; He, Yuxian

    2016-05-15

    T20 (enfuvirtide) is the first approved HIV entry inhibitor and currently the only viral fusion inhibitor, but its low efficacy and genetic barrier to resistance significantly limit its application, calling for a next-generation drug. On the basis of the M-T hook structure, we recently developed a short-peptide named HP23, which mainly targets the deep pocket site of gp41 and possesses highly potent antiviral activity. To improve the pharmaceutical properties of a peptide-based inhibitor, we modified HP23 by different classes of lipids including fatty acid, cholesterol, and sphingolipids. To avoid the potential problem of oxidation, the methionine residue in the M-T hook sequence of HP23 was replaced with leucine. Peptides were synthesized and their anti-HIV activity and biophysical properties were determined. A group of lipopeptides were generated with greatly improved anti-HIV activity. Promisingly, a fatty acid-conjugated lipopeptide named LP-11 showed potent and broad inhibitory activity against diverse primary HIV-1 isolates and clinically drug-resistant mutants, and it had dramatically increased ex-vivo antiviral activity and extended half-life. Also, LP-11 displayed highly enhanced α-helicity and thermal stability, and it was physically stable under high temperature and humidity. LP-11 has high potentials for clinical development and it can serve as an ideal tool for exploring the mechanisms of HIV-1 fusion and inhibition.

  5. 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.

  6. Analysis of memory B cell responses and isolation of novel monoclonal antibodies with neutralizing breadth from HIV-1-infected individuals.

    Directory of Open Access Journals (Sweden)

    Davide Corti

    2010-01-01

    Full Text Available The isolation of human monoclonal antibodies (mAbs that neutralize a broad spectrum of primary HIV-1 isolates and the characterization of the human neutralizing antibody B cell response to HIV-1 infection are important goals that are central to the design of an effective antibody-based vaccine.We immortalized IgG(+ memory B cells from individuals infected with diverse clades of HIV-1 and selected on the basis of plasma neutralization profiles that were cross-clade and relatively potent. Culture supernatants were screened using various recombinant forms of the envelope glycoproteins (Env in multiple parallel assays. We isolated 58 mAbs that were mapped to different Env surfaces, most of which showed neutralizing activity. One mAb in particular (HJ16 specific for a novel epitope proximal to the CD4 binding site on gp120 selectively neutralized a multi-clade panel of Tier-2 HIV-1 pseudoviruses, and demonstrated reactivity that was comparable in breadth, but distinct in neutralization specificity, to that of the other CD4 binding site-specific neutralizing mAb b12. A second mAb (HGN194 bound a conserved epitope in the V3 crown and neutralized all Tier-1 and a proportion of Tier-2 pseudoviruses tested, irrespective of clade. A third mAb (HK20 with broad neutralizing activity, particularly as a Fab fragment, recognized a highly conserved epitope in the HR-1 region of gp41, but showed striking assay-dependent selectivity in its activity.This study reveals that by using appropriate screening methods, a large proportion of memory B cells can be isolated that produce mAbs with HIV-1 neutralizing activity. Three of these mAbs show unusual breadth of neutralization and therefore add to the current panel of HIV-1 neutralizing antibodies with potential for passive protection and template-based vaccine design.

  7. Drift of the HIV-1 envelope glycoprotein gp120 toward increased neutralization resistance over the course of the epidemic: a comprehensive study using the most potent and broadly neutralizing monoclonal antibodies.

    Science.gov (United States)

    Bouvin-Pley, M; Morgand, M; Meyer, L; Goujard, C; Moreau, A; Mouquet, H; Nussenzweig, M; Pace, C; Ho, D; Bjorkman, P J; Baty, D; Chames, P; Pancera, M; Kwong, P D; Poignard, P; Barin, F; Braibant, M

    2014-12-01

    Extending our previous analyses to the most recently described monoclonal broadly neutralizing antibodies (bNAbs), we confirmed a drift of HIV-1 clade B variants over 2 decades toward higher resistance to bNAbs targeting almost all the identified gp120-neutralizing epitopes. In contrast, the sensitivity to bNAbs targeting the gp41 membrane-proximal external region remained stable, suggesting a selective pressure on gp120 preferentially. Despite this evolution, selected combinations of bNAbs remain capable of neutralizing efficiently most of the circulating variants. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  8. Enfuvirtide (T20)-Based Lipopeptide Is a Potent HIV-1 Cell Fusion Inhibitor: Implications for Viral Entry and Inhibition.

    Science.gov (United States)

    Ding, Xiaohui; Zhang, Xiujuan; Chong, Huihui; Zhu, Yuanmei; Wei, Huamian; Wu, Xiyuan; He, Jinsheng; Wang, Xinquan; He, Yuxian

    2017-09-15

    The peptide drug enfuvirtide (T20) is the only viral fusion inhibitor used in combination therapy for HIV-1 infection, but it has relatively low antiviral activity and easily induces drug resistance. Emerging studies demonstrate that lipopeptide-based fusion inhibitors, such as LP-11 and LP-19, which mainly target the gp41 pocket site, have greatly improved antiviral potency and in vivo stability. In this study, we focused on developing a T20-based lipopeptide inhibitor that lacks pocket-binding sequence and targets a different site. First, the C-terminal tryptophan-rich motif (TRM) of T20 was verified to be essential for its target binding and inhibition; then, a novel lipopeptide, termed LP-40, was created by replacing the TRM with a fatty acid group. LP-40 showed markedly enhanced binding affinity for the target site and dramatically increased inhibitory activity on HIV-1 membrane fusion, entry, and infection. Unlike LP-11 and LP-19, which required a flexible linker between the peptide sequence and the lipid moiety, addition of a linker to LP-40 sharply reduced its potency, implying different binding modes with the extended N-terminal helices of gp41. Also, interestingly, LP-40 showed more potent activity than LP-11 in inhibiting HIV-1 Env-mediated cell-cell fusion while it was less active than LP-11 in inhibiting pseudovirus entry, and the two inhibitors displayed synergistic antiviral effects. The crystal structure of LP-40 in complex with a target peptide revealed their key binding residues and motifs. Combined, our studies have not only provided a potent HIV-1 fusion inhibitor, but also revealed new insights into the mechanisms of viral inhibition. IMPORTANCE T20 is the only membrane fusion inhibitor available for treatment of viral infection; however, T20 requires high doses and has a low genetic barrier for resistance, and its inhibitory mechanism and structural basis remain unclear. Here, we report the design of LP-40, a T20-based lipopeptide inhibitor

  9. Peptide-derivatized SB105-A10 dendrimer inhibits the infectivity of R5 and X4 HIV-1 strains in primary PBMCs and cervicovaginal histocultures.

    Directory of Open Access Journals (Sweden)

    Isabella Bon

    Full Text Available Peptide dendrimers are a class of molecules that exhibit a large array of biological effects including antiviral activity. In this report, we analyzed the antiviral activity of the peptide-derivatized SB105-A10 dendrimer, which is a tetra-branched dendrimer synthetized on a lysine core, in activated peripheral blood mononuclear cells (PBMCs that were challenged with reference and wild-type human immunodeficiency virus type 1 (HIV-1 strains. SB105-A10 inhibited infections by HIV-1 X4 and R5 strains, interfering with the early phases of the viral replication cycle. SB105-A10 targets heparan sulfate proteoglycans (HSPGs and, importantly, the surface plasmon resonance (SPR assay revealed that SB105-A10 strongly binds gp41 and gp120, most likely preventing HIV-1 attachment/entry through multiple mechanisms. Interestingly, the antiviral activity of SB105-A10 was also detectable in an organ-like structure of human cervicovaginal tissue, in which SB105-A10 inhibited the HIV-1ada R5 strain infection without altering the tissue viability. These results demonstrated the strong antiviral activity of SB105-A10 and suggest a potential microbicide use of this dendrimer to prevent the heterosexual transmission of HIV-1.

  10. History and Diagnostic Significance of C-Peptide

    Directory of Open Access Journals (Sweden)

    Dietrich Brandenburg

    2008-01-01

    Today, C-peptide continues to serve as a special diagnostic tool in Diabetology and related fields. Thus, its passive role is well established. Evidence for its active role in physiology and pathophysiology is more recent and is subject of the following contributions.

  11. Functional stability of unliganded envelope glycoprotein spikes among isolates of human immunodeficiency virus type 1 (HIV-1.

    Directory of Open Access Journals (Sweden)

    Nitish Agrawal

    Full Text Available The HIV-1 envelope glycoprotein (Env spike is challenging to study at the molecular level, due in part to its genetic variability, structural heterogeneity and lability. However, the extent of lability in Env function, particularly for primary isolates across clades, has not been explored. Here, we probe stability of function for variant Envs of a range of isolates from chronic and acute infection, and from clades A, B and C, all on a constant virus backbone. Stability is elucidated in terms of the sensitivity of isolate infectivity to destabilizing conditions. A heat-gradient assay was used to determine T(90 values, the temperature at which HIV-1 infectivity is decreased by 90% in 1 h, which ranged between ∼40 to 49°C (n = 34. For select Envs (n = 10, the half-lives of infectivity decay at 37°C were also determined and these correlated significantly with the T(90 (p = 0.029, though two 'outliers' were identified. Specificity in functional Env stability was also evident. For example, Env variant HIV-1(ADA was found to be labile to heat, 37°C decay, and guanidinium hydrochloride but not to urea or extremes of pH, when compared to its thermostable counterpart, HIV-1(JR-CSF. Blue native PAGE analyses revealed that Env-dependent viral inactivation preceded complete dissociation of Env trimers. The viral membrane and membrane-proximal external region (MPER of gp41 were also shown to be important for maintaining trimer stability at physiological temperature. Overall, our results indicate that primary HIV-1 Envs can have diverse sensitivities to functional inactivation in vitro, including at physiological temperature, and suggest that parameters of functional Env stability may be helpful in the study and optimization of native Env mimetics and vaccines.

  12. HIV-1 assembly in macrophages

    Directory of Open Access Journals (Sweden)

    Benaroch Philippe

    2010-04-01

    Full Text Available Abstract The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected macrophages represent a viral reservoir and probably play a key role in HIV-1 physiopathology. Indeed macrophages retain infectious particles for long periods of time, keeping them protected from anti-viral immune response or drug treatments. Here, we present an overview of what is known about HIV-1 assembly in macrophages as compared to T lymphocytes or cell lines. Early electron microscopy studies suggested that viral assembly takes place at the limiting membrane of an intracellular compartment in macrophages and not at the plasma membrane as in T cells. This was first considered as a late endosomal compartment in which viral budding seems to be similar to the process of vesicle release into multi-vesicular bodies. This view was notably supported by a large body of evidence involving the ESCRT (Endosomal Sorting Complex Required for Transport machinery in HIV-1 budding, the observation of viral budding profiles in such compartments by immuno-electron microscopy, and the presence of late endosomal markers associated with macrophage-derived virions. However, this model needs to be revisited as recent data indicate that the viral compartment has a neutral pH and can be connected to the plasma membrane via very thin micro-channels. To date, the exact nature and biogenesis of the HIV assembly compartment in macrophages remains elusive. Many cellular proteins potentially involved in the late phases of HIV-1 cycle have been identified; and, recently, the list has grown rapidly with the publication of four independent genome-wide screens. However, their respective

  13. Correlations between fasting plasma C-peptide, glucagon-stimulated plasma C-peptide, and urinary C-peptide in insulin-treated diabetics

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Frøland, A

    1987-01-01

    This study correlated fasting plasma C-peptide (CP), plasma CP 6 min after stimulation with 1 mg glucagon i.v., and the mean of three 24-h urinary excretions of C-peptide (UCP)/creatinine in 132 insulin-treated diabetics. Patients were divided into three groups: group 1, stimulated CP less than 0.......06 nM (n = 51); group 2, stimulated CP 0.06-0.60 nM (n = 48); and group 3, stimulated CP greater than 0.60 nM (n = 33). In all patients fasting CP was closely correlated to stimulated CP (r = .988, P less than .001), whereas the correlations between UCP and both fasting CP (r = .904, P less than .001......) and stimulated CP r = .902, P less than .001) were slightly less pronounced. The associations between UCP and both fasting CP (r = .716, P less than .001) and stimulated CP (r = .731, P less than .001) were modest in group 2, and even more so in group 3 (r = .557, P less than .001 and r = .641, P less than .001...

  14. Contribution of intrinsic reactivity of the HIV-1 envelope glycoproteins to CD4-independent infection and global inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillel Haim

    2011-06-01

    Full Text Available Human immunodeficiency virus (HIV-1 enters cells following sequential activation of the high-potential-energy viral envelope glycoprotein trimer by target cell CD4 and coreceptor. HIV-1 variants differ in their requirements for CD4; viruses that can infect coreceptor-expressing cells that lack CD4 have been generated in the laboratory. These CD4-independent HIV-1 variants are sensitive to neutralization by multiple antibodies that recognize different envelope glycoprotein epitopes. The mechanisms underlying CD4 independence, global sensitivity to neutralization and the association between them are still unclear. By studying HIV-1 variants that differ in requirements for CD4, we investigated the contribution of CD4 binding to virus entry. CD4 engagement exposes the coreceptor-binding site and increases the "intrinsic reactivity" of the envelope glycoproteins; intrinsic reactivity describes the propensity of the envelope glycoproteins to negotiate transitions to lower-energy states upon stimulation. Coreceptor-binding site exposure and increased intrinsic reactivity promote formation/exposure of the HR1 coiled coil on the gp41 transmembrane glycoprotein and allow virus entry upon coreceptor binding. Intrinsic reactivity also dictates the global sensitivity of HIV-1 to perturbations such as exposure to cold and the binding of antibodies and small molecules. Accordingly, CD4 independence of HIV-1 was accompanied by increased susceptibility to inactivation by these factors. We investigated the role of intrinsic reactivity in determining the sensitivity of primary HIV-1 isolates to inhibition. Relative to the more common neutralization-resistant ("Tier 2-like" viruses, globally sensitive ("Tier 1" viruses exhibited increased intrinsic reactivity, i.e., were inactivated more efficiently by cold exposure or by a given level of antibody binding to the envelope glycoprotein trimer. Virus sensitivity to neutralization was dictated both by the efficiency of

  15. Contribution of Intrinsic Reactivity of the HIV-1 Envelope Glycoproteins to CD4-Independent Infection and Global Inhibitor Sensitivity

    Science.gov (United States)

    Haim, Hillel; Strack, Bettina; Kassa, Aemro; Madani, Navid; Wang, Liping; Courter, Joel R.; Princiotto, Amy; McGee, Kathleen; Pacheco, Beatriz; Seaman, Michael S.; Smith, Amos B.; Sodroski, Joseph

    2011-01-01

    Human immunodeficiency virus (HIV-1) enters cells following sequential activation of the high-potential-energy viral envelope glycoprotein trimer by target cell CD4 and coreceptor. HIV-1 variants differ in their requirements for CD4; viruses that can infect coreceptor-expressing cells that lack CD4 have been generated in the laboratory. These CD4-independent HIV-1 variants are sensitive to neutralization by multiple antibodies that recognize different envelope glycoprotein epitopes. The mechanisms underlying CD4 independence, global sensitivity to neutralization and the association between them are still unclear. By studying HIV-1 variants that differ in requirements for CD4, we investigated the contribution of CD4 binding to virus entry. CD4 engagement exposes the coreceptor-binding site and increases the “intrinsic reactivity” of the envelope glycoproteins; intrinsic reactivity describes the propensity of the envelope glycoproteins to negotiate transitions to lower-energy states upon stimulation. Coreceptor-binding site exposure and increased intrinsic reactivity promote formation/exposure of the HR1 coiled coil on the gp41 transmembrane glycoprotein and allow virus entry upon coreceptor binding. Intrinsic reactivity also dictates the global sensitivity of HIV-1 to perturbations such as exposure to cold and the binding of antibodies and small molecules. Accordingly, CD4 independence of HIV-1 was accompanied by increased susceptibility to inactivation by these factors. We investigated the role of intrinsic reactivity in determining the sensitivity of primary HIV-1 isolates to inhibition. Relative to the more common neutralization-resistant (“Tier 2-like”) viruses, globally sensitive (“Tier 1”) viruses exhibited increased intrinsic reactivity, i.e., were inactivated more efficiently by cold exposure or by a given level of antibody binding to the envelope glycoprotein trimer. Virus sensitivity to neutralization was dictated both by the efficiency of

  16. Immunogenic Display of Purified Chemically Cross-Linked HIV-1 Spikes

    Science.gov (United States)

    Leaman, Daniel P.; Lee, Jeong Hyun; Ward, Andrew B.

    2015-01-01

    ABSTRACT HIV-1 envelope glycoprotein (Env) spikes are prime vaccine candidates, at least in principle, but suffer from instability, molecular heterogeneity and a low copy number on virions. We anticipated that chemical cross-linking of HIV-1 would allow purification and molecular characterization of trimeric Env spikes, as well as high copy number immunization. Broadly neutralizing antibodies bound tightly to all major quaternary epitopes on cross-linked spikes. Covalent cross-linking of the trimer also stabilized broadly neutralizing epitopes, although surprisingly some individual epitopes were still somewhat sensitive to heat or reducing agent. Immunodepletion using non-neutralizing antibodies to gp120 and gp41 was an effective method for removing non-native-like Env. Cross-linked spikes, purified via an engineered C-terminal tag, were shown by negative stain EM to have well-ordered, trilobed structure. An immunization was performed comparing a boost with Env spikes on virions to spikes cross-linked and captured onto nanoparticles, each following a gp160 DNA prime. Although differences in neutralization did not reach statistical significance, cross-linked Env spikes elicited a more diverse and sporadically neutralizing antibody response against Tier 1b and 2 isolates when displayed on nanoparticles, despite attenuated binding titers to gp120 and V3 crown peptides. Our study demonstrates display of cross-linked trimeric Env spikes on nanoparticles, while showing a level of control over antigenicity, purity and density of virion-associated Env, which may have relevance for Env based vaccine strategies for HIV-1. IMPORTANCE The envelope spike (Env) is the target of HIV-1 neutralizing antibodies, which a successful vaccine will need to elicit. However, native Env on virions is innately labile, as well as heterogeneously and sparsely displayed. We therefore stabilized Env spikes using a chemical cross-linker and removed non-native Env by immunodepletion with non

  17. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  18. C-Peptide and Atherogenesis: C-Peptide as a Mediator of Lesion Development in Patients with Type 2 Diabetes Mellitus?

    Directory of Open Access Journals (Sweden)

    Nikolaus Marx

    2008-01-01

    Full Text Available Patients with insulin resistance and early type 2 diabetes exhibit an increased propensity to develop a diffuse and extensive pattern of arteriosclerosis. Typically, these patients show increased levels of C-peptide and over the last years various groups examined the effect of C-peptide in vascular cells as well as its potential role in lesion development. While some studies demonstrated beneficial effects of C-peptide, for example, by showing an inhibition of smooth muscle cell proliferation, others suggested proatherogenic mechanisms in patients with type 2 diabetes. Among them, C-peptide may facilitate the recruitment of inflammatory cells into early lesions and promote lesion progression by inducing smooth muscle cell proliferation. The following review will summarize the effects of C-peptide in vascular cells and discuss the potential role of C-peptide in atherogenesis in patients with type 2 diabetes.

  19. A macaque model of HIV-1 infection

    OpenAIRE

    Hatziioannou, Theodora; Ambrose, Zandrea; Chung, Nancy P. Y.; Piatak, Michael; Yuan, Fang; Trubey, Charles M.; Coalter, Vicky; Kiser, Rebecca; Schneider, Doug; Smedley, Jeremy; Pung, Rhonda; Gathuka, Mercy; Estes, Jacob D.; Veazey, Ronald S.; KewalRamani, Vineet N.

    2009-01-01

    The lack of a primate model that utilizes HIV-1 as the challenge virus is an impediment to AIDS research; existing models generally employ simian viruses that are divergent from HIV-1, reducing their usefulness in preclinical investigations. Based on an understanding of species-specific variation in primate TRIM5 and APOBEC3 antiretroviral genes, we constructed simian-tropic (st)HIV-1 strains that differ from HIV-1 only in the vif gene. We demonstrate that such minimally modified stHIV-1 stra...

  20. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Directory of Open Access Journals (Sweden)

    Damien C Tully

    2016-05-01

    Full Text Available Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU, we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  1. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Science.gov (United States)

    Tully, Damien C; Ogilvie, Colin B; Batorsky, Rebecca E; Bean, David J; Power, Karen A; Ghebremichael, Musie; Bedard, Hunter E; Gladden, Adrianne D; Seese, Aaron M; Amero, Molly A; Lane, Kimberly; McGrath, Graham; Bazner, Suzane B; Tinsley, Jake; Lennon, Niall J; Henn, Matthew R; Brumme, Zabrina L; Norris, Philip J; Rosenberg, Eric S; Mayer, Kenneth H; Jessen, Heiko; Kosakovsky Pond, Sergei L; Walker, Bruce D; Altfeld, Marcus; Carlson, Jonathan M; Allen, Todd M

    2016-05-01

    Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  2. The gp41659 - 671 HIV-1 antibody epitope: a structurally challenging small peptide

    Science.gov (United States)

    Zhang, Yuan; Sagui, Celeste

    2014-03-01

    We present the results of extensive Molecular Dynamics (MD) simulations of the tridecapeptide corresponding to residues 659-671 of the envelope glycoprotein gp41 of HIV-1, which spans the 2F5 monoclonal antibody epitope ELDKWA. The most recent AMBER force fields ff99SB and ff12SB in both implicit and explicit solvents have been used for a cumulative time longer than 7.2 μs . We have analyzed the conformational ensembles of the peptide both with and without applied tensile restraints, and found that: (1) The amount of helical populations is important in aqueous solution, but this structure forms part of a flexible conformational ensemble with a rugged free energy landscape with shallow minima, which agrees well with the bulk of the experimental observations; (2) our results are more consistent with the experimental results than those from previous simulations; (3) under uniaxial tension, the disordered peptide first becomes fully helical before melting into turns, loops and 310-helices.

  3. Improving the Immunogenicity of Native-like HIV-1 Envelope Trimers by Hyperstabilization

    Directory of Open Access Journals (Sweden)

    Alba Torrents de la Peña

    2017-08-01

    Full Text Available The production of native-like recombinant versions of the HIV-1 envelope glycoprotein (Env trimer requires overcoming the natural flexibility and instability of the complex. The engineered BG505 SOSIP.664 trimer mimics the structure and antigenicity of native Env. Here, we describe how the introduction of new disulfide bonds between the glycoprotein (gp120 and gp41 subunits of SOSIP trimers of the BG505 and other genotypes improves their stability and antigenicity, reduces their conformational flexibility, and helps maintain them in the unliganded conformation. The resulting next-generation SOSIP.v5 trimers induce strong autologous tier-2 neutralizing antibody (NAb responses in rabbits. In addition, the BG505 SOSIP.v6 trimers induced weak heterologous NAb responses against a subset of tier-2 viruses that were not elicited by the prototype BG505 SOSIP.664. These stabilization methods can be applied to trimers from multiple genotypes as components of multivalent vaccines aimed at inducing broadly NAbs (bNAbs.

  4. Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

    African Journals Online (AJOL)

    Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

  5. A European multicientre study on the comparison of HIV-1 viral loads between VERIS HIV-1 Assay and Roche COBAS® TAQMAN® HIV-1 test, Abbott RealTime HIV-1 Assay, and Siemens VERSANT HIV-1 Assay.

    Science.gov (United States)

    Braun, Patrick; Delgado, Rafael; Drago, Monica; Fanti, Diana; Fleury, Hervé; Hofmann, Jörg; Izopet, Jacques; Kühn, Sebastian; Lombardi, Alessandra; Mancon, Alessandro; Marcos, Mª Angeles; Mileto, Davide; Sauné, Karine; O'Shea, Siobhan; Pérez-Rivilla, Alfredo; Ramble, John; Trimoulet, Pascale; Vila, Jordi; Whittaker, Duncan; Artus, Alain; Rhodes, Daniel

    2017-07-01

    Viral load monitoring is essential for patients under treatment for HIV. Beckman Coulter has developed the VERIS HIV-1 Assay for use on the novel, automated DxN VERIS Molecular Diagnostics System. ¥ OBJECTIVES: Evaluation of the clinical performance of the new quantitative VERIS HIV-1 Assay at multiple EU laboratories. Method comparison with the VERIS HIV-1 Assay was performed with 415 specimens at 5 sites tested with COBAS ® AmpliPrep/COBAS ® TaqMan ® HIV-1 Test, v2.0, 169 specimens at 3 sites tested with RealTime HIV-1 Assay, and 202 specimens from 2 sites tested with VERSANT HIV-1 Assay. Patient monitoring sample results from 4 sites were also compared. Bland-Altman analysis showed the average bias between VERIS HIV-1 Assay and COBAS HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay to be 0.28, 0.39, and 0.61 log 10 cp/mL, respectively. Bias at low end levels below 1000cp/mL showed predicted bias to be HIV-1 Assay versus COBAS HIV-1 Test and RealTime HIV-1 Assay, and HIV-1 Assay. Analysis on 174 specimens tested with the 0.175mL volume VERIS HIV-1 Assay and COBAS HIV-1 Test showed average bias of 0.39 log 10 cp/mL. Patient monitoring results using VERIS HIV-1 Assay demonstrated similar viral load trends over time to all comparators. The VERIS HIV-1 Assay for use on the DxN VERIS System demonstrated comparable clinical performance to COBAS ® HIV-1 Test, RealTime HIV-1 Assay, and VERSANT HIV-1 Assay. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Human Non-neutralizing HIV-1 Envelope Monoclonal Antibodies Limit the Number of Founder Viruses during SHIV Mucosal Infection in Rhesus Macaques.

    Science.gov (United States)

    Santra, Sampa; Tomaras, Georgia D; Warrier, Ranjit; Nicely, Nathan I; Liao, Hua-Xin; Pollara, Justin; Liu, Pinghuang; Alam, S Munir; Zhang, Ruijun; Cocklin, Sarah L; Shen, Xiaoying; Duffy, Ryan; Xia, Shi-Mao; Schutte, Robert J; Pemble Iv, Charles W; Dennison, S Moses; Li, Hui; Chao, Andrew; Vidnovic, Kora; Evans, Abbey; Klein, Katja; Kumar, Amit; Robinson, James; Landucci, Gary; Forthal, Donald N; Montefiori, David C; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Robb, Merlin L; Michael, Nelson L; Kim, Jerome H; Soderberg, Kelly A; Giorgi, Elena E; Blair, Lily; Korber, Bette T; Moog, Christiane; Shattock, Robin J; Letvin, Norman L; Schmitz, Joern E; Moody, M A; Gao, Feng; Ferrari, Guido; Shaw, George M; Haynes, Barton F

    2015-08-01

    HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.

  7. New crown motif of an HIV-1 V3 loop sequence from a Ugandan AIDS patient.

    Science.gov (United States)

    von Brunn, A; von Brunn, B; Eberle, J; Biryahwaho, B; Downing, R G; Gürtler, L

    1995-01-01

    HIV-1 V3 loop sequences from Ugandan patients include motifs from subtypes A, B, and D. To characterize further HIV isolates, V3 loop sequences were amplified from HIV-1 isolated in 1987 from peripheral blood mononuclear cells (PBL) of three patients with full-blown AIDS from Kampala, Uganda. The PBL were separated by Ficoll Paque gradients and cocultivated with noninfected donor lymphocytes for two weeks. The HIV was then transferred to HUT-78 cells. From extracted DNA of the permanently-infected HUT-78 cells, nested polymerase chain reaction (PCR) was conducted, with V3 loop sequencing performed directly upon PCR fragments derived from two independent DNA preparations and on cloned fragments. Isolates MVP-9801, -9802, and -9803 show 35.6%, 32.4%, and 29.7% nucleotide sequence divergence from the ELI subtype D sequence; 31.5%, 25.7%, and 18.9% divergence from the Z2Z6 subtype D sequence; and 21.9%, 12.2%, and 12.2% divergence from the subtype D consensus sequence. All three deduced amino acid sequences fit into the subtype D consensus sequence rather than into other V3 loop sequences described for Ugandan subtype A isolates. MVP-9802 and MVP-9803 contain the GSGQA pentapeptide motif at the tip of the V3 loop, while MVP-9801 contains GGRA. This may be explained by a deletion of proline codon between the codons for the two glycine residues. The authors believe that this deletion has not been previously reported. They also note that the deletion does not appear to be associated with a growth difference in vitro or with a difference in pathogenicity in vivo. The immunogenic implications of this altered V3 loop crest remain unclear. The Western blot profiles for the gp160, gp120, and gp41 proteins of the three Ugandan isolates manifest normal molecular weights.

  8. Isolation of HIV-1-neutralizing mucosal monoclonal antibodies from human colostrum.

    Directory of Open Access Journals (Sweden)

    James Friedman

    Full Text Available Generation of potent anti-HIV antibody responses in mucosal compartments is a potential requirement of a transmission-blocking HIV vaccine. HIV-specific, functional antibody responses are present in breast milk, and these mucosal antibody responses may play a role in protection of the majority of HIV-exposed, breastfeeding infants. Therefore, characterization of HIV-specific antibodies produced by B cells in milk could guide the development of vaccines that elicit protective mucosal antibody responses.We isolated B cells from colostrum of an HIV-infected lactating woman with a detectable neutralization response in milk and recombinantly produced and characterized the resulting HIV-1 Envelope (Env-specific monoclonal antibodies (mAbs.The identified HIV-1 Env-specific colostrum mAbs, CH07 and CH08, represent two of the first mucosally-derived anti-HIV antibodies yet to be reported. Colostrum mAb CH07 is a highly-autoreactive, weakly-neutralizing gp140-specific mAb that binds to linear epitopes in the gp120 C5 region and gp41 fusion domain. In contrast, colostrum mAb CH08 is a nonpolyreactive CD4-inducible (CD4i gp120-specific mAb with moderate breadth of neutralization.These novel HIV-neutralizing mAbs isolated from a mucosal compartment provide insight into the ability of mucosal B cell populations to produce functional anti-HIV antibodies that may contribute to protection against virus acquisition at mucosal surfaces.

  9. Mutagenesis of tyrosine and di-leucine motifs in the HIV-1 envelope cytoplasmic domain results in a loss of Env-mediated fusion and infectivity

    Directory of Open Access Journals (Sweden)

    Claiborne Daniel T

    2011-05-01

    Full Text Available Abstract Background The gp41 component of the Human Immunodeficiency Virus (HIV envelope glycoprotein (Env contains a long cytoplasmic domain (CD with multiple highly conserved tyrosine (Y and dileucine (LL motifs. Studies suggest that the motifs distal to major endocytosis motif (Y712HRL, located at residues 712-715 of Env, may contribute to Env functionality in the viral life cycle. In order to examine the biological contribution of these motifs in the biosynthesis, transport, and function of Env, we constructed two panels of mutants in which the conserved Y- and LL-motifs were sequentially substituted by alternative residues, either in the presence or absence of Y712. Additional mutants targeting individual motifs were then constructed. Results All mutant Envs, when expressed in the absence of other viral proteins, maintained at least WT levels of Env surface staining by multiple antibodies. The Y712 mutation (Y712C contributed to at least a 4-fold increase in surface expression for all mutants containing this change. Sequential mutagenesis of the Y- and LL-motifs resulted in a generally progressive decrease in Env fusogenicity. However, additive mutation of dileucine and tyrosine motifs beyond the tyrosine at residue 768 resulted in the most dramatic effects on Env incorporation into virions, viral infectivity, and virus fusion with target cells. Conclusions From the studies reported here, we show that mutations of the Y- and LL-motifs, which effectively eliminate the amphipathic nature of the lytic peptide 2 (LLP2 domain or disrupt YW and LL motifs in a region spanning residues 795-803 (YWWNLLQYW, just C-terminal of LLP2, can dramatically interfere with biological functions of HIV-1 Env and abrogate virus replication. Because these mutant proteins are expressed at the cell surface, we conclude that tyrosine and di-leucine residues within the cytoplasmic domain of gp41 play critical roles in HIV-1 replication that are distinct from that of

  10. A next-generation cleaved, soluble HIV-1 Env trimer, BG505 SOSIP.664 gp140, expresses multiple epitopes for broadly neutralizing but not non-neutralizing antibodies.

    Science.gov (United States)

    Sanders, Rogier W; Derking, Ronald; Cupo, Albert; Julien, Jean-Philippe; Yasmeen, Anila; de Val, Natalia; Kim, Helen J; Blattner, Claudia; de la Peña, Alba Torrents; Korzun, Jacob; Golabek, Michael; de Los Reyes, Kevin; Ketas, Thomas J; van Gils, Marit J; King, C Richter; Wilson, Ian A; Ward, Andrew B; Klasse, P J; Moore, John P

    2013-09-01

    A desirable but as yet unachieved property of a human immunodeficiency virus type 1 (HIV-1) vaccine candidate is the ability to induce broadly neutralizing antibodies (bNAbs). One approach to the problem is to create trimeric mimics of the native envelope glycoprotein (Env) spike that expose as many bNAb epitopes as possible, while occluding those for non-neutralizing antibodies (non-NAbs). Here, we describe the design and properties of soluble, cleaved SOSIP.664 gp140 trimers based on the subtype A transmitted/founder strain, BG505. These trimers are highly stable, more so even than the corresponding gp120 monomer, as judged by differential scanning calorimetry. They are also homogenous and closely resemble native virus spikes when visualized by negative stain electron microscopy (EM). We used several techniques, including ELISA and surface plasmon resonance (SPR), to determine the relationship between the ability of monoclonal antibodies (MAbs) to bind the soluble trimers and neutralize the corresponding virus. In general, the concordance was excellent, in that virtually all bNAbs against multiple neutralizing epitopes on HIV-1 Env were highly reactive with the BG505 SOSIP.664 gp140 trimers, including quaternary epitopes (CH01, PG9, PG16 and PGT145). Conversely, non-NAbs to the CD4-binding site, CD4-induced epitopes or gp41ECTO did not react with the trimers, even when their epitopes were present on simpler forms of Env (e.g. gp120 monomers or dissociated gp41 subunits). Three non-neutralizing MAbs to V3 epitopes did, however, react strongly with the trimers but only by ELISA, and not at all by SPR and to only a limited extent by EM. These new soluble trimers are useful for structural studies and are being assessed for their performance as immunogens.

  11. A next-generation cleaved, soluble HIV-1 Env trimer, BG505 SOSIP.664 gp140, expresses multiple epitopes for broadly neutralizing but not non-neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Rogier W Sanders

    2013-09-01

    Full Text Available A desirable but as yet unachieved property of a human immunodeficiency virus type 1 (HIV-1 vaccine candidate is the ability to induce broadly neutralizing antibodies (bNAbs. One approach to the problem is to create trimeric mimics of the native envelope glycoprotein (Env spike that expose as many bNAb epitopes as possible, while occluding those for non-neutralizing antibodies (non-NAbs. Here, we describe the design and properties of soluble, cleaved SOSIP.664 gp140 trimers based on the subtype A transmitted/founder strain, BG505. These trimers are highly stable, more so even than the corresponding gp120 monomer, as judged by differential scanning calorimetry. They are also homogenous and closely resemble native virus spikes when visualized by negative stain electron microscopy (EM. We used several techniques, including ELISA and surface plasmon resonance (SPR, to determine the relationship between the ability of monoclonal antibodies (MAbs to bind the soluble trimers and neutralize the corresponding virus. In general, the concordance was excellent, in that virtually all bNAbs against multiple neutralizing epitopes on HIV-1 Env were highly reactive with the BG505 SOSIP.664 gp140 trimers, including quaternary epitopes (CH01, PG9, PG16 and PGT145. Conversely, non-NAbs to the CD4-binding site, CD4-induced epitopes or gp41ECTO did not react with the trimers, even when their epitopes were present on simpler forms of Env (e.g. gp120 monomers or dissociated gp41 subunits. Three non-neutralizing MAbs to V3 epitopes did, however, react strongly with the trimers but only by ELISA, and not at all by SPR and to only a limited extent by EM. These new soluble trimers are useful for structural studies and are being assessed for their performance as immunogens.

  12. Pregnancy-induced rise in serum C-peptide concentrations in women with type 1 diabetes

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Rehfeld, Jens F; Pedersen-Bjergaard, Ulrik

    2009-01-01

    diabetes. At 8, 14, 21, 27, and 33 weeks blood samples were drawn for measurements of A1C, C-peptide, and serum glucose. C-peptide (detection limit: 6 pmol/l) was considered stimulated at a corresponding serum glucose concentration >or=5.0 mmol/l. GAD antibody concentration was determined at 8 and 33 weeks...... in 35 women. RESULTS: C-peptide concentrations gradually increased throughout pregnancy regardless of serum glucose concentrations in the 90 women with a median duration of diabetes of 17 years (range 1-36 years). Among 35 women with paired recordings of stimulated C-peptide, C-peptide production.......85). Multivariate regression analysis revealed a positive association between the absolute increase in C-peptide concentrations during pregnancy and decreased A1C from 8 to 33 weeks (P = 0.003). CONCLUSIONS: A pregnancy-induced increase in C-peptide concentrations in women with long-term type 1 diabetes...

  13. Diagnostik af HIV-1 infektionen

    DEFF Research Database (Denmark)

    Christiansen, C B; Dickmeiss, E; Bygbjerg, Ib Christian

    1991-01-01

    Different methods have been developed for the diagnosis of HIV infection, i.e. detection of antibodies, antigen and proviral DNA. ELISA methods for detecting HIV-1 antibodies are widely used as screening assays. A sample which is repeatedly positive with ELISA is re-tested with a confirmatory test...... in a proportion of patients. Detection and quantitation of HIV antigen are used as indicators of disease progression and for monitoring the antiviral efficacy of therapeutic interventions. When no antibodies or antigens can be detected in persons suspected of having HIV infection, culture of HIV can be performed....... For research purposes, detection of small amounts of proviral DNA can be made with polymerase chain reaction (PCR). The method is not yet applicable in routine diagnosis of HIV infection....

  14. C-peptide promotes lesion development in a mouse model of arteriosclerosis.

    Science.gov (United States)

    Vasic, Dusica; Marx, Nikolaus; Sukhova, Galina; Bach, Helga; Durst, Renate; Grüb, Miriam; Hausauer, Angelina; Hombach, Vinzenz; Rottbauer, Wolfgang; Walcher, Daniel

    2012-04-01

    Patients with insulin resistance and early type 2 diabetes exhibit an increased propensity to develop a diffuse and extensive pattern of arteriosclerosis. Typically, these patients show elevated serum levels of the proinsulin cleavage product C-peptide and immunohistochemical data from our group revealed C-peptide deposition in early lesions of these individuals. Moreover, in vitro studies suggest that C-peptide could promote atherogenesis. This study examined whether C-peptide promotes vascular inflammation and lesion development in a mouse model of arteriosclerosis. ApoE-deficient mice on a high fat diet were treated with C-peptide or control injections for 12 weeks and the effect on lesion size and plaque composition was analysed. C-peptide treatment significantly increased C-peptide blood levels by 4.8-fold without having an effect on glucose or insulin levels, nor on the lipid profile. In these mice, C-peptide deposition in atherosclerotic plaques was significantly increased compared with controls. Moreover, lesions of C-peptide-treated mice contained significantly more macrophages (1.6 ± 0.3% versus 0.7 ± 0.2% positive area; P arteriosclerosis support the hypothesis that C-peptide may have an active role in atherogenesis in patients with diabetes and insulin resistance. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  15. Neutralizing antibody escape during HIV-1 mother-to-child transmission involves conformational masking of distal epitopes in envelope.

    Science.gov (United States)

    Goo, Leslie; Milligan, Caitlin; Simonich, Cassandra A; Nduati, Ruth; Overbaugh, Julie

    2012-09-01

    HIV-1 variants transmitted to infants are often resistant to maternal neutralizing antibodies (NAbs), suggesting that they have escaped maternal NAb pressure. To define the molecular basis of NAb escape that contributes to selection of transmitted variants, we analyzed 5 viruses from 2 mother-to-child transmission pairs, in which the infant virus, but not the maternal virus, was resistant to neutralization by maternal plasma near transmission. We generated chimeric viruses between maternal and infant envelope clones obtained near transmission and examined neutralization by maternal plasma. The molecular determinants of NAb escape were distinct, even when comparing two maternal variants to the transmitted infant virus within one pair, in which insertions in V4 of gp120 and substitutions in HR2 of gp41 conferred neutralization resistance. In another pair, deletions and substitutions in V1 to V3 conferred resistance, but neither V1/V2 nor V3 alone was sufficient. Although the sequence determinants of escape were distinct, all of them involved modifications of potential N-linked glycosylation sites. None of the regions that mediated escape were major linear targets of maternal NAbs because corresponding peptides failed to compete for neutralization. Instead, these regions disrupted multiple distal epitopes targeted by HIV-1-specific monoclonal antibodies, suggesting that escape from maternal NAbs occurred through conformational masking of distal epitopes. This strategy likely allows HIV-1 to utilize relatively limited changes in the envelope to preserve the ability to infect a new host while simultaneously evading multiple NAb specificities present in maternal plasma.

  16. Evolution of antibody landscape and viral envelope escape in an HIV-1 CRF02_AG infected patient with 4E10-like antibodies

    Directory of Open Access Journals (Sweden)

    Grupping Katrijn

    2009-12-01

    Full Text Available Abstract Background A minority of HIV-1 infected individuals develop broad cross-neutralizing (BCN plasma antibodies that are capable of neutralizing a spectrum of virus variants belonging to different HIV-1 clades. The aim of this study was to identify the targeted epitopes of an individual with BCN plasma antibodies, referred to as ITM4, using peptide phage display. This study also aimed to use the selected mimotopes as tools to unravel the evolution of the antibody landscape and the viral envelope escape which may provide us with new insights for vaccine design. Results This study led us to identify ITM4 plasma antibodies directed to the 4E10 epitope located in the gp41 membrane-proximal external region (MPER. Analysis of antibody specificities revealed unusual immunogenic properties of the ITM4 viral envelope, as not only the V3 loop and the gp41 MPER but also the C1 and lentivirus lytic peptide 2 (LLP2 region seem to be targets of the immune system. The 4E10-like antibodies are consistently elicited during the 6-year follow up period. HIV-1 ITM4 pseudoviruses showed an increasing resistance over time to MPER monoclonal antibodies 4E10 and 2F5, although no changes are found in the critical positions of the epitope. Neutralization of COT6.15 (subtype C; 4E10-sensitive pseudoviruses with alanine substitutions in the MPER region indicated an overlapping specificity of the 4E10 monoclonal antibody and the ITM4 follow up plasma. Moreover the 4E10-like antibodies of ITM4 contribute to the BCN capacity of the plasma. Conclusions Using ITM4 BCN plasma and peptide phage display technology, we have identified a patient with 4E10-like BCN antibodies. Our results indicate that the elicited 4E10-like antibodies play a role in virus neutralization. The viral RNA was isolated at different time points and the ITM4 envelope sequence analysis of both early (4E10-sensitive and late (4E10-resistant viruses suggest that other regions in the envelope, outside the

  17. Quantifying Ongoing HIV-1 Exposure in HIV-1–Serodiscordant Couples to Identify Individuals With Potential Host Resistance to HIV-1

    Science.gov (United States)

    Mackelprang, Romel D.; Baeten, Jared M.; Donnell, Deborah; Celum, Connie; Farquhar, Carey; de Bruyn, Guy; Essex, Max; McElrath, M. Juliana; Nakku-Joloba, Edith; Lingappa, Jairam R.

    2012-01-01

    Background. Immunogenetic correlates of resistance to HIV-1 in HIV-1–exposed seronegative (HESN) individuals with consistently high exposure may inform HIV-1 prevention strategies. We developed a novel approach for quantifying HIV-1 exposure to identify individuals remaining HIV-1 uninfected despite persistent high exposure. Methods. We used longitudinal predictors of HIV-1 transmission in HIV-1 serodiscordant couples to score HIV-1 exposure and define HESN clusters with persistently high, low, and decreasing risk trajectories. The model was validated in an independent cohort of serodiscordant couples. We describe a statistical tool that can be applied to other HESN cohorts to identify individuals with high exposure to HIV-1. Results. HIV-1 exposure was best quantified by frequency of unprotected sex with, plasma HIV-1 RNA levels among, and presence of genital ulcer disease among HIV-1–infected partners and by age, pregnancy status, herpes simplex virus 2 serostatus, and male circumcision status among HESN participants. Overall, 14% of HESN individuals persistently had high HIV-1 exposure and exhibited a declining incidence of HIV-1 infection over time. Conclusions. A minority of HESN individuals from HIV-1–discordant couples had persistent high HIV-1 exposure over time. Decreasing incidence of infection in this group suggests these individuals were selected for resistance to HIV-1 and may be most appropriate for identifying biological correlates of natural host resistance to HIV-1 infection. PMID:22926009

  18. HIV-1 as RNA evolution machine

    NARCIS (Netherlands)

    Berkhout, Ben

    2011-01-01

    We have over the years studied several sequence or structural elements within the HIV-1 RNA genome. Molecular mechanisms have been proposed for the role of these RNA motifs in virus replication. We have developed HIV-1 evolution as a powerful research method to study different aspects of the viral

  19. T cell dynamics in HIV-1 infection

    NARCIS (Netherlands)

    Clark, D.R.; Boer, R.J. de; Wolthers, K.C.; Miedema, F.

    1999-01-01

    One of the most prominent features of HIV-1 infection is CD4⁺ T cell depletion. This statement is widely used in papers on HIV-1 research; however, while true, it is deceptively simplistic in that it fails to describe what is actually a complex change in the representation of T cell

  20. HIV-1 Latency in Monocytes/Macrophages

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    2014-04-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 targets CD4+ T cells and cells of the monocyte/macrophage lineage. HIV pathogenesis is characterized by the depletion of T lymphocytes and by the presence of a population of cells in which latency has been established called the HIV-1 reservoir. Highly active antiretroviral therapy (HAART has significantly improved the life of HIV-1 infected patients. However, complete eradication of HIV-1 from infected individuals is not possible without targeting latent sources of infection. HIV-1 establishes latent infection in resting CD4+ T cells and findings indicate that latency can also be established in the cells of monocyte/macrophage lineage. Monocyte/macrophage lineage includes among others, monocytes, macrophages and brain resident macrophages. These cells are relatively more resistant to apoptosis induced by HIV-1, thus are important stable hideouts of the virus. Much effort has been made in the direction of eliminating HIV-1 resting CD4+ T-cell reservoirs. However, it is impossible to achieve a cure for HIV-1 without considering these neglected latent reservoirs, the cells of monocyte/macrophage lineage. In this review we will describe our current understanding of the mechanism of latency in monocyte/macrophage lineage and how such cells can be specifically eliminated from the infected host.

  1. Synthetic peptides derived from an N-terminal domain of the E2 protein of GB virus C in the study of GBV-C/HIV-1 co-infection.

    Science.gov (United States)

    Fernández, Leticia; Chan, Weng C; Egido, Meritxell; Gómara, María J; Haro, Isabel

    2012-05-01

    Synthetic peptides derived from GB virus C (GBV-C) have previously been studied in our group for the development of new systems capable of diagnosing diseases caused by this humanotropic virus. We also recently described specific peptide domains of the E2 envelop protein of GBV-C that have the capacity to interfere with the HIV-1 fusion peptide, produce a notable decrease in cellular membrane fusion, and perturb HIV-1 infectivity in a dose-dependent manner. The present work discloses the design and synthesis of both linear and cyclic branched peptides based on a previously reported N-terminal sequence of the GBV-C E2 protein. Immunoassays and cell-cell fusion assays were performed to evaluate their diagnostic value to detect anti-GBV-C antibodies in HIV-1 patients, as well as their putative anti-HIV-1 activity as entry inhibitors. Our results showed that chemical modifications of the selected E2(7-26) linear peptide to afford cyclic architecture do not result in an enhanced inhibition of gp41 HIV-1-mediated cell-cell fusion nor improved sensitivity in the detection of GBV-C antibodies in HIV-1 co-infected patients. Thus, the ELISA data reinforce the potential utility of linear versions of the E2(7-26) region for the development of new peptide-based immunosensor devices for the detection of anti-GBV-C antibodies in HIV-1 co-infected patients. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

  2. Infected cell killing by HIV-1 protease promotes NF-kappaB dependent HIV-1 replication.

    Directory of Open Access Journals (Sweden)

    Gary D Bren

    2008-05-01

    Full Text Available Acute HIV-1 infection of CD4 T cells often results in apoptotic death of infected cells, yet it is unclear what evolutionary advantage this offers to HIV-1. Given the independent observations that acute T cell HIV-1 infection results in (1 NF-kappaB activation, (2 caspase 8 dependent apoptosis, and that (3 caspase 8 directly activates NF-kappaB, we questioned whether these three events might be interrelated. We first show that HIV-1 infected T cell apoptosis, NF-kappaB activation, and caspase 8 cleavage by HIV-1 protease are coincident. Next we show that HIV-1 protease not only cleaves procaspase 8, producing Casp8p41, but also independently stimulates NF-kappaB activity. Finally, we demonstrate that the HIV protease cleavage of caspase 8 is necessary for optimal NF-kappaB activation and that the HIV-1 protease specific cleavage fragment Casp8p41 is sufficient to stimulate HIV-1 replication through NF-kappaB dependent HIV-LTR activation both in vitro as well as in cells from HIV infected donors. Consequently, the molecular events which promote death of HIV-1 infected T cells function dually to promote HIV-1 replication, thereby favoring the propagation and survival of HIV-1.

  3. [Role of C-peptide in the pathogenesis of diabetic nephropathy].

    Science.gov (United States)

    Martina, Valentina; Maestroni, Anna; Maestroni, Silvia; Zerbini, Gianpaolo

    2010-01-01

    Insulin and C-peptide are secreted by pancreatic beta cells in equimolar amounts. Although C-peptide has long been believed to have no biological function, in recent years this molecule has been recognized as an independent hormone with a specific G-protein-coupled receptor. Recent evidence suggests that C-peptide may also have a specific nephroprotective effect, particularly in cases of diabetic nephropathy. In animal models of diabetes this beneficial effect has been repeatedly confirmed. Contradictory results have been obtained in humans: on the one hand it was shown that patients with diabetic nephropathy have lower plasma levels of C-peptide than patients with diabetes of similar duration and normal renal function; on the other hand it is also evident that patients affected by type 2 diabetes develop nephropathy even in the presence of high plasma levels of C-peptide, suggesting that in humans C-peptide is likely to have multifaceted activity. This review describes the different arguments supporting or contrasting the notion of C-peptide as a potential new therapy for diabetic nephropathy. It is possible that only a well performed, large-scale clinical study with careful evaluation of the positive and negative effects of C-peptide will finally clarify whether C-peptide reintegration in patients with type 1 diabetes is able to prevent the development and/or control the progression of diabetic nephropathy.

  4. C-peptide inhibits leukocyte-endothelium interaction in the microcirculation during acute endothelial dysfunction.

    Science.gov (United States)

    Scalia, R; Coyle, K M; Levine, B J; Booth, G; Lefer, A M

    2000-11-01

    C-peptide is a cleavage product that comes from processing proinsulin to insulin that induces nitric oxide (NO) -mediated vasodilation. NO modulates leukocyte-endothelium interaction. We hypothesized that C-peptide might inhibit leukocyte-endothelium interaction via increased release of endothelial NO. Using intravital microscopy of the rat mesentery, we measured leukocyte-endothelium interactions after administration of C-peptide to the rat. Superfusion of the rat mesentery with either thrombin or L-NAME consistently and significantly increased the number of rolling, adhering, and transmigrated leukocytes. C-peptide significantly attenuated either thrombin- or L-NAME-induced leukocyte-endothelium interactions in rat mesenteric venules. A control scrambled sequence of C-peptide characterized by the same amino acid composition in a randomized sequence failed to inhibit leukocyte-endothelium interactions. These effects of C-peptide were associated with decreased surface expression of the cell adhesion molecules P-selectin and ICAM-1 on the microvascular endothelium. Endothelial nitric oxide synthase (eNOS) mRNA levels were increased in rats injected with C-peptide. This enhanced eNOS expression was associated with a marked increase in basal NO release from the aorta of C-peptide-treated rats. We conclude that C-peptide is a potent inhibitor of leukocyte-endothelium interaction and that this effect is specifically related to inhibition of endothelial cell adhesion molecules via maintenance of NO release from the vascular endothelium.

  5. GADD45 proteins inhibit HIV-1 replication through specific suppression of HIV-1 transcription.

    Science.gov (United States)

    Liang, Zhibin; Liu, Ruikang; Zhang, Hui; Zhang, Suzhen; Hu, Xiaomei; Tan, Juan; Liang, Chen; Qiao, Wentao

    2016-06-01

    GADD45 proteins are a group of stress-induced proteins and participate in various cellular pathways including cell cycle regulation, cell survival and death, DNA repair and demethylation. It was recently shown that HIV-1 infection induces the expression of GADD45 proteins. However, the effect of GADD45 on HIV-1 replication has not been studied. Here, we report that overexpression of GADD45 proteins reduces HIV-1 production through suppressing transcription from the HIV-1 LTR promoter. This inhibitory effect is specific to HIV-1, since GADD45 proteins neither inhibit the LTR promoters from other retroviruses nor reduce the production of these viruses. Knockdown of endogenous GADD45 modestly activates HIV-1 in the J-Lat A72 latency cell line, which suggests GADD45 proteins might play a role in maintaining HIV-1 latency. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Cytoplasmic Dynein Promotes HIV-1 Uncoating

    Directory of Open Access Journals (Sweden)

    Paulina Pawlica

    2014-11-01

    Full Text Available Retroviral capsid (CA cores undergo uncoating during their retrograde transport (toward the nucleus, and/or after reaching the nuclear membrane. However, whether HIV-1 CA core uncoating is dependent upon its transport is not understood. There is some evidence that HIV-1 cores retrograde transport involves cytoplasmic dynein complexes translocating on microtubules. Here we investigate the role of dynein-dependent transport in HIV-1 uncoating. To interfere with dynein function, we depleted dynein heavy chain (DHC using RNA interference, and we over-expressed p50/dynamitin. In immunofluorescence microscopy experiments, DHC depletion caused an accumulation of CA foci in HIV-1 infected cells. Using a biochemical assay to monitor HIV-1 CA core disassembly in infected cells, we observed an increase in amounts of intact (pelletable CA cores upon DHC depletion or p50 over-expression. Results from these two complementary assays suggest that inhibiting dynein-mediated transport interferes with HIV-1 uncoating in infected cells, indicating the existence of a functional link between HIV-1 transport and uncoating.

  7. Inhibiting sexual transmission of HIV-1 infection.

    Science.gov (United States)

    Shattock, Robin J; Moore, John P

    2003-10-01

    The worldwide infection rate for HIV-1 is estimated to be 14,000 per day, but only now, more than 20 years into the epidemic, are the immediate events between exposure to infectious virus and the establishment of infection becoming clear. Defining the mechanisms of HIV-1 transmission, the target cells involved and how the virus attaches to and fuses with these cells, could reveal ways to block the sexual spread of the virus. In this review, we will discuss how our increasing knowledge of the ways in which HIV-1 is transmitted is shaping the development of new, more sophisticated intervention strategies based on the application of vaginal or rectal microbicides.

  8. Comparative Analysis of the Glycosylation Profiles of Membrane-Anchored HIV-1 Envelope Glycoprotein Trimers and Soluble gp140

    Science.gov (United States)

    Go, Eden P.; Herschhorn, Alon; Gu, Christopher; Castillo-Menendez, Luis; Zhang, Shijian; Mao, Youdong; Chen, Haiyan; Ding, Haitao; Wakefield, John K.; Hua, David; Liao, Hua-Xin; Kappes, John C.; Sodroski, Joseph

    2015-01-01

    ABSTRACT The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer, which consists of the gp120 and gp41 subunits, is the focus of multiple strategies for vaccine development. Extensive Env glycosylation provides HIV-1 with protection from the immune system, yet the glycans are also essential components of binding epitopes for numerous broadly neutralizing antibodies. Recent studies have shown that when Env is isolated from virions, its glycosylation profile differs significantly from that of soluble forms of Env (gp120 or gp140) predominantly used in vaccine discovery research. Here we show that exogenous membrane-anchored Envs, which can be produced in large quantities in mammalian cells, also display a virion-like glycan profile, where the glycoprotein is extensively decorated with high-mannose glycans. Additionally, because we characterized the glycosylation with a high-fidelity profiling method, glycopeptide analysis, an unprecedented level of molecular detail regarding membrane Env glycosylation and its heterogeneity is presented. Each glycosylation site was characterized individually, with about 500 glycoforms characterized per Env protein. While many of the sites contain exclusively high-mannose glycans, others retain complex glycans, resulting in a glycan profile that cannot currently be mimicked on soluble gp120 or gp140 preparations. These site-level studies are important for understanding antibody-glycan interactions on native Env trimers. Additionally, we report a newly observed O-linked glycosylation site, T606, and we show that the full O-linked glycosylation profile of membrane-associated Env is similar to that of soluble gp140. These findings provide new insight into Env glycosylation and clarify key molecular-level differences between membrane-anchored Env and soluble gp140. IMPORTANCE A vaccine that protects against human immunodeficiency virus type 1 (HIV-1) infection should elicit antibodies that bind to the surface

  9. Cross-border sexual transmission of the newly emerging HIV-1 clade CRF51_01B.

    Directory of Open Access Journals (Sweden)

    Hui Ting Cheong

    Full Text Available A novel HIV-1 recombinant clade (CRF51_01B was recently identified among men who have sex with men (MSM in Singapore. As cases of sexually transmitted HIV-1 infection increase concurrently in two socioeconomically intimate countries such as Malaysia and Singapore, cross transmission of HIV-1 between said countries is highly probable. In order to investigate the timeline for the emergence of HIV-1 CRF51_01B in Singapore and its possible introduction into Malaysia, 595 HIV-positive subjects recruited in Kuala Lumpur from 2008 to 2012 were screened. Phylogenetic relationship of 485 amplified polymerase gene sequences was determined through neighbour-joining method. Next, near-full length sequences were amplified for genomic sequences inferred to be CRF51_01B and subjected to further analysis implemented through Bayesian Markov chain Monte Carlo (MCMC sampling and maximum likelihood methods. Based on the near full length genomes, two isolates formed a phylogenetic cluster with CRF51_01B sequences of Singapore origin, sharing identical recombination structure. Spatial and temporal information from Bayesian MCMC coalescent and maximum likelihood analysis of the protease, gp120 and gp41 genes suggest that Singapore is probably the country of origin of CRF51_01B (as early as in the mid-1990s and featured a Malaysian who acquired the infection through heterosexual contact as host for its ancestral lineages. CRF51_01B then spread rapidly among the MSM in Singapore and Malaysia. Although the importation of CRF51_01B from Singapore to Malaysia is supported by coalescence analysis, the narrow timeframe of the transmission event indicates a closely linked epidemic. Discrepancies in the estimated divergence times suggest that CRF51_01B may have arisen through multiple recombination events from more than one parental lineage. We report the cross transmission of a novel CRF51_01B lineage between countries that involved different sexual risk groups. Understanding

  10. Sensitive Next-Generation Sequencing Method Reveals Deep Genetic Diversity of HIV-1 in the Democratic Republic of the Congo.

    Science.gov (United States)

    Rodgers, Mary A; Wilkinson, Eduan; Vallari, Ana; McArthur, Carole; Sthreshley, Larry; Brennan, Catherine A; Cloherty, Gavin; de Oliveira, Tulio

    2017-03-15

    As the epidemiological epicenter of the human immunodeficiency virus (HIV) pandemic, the Democratic Republic of the Congo (DRC) is a reservoir of circulating HIV strains exhibiting high levels of diversity and recombination. In this study, we characterized HIV specimens collected in two rural areas of the DRC between 2001 and 2003 to identify rare strains of HIV. The env gp41 region was sequenced and characterized for 172 HIV-positive specimens. The env sequences were predominantly subtype A (43.02%), but 7 other subtypes (33.14%), 20 circulating recombinant forms (CRFs; 11.63%), and 20 unclassified (11.63%) sequences were also found. Of the rare and unclassified subtypes, 18 specimens were selected for next-generation sequencing (NGS) by a modified HIV-switching mechanism at the 5' end of the RNA template (SMART) method to obtain full-genome sequences. NGS produced 14 new complete genomes, which included pure subtype C (n = 2), D (n = 1), F1 (n = 1), H (n = 3), and J (n = 1) genomes. The two subtype C genomes and one of the subtype H genomes branched basal to their respective subtype branches but had no evidence of recombination. The remaining 6 genomes were complex recombinants of 2 or more subtypes, including subtypes A1, F, G, H, J, and K and unclassified fragments, including one subtype CRF25 isolate, which branched basal to all CRF25 references. Notably, all recombinant subtype H fragments branched basal to the H clade. Spatial-geographical analysis indicated that the diverse sequences identified here did not expand globally. The full-genome and subgenomic sequences identified in our study population significantly increase the documented diversity of the strains involved in the continually evolving HIV-1 pandemic.IMPORTANCE Very little is known about the ancestral HIV-1 strains that founded the global pandemic, and very few complete genome sequences are available from patients in the Congo Basin, where HIV-1 expanded early in the global pandemic. By

  11. Stoichiometric parameters of HIV-1 entry.

    Science.gov (United States)

    Zarr, Melissa; Siliciano, Robert

    2015-01-01

    During HIV type 1 (HIV-1) entry, trimers of gp120 bind to CD4 and either the CCR5 or CXCR4 coreceptor on the target cell. The stoichiometric parameters associated with HIV-1 entry remain unclear. Important unanswered questions include: how many trimers must attach to CD4 molecules, how many must bind coreceptors, and how many functional gp120 subunits per trimer are required for entry? We performed single round infectivity assays with chimeric viruses and compared the experimental relative infectivity curves with curves generated by mathematical models. Our results indicate that HIV-1 entry requires only a small number of functional spikes (one or two), that Env trimers may function with fewer than three active subunits, and that there is no major difference in the stoichiometric requirements for CCR5 vs. CXCR4 mediated HIV-1 entry into host cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Molecular Understanding of HIV-1 Latency

    Directory of Open Access Journals (Sweden)

    W. Abbas

    2012-01-01

    Full Text Available The introduction of highly active antiretroviral therapy (HAART has been an important breakthrough in the treatment of HIV-1 infection and has also a powerful tool to upset the equilibrium of viral production and HIV-1 pathogenesis. Despite the advent of potent combinations of this therapy, the long-lived HIV-1 reservoirs like cells from monocyte-macrophage lineage and resting memory CD4+ T cells which are established early during primary infection constitute a major obstacle to virus eradication. Further HAART interruption leads to immediate rebound viremia from latent reservoirs. This paper focuses on the essentials of the molecular mechanisms for the establishment of HIV-1 latency with special concern to present and future possible treatment strategies to completely purge and target viral persistence in the reservoirs.

  13. Production of peptide antisera specific for mouse and rat proinsulin C-peptide 2

    DEFF Research Database (Denmark)

    Blume, N; Madsen, O D; Kofod, Hans

    1990-01-01

    Mice and rats have two functional non-allelic insulin genes. By using a synthetic peptide representing a common sequence in mouse and rat C-peptide 2 as antigen, we have produced rabbit antisera specific for an epitope which is not present in mouse or rat C-peptide 1. Long-term immunization did n...

  14. Clinical research in HIV-1 infected children

    OpenAIRE

    Fraaij, Pieter

    2005-01-01

    textabstractAcquired immune deficiency syndrome (AIDS) was described for the first time in 1981. Two years later the previously unknown human immunodeficiency virus (HIV) was identified as the causative agent. HIV has been included in the genus Lent/viruses of the Retroviridae family. Two types are recognized: HIV-1 and HIV-2. Of these, HIV-1 is the primary etiologic agent of the current pandemic. HIV probably originates from simian immunodeficiency virus (SIV) which is endemic in African mon...

  15. Prospective Memory in HIV-1 Infection

    OpenAIRE

    CAREY, CATHERINE L.; WOODS, STEVEN PAUL; RIPPETH, JULIE D.; HEATON, ROBERT K.; GRANT, IGOR

    2006-01-01

    The cognitive deficits associated with HIV-1 infection are thought to primarily reflect neuropathophysiology within the fronto-striato-thalamo-cortical circuits. Prospective memory (ProM) is a cognitive function that is largely dependent on prefronto-striatal circuits, but has not previously been examined in an HIV-1 sample. A form of episodic memory, ProM involves the complex processes of forming, monitoring, and executing future intentions vis-à-vis ongoing distractions. The current study e...

  16. 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.

  17. Detailed topology mapping reveals substantial exposure of the "cytoplasmic" C-terminal tail (CTT sequences in HIV-1 Env proteins at the cell surface.

    Directory of Open Access Journals (Sweden)

    Jonathan D Steckbeck

    Full Text Available Substantial controversy surrounds the membrane topology of the HIV-1 gp41 C-terminal tail (CTT. While few studies have been designed to directly address the topology of the CTT, results from envelope (Env protein trafficking studies suggest that the CTT sequence is cytoplasmically localized, as interactions with intracellular binding partners are required for proper Env targeting. However, previous studies from our lab demonstrate the exposure of a short CTT sequence, the Kennedy epitope, at the plasma membrane of intact Env-expressing cells, the exposure of which is not observed on viral particles. To address the topology of the entire CTT sequence, we serially replaced CTT sequences with a VSV-G epitope tag sequence and examined reactivity of cell- and virion-surface Env to an anti-VSV-G monoclonal antibody. Our results demonstrate that the majority of the CTT sequence is accessible to antibody binding on the surface of Env expressing cells, and that the CTT-exposed Env constitutes 20-50% of the cell-surface Env. Cell surface CTT exposure was also apparent in virus-infected cells. Passive transfer of Env through cell culture media to Env negative (non-transfected cells was not responsible for the apparent cell surface CTT exposure. In contrast to the cell surface results, CTT-exposed Env was not detected on infectious pseudoviral particles containing VSV-G-substituted Env. Finally, a monoclonal antibody directed to the Kennedy epitope neutralized virus in a temperature-dependent manner in a post-attachment neutralization assay. Collectively, these results suggest that the membrane topology of the HIV gp41 CTT is more complex than the widely accepted intracytoplasmic model.

  18. Exosomes: Implications in HIV-1 Pathogenesis

    Science.gov (United States)

    Madison, Marisa N.; Okeoma, Chioma M.

    2015-01-01

    Exosomes are membranous nanovesicles of endocytic origin that carry host and pathogen derived genomic, proteomic, and lipid cargos. Exosomes are secreted by most cell types into the extracellular milieu and are subsequently internalized by recipient cells. Upon internalization, exosomes condition recipient cells by donating their cargos and/or activating various signal transduction pathways, consequently regulating physiological and pathophysiological processes. The role of exosomes in viral pathogenesis, especially human immunodeficiency virus type 1 [HIV-1] is beginning to unravel. Recent research reports suggest that exosomes from various sources play important but different roles in the pathogenesis of HIV-1. From these reports, it appears that the source of exosomes is the defining factor for the exosomal effect on HIV-1. In this review, we will describe how HIV-1 infection is modulated by exosomes and in turn how exosomes are targeted by HIV-1 factors. Finally, we will discuss potentially emerging therapeutic options based on exosomal cargos that may have promise in preventing HIV-1 transmission. PMID:26205405

  19. Prospective memory in HIV-1 infection.

    Science.gov (United States)

    Carey, Catherine L; Woods, Steven Paul; Rippeth, Julie D; Heaton, Robert K; Grant, Igor

    2006-05-01

    The cognitive deficits associated with HIV-1 infection are thought to primarily reflect neuropathophysiology within the fronto-striato-thalamo-cortical circuits. Prospective memory (ProM) is a cognitive function that is largely dependent on prefronto-striatal circuits, but has not previously been examined in an HIV-1 sample. A form of episodic memory, ProM involves the complex processes of forming, monitoring, and executing future intentions vis-à-vis ongoing distractions. The current study examined ProM in 42 participants with HIV-1 infection and 29 demographically similar seronegative healthy comparison (HC) subjects. The HIV-1 sample demonstrated deficits in time- and event-based ProM, as well as more frequent 24-hour delay ProM failures and task substitution errors relative to the HC group. In contrast, there were no significant differences in recognition performance, indicating that the HIV-1 group was able to accurately retain and recognize the ProM intention when retrieval demands were minimized. Secondary analyses revealed that ProM performance correlated with validated clinical measures of executive functions, episodic memory (free recall), and verbal working memory, but not with tests of semantic memory, retention, or recognition discrimination. Taken together, these findings indicate that HIV-1 infection is associated with ProM impairment that is primarily driven by a breakdown in the strategic (i.e., executive) aspects of retrieving future intentions, which is consistent with a prefronto-striatal circuit neuropathogenesis.

  20. HIV-1 transmission linkage in an HIV-1 prevention clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Thomas [Los Alamos National Laboratory; Campbell, Mary S [UNIV OF WASHINGTON; Mullins, James I [UNIV OF WASHINGTON; Hughes, James P [UNIV OF WASHINGTON; Wong, Kim G [UNIV OF WASHINGTON; Raugi, Dana N [UNIV OF WASHINGTON; Scrensen, Stefanie [UNIV OF WASHINGTON

    2009-01-01

    HIV-1 sequencing has been used extensively in epidemiologic and forensic studies to investigate patterns of HIV-1 transmission. However, the criteria for establishing genetic linkage between HIV-1 strains in HIV-1 prevention trials have not been formalized. The Partners in Prevention HSV/HIV Transmission Study (ClinicaITrials.gov NCT00194519) enrolled 3408 HIV-1 serodiscordant heterosexual African couples to determine the efficacy of genital herpes suppression with acyclovir in reducing HIV-1 transmission. The trial analysis required laboratory confirmation of HIV-1 linkage between enrolled partners in couples in which seroconversion occurred. Here we describe the process and results from HIV-1 sequencing studies used to perform transmission linkage determination in this clinical trial. Consensus Sanger sequencing of env (C2-V3-C3) and gag (p17-p24) genes was performed on plasma HIV-1 RNA from both partners within 3 months of seroconversion; env single molecule or pyrosequencing was also performed in some cases. For linkage, we required monophyletic clustering between HIV-1 sequences in the transmitting and seroconverting partners, and developed a Bayesian algorithm using genetic distances to evaluate the posterior probability of linkage of participants sequences. Adjudicators classified transmissions as linked, unlinked, or indeterminate. Among 151 seroconversion events, we found 108 (71.5%) linked, 40 (26.5%) unlinked, and 3 (2.0%) to have indeterminate transmissions. Nine (8.3%) were linked by consensus gag sequencing only and 8 (7.4%) required deep sequencing of env. In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner, illustrating the relevance of these methods in the design of future HIV-1 prevention trials in serodiscordant couples. A hierarchy of sequencing techniques, analysis methods, and expert adjudication contributed to the linkage

  1. Synthetic peptides of hepatitis G virus (GBV-C/HGV) in the selection of putative peptide inhibitors of the HIV-1 fusion peptide.

    Science.gov (United States)

    Herrera, Elena; Gomara, Maria J; Mazzini, Stefania; Ragg, Enzio; Haro, Isabel

    2009-05-21

    The GB virus C or hepatitis G virus (GBV-C/HGV) is a single-stranded positive sense RNA virus that belongs to the Flaviviridae family. Recent years have seen the publication of numerous works in which coinfection with GBV-C/HGV and HIV has been associated with slower progression of the illness and a higher survival rate of patients once AIDS has developed. The mechanism by which the GBV-C/HGV virus has a "protective effect" in patients with HIV has still not been defined. Study of the interaction of the GBV-C/HGV and HIV viruses could lead to the development of new therapeutic agents for the treatment of AIDS. Given that the mechanism responsible for the beneficial effect exercised by the GBV-C/HGV virus in the course of HIV infection has not been defined, the present work is intended as a study of the structure and interactions between the fusion peptide of HIV-1, gp41(1-23), and synthetic peptide sequences of the E2 envelope protein of GBV-C/HGV using biophysical techniques. Our results highlight that the E2(269-286) sequence interacts with the target fusion peptide of HIV-1 and modifies its conformation.

  2. A heterologous prime-boosting strategy with replicating Vaccinia virus vectors and plant-produced HIV-1 Gag/dgp41 virus-like particles.

    Science.gov (United States)

    Meador, Lydia R; Kessans, Sarah A; Kilbourne, Jacquelyn; Kibler, Karen V; Pantaleo, Giuseppe; Roderiguez, Mariano Esteban; Blattman, Joseph N; Jacobs, Bertram L; Mor, Tsafrir S

    2017-07-01

    Showing modest efficacy, the RV144 HIV-1 vaccine clinical trial utilized a non-replicating canarypox viral vector and a soluble gp120 protein boost. Here we built upon the RV144 strategy by developing a novel combination of a replicating, but highly-attenuated Vaccinia virus vector, NYVAC-KC, and plant-produced HIV-1 virus-like particles (VLPs). Both components contained the full-length Gag and a membrane anchored truncated gp41 presenting the membrane proximal external region with its conserved broadly neutralizing epitopes in the pre-fusion conformation. We tested different prime/boost combinations of these components in mice and showed that the group primed with NYVAC-KC and boosted with both the viral vectors and plant-produced VLPs have the most robust Gag-specific CD8 T cell responses, at 12.7% of CD8 T cells expressing IFN-γ in response to stimulation with five Gag epitopes. The same immunization group elicited the best systemic and mucosal antibody responses to Gag and dgp41 with a bias towards IgG1. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. 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.

  4. Decoding distinct membrane interactions of HIV-1 fusion inhibitors using a combined atomic force and fluorescence microscopy approach.

    Science.gov (United States)

    Franquelim, Henri G; Gaspar, Diana; Veiga, A Salomé; Santos, Nuno C; Castanho, Miguel A R B

    2013-08-01

    Enfuvirtide and T-1249 are two potent HIV-1 fusion inhibitor peptides. Recent studies indicate that lipids play an important role in the mode of action of those bioactive molecules. Using a combined tandem atomic force microscopy (AFM)-epifluorescence microscopy approach, we studied the interaction of both enfuvirtide and T-1249 with supported lipid bilayers. Fluid (ld)-gel (so) and ld-liquid ordered (lo) phase-separated membrane systems were tested. Results, especially for T-1249, show significant lipid membrane activity at a 15μM peptide concentration. T-1249, in opposition to enfuvirtide, induces an increase in membrane surface roughness, decrease in membrane fluidity, bilayer thinning at ld domains and disruption of the so domain borders. In terms of structural properties, both enfuvirtide and T-1249 possess distinct functional hydrophobic and amphipathic domains of HIV gp41. While enfuvirtide only yields the tryptophan-rich domain (TRD), T-1249 possesses both TRD and pocket-binding domain (PBD). TRD increases the hydrophobicity of the peptide while PBD enhances the amphipathic characteristics. As such, the enhanced membrane activity of T-1249 may be explained by a synergism between its amphipathic N-terminal segment and its hydrophophic C-terminal. Our findings provide valuable insights on the molecular-level mode of action of HIV-1 fusion inhibitors, unraveling the correlation between their structural properties and membrane interactions as a factor influencing their antiviral activity. Ultimately, this work validates the applicability of a combined AFM and fluorescence approach to evaluate the mechanic and structural properties of supported lipid bilayers upon interaction with membrane-active peptides. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Stabilizing exposure of conserved epitopes by structure guided insertion of disulfide bond in HIV-1 envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Aemro Kassa

    Full Text Available Entry of HIV-1 into target cells requires binding of the viral envelope glycoprotein (Env to cellular receptors and subsequent conformational changes that culminates in fusion of viral and target cell membranes. Recent structural information has revealed that these conformational transitions are regulated by three conserved but potentially flexible layers stacked between the receptor-binding domain (gp120 and the fusion arm (gp41 of Env. We hypothesized that artificial insertion of a covalent bond will 'snap' Env into a conformation that is less mobile and stably expose conserved sites. Therefore, we analyzed the interface between these gp120 layers (layers 1, 2 and 3 and identified residues that may form disulfide bonds when substituted with cysteines. We subsequently probed the structures of the resultant mutant gp120 proteins by assaying their binding to a variety of ligands using Surface Plasmon Resonance (SPR assay. We found that a single disulfide bond strategically inserted between the highly conserved layers 1 and 2 (C65-C115 is able to 'lock' gp120 in a CD4 receptor bound conformation (in the absence of CD4, as indicated by the lower dissociation constant (Kd for the CD4-induced (CD4i epitope binding 17b antibody. When disulfide-stabilized monomeric (gp120 and trimeric (gp140 Envs were used to immunize rabbits, they were found to elicit a higher proportion of antibodies directed against both CD4i and CD4 binding site epitopes than the wild-type proteins. These results demonstrate that structure-guided stabilization of inter-layer interactions within HIV-1 Env can be used to expose conserved epitopes and potentially overcome the sequence diversity of these molecules.

  6. HIV-1 vaccine induced immune responses in newborns of HIV-1 infected mothers.

    Science.gov (United States)

    McFarland, Elizabeth J; Johnson, Daniel C; Muresan, Petronella; Fenton, Terence; Tomaras, Georgia D; McNamara, James; Read, Jennifer S; Douglas, Steven D; Deville, Jaime; Gurwith, Marc; Gurunathan, Sanjay; Lambert, John S

    2006-07-13

    Breast milk transmission continues to account for a large proportion of cases of mother-to-child transmission of HIV-1 worldwide. An effective HIV-1 vaccine coupled with either passive immunization or short-term antiretroviral prophylaxis represents a potential strategy to prevent breast milk transmission. This study evaluated the safety and immunogenicity of ALVAC HIV-1 vaccine with and without a subunit envelope boost in infants born to HIV-1-infected women. : Placebo-controlled, double-blinded study. Infants born to HIV-1-infected mothers in the US were immunized with a prime-boost regimen using a canarypox virus HIV-1 vaccine (vCP1452) and a recombinant glycoprotein subunit vaccine (rgp120). Infants (n = 30) were randomized to receive: vCP1452 alone, vCP1452 + rgp120, or corresponding placebos. Local reactions were mild or moderate and no significant systemic toxicities occurred. Subjects receiving both vaccines had gp120-specific binding serum antibodies that were distinguishable from maternal antibody. Repeated gp160-specific lymphoproliferative responses were observed in 75%. Neutralizing activity to HIV-1 homologous to the vaccine strain was observed in 50% of the vCP1452 + rgp120 subjects who had lost maternal antibody by week 24. In some infants HIV-1-specific proliferative and antibody responses persisted until week 104. HIV-1-specific cytotoxic T lymphocyte responses were detected in two subjects in each treatment group; the frequency of HIV-1 specific cytotoxic T lymphocyte responses did not differ between vaccine and placebo recipients. The demonstration of vaccine-induced immune responses in early infancy supports further study of HIV-1 vaccination as a strategy to reduce breast milk transmission.

  7. Improving the Expression and Purification of Soluble, Recombinant Native-Like HIV-1 Envelope Glycoprotein Trimers by Targeted Sequence Changes.

    Science.gov (United States)

    Ringe, Rajesh P; Ozorowski, Gabriel; Yasmeen, Anila; Cupo, Albert; Cruz Portillo, Victor M; Pugach, Pavel; Golabek, Michael; Rantalainen, Kimmo; Holden, Lauren G; Cottrell, Christopher A; Wilson, Ian A; Sanders, Rogier W; Ward, Andrew B; Klasse, P J; Moore, John P

    2017-06-15

    Soluble, recombinant native-like envelope glycoprotein (Env) trimers of various human immunodeficiency virus type 1 (HIV-1) genotypes are being developed for structural studies and as vaccine candidates aimed at the induction of broadly neutralizing antibodies (bNAbs). The prototypic design is designated SOSIP.664, but many HIV-1 env genes do not yield fully native-like trimers efficiently. One such env gene is CZA97.012 from a neutralization-resistant (tier 2) clade C virus. As appropriately purified, native-like CZA97.012 SOSIP.664 trimers induce autologous neutralizing antibodies (NAbs) efficiently in immunized rabbits, we sought to improve the efficiency with which they can be produced and to better understand the limitations to the original design. By using structure- and antigenicity-guided mutagenesis strategies focused on the V2 and V3 regions and the gp120-gp41 interface, we developed the CZA97 SOSIP.v4.2-M6.IT construct. Fully native-like, stable trimers that display multiple bNAb epitopes could be expressed from this construct in a stable CHO cell line and purified at an acceptable yield using either a PGT145 or a 2G12 bNAb affinity column. We also show that similar mutagenesis strategies can be used to improve the yields and properties of SOSIP.664 trimers of the DU422, 426c, and 92UG037 genotypes.IMPORTANCE Recombinant trimeric proteins based on HIV-1 env genes are being developed for future vaccine trials in humans. A feature of these proteins is their mimicry of the envelope glycoprotein (Env) structure on virus particles that is targeted by neutralizing antibodies, i.e., antibodies that prevent cells from becoming infected. The vaccine concept under exploration is that recombinant trimers may be able to elicit virus-neutralizing antibodies when delivered as immunogens. Because HIV-1 is extremely variable, a practical vaccine may need to incorporate Env trimers derived from multiple different virus sequences. Accordingly, we need to understand how to

  8. V3 loop truncations in HIV-1 envelope impart resistance to coreceptor inhibitors and enhanced sensitivity to neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Meg M Laakso

    2007-08-01

    Full Text Available The V1/V2 region and the V3 loop of the human immunodeficiency virus type I (HIV-1 envelope (Env protein are targets for neutralizing antibodies and also play an important functional role, with the V3 loop largely determining whether a virus uses CCR5 (R5, CXCR4 (X4, or either coreceptor (R5X4 to infect cells. While the sequence of V3 is variable, its length is highly conserved. Structural studies indicate that V3 length may be important for interactions with the extracellular loops of the coreceptor. Consistent with this view, genetic truncation of the V3 loop is typically associated with loss of Env function. We removed approximately one-half of the V3 loop from three different HIV-1 strains, and found that only the Env protein from the R5X4 strain R3A retained some fusion activity. Loss of V1/V2 (DeltaV1/V2 was well tolerated by this virus. Passaging of virus with the truncated V3 loop resulted in the derivation of a virus strain that replicated with wild-type kinetics. This virus, termed TA1, retained the V3 loop truncation and acquired several adaptive changes in gp120 and gp41. TA1 could use CCR5 but not CXCR4 to infect cells, and was extremely sensitive to neutralization by HIV-1 positive human sera, and by antibodies to the CD4 binding site and to CD4-induced epitopes in the bridging sheet region of gp120. In addition, TA1 was completely resistant to CCR5 inhibitors, and was more dependent upon the N-terminal domain of CCR5, a region of the receptor that is thought to contact the bridging sheet of gp120 and the base of the V3 loop, and whose conformation may not be greatly affected by CCR5 inhibitors. These studies suggest that the V3 loop protects HIV from neutralization by antibodies prevalent in infected humans, that CCR5 inhibitors likely act by disrupting interactions between the V3 loop and the coreceptor, and that altered use of CCR5 by HIV-1 associated with increased sensitivity to changes in the N-terminal domain can be linked

  9. CCR5 inhibitors in HIV-1 therapy.

    Science.gov (United States)

    Dorr, Patrick; Perros, Manos

    2008-11-01

    The human immunodeficiency virus 1 (HIV-1) is the causative pathogen of AIDS, the world's biggest infectious disease killer. About 33 million people are infected worldwide, with 2.1 million deaths a year as a direct consequence. The devastating nature of AIDS has prompted widespread research, which has led to an extensive array of therapies to suppress viral replication and enable recovery of the immune system to prolong and improve patient life substantially. However, the genetic plasticity and replication rate of HIV-1 are considerable, which has lead to rapid drug resistance. This, together with the need for reducing drug side effects and increasing regimen compliance, has led researchers to identify antiretroviral drugs with new modes of action. This review describes the discovery and clinical development of CCR5 antagonists and the recent approval of maraviroc as a breakthrough in anti-HIV-1 therapy. CCR5 inhibitors target a human cofactor to disable HIV-1 entry into the cells, and thereby provide a new hurdle for the virus to overcome. The status and expert opinion of CCR5 antagonists for the treatment of HIV-1 infection are detailed.

  10. Association between low C-peptide and fragility fractures in postmenopausal women without diabetes.

    Science.gov (United States)

    Ferro, Y; Russo, C; Russo, D; Gazzaruso, C; Coppola, A; Gallotti, P; Zambianchi, V; Fodaro, M; Romeo, S; Galliera, E; Marazzi, M G; Romanelli, M M C; Giannini, S; Pujia, A; Montalcini, T

    2017-04-11

    C-peptide has been shown to exert several, previously unknown, biological effects. A recent cross-sectional study demonstrated an association between low C-peptide serum levels and low lumbar bone density of postmenopausal women not affected by diabetes. To date, very little research attention has been directed toward the association between C-peptide and osteoporotic fractures. To contribute toward filling this gap, we investigated the association between C-peptide and fractures in postmenopausal women. A cohort of 133 non-diabetic postmenopausal women with and without a history of fractures was evaluated in this cross-sectional investigation. Standardized interviews were performed to gather information on the patients' fracture history. All of the participants underwent a bone mineral density assessment by DXA, radiographs, and a serum C-peptide measurement. Thirty-four women presented fractures. Bivariate analysis revealed an inverse correlation between C-peptide and fractures (r = -0.27, p = 0.002). A significant difference in mean C-peptide levels was also found between women with vs. without fractures (p = 0.01, adjusted for age, BMI and glucose). Logistic regression analysis showed that C-peptide levels, femoral and vertebral BMD were all negatively associated with fracture status (B = -1.097, ES = 0.401, p = 0.006, 95% CI 0.15-0.73; B = -15.6, SE = 4.17, p C-peptide levels and a history of fractures in postmenopausal women without diabetes. These results suggest that C-peptidemay exert an effect on bone mineral density. However, further large-scale studies are needed to corroborate this finding and investigate the potential underlying mechanisms involved.

  11. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules.

    Science.gov (United States)

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S Y

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells.

  12. Identification of HIV-1 Tat-Associated Proteins Contributing to HIV-1 Transcription and Latency

    Science.gov (United States)

    Jean, Maxime Junior; Power, Derek; Kong, Weili; Huang, Huachao; Santoso, Netty; Zhu, Jian

    2017-01-01

    Human immunodeficiency virus type 1 (HIV-1) Tat is a virus-encoded trans-activator that plays a central role in viral transcription. We used our recently developed parallel analysis of in vitro translated open reading frames (ORFs) (PLATO) approach to identify host proteins that associate with HIV-1 Tat. From this proteomic assay, we identify 89 Tat-associated proteins (TAPs). We combine our results with other datasets of Tat or long terminal repeat (LTR)-associated proteins. For some of these proteins (NAT10, TINP1, XRCC5, SIN3A), we confirm their strong association with Tat. These TAPs also suppress Tat-mediated HIV-1 transcription. Removing suppression of HIV-1 transcription benefits the reversal of post-integrated, latent HIV-1 proviruses. We demonstrate that these transcriptionally suppressing TAPs contribute to HIV-1 latency in Jurkat latency (J-LAT) cells. Therefore, our proteomic analysis highlights the previously unappreciated TAPs that play a role in maintaining HIV-1 latency and can be further studied as potential pharmacological targets for the “shock and kill” HIV-1 cure strategy. PMID:28368303

  13. Cross-Reactivity of Anti-HIV-1 T Cell Immune Responses among the Major HIV-1 Clades in HIV-1-Positive Individuals from 4 Continents

    National Research Council Canada - National Science Library

    Paul M. Coplan; Swati B. Gupta; Sheri A. Dubey; Punnee Pitisuttithum; Alex Nikas; Bernard Mbewe; Efthyia Vardas; Mauro Schechter; Esper G. Kallas; Dan C. Freed; Tong-Ming Fu; Christopher T. Mast; Pilaipan Puthavathana; James Kublin; Kelly Brown Collins; John Chisi; Richard Pendame; Scott J. Thaler; Glenda Gray; James Mcintyre; Walter L. Straus; Jon H. Condra; Devan V. Mehrotra; Harry A. Guess; Emilio A. Emini; John W. Shiver

    2005-01-01

    .... Therefore, we quantified the cross-clade reactivity, among unvaccinated individuals, of anti-HIV-1 T cell responses to the infecting HIV-1 clade relative to other major circulating clades. Methods...

  14. C-peptide exhibits a late induction effect on matrix metallopeptidase-9 in high glucose-stimulated rat mesangial cells.

    Science.gov (United States)

    Wang, Junxia; Li, Yanning; Xu, Mingzhi; Li, Dandan; Wang, Yu; Qi, Jinsheng; He, Kunyu

    2016-12-01

    Insufficient matrix metalloproteinase (MMP)-9 and MMP-2 is considered to be a contributor of extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can reverse fibrosis, thus exerting a beneficial effect on DN. Whether C-peptide induces MMP-9 and MMP-2 to reverse ECM accumulation is not clear. In the present study, in order to determine ECM metabolism, rat mesangial cells were treated with high glucose (HG) and C-peptide intervention, then the early and late effects of C-peptide on HG-affected MMP-9 and MMP-2 were evaluated. Firstly, it was confirmed that HG mainly suppressed MMP-9 expression levels. Furthermore, C-peptide treatment induced MMP-9 expression at 6 h and suppressed it at 24 h, revealing the early dual effects of C-peptide on MMP-9 expression. Subsequently, significant increase in MMP-9 expression at 72, 96 and 120 h C-peptide treatment was observed. These changes in MMP-9 protein content confirmed its expression changes following late C-peptide treatment. Furthermore, at 96 and 120 h C-peptide treatment reversed the HG-inhibited MMP-9 secretion, further indicating the late induction effect of C-peptide on MMP-9. The present results demonstrated that C-peptide exerted a late induction effect on MMP-9 in HG-stimulated rat mesangial cells, which may be associated with the underlying mechanism of C-peptide's reversal effects on DN.

  15. HIV-1 Reservoir Association with Immune Activation

    Directory of Open Access Journals (Sweden)

    Alejandro Vallejo

    2015-09-01

    Full Text Available In this issue of EBioMedicine, Ruggiero and colleagues describe immune activation biomarkers associated with the size of the HIV reservoir in a carefully designed cross-sectional study. The cohort consists of a homogeneous sample of HIV-1-infected patients with long-term plasma HIV-1 RNA suppression under antiretroviral treatment (ART. It is crucial to explore the potential utility of biomarkers that are easier (less labor intensive, less expensive to measure than integrated HIV DNA load, in order to quickly and accurately quantify cellular reservoirs of HIV.

  16. 21 CFR 862.1135 - C-peptides of proinsulin test system.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test... test system is a device intended to measure C-peptides of proinsulin levels in serum, plasma, and urine...

  17. Carbohydrate-binding agents efficiently prevent dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN)-directed HIV-1 transmission to T lymphocytes.

    Science.gov (United States)

    Balzarini, Jan; Van Herrewege, Yven; Vermeire, Kurt; Vanham, Guido; Schols, Dominique

    2007-01-01

    Exposure of HIV-1 to dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN)-expressing B-lymphoblast Raji cells (Raji/DC-SIGN) but not to wild-type Raji/0 cells results in the capture of HIV-1 particles to the cells as measured by the quantification of cell-associated p24 antigen. Cocultivation of HIV-1-captured Raji/DC-SIGN cells with uninfected CD4+ T lymphocyte C8166 cells results in abundant formation of syncytia within 36 h after cocultivation. Short preexposure of HIV-1 to carbohydrate-binding agents (CBA) dose dependently prevents the Raji/DC-SIGN cells from efficiently binding the virus particles, and no syncytia formation occurs upon subsequent cocultivation with C8166 cells. Thus, the mannose-specific [i.e., the plant lectins Hippeastrum hybrid agglutinin (HHA), Galanthus nivalis agglutinin (GNA), Narcissus pseudonarcissus agglutinin; and Cymbidium agglutinin (CA); the procaryotic cyanovirin-N (CV-N); and the monoclonal antibody 2G12) and N-acetylglucosamine-specific (i.e., the plant lectin Urtica dioica agglutinin) CBAs efficiently abrogate the DC-SIGN-directed HIV-1 capture and subsequent transmission to T lymphocytes. In this assay, the CD4-down-regulating cyclotriazodisulfonamide derivative, the CXCR4 and CCR5 coreceptor antagonists 1-[[4-(1,4,8,11-tetrazacyclotetradec-1-ylmethyl)phenyl]methyl] - 1,4,8,11 - tetrazacyclotetradecane (AMD3100) and maraviroc, the gp41-binding enfuvirtide, and the polyanionic substances dextran sulfate (M(r) 5000), sulfated polyvinyl alcohol, and the naphthalene sulfonate polymer PRO-2000 were markedly less efficient or even completely ineffective. Similar observations were made in primary monocyte-derived dendritic cell cultures that were infected with HIV-1 particles that had been shortly pre-exposed to the CBAs CV-N, CA, HHA, and GNA and the polyanions DS-5000 and PRO-2000. The potential of CBAs, but not polyanions and other structural/functional classes of entry inhibitors, to impair

  18. Viral linkage in HIV-1 seroconverters and their partners in an HIV-1 prevention clinical trial.

    Directory of Open Access Journals (Sweden)

    Mary S Campbell

    2011-03-01

    Full Text Available Characterization of viruses in HIV-1 transmission pairs will help identify biological determinants of infectiousness and evaluate candidate interventions to reduce transmission. Although HIV-1 sequencing is frequently used to substantiate linkage between newly HIV-1 infected individuals and their sexual partners in epidemiologic and forensic studies, viral sequencing is seldom applied in HIV-1 prevention trials. The Partners in Prevention HSV/HIV Transmission Study (ClinicalTrials.gov #NCT00194519 was a prospective randomized placebo-controlled trial that enrolled serodiscordant heterosexual couples to determine the efficacy of genital herpes suppression in reducing HIV-1 transmission; as part of the study analysis, HIV-1 sequences were examined for genetic linkage between seroconverters and their enrolled partners.We obtained partial consensus HIV-1 env and gag sequences from blood plasma for 151 transmission pairs and performed deep sequencing of env in some cases. We analyzed sequences with phylogenetic techniques and developed a Bayesian algorithm to evaluate the probability of linkage. For linkage, we required monophyletic clustering between enrolled partners' sequences and a Bayesian posterior probability of ≥ 50%. Adjudicators classified each seroconversion, finding 108 (71.5% linked, 40 (26.5% unlinked, and 3 (2.0% indeterminate transmissions, with linkage determined by consensus env sequencing in 91 (84%. Male seroconverters had a higher frequency of unlinked transmissions than female seroconverters. The likelihood of transmission from the enrolled partner was related to time on study, with increasing numbers of unlinked transmissions occurring after longer observation periods. Finally, baseline viral load was found to be significantly higher among linked transmitters.In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner

  19. C-peptide comparative radioimmunoassays: a study of three commercial kits

    Energy Technology Data Exchange (ETDEWEB)

    Villaume, C.; Beck, B. (INSERM U, 59, Groupe de Nutrition et Dietetique, 54 - Nancy (France))

    1983-01-01

    Plasma C-peptide immunoreactivity (CPR) was measured in 18 fasting subjects with three different commercial kits (RIA-mat C-peptide-, Byk-Mallinckrodt; RIA-gnost-hC-peptide, Hoechst-Behring; human C-peptide radioimmunoassay kit, Novo) The subjects were chosen as to cover a wide range of CPR concentrations (five healthy subjects, six obese subjects, three insulin-dependent diabetics, four normal subjects whose plasmas had been kept at - 20/sup 0/C for periods of 16 or 36 months). CPR was measured with the Novo kit in eight other plasmas which were kept over a period of 36 months, with or without aprotinin. Good correlations have been established among the values found with the three kits. However, absolute concentration values for each subject as well as the dispersion of all plasma C-peptide values varied as a function of the kit used because of antibody specificity differences and because of the various separation methods. The normal range proposed changes with each kit and the blood CPR of a subject can be a normal, reduced or increased one, depending on the kit used. After several months of storage, plasma CPR degradation is observed with the three kits. A protease-inhibitor is necessary in order to avoid this C-peptide degradation due to the apparent existence of a plasma proteolytic enzyme.

  20. C-Peptides for diagnostics and therapy: a veterinary medicine point of view

    Directory of Open Access Journals (Sweden)

    Derek A. Rosenfield

    Full Text Available ABSTRACT: Empirical studies proved that C-peptides are performing numerous intrinsic biological roles, and serve as a marker for pancreatic performance analysis. Since the last decade, C-peptide assays for differential diagnosis in veterinary diabetic patients are becoming more available, but still only for a very limited number of species. Studies on C-peptide as a diagnostic tool, therapy for associated complications, or as replacement therapies for C-peptide deficiency still showed not to be a common practice in veterinary medicine. This review was conducted to determine the potential importance of C-peptide in Veterinary Medicine, relevant in the diagnosis of diabetes and for other metabolic processes, as well as its proposed therapeutic benefits. Numerous articles were identified that reported positive results in their experimental studies, whether C-peptide as a biomarker for pancreatic performance in dogs, cats, and horses, as a non-invasive method to monitor nutritional status in primates, or to investigate its potential therapeutic benefits for diabetes-related illnesses.

  1. Epidemiology of HIV-1 and emerging problems

    NARCIS (Netherlands)

    Lukashov, V. V.; de Ronde, A.; de Jong, J. J.; Goudsmit, J.

    2000-01-01

    Broad use of antiretroviral drugs is becoming a factor that is important to consider for understanding the HIV-1 epidemiology. Since 1993, we observe that a proportion of new infections within major risk groups in Amsterdam is caused by azidothymidine (AZT)-resistant viruses. After the introduction

  2. HIV-1 transcription and latency: an update.

    Science.gov (United States)

    Van Lint, Carine; Bouchat, Sophie; Marcello, Alessandro

    2013-06-26

    Combination antiretroviral therapy, despite being potent and life-prolonging, is not curative and does not eradicate HIV-1 infection since interruption of treatment inevitably results in a rapid rebound of viremia. Reactivation of latently infected cells harboring transcriptionally silent but replication-competent proviruses is a potential source of persistent residual viremia in cART-treated patients. Although multiple reservoirs may exist, the persistence of resting CD4+ T cells carrying a latent infection represents a major barrier to eradication. In this review, we will discuss the latest reports on the molecular mechanisms that may regulate HIV-1 latency at the transcriptional level, including transcriptional interference, the role of cellular factors, chromatin organization and epigenetic modifications, the viral Tat trans-activator and its cellular cofactors. Since latency mechanisms may also operate at the post-transcriptional level, we will consider inhibition of nuclear RNA export and inhibition of translation by microRNAs as potential barriers to HIV-1 gene expression. Finally, we will review the therapeutic approaches and clinical studies aimed at achieving either a sterilizing cure or a functional cure of HIV-1 infection, with a special emphasis on the most recent pharmacological strategies to reactivate the latent viruses and decrease the pool of viral reservoirs.

  3. Molecular mechanisms of HIV-1 associated neurodegeneration

    Indian Academy of Sciences (India)

    Unknown

    Erichsen D, Lopez A L, Peng H, Niemann D, Williams C,. Bauer M, Morgello S, Cotter R L, Ryan L A, Ghorpade A,. Gendelman H E and Zheng J 2003 Neuronal injury regulates fractalkine: relevance for HIV-1 associated dementia; J. Neu- roimmunol. 138 144–155. Enting R H, Hoetelmans R M, Lange J M, Burger D M and.

  4. Molecular mechanisms of HIV-1 associated neurodegeneration

    Indian Academy of Sciences (India)

    Since identification of the human immunodeficiency virus-1 (HIV-1), numerous studies suggest a link between neurological impairments, in particular dementia, with acquired immunodeficiency syndrome (AIDS) with alarming occurrence worldwide. Approximately, 60% of HIV-infected people show some form of neurological ...

  5. Epigenetic heterogeneity in HIV-1 latency establishment.

    Science.gov (United States)

    Matsuda, Yuka; Kobayashi-Ishihara, Mie; Fujikawa, Dai; Ishida, Takaomi; Watanabe, Toshiki; Yamagishi, Makoto

    2015-01-09

    Despite prolonged antiretroviral therapy, HIV-1 persists as transcriptionally inactive proviruses. The HIV-1 latency remains a principal obstacle in curing AIDS. It is important to understand mechanisms by which HIV-1 latency is established to make the latent reservoir smaller. We present a molecular characterization of distinct populations at an early phase of infection. We developed an original dual-color reporter virus to monitor LTR kinetics from establishment to maintenance stage. We found that there are two ways of latency establishment i.e., by immediate silencing and slow inactivation from active infection. Histone covalent modifications, particularly polycomb repressive complex 2 (PRC2)-mediated H3K27 trimethylation, appeared to dominate viral transcription at the early phase. PRC2 also contributes to time-dependent LTR dormancy in the chronic phase of the infection. Significant differences in sensitivity against several stimuli were observed between these two distinct populations. These results will expand our understanding of heterogeneous establishment of HIV-1 latency populations.

  6. Enteric viruses in HIV-1 seropositive and HIV-1 seronegative children with diarrheal diseases in Brazil

    Science.gov (United States)

    Rocha, Monica Simões; Fumian, Tulio Machado; Maranhão, Adriana Gonçalves; de Assis, Rosane Maria; Xavier, Maria da Penha Trindade Pinheiro; Rocha, Myrna Santos; Miagostovich, Marize Pereira; Leite, José Paulo Gagliardi; Volotão, Eduardo de Mello

    2017-01-01

    Diarrheal diseases (DD) have distinct etiological profiles in immune-deficient and immune-competent patients. This study compares detection rates, genotype distribution and viral loads of different enteric viral agents in HIV-1 seropositive (n = 200) and HIV-1 seronegative (n = 125) children hospitalized with DD in Rio de Janeiro, Brazil. Except for group A rotavirus (RVA), which were detected through enzyme immunoassay, the other enteric viruses (norovirus [NoV], astrovirus [HAstV], adenovirus [HAdV] and bocavirus [HBoV]) were detected through PCR or RT-PCR. A quantitative PCR was performed for RVA, NoV, HAstV, HAdV and HBoV. Infections with NoV (19% vs. 9.6%; p<0.001), HBoV (14% vs. 7.2%; p = 0.042) and HAdV (30.5% vs. 14.4%; p<0.001) were significantly more frequent among HIV-1 seropositive children. RVA was significantly less frequent among HIV-1 seropositive patients (6.5% vs. 20%; p<0.001). Similarly, frequency of infection with HAstV was lower among HIV-1 seropositive children (5.5% vs. 12.8%; p = 0.018). Among HIV-1 seropositive children 33 (16.5%) had co-infections, including three enteric viruses, such as NoV, HBoV and HAdV (n = 2) and NoV, HAstV and HAdV (n = 2). The frequency of infection with more than one virus was 17 (13.6%) in the HIV-1 negative group, triple infection (NoV + HAstV + HBoV) being observed in only one patient. The median viral load of HAstV in feces was significantly higher among HIV-1 positive children compared to HIV-1 negative children. Concerning children infected with RVA, NoV, HBoV and HAdV, no statistically significant differences were observed in the medians of viral loads in feces, comparing HIV-1 seropositive and HIV-1 seronegative children. Similar detection rates were observed for RVA, HAstV and HAdV, whilst NoV and HBoV were significantly more prevalent among children with CD4+ T lymphocyte count below 200 cells/mm3. Enteric viruses should be considered an important cause of DD in HIV-1 seropositive children, along with

  7. Enteric viruses in HIV-1 seropositive and HIV-1 seronegative children with diarrheal diseases in Brazil.

    Directory of Open Access Journals (Sweden)

    Silvana Augusta Rodrigues Portes

    Full Text Available Diarrheal diseases (DD have distinct etiological profiles in immune-deficient and immune-competent patients. This study compares detection rates, genotype distribution and viral loads of different enteric viral agents in HIV-1 seropositive (n = 200 and HIV-1 seronegative (n = 125 children hospitalized with DD in Rio de Janeiro, Brazil. Except for group A rotavirus (RVA, which were detected through enzyme immunoassay, the other enteric viruses (norovirus [NoV], astrovirus [HAstV], adenovirus [HAdV] and bocavirus [HBoV] were detected through PCR or RT-PCR. A quantitative PCR was performed for RVA, NoV, HAstV, HAdV and HBoV. Infections with NoV (19% vs. 9.6%; p<0.001, HBoV (14% vs. 7.2%; p = 0.042 and HAdV (30.5% vs. 14.4%; p<0.001 were significantly more frequent among HIV-1 seropositive children. RVA was significantly less frequent among HIV-1 seropositive patients (6.5% vs. 20%; p<0.001. Similarly, frequency of infection with HAstV was lower among HIV-1 seropositive children (5.5% vs. 12.8%; p = 0.018. Among HIV-1 seropositive children 33 (16.5% had co-infections, including three enteric viruses, such as NoV, HBoV and HAdV (n = 2 and NoV, HAstV and HAdV (n = 2. The frequency of infection with more than one virus was 17 (13.6% in the HIV-1 negative group, triple infection (NoV + HAstV + HBoV being observed in only one patient. The median viral load of HAstV in feces was significantly higher among HIV-1 positive children compared to HIV-1 negative children. Concerning children infected with RVA, NoV, HBoV and HAdV, no statistically significant differences were observed in the medians of viral loads in feces, comparing HIV-1 seropositive and HIV-1 seronegative children. Similar detection rates were observed for RVA, HAstV and HAdV, whilst NoV and HBoV were significantly more prevalent among children with CD4+ T lymphocyte count below 200 cells/mm3. Enteric viruses should be considered an important cause of DD in HIV-1 seropositive children, along

  8. The Changes of Positive Selection Within env Gene of HIV-1 B', CRF07_BC and CRF08_BC from China Over Time.

    Science.gov (United States)

    Li, Tingting; Sun, Binlian; Jiang, Yanyan; Zeng, Haiyan; Li, Yanpeng; Wang, Yan; Yang, Rongge

    2017-01-01

    It is not clear about the possible evolutionary changes of the three predominant strains of HIV-1 in China over the course of the epidemic. Envelope (env) gene of HIV-1 is a good target for this evolutionary pressure for its enriched epitopes. We collected 159 full or part of env sequences sampled between 1997 and 2010 from database of China, we calculated the genetic distance, detected the positively selected sites by PAML suite and then compared the number using Fisher's exact test between the early period 1997 to 2003 and the late period 2004 to 2010. We found that the diversity of env genes had increased significantly and the positively selected sites were significantly becoming more over time. V2, V4, and C3 regions had suffered an increase positive selection pressure, while V1, V3, V5 and other conserved regions were relatively stable. Several sites were widely selected and compactly located in C3 and V4, five sites were consecutive in V4.There were two common positively selected sites in all groups: 413T in gp120 and 619L in gp41. The common positively selected sites identified in our study implied that they are important in viral survival and adaptation. Based on the role of V3 region in coreceptor determination and disease progression, our results suggested that the virulence of HIV-1 in China might be stable in the short time span. Given the overall increased tendency of positively selection sites in env, we might predict a less virulent state in the long run. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Modeling Anti-HIV-1 HSPC-Based Gene Therapy in Humanized Mice Previously Infected with HIV-1.

    Science.gov (United States)

    Khamaikawin, Wannisa; Shimizu, Saki; Kamata, Masakazu; Cortado, Ruth; Jung, Yujin; Lam, Jennifer; Wen, Jing; Kim, Patrick; Xie, Yiming; Kim, Sanggu; Arokium, Hubert; Presson, Angela P; Chen, Irvin S Y; An, Dong Sung

    2018-06-15

    Investigations of anti-HIV-1 human hematopoietic stem/progenitor cell (HSPC)-based gene therapy have been performed by HIV-1 challenge after the engraftment of gene-modified HSPCs in humanized mouse models. However, the clinical application of gene therapy is to treat HIV-1-infected patients. Here, we developed a new method to investigate an anti-HIV-1 HSPC-based gene therapy in humanized mice previously infected with HIV-1. First, humanized mice were infected with HIV-1. When plasma viremia reached >107 copies/mL 3 weeks after HIV-1 infection, the mice were myeloablated with busulfan and transplanted with anti-HIV-1 gene-modified CD34+ HSPCs transduced with a lentiviral vector expressing two short hairpin RNAs (shRNAs) against CCR5 and HIV-1 long terminal repeat (LTR), along with human thymus tissue under the kidney capsule. Anti-HIV-1 vector-modified human CD34+ HSPCs successfully repopulated peripheral blood and lymphoid tissues in HIV-1 previously infected humanized mice. Anti-HIV-1 shRNA vector-modified CD4+ T lymphocytes showed selective advantage in HIV-1 previously infected humanized mice. This new method will be useful for investigations of anti-HIV-1 gene therapy when testing in a more clinically relevant experimental setting.

  10. Identification of Acute HIV-1 Infection by Hologic Aptima HIV-1 RNA Qualitative Assay

    Science.gov (United States)

    Eller, Leigh Anne; Malia, Jennifer; Jagodzinski, Linda L.; Trichavaroj, Rapee; Oundo, Joseph; Lueer, Cornelia; Cham, Fatim; de Souza, Mark; Michael, Nelson L.; Robb, Merlin L.; Peel, Sheila A.

    2017-01-01

    ABSTRACT The Hologic Aptima HIV-1 Qualitative RNA assay was used in a rigorous screening approach designed to identify individuals at the earliest stage of HIV-1 infection for enrollment into subsequent studies of cellular and viral events in early infection (RV 217/Early Capture HIV Cohort [ECHO] study). Volunteers at high risk for HIV-1 infection were recruited from study sites in Thailand, Tanzania, Uganda, and Kenya with high HIV-1 prevalence rates among the populations examined. Small-volume blood samples were collected by finger stick at twice-weekly intervals and tested with the Aptima assay. Participants with reactive Aptima test results were contacted immediately for entry into a more comprehensive follow-up schedule with frequent blood draws. Evaluation of the Aptima test prior to use in this study showed a detection sensitivity of 5.5 copies/ml (50%), with all major HIV-1 subtypes detected. A total of 54,306 specimens from 1,112 volunteers were examined during the initial study period (August 2009 to November 2010); 27 individuals were identified as converting from uninfected to infected status. A sporadic reactive Aptima signal was observed in HIV-1-infected individuals under antiretroviral therapy. Occasional false-reactive Aptima results in uninfected individuals, or nonreactive results in HIV-1-infected individuals not on therapy, were observed and used to calculate assay sensitivity and specificity. The sensitivity and specificity of the Aptima assay were 99.03% and 99.23%, respectively; positive and negative predictive values were 92.01% and 99.91%, respectively. Conversion from HIV-1-uninfected to -infected status was rapid, with no evidence of a prolonged period of intermittent low-level viremia. PMID:28424253

  11. 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.

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

    Science.gov (United States)

    Huang, Li; Ho, Phong; Yu, Jie; Zhu, Lei; Lee, Kuo-Hsiung; Chen, Chin-Ho

    2011-01-01

    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.

  13. Assessment of HIV-1 entry inhibitors by MLV/HIV-1 pseudotyped vectors

    Directory of Open Access Journals (Sweden)

    Thaler Sonja

    2005-09-01

    Full Text Available Abstract Background Murine leukemia virus (MLV vector particles can be pseudotyped with a truncated variant of the human immunodeficiency virus type 1 (HIV-1 envelope protein (Env and selectively target gene transfer to human cells expressing both CD4 and an appropriate co-receptor. Vector transduction mimics the HIV-1 entry process and is therefore a safe tool to study HIV-1 entry. Results Using FLY cells, which express the MLV gag and pol genes, we generated stable producer cell lines that express the HIV-1 envelope gene and a retroviral vector genome encoding the green fluorescent protein (GFP. The BH10 or 89.6 P HIV-1 Env was expressed from a bicistronic vector which allowed the rapid selection of stable cell lines. A codon-usage-optimized synthetic env gene permitted high, Rev-independent Env expression. Vectors generated by these producer cells displayed different sensitivity to entry inhibitors. Conclusion These data illustrate that MLV/HIV-1 vectors are a valuable screening system for entry inhibitors or neutralizing antisera generated by vaccines.

  14. Urinary C-peptide is not an accurate bioindicator of energy balance in humans.

    Science.gov (United States)

    Bergouignan, Audrey; Habold, Caroline; Rudwill, Floriane; Gauquelin-Koch, Guillemette; Normand, Sylvie; Simon, Chantal; Blanc, Stéphane

    2012-03-01

    The apprehension of the factors that affect long term regulation of energy balance is indispensable to understand the rise in obesity prevalence as well as to delineate levers to prevent it. Accurate measurements of energy balance are however challenging during free-living conditions. Recent studies proposed urinary C-peptide, a metabolic byproduct of insulin synthesis, as reliable noninvasive assessment of energy balance. These studies were in fact essentially based on correlations between urinary C-peptide and energy intake and only focused on nonhuman primates. During a bed-rest study conducted in 16 healthy women in a controlled environment, we tested the existence of a relationship between 24 h-urinary C-peptide and energy balance in humans. Daily energy intake and body mass, body composition (dual-energy X-ray absorptiometry (DXA)) and total energy expenditure (doubly labeled water (DLW) method) was measured and energy balance was calculated as the difference between energy intake and expenditure. Urinary C-peptide was positively correlated with bed-rest-induced changes in fat mass (r(2) = 0.285; P = 0.03) and energy balance assessed at the end of the bed-rest (r(2) = 0.302; P = 0.027). However, in this tightly controlled environment, urinary C-peptide only accounted for 30% of variations in energy balance. No relationship was noted between urinary C-peptide and body or fat mass both at baseline and at the end of the bed-rest. These results indicate that urinary C-peptide cannot be used as an accurate biomarker of energy balance in the general human population in free-living conditions.

  15. Dual role of autophagy in HIV-1 replication and pathogenesis

    Directory of Open Access Journals (Sweden)

    Killian M

    2012-05-01

    Full Text Available Abstract Autophagy, the major mechanism for degrading long-lived intracellular proteins and organelles, is essential for eukaryotic cell homeostasis. Autophagy also defends the cell against invasion by microorganisms and has important roles in innate and adaptive immunity. Increasingly evident is that HIV-1 replication is dependent on select components of autophagy. Fittingly, HIV-1 proteins are able to modulate autophagy to maximize virus production. At the same time, HIV-1 proteins appear to disrupt autophagy in uninfected cells, thereby contributing to CD4+ cell death and HIV-1 pathogenesis. These observations allow for new approaches for the treatment and possibly the prevention of HIV-1 infection. This review focuses on the relationship between autophagy and HIV-1 infection. Discussed is how autophagy plays dual roles in HIV-1 replication and HIV-1 disease progression.

  16. Intestinal microbiota and HIV-1 infection

    Directory of Open Access Journals (Sweden)

    E. B. S. M. Trindade

    2007-01-01

    Full Text Available The intestinal microbiota consists of a qualitatively and quantitatively diverse range of microorganisms dynamically interacting with the host. It is remarkably stable with regard to the presence of microorganisms and their roles which, however, can be altered due to pathological conditions, diet composition, gastrointestinal disturbances and/or drug ingestion. The present review aimed at contributing to the discussion about changes in the intestinal microbiota due to HIV-1 infection, focusing on the triad infection-microbiota-nutrition as factors that promote intestinal bacterial imbalance. Intestinal microbiota alterations can be due to the HIV-1 infection as a primary factor or the pharmacotherapy employed, or they can be one of the consequences of the disease.

  17. Limits on oral transmission of HIV-1.

    Science.gov (United States)

    Cohen, M S; Shugars, D C; Fiscus, S A

    2000-07-22

    This article discusses the potential of acquiring an HIV-1 infection through an oral route, with a view of offering clues for its prevention. In a study of adult animals given low concentration cell-free simian immunodeficiency virus (SIV) orally, histological examination suggested that SIV infected lymphoid tissue through the antigen-transporting crypt epithelium rather than through dendritic cells. The investigators found no evidence of acquiring SIV via the gastrointestinal tract. For humans, HIV transmission from saliva or intimate family contact seems to be extremely rare. This could be because of the low concentration of HIV-1 in saliva. A study of 40 people found that significantly less HIV was found in salivary secretions than in plasma. Another possible explanation for inefficient oral transmission might be that HIV-1 in the oropharynx is inhibited by components found in salivary secretions. Conversely, studies have noted that risk of oral transmission of HIV from contaminated breast milk and semen is higher than from saliva. Breast-feeding by an HIV-infected woman puts the baby at substantial risk of infection and receptive fellatio cannot be considered a safe sex act.

  18. HIV-1 vaccine design: Learning from natural infection

    NARCIS (Netherlands)

    van den Kerkhof, T.L.G.M.

    2016-01-01

    Het humane immuundeficiëntie virus type 1 (hiv-1) is het virus dat aids veroorzaakt. Er is nog steeds geen bescherming tegen een hiv-1 infectie en de beëindiging van de wereldwijde epidemie kan waarschijnlijk alleen worden bereikt met behulp van een vaccin. Een hiv-1 vaccin zal bescherming moeten

  19. HIV-1 envelope trimer fusion proteins and their applications

    NARCIS (Netherlands)

    Sliepen, K.H.E.W.J.

    2016-01-01

    HIV-1 is a major threat to global health and a vaccine is not yet on the horizon. A successful HIV-1 vaccine should probably induce HIV-1 neutralizing antibodies that target the envelope glycoprotein (Env) trimer on the outside of the virion. A possible starting point for such a vaccine are soluble

  20. Quantification of the Epitope Diversity of HIV-1-Specific Binding Antibodies by Peptide Microarrays for Global HIV-1 Vaccine Development

    OpenAIRE

    Stephenson, Kathryn E.; Neubauer, George H.; Reimer, Ulf; Pawlowski, Nikolaus; Knaute, Tobias; Zerweck, Johannes; Korber, Bette T; Barouch, Dan H.

    2014-01-01

    An effective vaccine against human immunodeficiency virus type 1 (HIV-1) will have to provide protection against a vast array of different HIV-1 strains. Current methods to measure HIV-1-specific binding antibodies following immunization typically focus on determining the magnitude of antibody responses, but the epitope diversity of antibody responses has remained largely unexplored. Here we describe the development of a global HIV-1 peptide microarray that contains 6,564 peptides from across...

  1. HIV-1 Phylogenetic analysis shows HIV-1 transits through the meninges to brain and peripheral tissues

    Science.gov (United States)

    Lamers, Susanna L.; Gray, Rebecca R.; Salemi, Marco; Huysentruyt, Leanne C.; McGrath, Michael

    2010-01-01

    Brain infection by the human immunodeficiency virus type 1 (HIV-1) has been investigated in many reports with a variety of conclusions concerning the time of entry and degree of viral compartmentalization. To address these diverse findings, we sequenced HIV-1 gp120 clones from a wide range of brain, peripheral and meningeal tissues from five patients who died from several HIV-1 associated disease pathologies. High-resolution phylogenetic analysis confirmed previous studies that showed a significant degree of compartmentalization in brain and peripheral tissue subpopulations. Some intermixing between the HIV-1 subpopulations was evident, especially in patients that died from pathologies other than HIV-associated dementia. Interestingly, the major tissue harboring virus from both the brain and peripheral tissues was the meninges. These results show that 1) HIV-1 is clearly capable of migrating out of the brain, 2) the meninges are the most likely primary transport tissues, and 3) infected brain macrophages comprise an important HIV reservoir during highly active antiretroviral therapy. PMID:21055482

  2. Evaluation of Xpert HIV-1 Qual assay for resolution of HIV-1 infection in samples with negative or indeterminate Geenius HIV-1/2 results.

    Science.gov (United States)

    Michaeli, Michal; Wax, Marina; Gozlan, Yael; Rakovsky, Aviya; Mendelson, Ella; Mor, Orna

    2016-03-01

    Diagnosis of HIV infection is a multistage algorithm. Following screening with 4(th) generation combination immunoassay, confirmation of HIV infection is performed with an antibody assay that differentiates HIV-1 from HIV-2 infection. In the newly updated algorithm, samples that are nonreactive or indeterminate in the differentiation assay are to be tested with an HIV-1 nucleic acid amplification (NAAT) test for resolution. Xpert HIV-1 Qual is a new NAAT assay approved for the identification of HIV infection in whole and dried blood. To assess the performance of Xpert HIV-1 Qual supplementary assay in resolving the clinical status of serum samples reactive by 4(th) generation immunoassays and indeterminate or negative by Geenius HIV-1/2 confirmatory assay. In a retrospective study, samples from 97 individuals for whom the true HIV-1 status was already known (by follow-up samples) and which were negative or indeterminate by HIV-1/2 Geenius assay were tested with Xpert Qual HIV-1 assay. Xpert Qual assay correctly classified all 97 samples from HIV-1 positive (n=49) and negative (n=48) individuals. The sensitivity and specificity of Xpert Qual when using the true HIV status as a reference were 100% (92.7-100% at 95% confidence interval [CI] and 92.6-100% at 95% CI, respectively). Applying Xpert Qual HIV-1 assay in the new HIV multi-stage diagnostic algorithm correctly classified 100% of HIV-1 infections including 49 from HIV-1 carriers who have not yet seroconverted. With this assay the total time required for acute HIV diagnosis could be significantly reduced. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Escape from autologous neutralizing antibodies in acute/early subtype C HIV-1 infection requires multiple pathways.

    Science.gov (United States)

    Rong, Rong; Li, Bing; Lynch, Rebecca M; Haaland, Richard E; Murphy, Megan K; Mulenga, Joseph; Allen, Susan A; Pinter, Abraham; Shaw, George M; Hunter, Eric; Robinson, James E; Gnanakaran, S; Derdeyn, Cynthia A

    2009-09-01

    One aim for an HIV vaccine is to elicit neutralizing antibodies (Nab) that can limit replication of genetically diverse viruses and prevent establishment of a new infection. Thus, identifying the strengths and weaknesses of Nab during the early stages of natural infection could prove useful in achieving this goal. Here we demonstrate that viral escape readily occurred despite the development of high titer autologous Nab in two subjects with acute/early subtype C infection. To provide a detailed portrayal of the escape pathways, Nab resistant variants identified at multiple time points were used to create a series of envelope (Env) glycoprotein chimeras and mutants within the background of a corresponding newly transmitted Env. In one subject, Nab escape was driven predominantly by changes in the region of gp120 that extends from the beginning of the V3 domain to the end of the V5 domain (V3V5). However, Nab escape pathways in this subject oscillated and at times required cooperation between V1V2 and the gp41 ectodomain. In the second subject, escape was driven by changes in V1V2. This V1V2-dependent escape pathway was retained over time, and its utility was reflected in the virus's ability to escape from two distinct monoclonal antibodies (Mabs) derived from this same patient via introduction of a single potential N-linked glycosylation site in V2. Spatial representation of the sequence changes in gp120 suggested that selective pressure acted upon the same regions of Env in these two subjects, even though the Env domains that drove escape were different. Together the findings argue that a single mutational pathway is not sufficient to confer escape in early subtype C HIV-1 infection, and support a model in which multiple strategies, including potential glycan shifts, direct alteration of an epitope sequence, and cooperative Env domain conformational masking, are used to evade neutralization.

  4. Deletion of the highly conserved N-glycan at Asn260 of HIV-1 gp120 affects folding and lysosomal degradation of gp120, and results in loss of viral infectivity.

    Directory of Open Access Journals (Sweden)

    Leen Mathys

    Full Text Available N-linked glycans covering the surface of the HIV-1 glycoprotein gp120 are of major importance for the correct folding of this glycoprotein. Of the, on average, 24 N-linked glycans present on gp120, the glycan at Asn260 was reported to be essential for the correct expression of gp120 and gp41 in the virus particle and deletion of the N260 glycan in gp120 heavily compromised virus infectivity. We show here that gp160 containing the N260Q mutation reaches the Golgi apparatus during biosynthesis. Using pulse-chase experiments with [35S] methionine/cysteine, we show that oxidative folding was slightly delayed in case of mutant N260Q gp160 and that CD4 binding was markedly compromised compared to wild-type gp160. In the search of compensatory mutations, we found a mutation in the V1/V2 loop of gp120 (S128N that could partially restore the infectivity of mutant N260Q gp120 virus. However, the mutation S128N did not enhance any of the above-mentioned processes so its underlying compensatory mechanism must be a conformational effect that does not affect CD4 binding per se. Finally, we show that mutant N260Q gp160 was cleaved to gp120 and gp41 to a much lower extent than wild-type gp160, and that it was subject of lysosomal degradation to a higher extent than wild-type gp160 showing a prominent role of this process in the breakdown of N260-glycan-deleted gp160, which could not be counteracted by the S128N mutation. Moreover, at least part of the wild-type or mutant gp160 that is normally targeted for lysosomal degradation reached a conformation that enabled CD4 binding.

  5. Photochemical neutralization of HIV-1 and inhibition of HIV-1 induced syncytium formation

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.E.; Utecht, R.E. [South Dakota State Univ., Brookings, SD (United States); Chanh, T.C.; Allan, J.S. [Southwest Foundation for Biomedical Research, San Antonio, TX (United States); Sogandares-Bernal, F.; Judy, M.M.; Matthews J.L. [Baylor Research Foundation, Dallas, TX (United States)

    1993-12-31

    The authors have prepared a new class of photochemically activatable antiviral compounds based on the 1,8-naphthalimide skeleton which are excited by visible (420 nm) light, and which are highly effective in causing neutralization of enveloped viruses including HIV-1, HSV-1, and VSV. One such photoactive compound, 1,14-bis-(N-hexyl-3-bromo-1,8-naphthalimid-4-yl)-1,4,11,14-tetrazatetradecane-5,10-dione (diED66Br) effectively neutralized HIV-1 in vitro at concentrations below .1{mu}M; similar results are obtained for HSV-1 and VSV. DiED66Br also effectively inhibits syncytium formation induced by cells infected with HIV-1 at doses which had no effect on normal human blood peripheral mononuclear cells. The synthesis of the photochemically active compounds and the mode of antiviral action will be discussed.

  6. Defining HIV-1 transmission clusters based on sequence data.

    Science.gov (United States)

    Hassan, Amin S; Pybus, Oliver G; Sanders, Eduard J; Albert, Jan; Esbjörnsson, Joakim

    2017-06-01

    : Understanding HIV-1 transmission dynamics is relevant to both screening and intervention strategies of HIV-1 infection. Commonly, HIV-1 transmission chains are determined based on sequence similarity assessed either directly from a sequence alignment or by inferring a phylogenetic tree. This review is aimed at both nonexperts interested in understanding and interpreting studies of HIV-1 transmission, and experts interested in finding the most appropriate cluster definition for a specific dataset and research question. We start by introducing the concepts and methodologies of how HIV-1 transmission clusters usually have been defined. We then present the results of a systematic review of 105 HIV-1 molecular epidemiology studies summarizing the most common methods and definitions in the literature. Finally, we offer our perspectives on how HIV-1 transmission clusters can be defined and provide some guidance based on examples from real life datasets.

  7. Factors of intermittent HIV-1 excretion in semen and efficiency of sperm processing in obtaining spermatozoa without HIV-1 genomes.

    Science.gov (United States)

    Bujan, Louis; Daudin, Myriam; Matsuda, Tomohiro; Righi, Laurence; Thauvin, Laurence; Berges, Laetitia; Izopet, Jacques; Berrebi, Alain; Massip, Patrice; Pasquier, Christophe

    2004-03-26

    To study the risk factors for HIV-1 in semen according to the localization of HIV-1 in sperm cell fractions and to assess the efficiency of sperm processing in obtaining spermatozoa without HIV-1 genomes. Ninety-four HIV-infected patients provided 281 paired blood and semen samples. Sperm cell separation was performed using two successive methods. HIV-1 RNA was quantified in blood and seminal plasma. HIV-1 RNA and DNA were detected in cell fractions. HIV-1 RNA was found in 14% of seminal plasma samples and up to 8.7% of native semen cells were positive for HIV-1 RNA and DNA. Ten seminal plasma samples had detectable RNA although blood viral load was undetectable. Antiretroviral treatment reduced the likelihood of RNA detection in seminal plasma. For semen with polynuclear cells and HIV-1 RNA in seminal plasma, the likelihood of detecting HIV-1 genomes in semen cells was increased fourfold and sixfold, respectively. In 25% of patients, HIV-1 excretion was intermittent. In the group of patients with systematic negative seminal plasma, HIV-1 genomes were detected in up to 10% of sperm cell samples. Our method of sperm processing always enabled us to obtain spermatozoa without detectable HIV-1 genomes. Polynuclear cells in semen are a risk factor for seminal HIV-1 excretion. Blood viral load was the only predictive factor for the intermittence of HIV-1 excretion in semen over time. Sperm processing using two successive methods was effective in obtaining spermatozoa without detectable HIV-1 genomes regardless of the viral load level in native semen.

  8. Plasmacytoid dendritic cells suppress HIV-1 replication but contribute to HIV-1 induced immunopathogenesis in humanized mice.

    Directory of Open Access Journals (Sweden)

    Guangming Li

    2014-07-01

    Full Text Available The role of plasmacytoid dendritic cells (pDC in human immunodeficiency virus type 1 (HIV-1 infection and pathogenesis remains unclear. HIV-1 infection in the humanized mouse model leads to persistent HIV-1 infection and immunopathogenesis, including type I interferons (IFN-I induction, immune-activation and depletion of human leukocytes, including CD4 T cells. We developed a monoclonal antibody that specifically depletes human pDC in all lymphoid organs in humanized mice. When pDC were depleted prior to HIV-1 infection, the induction of IFN-I and interferon-stimulated genes (ISGs were abolished during acute HIV-1 infection with either a highly pathogenic CCR5/CXCR4-dual tropic HIV-1 or a standard CCR5-tropic HIV-1 isolate. Consistent with the anti-viral role of IFN-I, HIV-1 replication was significantly up-regulated in pDC-depleted mice. Interestingly, the cell death induced by the highly pathogenic HIV-1 isolate was severely reduced in pDC-depleted mice. During chronic HIV-1 infection, depletion of pDC also severely reduced the induction of IFN-I and ISGs, associated with elevated HIV-1 replication. Surprisingly, HIV-1 induced depletion of human immune cells including T cells in lymphoid organs, but not the blood, was reduced in spite of the increased viral replication. The increased cell number in lymphoid organs was associated with a reduced level of HIV-induced cell death in human leukocytes including CD4 T cells. We conclude that pDC play opposing roles in suppressing HIV-1 replication and in promoting HIV-1 induced immunopathogenesis. These findings suggest that pDC-depletion and IFN-I blockade will provide novel strategies for treating those HIV-1 immune non-responsive patients with persistent immune activation despite effective anti-retrovirus treatment.

  9. Increased Risk of HIV-1 Transmission in Pregnancy: A Prospective Study among African HIV-1 Serodiscordant Couples

    Science.gov (United States)

    MUGO, Nelly R.; HEFFRON, Renee; DONNELL, Deborah; WALD, Anna; WERE, Edwin O.; REES, Helen; CELUM, Connie; KIARIE, James N.; COHEN, Craig R.; KAYINTEKORE, Kayitesi; BAETEN, Jared M.

    2011-01-01

    Background Physiologic and behavioral changes during pregnancy may alter HIV-1 susceptibility and infectiousness. Prospective studies exploring pregnancy and HIV-1 acquisition risk in women have found inconsistent results. No study has explored the effect of pregnancy on HIV-1 transmission risk from HIV-1 infected women to male partners. Methods In a prospective study of African HIV-1 serodiscordant couples, we evaluated the relationship between pregnancy and the risk of 1) HIV-1 acquisition among women and 2) HIV-1 transmission from women to men. Results 3321 HIV-1 serodiscordant couples were enrolled, 1085 (32.7%) with HIV-1 susceptible female partners and 2236 (67.3%) with susceptible male partners. HIV-1 incidence in women was 7.35 versus 3.01 per 100 person-years during pregnant and non-pregnant periods (hazard ratio [HR] 2.34, 95% confidence interval [CI] 1.33–4.09). This effect was attenuated and not statistically significant after adjusting for sexual behavior and other confounding factors (adjusted HR 1.71, 95% CI 0.93–3.12). HIV-1 incidence in male partners of infected women was 3.46 versus 1.58 per 100 person-years when their partners were pregnant versus not pregnant (HR 2.31, 95% CI 1.22–4.39). This effect was not attenuated in adjusted analysis (adjusted HR 2.47, 95% CI 1.26–4.85). Conclusions HIV-1 risk increased two-fold during pregnancy. Elevated risk of HIV-1 acquisition in pregnant women appeared in part to be explained by behavioral and other factors. This is the first study to show pregnancy increased the risk of female-to-male HIV-1 transmission, which may reflect biological changes of pregnancy that could increase HIV-1 infectiousness. PMID:21785321

  10. An autoreactive antibody from an SLE/HIV-1 individual broadly neutralizes HIV-1

    Science.gov (United States)

    Bonsignori, Mattia; Wiehe, Kevin; Grimm, Sebastian K.; Lynch, Rebecca; Yang, Guang; Kozink, Daniel M.; Perrin, Florence; Cooper, Abby J.; Hwang, Kwan-Ki; Chen, Xi; Liu, Mengfei; McKee, Krisha; Parks, Robert J.; Eudailey, Joshua; Wang, Minyue; Clowse, Megan; Criscione-Schreiber, Lisa G.; Moody, M. Anthony; Ackerman, Margaret E.; Boyd, Scott D.; Gao, Feng; Kelsoe, Garnett; Verkoczy, Laurent; Tomaras, Georgia D.; Liao, Hua-Xin; Kepler, Thomas B.; Montefiori, David C.; Mascola, John R.; Haynes, Barton F.

    2014-01-01

    Broadly HIV-1–neutralizing antibodies (BnAbs) display one or more unusual traits, including a long heavy chain complementarity-determining region 3 (HCDR3), polyreactivity, and high levels of somatic mutations. These shared characteristics suggest that BnAb development might be limited by immune tolerance controls. It has been postulated that HIV-1–infected individuals with autoimmune disease and defective immune tolerance mechanisms may produce BnAbs more readily than those without autoimmune diseases. In this study, we identified an HIV-1–infected individual with SLE who exhibited controlled viral load (<5,000 copies/ml) in the absence of controlling HLA phenotypes and developed plasma HIV-1 neutralization breadth. We collected memory B cells from this individual and isolated a BnAb, CH98, that targets the CD4 binding site (CD4bs) of HIV-1 envelope glycoprotein 120 (gp120). CH98 bound to human antigens including dsDNA, which is specifically associated with SLE. Anti-dsDNA reactivity was also present in the patient’s plasma. CH98 had a mutation frequency of 25% and 15% nt somatic mutations in the heavy and light chain variable domains, respectively, a long HCDR3, and a deletion in the light chain CDR1. The occurrence of anti-dsDNA reactivity by a HIV-1 CD4bs BnAb in an individual with SLE raises the possibility that some BnAbs and SLE-associated autoantibodies arise from similar pools of B cells. PMID:24614107

  11. Role of Endolysosomes in HIV-1 Tat-Induced Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Liang Hui

    2012-05-01

    Full Text Available Combined anti-retroviral therapeutic drugs effectively increase the lifespan of HIV-1-infected individuals who then have a higher prevalence of HAND (HIV-1 associated neurocognitive disorder. Soluble factors including HIV-1 proteins released from HIV-1-infected cells have been implicated in the pathogenesis of HAND, and particular attention has been paid to the HIV-1 Tat (transactivator of transcription protein because of its ability to directly excite neurons and cause neuronal cell death. Since HIV-1 Tat enters cells by receptor-mediated endocytosis and since endolysosomes play an important role in neuronal cell life and death, we tested here the hypothesis that HIV-1 Tat neurotoxicity is associated with changes in the endolysosome structure and function and also autophagy. Following the treatment of primary cultured rat hippocampal neurons with HIV-1 Tat or as controls mutant-Tat or PBS, neuronal viability was determined using a triple staining method. Preceding observations of HIV-1 Tat-induced neuronal cell death, we observed statistically significant changes in the structure and membrane integrity of endolysosomes, endolysosome pH and autophagy. As early as 24 h after HIV-1 Tat was applied to neurons, HIV-1 Tat accumulated in endolysosomes, endolysosome morphology was affected and their size increased, endolysosome membrane integrity was disrupted, endolysosome pH increased, specific activities of endolysosome enzymes decreased and autophagy was inhibited, as indicated by the significant changes in three markers for autophagy. In contrast, statistically significant levels of HIV-1 Tat-induced neuronal cell death were observed only after 48 h of HIV-1 Tat treatment. Our findings suggest that endolysosomes are involved in HIV-1 Tat-induced neurotoxicity and may represent a target for therapeutic intervention against HAND.

  12. Human Cytosolic Extracts Stabilize the HIV-1 Core

    Science.gov (United States)

    Fricke, Thomas; Brandariz-Nuñez, Alberto; Wang, Xiaozhao; Smith, Amos B.

    2013-01-01

    The stability of the HIV-1 core in the cytoplasm is crucial for productive HIV-1 infection. Mutations that stabilize or destabilize the core showed defects on HIV-1 reverse transcription and infection. We developed a novel and simple assay to measure the stability of in vitro-assembled HIV-1 CA-NC complexes. The assay allowed us to demonstrate that cytosolic extracts strongly stabilize the HIV-1 core. Interestingly, stabilization of in vitro-assembled HIV-1 CA-NC complexes is not due solely to macromolecular crowding, suggesting the presence of specific cellular factors that stabilize the HIV-1 core. By using our novel assay, we measured the abilities of different drugs, such as PF74, CAP-1, IXN-053, cyclosporine, Bi2 (also known as BI-2), and the peptide CAI, to modulate the stability of in vitro-assembled HIV-1 CA-NC complexes. Interestingly, we found that PF74 and Bi2 strongly stabilized HIV-1 CA-NC complexes. On the other hand, the peptide CAI destabilized HIV-1 CA-NC complexes. We also found that purified cyclophilin A destabilizes in vitro-assembled HIV-1 CA-NC complexes in the presence of cellular extracts in a cyclosporine-sensitive manner. In agreement with previous observations using the fate-of-the-capsid assay, we also demonstrated the ability of recombinant CPSF6 to stabilize HIV-1 CA-NC complexes. Overall, our findings suggested that cellular extracts specifically stabilize the HIV-1 core. We believe that our assay can be a powerful tool to assess HIV-1 core stability in vitro. PMID:23885082

  13. Inhibitory effects of Sudanese plant extracts on HIV-1 replication and HIV-1 protease.

    Science.gov (United States)

    Hussein, G; Miyashiro, H; Nakamura, N; Hattori, M; Kawahata, T; Otake, T; Kakiuchi, N; Shimotohno, K

    1999-02-01

    Forty-eight methanol and aqueous extracts from Sudanese plants were screened for their inhibitory activity on viral replication. Nineteen extracts showed inhibitory effects on HIV-induced cytopathic effects (CPE) on MT-4 cells. The extracts were further screened against HIV-1 protease (PR) using an HPLC assay method. Of the tested extracts, the methanol extracts of Acacia nilotica (bark and pods), Euphorbia granulata (leaves), Maytenus senegalensis (stem-bark) and aqueous extracts of A. nilotica (pods) and M. senegalensis (stem-bark) showed considerable inhibitory effects against HIV-1 PR. Inhibitory principles were isolated from M. senegalensis and their activities were also discussed.

  14. Development of SI-traceable C-peptide certified reference material NMIJ CRM 6901-a using isotope-dilution mass spectrometry-based amino acid analyses.

    Science.gov (United States)

    Kinumi, Tomoya; Goto, Mari; Eyama, Sakae; Kato, Megumi; Kasama, Takeshi; Takatsu, Akiko

    2012-07-01

    A certified reference material (CRM) is a higher-order calibration material used to enable a traceable analysis. This paper describes the development of a C-peptide CRM (NMIJ CRM 6901-a) by the National Metrology Institute of Japan using two independent methods for amino acid analysis based on isotope-dilution mass spectrometry. C-peptide is a 31-mer peptide that is utilized for the evaluation of β-cell function in the pancreas in clinical testing. This CRM is a lyophilized synthetic peptide having the human C-peptide sequence, and contains deamidated and pyroglutamylated forms of C-peptide. By adding water (1.00 ± 0.01) g into the vial containing the CRM, the C-peptide solution in 10 mM phosphate buffer saline (pH 6.6) is reconstituted. We assigned two certified values that represent the concentrations of total C-peptide (mixture of C-peptide, deamidated C-peptide, and pyroglutamylated C-peptide) and C-peptide. The certified concentration of total C-peptide was determined by two amino acid analyses using pre-column derivatization liquid chromatography-mass spectrometry and hydrophilic chromatography-mass spectrometry following acid hydrolysis. The certified concentration of C-peptide was determined by multiplying the concentration of total C-peptide by the ratio of the relative area of C-peptide to that of the total C-peptide measured by liquid chromatography. The certified value of C-peptide (80.7 ± 5.0) mg/L represents the concentration of the specific entity of C-peptide; on the other hand, the certified value of total C-peptide, (81.7 ± 5.1) mg/L can be used for analyses that does not differentiate deamidated and pyroglutamylated C-peptide from C-peptide itself, such as amino acid analyses and immunochemical assays.

  15. HIV-1 genetic variants in Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    V Laga

    2012-11-01

    Full Text Available Objectives: During the last two decades, HIV-1 has been spreading rapidly in former Soviet Union republics including Kyrgyzstan. The current molecular monitoring of HIV-infection epidemic is carried out in Russia only with no or limited data from the other FSU countries. The aim of this work was to investigate the prevalence of HIV-1 genetic variants circulating in Kyrgyzstan. Methods: Blood collection from the HIV-infected patients was carried out by local specialists with the informed consent and the questionnaire was answered by each of the patients. The total number of samples was 100. The washed cell pellets were transferred to Moscow following with proviral DNA extraction, PCR amplification and gag, pol and env genes sequencing. The phylogenetic analysis of nucleotide sequences using neighbor-joining method was carried out by MEGA 3 program. The preliminary data were obtained in 22 samples isolated from PBMC of HIV-infected patients from Kyrgyzstan. Results: Among the samples studied 6 (27.3% samples belonged to a subtype CRF02_AG, 16 samples - to subtype A (A1. One of the samples belonging to CRF02_AG, probably, is a recombinant between CRF02_AG and A1. There was no major drug resistance mutations in the samples studied. The minor mutations were presented in small proportions: 1 in PR (L10I, 6 in RT (A62V - in 3 samples, V108G, E138A, Y181F, M184I, L210M - on one sample and 1 in IN (L74M. It was impossible to associate the distribution of mutations with HIV-1 genetic variant. The V3 loop (env gene in 17 samples was analyzed for tropism using geno2pheno program; all samples were found to be R5-viruses. Conclusion: The HIV-1 subtype A seems to dominate in Kyrgyzstan like in other FSU countries. The recombinant CRF02_AG epidemiologically linked to Uzbekistan is quite widespread. The rest of Kyrgyzstan collection is under investigation and the data will be refined soon.

  16. Rigidity analysis of HIV-1 protease

    Science.gov (United States)

    Heal, J. W.; Wells, S. A.; Jimenez-Roldan, E.; Freedman, R. F.; Römer, R. A.

    2011-03-01

    We present a rigidity analysis on a large number of X-ray crystal structures of the enzyme HIV-1 protease using the 'pebble game' algorithm of the software FIRST. We find that although the rigidity profile remains similar across a comprehensive set of high resolution structures, the profile changes significantly in the presence of an inhibitor. Our study shows that the action of the inhibitors is to restrict the flexibility of the β-hairpin flaps which allow access to the active site. The results are discussed in the context of full molecular dynamics simulations as well as data from NMR experiments.

  17. Humoral Immunogenicity of an HIV-1 Envelope Residue 649-684 Membrane-proximal Region Peptide Fused to the Plague Antigen F1-V

    Science.gov (United States)

    Matoba, Nobuyuki; Shah, Namrata Rahul; Mor, Tsafrir S

    2011-01-01

    The membrane-proximal region spanning residues 649-684 of the HIV-1 envelope protein gp41 (MPR649-684) is an attractive vaccine target for humoral immunity that blocks viral transcytosis across the mucosal epithelia. However, induction of high-titer MPR649-684-specific antibodies remains a challenging task. To explore potential solutions for this challenge, we tested a new translational fusion protein comprising the plague F1-V antigen and MPR649-684 (F1-V-MPR649-684). We employed systemic immunization for initial feasibility analyses. Despite strong immunogenicity demonstrated for the immunogen, repeated systemic immunizations of mice with F1-V-MPR649-684 hardly induced MPR649-684-specific IgG. In contrast, a single immunization with F1-V-MPR649-684 mounted a significant anti-MPR649-684 IgG response in animals that were primed with another MPR649-684 fusion protein based on the cholera toxin B subunit. Additional boost immunizations with F1-V-MPR649-684 recalled and maintained the antibody response and expanded the number of specific antibody-secreting B cells. Thus, while F1-V-MPR649-684 alone was not sufficiently immunogenic to induce detectable levels of MPR649-684-specific antibodies, these results suggest that prime-boost immunization using heterologous antigen-display platforms may overcome the poor humoral immunogenicity of MPR649-684 for the induction of durable humoral immunity. Further studies are warranted to evaluate the feasibility of this strategy in mucosal immunization. Lastly, our findings add to a growing body of evidence in support of this strategy for immunogen design for poorly immunogenic epitopes besides the MPR of HIV-1's transmembrane envelope protein. PMID:21693158

  18. Kinetics of circulating endogenous insulin, C-peptide, and proinsulin in fasting nondiabetic man

    DEFF Research Database (Denmark)

    Henriksen, J H; Tronier, B; Bülow, J B

    1987-01-01

    Plasma concentrations of insulin, C-peptide, and proinsulin were measured in different vascular beds in order to determine renal, hepatic, and systemic kinetics of the endogenous peptides in the fasting condition. Nineteen nondiabetic subjects were studied, two were normal, nine had minor vascular...

  19. HIV-1 is not a major driver of increased plasma IL-6 levels in chronic HIV-1 disease

    Science.gov (United States)

    Shive, Carey L.; Biancotto, Angélique; Funderburg, Nicholas T.; Pilch-Cooper, Heather A.; Valdez, Hernan; Margolis, Leonid; Sieg, Scott F.; McComsey, Grace A.; Rodriguez, Benigno; Lederman, Michael M.

    2012-01-01

    Objective Increased plasma IL-6 levels have been associated with HIV-1 disease progression risk, yet the drivers of IL-6 production in HIV-1 infection are not known. This study was designed to explore the relationship between HIV-1 replication and IL-6 induction. Design Correlations between plasma levels of IL-6 and HIV-1 RNA were examined in two clinical studies. To more directly assess the induction of IL-6 by HIV-1, several cell and tissue types that support HIV-1 replication in vivo were infected with HIV-1 and expression of IL-6 was measured. Methods Spearman’s rank correlations were used to examine the relationship between plasma levels of IL-6 and HIV-1 RNA. Macrophages, and colonic and lymph node histocultures were infected with HIV-1 or stimulated with bacterial products, LPS or flagellin, and IL-6 levels in supernatant were measured by ELISA or multiplex bead assay. Results In the clinical studies there was weak or no correlation between plasma levels of IL-6 and HIV-1 RNA but IL-6 levels were correlated with plasma levels of the LPS coreceptor CD14. Macrophages stimulated with LPS or flagellin showed robust production of IL-6, but there was no increase in IL-6 production after HIV-1 infection. IL-6 expression was not increased in lymph node histocultures obtained from HIV-1 infected subjects nor after productive HIV-1 infection of colonic or lymph node histocultures ex vivo. Conclusions We find no evidence that HIV-1 replication is an important driver of IL-6 expression in vivo or in in vitro systems. PMID:22659649

  20. Cyclophilin B enhances HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    DeBoer, Jason; Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE (United States); The Nebraska Center for Virology, University of Nebraska, Lincoln, NE (United States)

    2016-02-15

    Cyclophilin B (CypB) is a member of the immunophilin family and intracellular chaperone. It predominantly localizes to the ER, but also contains a nuclear localization signal and is secreted from cells. CypB has been shown to interact with the Gag protein of human immunodeficiency type 1 (HIV-1). Several proteomic and genetic studies identified it as a potential factor involved in HIV replication. Herein, we show that over-expression of CypB enhances HIV infection by increasing nuclear import of viral DNA. This enhancement was unaffected by cyclosporine treatment and requires the N-terminus of the protein. The N-terminus contains an ER leader sequence, putative nuclear localization signal, and is required for secretion. Deletion of the N-terminus resulted in mislocalization from the ER and suppression of HIV infection. Passive transfer experiments showed that secreted CypB did not impact HIV infection. Combined, these experiments show that intracellular CypB modulates a pathway of HIV nuclear import. - Highlights: • CypB has been identified in several proteomic studies of HIV-1 infection. • CypB expression is upregulated in activated and infected T-cells. • Over-expression of CypB enhances HIV nuclear import and infection. • The N-terminus of CypB is necessary for these effects.

  1. Evaluation of three enzyme immunoassays for HIV-1 antigen detection.

    Science.gov (United States)

    Willoughby, P B; Lisker, A; Folds, J D

    1989-01-01

    Three enzyme immunoassay (EIA) methods for the detection of human immunodeficiency virus (HIV-1) were evaluated. Serum or plasma samples from 22 individuals seropositive for HIV-1 antibodies were tested with the Abbott, Coulter, and DuPont kits for presence of HIV-1 p24 antigen. Another 12 samples were tested with two kits only. Discordant results were obtained with 9 of 34 (26%) HIV-1-antibody-positive patient samples tested. Most of these discrepancies were found in samples containing less than 30 pg/ml of HIV-1 p24 core antigen. A sampling of sera from normal blood donors and patients with infectious or autoimmune diseases revealed a low level of false positive reactions, especially with sera containing antinuclear antibodies or rheumatoid factor. Noteworthy is the frequency of false positive reactions seen with the DuPont EIA for HIV-1 p24 antigen. 18/111 sera (16.2%) containing auto-antibodies tested positively with the DuPont HIV-1 p24 antigen EIA. The nonspecific nature of the test reactivity for 9/10 of these samples was confirmed using an HIV-1 p24 antigen inhibition assay. These findings are discussed in light of the need for HIV-1 antigen detection in the clinical laboratory and of other methods for HIV-1 detection: the polymerase chain reaction and measurements of reverse transcriptase activity.

  2. Genetic composition of replication competent clonal HIV-1 variants isolated from peripheral blood mononuclear cells (PBMC), HIV-1 proviral DNA from PBMC and HIV-1 RNA in serum in the course of HIV-1 infection.

    Science.gov (United States)

    Edo-Matas, Diana; van Gils, Marit J; Bowles, Emma J; Navis, Marjon; Rachinger, Andrea; Boeser-Nunnink, Brigitte; Stewart-Jones, Guillaume B; Kootstra, Neeltje A; van 't Wout, Angélique B; Schuitemaker, Hanneke

    2010-09-30

    The HIV-1 quasispecies in peripheral blood mononuclear cells (PBMC) is considered to be a mix of actively replicating, latent, and archived viruses and may be genetically distinct from HIV-1 variants in plasma that are considered to be recently produced. Here we analyzed the genetic relationship between gp160 env sequences from replication competent clonal HIV-1 variants that were isolated from PBMC and from contemporaneous HIV-1 RNA in serum and HIV-1 proviral DNA in PBMC of four longitudinally studied therapy naïve HIV-1 infected individuals. Replication competent clonal HIV-1 variants, HIV-1 RNA from serum, and HIV-1 proviral DNA from PBMC formed a single virus population at most time points analyzed. However, an under-representation in serum of HIV-1 sequences with predicted CXCR4 usage was sometimes observed implying that the analysis of viral sequences from different sources may provide a more complete assessment of the viral quasispecies in peripheral blood in vivo. Copyright 2010 Elsevier Inc. All rights reserved.

  3. Bispecific engineered antibody domains (nanoantibodies that interact noncompetitively with an HIV-1 neutralizing epitope and FcRn.

    Directory of Open Access Journals (Sweden)

    Rui Gong

    Full Text Available Libraries based on an isolated human immunoglobulin G1 (IgG1 constant domain 2 (CH2 have been previously diversified by random mutagenesis. However, native isolated CH2 is not very stable and the generation of many mutations could lead to an increase in immunogenicity. Recently, we demonstrated that engineering an additional disulfide bond and removing seven N-terminal residues results in an engineered antibody domain (eAd (m01s with highly increased stability and enhanced binding to human neonatal Fc receptor (FcRn (Gong et al, JBC, 2009 and 2011. We and others have also previously shown that grafting of the heavy chain complementarity region 3 (CDR-H3 (H3 onto cognate positions of the variable domain leads to highly diversified libraries from which a number of binders to various antigens have been selected. However, grafting of H3s to non-cognate positions in constant domains results in additional residues at the junctions of H3s and the CH2 framework. Here we describe a new method based on multi-step PCR that allows the precise replacement of loop FG (no changes in its flanking sequences by human H3s from another library. Using this method and limited mutagenesis of loops BC and DE we generated an eAd phage-displayed library. Panning of this library against an HIV-1 gp41 MPER peptide resulted in selection of a binder, m2a1, which neutralized HIV-1 isolates from different clades with modest activity and retained the m01s capability of binding to FcRn. This result provides a proof of concept that CH2-based antigen binders that also mimic to certain extent other functions of full-size antibodies (binding to FcRn can be generated; we have previously hypothesized that such binders can be made and coined the term nanoantibodies (nAbs. Further studies in animal models and in humans will show how useful nAbs could be as therapeutics and diagnostics.

  4. Nup153 and Nup98 bind the HIV-1 core and contribute to the early steps of HIV-1 replication.

    Science.gov (United States)

    Di Nunzio, Francesca; Fricke, Thomas; Miccio, Annarita; Valle-Casuso, Jose Carlos; Perez, Patricio; Souque, Philippe; Rizzi, Ermanno; Severgnini, Marco; Mavilio, Fulvio; Charneau, Pierre; Diaz-Griffero, Felipe

    2013-05-25

    The early steps of HIV-1 replication involve the entry of HIV-1 into the nucleus, which is characterized by viral interactions with nuclear pore components. HIV-1 developed an evolutionary strategy to usurp the nuclear pore machinery and chromatin in order to integrate and efficiently express viral genes. In the current work, we studied the role of nucleoporins 153 and 98 (Nup153 and Nup98) in infection of human Jurkat lymphocytes by HIV-1. We showed that Nup153-depleted cells exhibited a defect in nuclear import, while depletion of Nup 98 caused a slight defect in HIV integration. To explore the biochemical viral determinants for the requirement of Nup153 and Nup98 during HIV-1 infection, we tested the ability of these nucleoporins to interact with HIV-1 cores. Our findings showed that both nucleoporins bind HIV-1 cores suggesting that this interaction is important for HIV-1 nuclear import and/or integration. Distribution analysis of integration sites in Nup153-depleted cells revealed a reduced tendency of HIV-1 to integrate in intragenic sites, which in part could account for the large infectivity defect observed in Nup153-depleted cells. Our work strongly supports a role for Nup153 in HIV-1 nuclear import and integration. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. HIV-Selectest enzyme immunoassay and rapid test: ability to detect seroconversion following HIV-1 infection.

    Science.gov (United States)

    Khurana, Surender; Norris, Philip J; Busch, Michael P; Haynes, Barton F; Park, Susan; Sasono, Pretty; Mlisana, Koleka; Salim, Abdool Karim; Hecht, Frederick M; Mulenga, Joseph; Chomba, Elwyn; Hunter, Eric; Allen, Susan; Nemo, George; Rodriguez-Chavez, Isaac R; Margolick, Joseph B; Golding, Hana

    2010-01-01

    HIV-Selectest is a serodiagnostic enzyme immunoassay (EIA), containing p6 and gp41 peptides, designed to differentiate between vaccine-induced antibodies and true infections. A rapid test version of the HIV-Selectest was developed. Both assays detected HIV antibodies in men and women within 2 to 4 weeks of infection, with sensitivity similar to third-generation EIAs.

  6. Species tropism of HIV-1 modulated by viral accessory proteins

    OpenAIRE

    Masako eNomaguchi; Naoya eDoi; Yui eMatsumoto; Yosuke eSakai; Sachi eFujiwara; Akio eAdachi

    2012-01-01

    Human immunodeficiency virus type 1 (HIV-1) is tropic and pathogenic only for humans, and does not replicate in macaque monkeys routinely used for experimental infections. This specially narrow host range (species tropism) has impeded much the progress of HIV-1/acquired immunodeficiency syndrome (AIDS) basic research. Extensive studies on the underlying mechanism have revealed that Vif, one of viral accessory proteins, is critical for the HIV-1 species tropism in addition to Gag-capsid protei...

  7. Reverse transcription of the HIV-1 pandemic.

    Science.gov (United States)

    Basavapathruni, Aravind; Anderson, Karen S

    2007-12-01

    The HIV/AIDS pandemic has existed for >25 years. Extensive work globally has provided avenues to combat viral infection, but the disease continues to rage on in the human population and infected approximately 4 million people in 2006 alone. In this review, we provide a brief history of HIV/AIDS, followed by analysis of one therapeutic target of HIV-1: its reverse transcriptase (RT). We discuss the biochemical characterization of RT in order to place emphasis on possible avenues of inhibition, which now includes both nucleoside and non-nucleoside modalities. Therapies against RT remain a cornerstone of anti-HIV treatment, but the virus eventually resists inhibition through the selection of drug-resistant RT mutations. Current inhibitors and associated resistance are discussed, with the hopes that new therapeutics can be developed against RT.

  8. TIM-family proteins inhibit HIV-1 release.

    Science.gov (United States)

    Li, Minghua; Ablan, Sherimay D; Miao, Chunhui; Zheng, Yi-Min; Fuller, Matthew S; Rennert, Paul D; Maury, Wendy; Johnson, Marc C; Freed, Eric O; Liu, Shan-Lu

    2014-09-02

    Accumulating evidence indicates that T-cell immunoglobulin (Ig) and mucin domain (TIM) proteins play critical roles in viral infections. Herein, we report that the TIM-family proteins strongly inhibit HIV-1 release, resulting in diminished viral production and replication. Expression of TIM-1 causes HIV-1 Gag and mature viral particles to accumulate on the plasma membrane. Mutation of the phosphatidylserine (PS) binding sites of TIM-1 abolishes its ability to block HIV-1 release. TIM-1, but to a much lesser extent PS-binding deficient mutants, induces PS flipping onto the cell surface; TIM-1 is also found to be incorporated into HIV-1 virions. Importantly, TIM-1 inhibits HIV-1 replication in CD4-positive Jurkat cells, despite its capability of up-regulating CD4 and promoting HIV-1 entry. In addition to TIM-1, TIM-3 and TIM-4 also block the release of HIV-1, as well as that of murine leukemia virus (MLV) and Ebola virus (EBOV); knockdown of TIM-3 in differentiated monocyte-derived macrophages (MDMs) enhances HIV-1 production. The inhibitory effects of TIM-family proteins on virus release are extended to other PS receptors, such as Axl and RAGE. Overall, our study uncovers a novel ability of TIM-family proteins to block the release of HIV-1 and other viruses by interaction with virion- and cell-associated PS. Our work provides new insights into a virus-cell interaction that is mediated by TIMs and PS receptors.

  9. RNA Interference Therapies for an HIV-1 Functional Cure.

    Science.gov (United States)

    Scarborough, Robert J; Gatignol, Anne

    2017-12-27

    HIV-1 drug therapies can prevent disease progression but cannot eliminate HIV-1 viruses from an infected individual. While there is hope that elimination of HIV-1 can be achieved, several approaches to reach a functional cure (control of HIV-1 replication in the absence of drug therapy) are also under investigation. One of these approaches is the transplant of HIV-1 resistant cells expressing anti-HIV-1 RNAs, proteins or peptides. Small RNAs that use RNA interference pathways to target HIV-1 replication have emerged as competitive candidates for cell transplant therapy and have been included in all gene combinations that have so far entered clinical trials. Here, we review RNA interference pathways in mammalian cells and the design of therapeutic small RNAs that use these pathways to target pathogenic RNA sequences. Studies that have been performed to identify anti-HIV-1 RNA interference therapeutics are also reviewed and perspectives on their use in combination gene therapy to functionally cure HIV-1 infection are provided.

  10. Chronic HIV-1 infection frequently fails to protect against superinfection.

    Directory of Open Access Journals (Sweden)

    Anne Piantadosi

    2007-11-01

    Full Text Available Reports of HIV-1 superinfection (re-infection have demonstrated that the immune response generated against one strain of HIV-1 does not always protect against other strains. However, studies to determine the incidence of HIV-1 superinfection have yielded conflicting results. Furthermore, few studies have attempted to identify superinfection cases occurring more than a year after initial infection, a time when HIV-1-specific immune responses would be most likely to have developed. We screened a cohort of high-risk Kenyan women for HIV-1 superinfection by comparing partial gag and envelope sequences over a 5-y period beginning at primary infection. Among 36 individuals, we detected seven cases of superinfection, including cases in which both viruses belonged to the same HIV-1 subtype, subtype A. In five of these cases, the superinfecting strain was detected in only one of the two genome regions examined, suggesting that recombination frequently occurs following HIV-1 superinfection. In addition, we found that superinfection occurred throughout the course of the first infection: during acute infection in two cases, between 1-2 y after infection in three cases, and as late as 5 y after infection in two cases. Our results indicate that superinfection commonly occurs after the immune response against the initial infection has had time to develop and mature. Implications from HIV-1 superinfection cases, in which natural re-exposure leads to re-infection, will need to be considered in developing strategies for eliciting protective immunity to HIV-1.

  11. Progress in HIV-1 antibody research using humanized mice.

    Science.gov (United States)

    Gruell, Henning; Klein, Florian

    2017-05-01

    Recent discoveries of highly potent broadly HIV-1 neutralizing antibodies provide new opportunities to successfully prevent, treat, and potentially cure HIV-1 infection. To test their activity in vivo, humanized mice have been shown to be a powerful model and were used to investigate antibody-mediated prevention and therapy approaches. In this review, we will summarize recent findings in humanized mice that have informed on the potential use of broadly neutralizing antibodies targeting HIV-1 in humans. Humanized mouse models have been used to demonstrate the antiviral efficacy of HIV-1 neutralizing antibodies in vivo. It has been shown that a combination of antibodies can suppress viremia below the limit of detection and targets the HIV-1 reservoir. Moreover, passively administered antibodies and vector-mediated antibody production protect humanized mice from HIV-1 infection. Finally, immunization studies in knock-in/transgenic mice carrying human antibody gene segments have informed on potential vaccination strategies to induce broad and potent HIV-1 neutralizing antibodies. Humanized mouse models are of great value for HIV-1 research. They represent a highly versatile in vivo system to investigate novel approaches for HIV-1 prevention and therapy and expedite the critical translation from basic findings to clinical application.

  12. Innate immune sensing of HIV-1 infection.

    Science.gov (United States)

    Jakobsen, Martin R; Olagnier, David; Hiscott, John

    2015-03-01

    The innate immune system plays a critical role in the control of viral infections. Although the mechanisms involved in sensing and response to viral pathogens has progressed tremendously in the last decade, an understanding of the innate antiviral response to human retroviruses lagged behind. Recent studies now demonstrate that human retroviruses such as human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus 1 (HTLV-1) trigger a type I interferon antiviral response through novel cytosolic sensors that detect DNA intermediates of reverse transcription; in addition, these early host-pathogen interactions may trigger cell death pathways depending on the activation state of the target cell. The purpose of this review is to summarize the recent progress in the understanding of innate immune sensing of human retroviruses. Innate immune sensing of HIV-1 and HTLV-1 is influenced by the target cell phenotype, viral replicative intermediates, and host restriction factors that limit retroviral replication. Macrophages and dendritic cells detect HIV-DNA intermediates, whereas CD4 T cells differentially sense HIV DNA depending on the level of T-cell activation. Furthermore, the structure of the viral capsid and interplay between innate DNA sensors and host restriction factors all contribute to the magnitude of the ensuing innate immune response. The interplay between HIV infection and the innate immune system has emerged as an important component of HIV pathogenesis, linked to both induction of innate immunity and stimulation of cell death mechanisms. Ultimately, an in-depth knowledge of the mechanisms of innate immune control of human retrovirus infection may facilitate the development of novel treatment strategies to control retrovirus-induced immunopathology.

  13. Independent association between serum C-peptide levels and fat mass-to-lean mass ratio in the aging process.

    Science.gov (United States)

    Li, Ying; Zheng, Lian Shun; Li, Yue; Zhao, Duo Duo; Meng, Lu

    2015-07-01

    The changes in body composition and biomarker levels that occur during the aging process are complex and remain poorly understood. The present study aimed to evaluate changes in serum C-peptide levels and fat mass-to-lean mass ratio (FM/LM ratio) with increasing age, and to explore the associations between serum C-peptide levels and FM/LM ratio. This was a population-based cross-sectional study that included 3912 participants aged 30-85 years. Body composition was measured using dual-energy X-ray absorptiometry. Analysis of covariance was used to evaluate how the serum C-peptide level and FM/LM ratio change with increasing age, as well as how the FM/LM ratio changes in line with increasing serum C-peptide level. A multiple linear regression analysis was carried out to determine the association between serum C-peptide level and FM/LM ratio. Analysis of covariance showed that serum C-peptide levels, and most regional FM/LM ratios tended to increase in line with increasing age. Total fat mass, total lean mass, percentage total fat mass and total FM/LM ratio were significantly elevated, and percentage total lean mass decreased significantly with increasing serum C-peptide levels in both men and women. Multiple linear regression analysis showed that serum C-peptide level was strongly associated with the total FM/LM ratio. The findings showed that both serum C-peptide level and FM/LM ratio increased with increasing age, and the serum C-peptide level was closely associated with changes in the total FM/LM ratio. © 2014 Japan Geriatrics Society.

  14. Niacin increased glucose, insulin, and C-peptide levels in sedentary nondiabetic postmenopausal women

    Directory of Open Access Journals (Sweden)

    Koh Y

    2014-10-01

    Full Text Available Yunsuk Koh,1 Heidi Bidstrup,2 David L Nichols2 1Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA; 2Department of Kinesiology, Texas Woman's University, Denton, TX, USA Abstract: The current study examined the effects of niacin and a single bout of aerobic exercise on plasma glucose, insulin, and C-peptide in sedentary, nondiabetic postmenopausal women. As a crossover design, 17 participants underwent four different trials: rest during the no-niacin condition (R, exercise during the no-niacin condition (E, rest during the with-niacin condition (RN, and exercise during the with-niacin condition (EN. All participants took 1,000 mg/day of extended-release niacin for 4 weeks during the with-niacin conditions (RN and EN. The exercise treatment consisted of a single bout of treadmill walking at 60% heart rate reserve until 400 kcal were expended. Blood samples were collected at 24 hours after each trial and analyzed for changes in plasma glucose, insulin, and C-peptide. A two by two analysis of variance was used to examine the changes in dependent variables, and the Bonferroni adjustment was employed as the post hoc test. The level of statistical significance was set at P<0.05. There was no significant interaction between exercise and niacin, nor was there a main effect of exercise for changes in glucose, insulin, or C-peptide. However, there was a significant main effect for niacin as mean glucose, insulin, and C-peptide values significantly increased with niacin; glucose increased 10.6% (P=0.001, from 95.03±10.67 mg/dL to 105.07±13.56 mg/dL; insulin increased 61.8% (P=0.001, from 16.98±12.49 µU/mL to 27.48±14.84 µU/mL; and C-peptide increased 46.1% (P=0.001, from 1.65±0.75 ng/mL to 2.41±0.97 ng/mL. Although niacin was generally well tolerated, given its adverse effects on glucose, insulin, and C-peptide profiles, the use of niacin should be done so with caution and under medical supervision. Keywords

  15. Characteristics of HIV-1 Serodiscordant Couples Enrolled in a Clinical Trial of Antiretroviral Pre-Exposure Prophylaxis for HIV-1 Prevention

    OpenAIRE

    Andrew Mujugira; Baeten, Jared M.; Deborah Donnell; Patrick Ndase; Mugo, Nelly R.; Linda Barnes; Campbell, James D.; Jonathan Wangisi; Tappero, Jordan W.; Elizabeth Bukusi; Cohen, Craig R.; Elly Katabira; Allan Ronald; Elioda Tumwesigye; Edwin Were

    2011-01-01

    Introduction Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort. Methods HIV-1...

  16. HIV-1 infection of in vitro cultured human monocytes: early events and influence of anti HIV-1 antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Olofsson, S; Nielsen, Jens Ole

    1994-01-01

    To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (M phi s) we examined the susceptibility of in vitro cultured monocyte/M phi s to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera...... on this infection. Depending on the period of in vitro cultivation and the virus isolate used different patterns of susceptibility were detected. One week old monocyte/M phi s were highly susceptible to HIV-1 infection, in contrast to monocyte/M phi s cultured 4 weeks. The infection by virus isolated immediately...

  17. Nup153 and Nup98 bind the HIV-1 core and contribute to the early steps of HIV-1 replication

    OpenAIRE

    Di Nunzio, Francesca; Fricke, Thomas; Miccio, Annarita; Valle-Casuso, Jose Carlos; Perez, Patricio; Souque, Philippe; Rizzi, Ermanno; Severgnini, Marco; Mavilio, Fulvio; Charneau, Pierre; Diaz-Griffero, Felipe

    2013-01-01

    The early steps of HIV-1 replication involve the entry of HIV-1 into the nucleus, which is characterized by viral interactions with nuclear pore components. HIV-1 developed an evolutionary strategy to usurp the nuclear pore machinery and chromatin in order to integrate and efficiently express viral genes. In the current work, we studied the role of nucleoporins 153 and 98 (Nup153 and Nup98) in infection of human Jurkat lymphocytes by HIV-1. We showed that Nup153-depleted cells exhibited a def...

  18. Human immunodeficiency virus type 1 specific cytotoxic T lymphocyte responses in Chinese infected with HIV-1 B'/C Recombinant (CRF07_BC

    Directory of Open Access Journals (Sweden)

    Yu Xu G

    2007-08-01

    Full Text Available Abstract Background The characterization of HIV-1-specific T cell responses in people infected with locally circulating HIV-1 strain will facilitate the development of HIV-1 vaccine. Sixty intravenous drug users infected with HIV-1 circulating recombinant form 07_BC (CRF07_BC, which has been spreading rapidly in western China from north to south, were recruited from Xinjiang, China to assess the HIV-1-specific T cell responses at single peptide level with overlapping peptides (OLP covering the whole concensus clades B and C proteome. Results The median of the total magnitude and total number of OLPs recognized by CTL responses were 10925 SFC/million PBMC and 25 OLPs, respectively, when tested by clade C peptides, which was significantly higher than when tested by clade B peptides. The immunodominant regions, which cover 14% (58/413 of the HIV-1 proteome, are widely distributed throughout the HIV-1 proteome except in Tat, Vpu and Pol-PR, with Gag, Pol-RT, Pol-Int and Nef being most frequently targeted. The subdominant epitopes are mostly located in p24, Nef, integrase, Vpr and Vif. Of the responses directed to clade C OLPs, 61.75% (972/1574 can be observed when tested with corresponding clade B OLPs. However, Pol-PR and Vpu tend to be targeted in the clade B sequence rather than the clade C sequence, which is in line with the recombinant pattern of CRF07_BC. Stronger and broader CTL responses in subjects with CD4 cell counts ranging from 200 to 400/mm3 were observed when compared to those with less than 200/mm3 or more than 400/mm3, though there have been no significant correlations identified between the accumulative CTL responses or overall breadth and CD4 cell count or plasma viral load. Conclusion This is the first study conducted to comprehensively address T cell responses in Chinese subjects infected with HIV-1 CRF07_BC in which subtle differences in cross-reactivity were observed, though similar patterns of overall immune responses were

  19. C-peptide levels and the risk of diabetes and pre-diabetes among Chinese women with gestational diabetes.

    Science.gov (United States)

    Yin, Ping; Shao, Ping; Liu, Huikun; Li, Weiqin; Wang, Leishen; Wang, Jing; Zhang, Shuang; Leng, Junhong; Li, Nan; Tian, Huiguang; Yang, Xilin; Yu, Zhijie; Hu, Gang

    2017-12-01

    To examine the association of connecting peptide (C-peptide) and the risks of postpartum diabetes and pre-diabetes among women with prior gestational diabetes. A cross-sectional study of 1263 women with prior gestational diabetes was carried out at 1-5years after delivery in Tianjin, China. Logistic regression was used to assess the associations of C-peptide and the risks of diabetes and pre-diabetes. The multivariable-adjusted odds ratios based on different levels of C-peptide (0-33%, 34-66%, 67-90%, and >90% as C-peptide cutpoints) were 1.00, 1.93 (95% confidence interval [CI] 0.85-4.39), 2.49 (95% CI 1.06-5.87), and 3.88 (95% CI 1.35-11.1) for diabetes (P for trend C-peptide as a continuous variable with the risks of type 2 diabetes and pre-diabetes. The positive association was significant when stratified by healthy weight and overweight participants. We found a positive association between serum C-peptide levels and the risks of diabetes and pre-diabetes among Chinese women with prior gestational diabetes. Our finding suggested that elevated C-peptide levels may be a predictor of diabetes and pre-diabetes. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Antiviral Therapy by HIV-1 Broadly Neutralizing and Inhibitory Antibodies

    Directory of Open Access Journals (Sweden)

    Zhiqing Zhang

    2016-11-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection causes acquired immune deficiency syndrome (AIDS, a global epidemic for more than three decades. HIV-1 replication is primarily controlled through antiretroviral therapy (ART but this treatment does not cure HIV-1 infection. Furthermore, there is increasing viral resistance to ART, and side effects associated with long-term therapy. Consequently, there is a need of alternative candidates for HIV-1 prevention and therapy. Recent advances have discovered multiple broadly neutralizing antibodies against HIV-1. In this review, we describe the key epitopes on the HIV-1 Env protein and the reciprocal broadly neutralizing antibodies, and discuss the ongoing clinical trials of broadly neutralizing and inhibitory antibody therapy as well as antibody combinations, bispecific antibodies, and methods that improve therapeutic efficacy by combining broadly neutralizing antibodies (bNAbs with latency reversing agents. Compared with ART, HIV-1 therapeutics that incorporate these broadly neutralizing and inhibitory antibodies offer the advantage of decreasing virus load and clearing infected cells, which is a promising prospect in HIV-1 prevention and treatment.

  1. HIV-1, how llamas help us fight the AIDS pandemic

    NARCIS (Netherlands)

    Strokappe, N.M.|info:eu-repo/dai/nl/314411534

    2013-01-01

    Human Immunodeficiency Virus type 1 (HIV-1) is one of the major health problems worldwide and has been for over thirty years. Most (67%) of the people infected with HIV-1 are living in sub-Saharan Africa. Here, the access to treatments is limited and most women are not in a position to protect

  2. Vaginalmycosis and HIV-1 infection in Kaduna, Nigeria. | Eni ...

    African Journals Online (AJOL)

    Vaginal mycosis and HIV-1 infection are common health problems in females. These infections cause high mortality, morbidity and reproductive health disorders in females. The study is to investigate to what extent these infections are prevalent in this centre. 300 non- pregnant females who tested positive with HIV-1 ...

  3. The origin and emergence of an HIV-1 epidemic:

    DEFF Research Database (Denmark)

    Bruhn, Christian Anders Wathne; Audelin, Anne M.; Helleberg, Marie

    2014-01-01

    To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic.......To describe, at patient-level detail, the determining events and factors involved in the development of a country's HIV-1 epidemic....

  4. Telomeres and HIV-1 infection: in search of exhaustion

    NARCIS (Netherlands)

    Wolthers, K. C.; Miedema, F.

    1998-01-01

    Telomere length analysis could be helpful in determining if exhaustion and replicative senescence are involved in HIV-1 pathogenesis. Evidence that CD8+ T cells have shorter telomeres may point towards an increased turnover of CD8+ T cells and exhaustion of the CD8+ T-cell responses in HIV-1

  5. Schistosomiasis and HIV-1 infection in rural Zimbabwe

    DEFF Research Database (Denmark)

    Kallestrup, Per; Zinyama, Rutendo; Gomo, Exnevia

    2005-01-01

    Stunted development and reduced fecundity of Schistosoma parasites in immunodeficient mice and the impaired ability of human immunodeficiency virus 1 (HIV-1)-infected humans to excrete schistosome eggs have been described. This study explores the effect that HIV-1-associated immunodeficiency has ...

  6. Development of aptamer based HIV-1 entry inhibitor prophylactic drugs

    CSIR Research Space (South Africa)

    London, G

    2013-08-01

    Full Text Available AIDS remains a major public health problem globally, especially in Southern Africa where over 6.4 million people are infected by the most prevalent HIV-1 subtype C. To help stop the spread of HIV-1 subtype C, we isolated 2ʹ-F-RNA aptamers against gp...

  7. Dendritic Cell Immune Responses in HIV-1 Controllers.

    Science.gov (United States)

    Martin-Gayo, Enrique; Yu, Xu G

    2017-02-01

    Robust HIV-1-specific CD8 T cell responses are currently regarded as the main correlate of immune defense in rare individuals who achieve natural, drug-free control of HIV-1; however, the mechanisms that support evolution of such powerful immune responses are not well understood. Dendritic cells (DCs) are specialized innate immune cells critical for immune recognition, immune regulation, and immune induction, but their possible contribution to HIV-1 immune defense in controllers remains ill-defined. Recent studies suggest that myeloid DCs from controllers have improved abilities to recognize HIV-1 through cytoplasmic immune sensors, resulting in more potent, cell-intrinsic type I interferon secretion in response to viral infection. This innate immune response may facilitate DC-mediated induction of highly potent antiviral HIV-1-specific T cells. Moreover, protective HLA class I isotypes restricting HIV-1-specific CD8 T cells may influence DC function through specific interactions with innate myelomonocytic MHC class I receptors from the leukocyte immunoglobulin-like receptor family. Bi-directional interactions between dendritic cells and HIV-1-specific T cells may contribute to natural HIV-1 immune control, highlighting the importance of a fine-tuned interplay between innate and adaptive immune activities for effective antiviral immune defense.

  8. Raltegravir with optimized background therapy for resistant HIV-1 infection

    DEFF Research Database (Denmark)

    Steigbigel, Roy T; Cooper, David A; Kumar, Princy N

    2008-01-01

    BACKGROUND: Raltegravir (MK-0518) is an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase active against HIV-1 susceptible or resistant to older antiretroviral drugs. METHODS: We conducted two identical trials in different geographic regions to evaluate the safety and efficacy...

  9. Antibody function in neutralization and protection against HIV-1

    NARCIS (Netherlands)

    Hessell, A.J.

    2009-01-01

    The ability to induce neutralizing antibodies is generally thought to be of great importance for vaccine efficacy. In HIV-1 research this quality has been elusive as the HIV-1 virus has evolved multiple mechanisms to evade neutralizing antibodies. This thesis traces studies with four broadly

  10. HTLV-1 Tax activates HIV-1 transcription in latency models.

    Science.gov (United States)

    Geddes, Victor Emmanuel Viana; José, Diego Pandeló; Leal, Fabio E; Nixon, Douglas F; Tanuri, Amilcar; Aguiar, Renato Santana

    2017-04-01

    HIV-1 latency is a major obstacle to HIV-1 eradication. Coinfection with HTLV-1 has been associated with faster progression to AIDS. HTLV-1 encodes the transactivator Tax which can activate both HTLV-1 and HIV-1 transcription. Here, we demonstrate that Tax activates HIV transcription in latent CD4(+) T cells. Tax promotes the activation of P-TEFb, releasing CDK9 and Cyclin T1 from inactive forms, promoting transcription elongation and reactivation of latent HIV-1. Tax mutants lacking interaction with the HIV-1-LTR promoter were not able to activate P-TEFb, with no subsequent activation of latent HIV. In HIV-infected primary resting CD4(+) T cells, Tax-1 reactivated HIV-1 transcription up to five fold, confirming these findings in an ex vivo latency model. Finally, our results confirms that HTLV-1/Tax hijacks cellular partners, promoting HIV-1 transcription, and this interaction should be further investigated in HIV-1 latency studies in patients with HIV/HTLV-1 co-infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Molecular Mechanisms in Activation of Latent HIV-1

    NARCIS (Netherlands)

    H. Rafati (Haleh)

    2014-01-01

    markdownabstract__Abstract__ Finding a cure for the human immunodeficiency virus type 1 (HIV-1) is extremely challenging. Development of highly active anti-retroviral therapy (HAART), transformed HIV-1 infection from an acute syndrome into chronic disease. Although using HAART results in

  12. Neutralizing antibodies in slowly progressing HIV-1 infection

    DEFF Research Database (Denmark)

    Schønning, Kristian; Nielsen, C; Iversen, Johan

    1995-01-01

    Ten asymptomatic individuals who had experienced only limited CD4+ cell loss after prolonged infection with HIV-1 were studied. These individuals had a mean CD4+ cell count of 674 x 10(6) cells/L and a mean duration of infection of 8.5 years. Also included were 10 asymptomatic HIV-1-infected...

  13. The role of polymorphonuclear neutrophils during HIV-1 infection.

    Science.gov (United States)

    Yaseen, Mahmoud Mohammad; Abuharfeil, Nizar Mohammad; Yaseen, Mohammad Mahmoud; Shabsoug, Barakat Mohammad

    2018-01-01

    It is well-recognized that human immunodeficiency virus type-1 (HIV-1) mainly targets CD4+ T cells and macrophages. Nonetheless, during the past three decades, a huge number of studies have reported that HIV-1 can directly or indirectly target other cellular components of the immune system including CD8+ T cells, B cells, dendritic cells, natural killer cells, and polymorphonuclear neutrophils (PMNs), among others. PMNs are the most abundant leukocytes in the human circulation, and are known to play principal roles in the elimination of invading pathogens, regulating different immune responses, healing of injured tissues, and maintaining mucosal homeostasis. Until recently, little was known about the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression. This is because early studies focused on neutropenia and recurrent microbial infections, particularly, during advanced disease. However, recent studies have extended the investigation area to cover new aspects of the interactions between HIV-1 and PMNs. This review aims to summarize these advances and address the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression to better understand the pathophysiology of HIV-1 infection.

  14. Probing the sequence space available for HIV-1 evolution

    NARCIS (Netherlands)

    ter Brake, Olivier; Von Eije, Karin J.; Berkhout, Ben

    2008-01-01

    We designed a novel experimental approach to probe the sequence space available for HIV-1 evolution. Selective pressure was put on conserved HIV-1 genomic sequences by means of RNA interference (RNAi). Virus escape was monitored in many parallel cultures, and we scored the mutations selected in the

  15. Intra- and inter-clade cross-reactivity by HIV-1 Gag specific T-cells reveals exclusive and commonly targeted regions: implications for current vaccine trials.

    Directory of Open Access Journals (Sweden)

    Lycias Zembe

    Full Text Available The genetic diversity of HIV-1 across the globe is a major challenge for developing an HIV vaccine. To facilitate immunogen design, it is important to characterize clusters of commonly targeted T-cell epitopes across different HIV clades. To address this, we examined 39 HIV-1 clade C infected individuals for IFN-γ Gag-specific T-cell responses using five sets of overlapping peptides, two sets matching clade C vaccine candidates derived from strains from South Africa and China, and three peptide sets corresponding to consensus clades A, B, and D sequences. The magnitude and breadth of T-cell responses against the two clade C peptide sets did not differ, however clade C peptides were preferentially recognized compared to the other peptide sets. A total of 84 peptides were recognized, of which 19 were exclusively from clade C, 8 exclusively from clade B, one peptide each from A and D and 17 were commonly recognized by clade A, B, C and D. The entropy of the exclusively recognized peptides was significantly higher than that of commonly recognized peptides (p = 0.0128 and the median peptide processing scores were significantly higher for the peptide variants recognized versus those not recognized (p = 0.0001. Consistent with these results, the predicted Major Histocompatibility Complex Class I IC(50 values were significantly lower for the recognized peptide variants compared to those not recognized in the ELISPOT assay (p<0.0001, suggesting that peptide variation between clades, resulting in lack of cross-clade recognition, has been shaped by host immune selection pressure. Overall, our study shows that clade C infected individuals recognize clade C peptides with greater frequency and higher magnitude than other clades, and that a selection of highly conserved epitope regions within Gag are commonly recognized and give rise to cross-clade reactivities.

  16. Daily Acyclovir Delays HIV-1 Disease Progression Among HIV-1/HSV-2 Dually-Infected Persons: A Randomized Trial

    Science.gov (United States)

    Lingappa, Jairam R.; Baeten, Jared M.; Wald, Anna; Hughes, James P.; Thomas, Katherine K.; Mujugira, Andrew; Mugo, Nelly; Bukusi, Elizabeth A.; Cohen, Craig R.; Katabira, Elly; Ronald, Allan; Kiarie, James; Farquhar, Carey; Stewart, Grace John; Makhema, Joseph; Essex, Myron; Were, Edwin; Fife, Kenneth H.; de Bruyn, Guy; Gray, Glenda E.; McIntyre, James; Manongi, Rachel; Kapiga, Saidi; Coetzee, David; Allen, Susan; Inambao, Mubiana; Kayitenkore, Kayitesi; Karita, Etienne; Kanweka, William; Delany, Sinead; Rees, Helen; Vwalika, Bellington; Magaret, Amalia; Wang, Richard S.; Kidoguchi, Lara; Barnes, Linda; Ridzon, Renee; Corey, Lawrence; Celum, Connie

    2010-01-01

    Background Well-tolerated medications that slow HIV-1 disease progression and delay initiation of antiretroviral therapy (ART) are needed. Most HIV-1-infected persons are dually-infected with herpes simplex virus type 2 (HSV-2). Daily HSV-2 suppression reduces plasma HIV-1 levels, but whether HSV-2 suppression delays HIV-1 disease progression is unknown. Methods Within a randomized, placebo-controlled trial of HSV-2 suppressive therapy (acyclovir 400 mg orally bid) to decrease HIV-1 transmission, 3381 HSV-2/HIV-1 dually-infected heterosexual Africans who at enrollment had CD4 counts ≥250 cells/mm3 and were not taking ART were followed for up to 24 months. We evaluated the effect of acyclovir on HIV-1 disease progression, defined by a primary composite endpoint of first occurrence of CD4 count death. As an exploratory analysis, we evaluated the endpoint of CD4 decline to HIV-1 plasma RNA was 4.1 log10 copies/mL. Acyclovir reduced risk of HIV-1 disease progression: 284 participants on acyclovir versus 324 on placebo reached the primary endpoint (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.71–0.98, p=0.03). Among participants with CD4 counts ≥350 cells/mm3, acyclovir delayed risk of CD4 decline to HIV-1 disease progression by 16% (95% CI 2–29%). The role of HSV-2 suppression in reducing HIV-1 disease progression prior to ART initiation warrants consideration (ClinicalTrials.gov #NCT00194519). PMID:20153888

  17. Serum C-peptide as a key contributor to lipid-related residual cardiovascular risk in the elderly.

    Science.gov (United States)

    Li, Ying; Zhao, DuoDuo; Li, Yue; Meng, Lu; Enwer, Gulmire

    2017-11-01

    The serum levels of C-peptide, an important risk factor for cardiovascular disease (CVD), increase with age. This study aimed to investigate the association between serum C-peptide and increased risk for CVD with altered lipid metabolism in the elderly. This was a population-based cross-sectional study that included 3091 elderly participants aged ≥65 years. Serum C-peptide and lipid levels were measured according to standard protocols. Sampling weights were used to estimate the characteristics of study participants. Stratified analysis of covariance was used to evaluate the changes in the serum lipid levels according to quartiles of serum C-peptide levels, and the linear trend was assessed using a linear model. The logistic regression model was carried out to determine the association between the serum C-peptide levels and serum lipid levels. The results of the analysis of covariance stratified by sex and serum insulin level showed that the serum triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) levels were significantly associated with changes in the serum C-peptide levels, independent of the serum insulin level. The logistic regression analyses indicated that the serum C-peptide levels were positively associated with the serum TG levels, and negatively associated with the serum HDL-C levels. A significant dose-response association was obtained in both men and women. Serum C-peptide levels were strongly associated with increased serum TG and reduced HDL-C levels in the elderly. Our results suggest that serum C-peptide increases the risk of CVD via a pathway that increases TG or decreases HDL-C levels. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Basal C-peptide Level as a Surrogate Marker of Subclinical Atherosclerosis in Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Sung-Tae Kim

    2011-02-01

    Full Text Available BackgroundRecent studies have revealed that C-peptide induces smooth muscle cell proliferation and causes human atherosclerotic lesions in diabetic patients. The present study was designed to examine whether the basal C-peptide levels correlate with cardiovascular risk in type 2 diabetes mellitus (T2DM patients.MethodsData was obtained from 467 patients with T2DM from two institutions who were followed for four years. The medical findings of all patients were reviewed, and patients with creatinine >1.4 mg/dL, any inflammation or infection, hepatitis, or type 1 DM were excluded. The relationships between basal C-peptide and other clinical values were statistically analyzed.ResultsA simple correlation was found between basal C-peptide and components of metabolic syndrome (MS. Statistically basal C-peptide levels were significantly higher than the three different MS criteria used in the present study, the Adult Treatment Panel III (ATP III of the National Cholesterol Education Program's (NCEP's, World Health Organization (WHO, and the International Diabetes Federation (IDF criteria (NCEP-ATP III, P=0.001; IDF, P<0.001; WHO, P=0.029. The multiple regression analysis between intima-media thickness (IMT and clinical values showed that basal C-peptide significantly correlated with IMT (P=0.043, while the analysis between the 10-year coronary heart disease risk by the United Kingdom Prospective Diabetes Study risk engine and clinical values showed that basal C-peptide did not correlate with IMT (P=0.226.ConclusionBasal C-peptide is related to cardiovascular predictors (IMT of T2DM, suggesting that basal C-peptide does provide a further indication of cardiovascular disease.

  19. Astrocytes Resist HIV-1 Fusion but Engulf Infected Macrophage Material

    Directory of Open Access Journals (Sweden)

    Rebecca A. Russell

    2017-02-01

    Full Text Available HIV-1 disseminates to diverse tissues and establishes long-lived viral reservoirs. These reservoirs include the CNS, in which macrophage-lineage cells, and as suggested by many studies, astrocytes, may be infected. Here, we have investigated astrocyte infection by HIV-1. We confirm that astrocytes trap and internalize HIV-1 particles for subsequent release but find no evidence that these particles infect the cell. Astrocyte infection was not observed by cell-free or cell-to-cell routes using diverse approaches, including luciferase and GFP reporter viruses, fixed and live-cell fusion assays, multispectral flow cytometry, and super-resolution imaging. By contrast, we observed intimate interactions between HIV-1-infected macrophages and astrocytes leading to signals that might be mistaken for astrocyte infection using less stringent approaches. These results have implications for HIV-1 infection of the CNS, viral reservoir formation, and antiretroviral therapy.

  20. AIDS in rural Africa: a paradigm for HIV-1 prevention.

    Science.gov (United States)

    Hudson, C P

    1996-07-01

    Networks of concurrent sexual partnerships may be the primary cause of epidemic spread of HIV-1 in parts of sub-Saharan Africa. This pattern of sexual behaviour increases the likelihood that individuals experiencing primary HIV-1 infection transmit the virus to other persons. Networks of concurrent partnerships are likely to be important in both the early ('epidemic') and late ('endemic') phases of HIV-1 transmission. Interventions should aim to break the sexual networks, whatever the stage of the epidemic. However, prevention of transmission in the endemic phase also requires a greater awareness of early clinical manifestations of HIV-1 infection in the general population. Such awareness, coupled with the availability of condoms and access to HIV-1 testing facilities, may reduce transmission in discordant couples.

  1. Sexually transmitted infections among HIV-1-discordant couples.

    Directory of Open Access Journals (Sweden)

    Brandon L Guthrie

    2009-12-01

    Full Text Available More new HIV-1 infections occur within stable HIV-1-discordant couples than in any other group in Africa, and sexually transmitted infections (STIs may increase transmission risk among discordant couples, accounting for a large proportion of new HIV-1 infections. Understanding correlates of STIs among discordant couples will aid in optimizing interventions to prevent HIV-1 transmission in these couples.HIV-1-discordant couples in which HIV-1-infected partners were HSV-2-seropositive were tested for syphilis, chlamydia, gonorrhea, and trichomoniasis, and HIV-1-uninfected partners were tested for HSV-2. We assessed sociodemographic, behavioral, and biological correlates of a current STI.Of 416 couples enrolled, 16% were affected by a treatable STI, and among these both partners were infected in 17% of couples. A treatable STI was found in 46 (11% females and 30 (7% males. The most prevalent infections were trichomoniasis (5.9% and syphilis (2.6%. Participants were 5.9-fold more likely to have an STI if their partner had an STI (P<0.01, and STIs were more common among those reporting any unprotected sex (OR = 2.43; P<0.01 and those with low education (OR = 3.00; P<0.01. Among HIV-1-uninfected participants with an HSV-2-seropositive partner, females were significantly more likely to be HSV-2-seropositive than males (78% versus 50%, P<0.01.Treatable STIs were common among HIV-1-discordant couples and the majority of couples affected by an STI were discordant for the STI, with relatively high HSV-2 discordance. Awareness of STI correlates and treatment of both partners may reduce HIV-1 transmission.ClinicalTrials.gov NCT00194519.

  2. HIV-1 activates macrophages independent of Toll-like receptors.

    Directory of Open Access Journals (Sweden)

    Joseph N Brown

    Full Text Available Macrophages provide an interface between innate and adaptive immunity and are important long-lived reservoirs for Human Immunodeficiency Virus Type-1 (HIV-1. Multiple genetic networks involved in regulating signal transduction cascades and immune responses in macrophages are coordinately modulated by HIV-1 infection.To evaluate complex interrelated processes and to assemble an integrated view of activated signaling networks, a systems biology strategy was applied to genomic and proteomic responses by primary human macrophages over the course of HIV-1 infection. Macrophage responses, including cell cycle, calcium, apoptosis, mitogen-activated protein kinases (MAPK, and cytokines/chemokines, to HIV-1 were temporally regulated, in the absence of cell proliferation. In contrast, Toll-like receptor (TLR pathways remained unaltered by HIV-1, although TLRs 3, 4, 7, and 8 were expressed and responded to ligand stimulation in macrophages. HIV-1 failed to activate phosphorylation of IRAK-1 or IRF-3, modulate intracellular protein levels of Mx1, an interferon-stimulated gene, or stimulate secretion of TNF, IL-1beta, or IL-6. Activation of pathways other than TLR was inadequate to stimulate, via cross-talk mechanisms through molecular hubs, the production of proinflammatory cytokines typical of a TLR response. HIV-1 sensitized macrophage responses to TLR ligands, and the magnitude of viral priming was related to virus replication.HIV-1 induced a primed, proinflammatory state, M1(HIV, which increased the responsiveness of macrophages to TLR ligands. HIV-1 might passively evade pattern recognition, actively inhibit or suppress recognition and signaling, or require dynamic interactions between macrophages and other cells, such as lymphocytes or endothelial cells. HIV-1 evasion of TLR recognition and simultaneous priming of macrophages may represent a strategy for viral survival, contribute to immune pathogenesis, and provide important targets for therapeutic

  3. HIV-1 infection of in vitro cultured human monocytes: early events and influence of anti HIV-1 antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Olofsson, S; Nielsen, Jens Ole

    1994-01-01

    To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (M phi s) we examined the susceptibility of in vitro cultured monocyte/M phi s to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera...... on this infection. Depending on the period of in vitro cultivation and the virus isolate used different patterns of susceptibility were detected. One week old monocyte/M phi s were highly susceptible to HIV-1 infection, in contrast to monocyte/M phi s cultured 4 weeks. The infection by virus isolated immediately...... to CD4 and that post binding events may be common to the infection of lymphocytes. Anti HIV-1 sera showed neutralizing activity against heterologous and even autologous escape virus. This finding, together with the observation that monocytes and M phi s are infected in vivo, suggests that protection...

  4. Trans-dissemination of exosomes from HIV-1-infected cells fosters both HIV-1 trans-infection in resting CD4+ T lymphocytes and reactivation of the HIV-1 reservoir.

    Science.gov (United States)

    Chiozzini, Chiara; Arenaccio, Claudia; Olivetta, Eleonora; Anticoli, Simona; Manfredi, Francesco; Ferrantelli, Flavia; d'Ettorre, Gabriella; Schietroma, Ivan; Andreotti, Mauro; Federico, Maurizio

    2017-09-01

    Intact HIV-1 and exosomes can be internalized by dendritic cells (DCs) through a common pathway leading to their transmission to CD4+ T lymphocytes by means of mechanisms defined as trans-infection and trans-dissemination, respectively. We previously reported that exosomes from HIV-1-infected cells activate both uninfected quiescent CD4+ T lymphocytes, which become permissive to HIV-1, and latently infected cells, with release of HIV-1 particles. However, nothing is known about the effects of trans-dissemination of exosomes produced by HIV-1-infected cells on uninfected or latently HIV-1-infected CD4+ T lymphocytes. Here, we report that trans-dissemination of exosomes from HIV-1-infected cells induces cell activation in resting CD4+ T lymphocytes, which appears stronger with mature than immature DCs. Using purified preparations of both HIV-1 and exosomes, we observed that mDC-mediated trans-dissemination of exosomes from HIV-1-infected cells to resting CD4+ T lymphocytes induces efficient trans-infection and HIV-1 expression in target cells. Most relevant, when both mDCs and CD4+ T lymphocytes were isolated from combination anti-retroviral therapy (ART)-treated HIV-1-infected patients, trans-dissemination of exosomes from HIV-1-infected cells led to HIV-1 reactivation from the viral reservoir. In sum, our data suggest a role of exosome trans-dissemination in both HIV-1 spread in the infected host and reactivation of the HIV-1 reservoir.

  5. Anti-HIV-1 activity of flavonoid myricetin on HIV-1 infection in a dual-chamber in vitro model.

    Science.gov (United States)

    Pasetto, Silvana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2014-01-01

    HIV infection by sexual transmission remains an enormous global health concern. More than 1 million new infections among women occur annually. Microbicides represent a promising prevention strategy that women can easily control. Among emerging therapies, natural small molecules such as flavonoids are an important source of new active substances. In this study we report the in vitro cytotoxicity and anti-HIV-1 and microbicide activity of the following flavonoids: Myricetin, Quercetin and Pinocembrin. Cytotoxicity tests were conducted on TZM-bl, HeLa, PBMC, and H9 cell cultures using 0.01-100 µM concentrations. Myricetin presented the lowest toxic effect, with Quercetin and Pinocembrin relatively more toxic. The anti-HIV-1 activity was tested with TZM-bl cell plus HIV-1 BaL (R5 tropic), H9 and PBMC cells plus HIV-1 MN (X4 tropic), and the dual tropic (X4R5) HIV-1 89.6. All flavonoids showed anti-HIV activity, although Myricetin was more effective than Quercetin or Pinocembrin. In TZM-bl cells, Myricetin inhibited ≥90% of HIV-1 BaL infection. The results were confirmed by quantification of HIV-1 p24 antigen in supernatant from H9 and PBMC cells following flavonoid treatment. In H9 and PBMC cells infected by HIV-1 MN and HIV-1 89.6, Myricetin showed more than 80% anti-HIV activity. Quercetin and Pinocembrin presented modest anti-HIV activity in all experiments. Myricetin activity was tested against HIV-RT and inhibited the enzyme by 49%. Microbicide activities were evaluated using a dual-chamber female genital tract model. In the in vitro microbicide activity model, Myricetin showed promising results against different strains of HIV-1 while also showing insignificant cytotoxic effects. Further studies of Myricetin should be performed to identify its molecular targets in order to provide a solid biological foundation for translational research.

  6. HIV-1 molecular epidemiology among newly diagnosed HIV-1 individuals in Hebei, a low HIV prevalence province in China.

    Directory of Open Access Journals (Sweden)

    Xinli Lu

    Full Text Available New human immunodeficiency virus type 1 (HIV-1 diagnoses are increasing rapidly in Hebei. The aim of this study presents the most extensive HIV-1 molecular epidemiology investigation in Hebei province in China thus far. We have carried out the most extensive systematic cross-sectional study based on newly diagnosed HIV-1 positive individuals in 2013, and characterized the molecular epidemiology of HIV-1 based on full length gag-partial pol gene sequences in the whole of Hebei. Nine HIV-1 genotypes based on full length gag-partial pol gene sequence were identified among 610 newly diagnosed naïve individuals. The four main genotypes were circulating recombinant form (CRF01_AE (53.4%, CRF07_BC (23.4%, subtype B (15.9%, and unique recombinant forms URFs (4.9%. Within 1 year, three new genotypes (subtype A1, CRF55_01B, CRF65_cpx, unknown before in Hebei, were first found among men who have sex with men (MSM. All nine genotypes were identified in the sexually contracted HIV-1 population. Among 30 URFs, six recombinant patterns were revealed, including CRF01_AE/BC (40.0%, CRF01_AE/B (23.3%, B/C (16.7%, CRF01_AE/C (13.3%, CRF01_AE/B/A2 (3.3% and CRF01_AE/BC/A2 (3.3%, plus two potential CRFs. This study elucidated the complicated characteristics of HIV-1 molecular epidemiology in a low HIV-1 prevalence northern province of China and revealed the high level of HIV-1 genetic diversity. All nine HIV-1 genotypes circulating in Hebei have spread out of their initial risk groups into the general population through sexual contact, especially through MSM. This highlights the urgency of HIV prevention and control in China.

  7. Anti-HIV-1 activity of flavonoid myricetin on HIV-1 infection in a dual-chamber in vitro model.

    Directory of Open Access Journals (Sweden)

    Silvana Pasetto

    Full Text Available HIV infection by sexual transmission remains an enormous global health concern. More than 1 million new infections among women occur annually. Microbicides represent a promising prevention strategy that women can easily control. Among emerging therapies, natural small molecules such as flavonoids are an important source of new active substances. In this study we report the in vitro cytotoxicity and anti-HIV-1 and microbicide activity of the following flavonoids: Myricetin, Quercetin and Pinocembrin. Cytotoxicity tests were conducted on TZM-bl, HeLa, PBMC, and H9 cell cultures using 0.01-100 µM concentrations. Myricetin presented the lowest toxic effect, with Quercetin and Pinocembrin relatively more toxic. The anti-HIV-1 activity was tested with TZM-bl cell plus HIV-1 BaL (R5 tropic, H9 and PBMC cells plus HIV-1 MN (X4 tropic, and the dual tropic (X4R5 HIV-1 89.6. All flavonoids showed anti-HIV activity, although Myricetin was more effective than Quercetin or Pinocembrin. In TZM-bl cells, Myricetin inhibited ≥90% of HIV-1 BaL infection. The results were confirmed by quantification of HIV-1 p24 antigen in supernatant from H9 and PBMC cells following flavonoid treatment. In H9 and PBMC cells infected by HIV-1 MN and HIV-1 89.6, Myricetin showed more than 80% anti-HIV activity. Quercetin and Pinocembrin presented modest anti-HIV activity in all experiments. Myricetin activity was tested against HIV-RT and inhibited the enzyme by 49%. Microbicide activities were evaluated using a dual-chamber female genital tract model. In the in vitro microbicide activity model, Myricetin showed promising results against different strains of HIV-1 while also showing insignificant cytotoxic effects. Further studies of Myricetin should be performed to identify its molecular targets in order to provide a solid biological foundation for translational research.

  8. Assessment of recent HIV-1 infection by a line immunoassay for HIV-1/2 confirmation.

    Directory of Open Access Journals (Sweden)

    Jörg Schüpbach

    2007-12-01

    Full Text Available BACKGROUND: Knowledge of the number of recent HIV infections is important for epidemiologic surveillance. Over the past decade approaches have been developed to estimate this number by testing HIV-seropositive specimens with assays that discriminate the lower concentration and avidity of HIV antibodies in early infection. We have investigated whether this "recency" information can also be gained from an HIV confirmatory assay. METHODS AND FINDINGS: The ability of a line immunoassay (INNO-LIA HIV I/II Score, Innogenetics to distinguish recent from older HIV-1 infection was evaluated in comparison with the Calypte HIV-1 BED Incidence enzyme immunoassay (BED-EIA. Both tests were conducted prospectively in all HIV infections newly diagnosed in Switzerland from July 2005 to June 2006. Clinical and laboratory information indicative of recent or older infection was obtained from physicians at the time of HIV diagnosis and used as the reference standard. BED-EIA and various recency algorithms utilizing the antibody reaction to INNO-LIA's five HIV-1 antigen bands were evaluated by logistic regression analysis. A total of 765 HIV-1 infections, 748 (97.8% with complete test results, were newly diagnosed during the study. A negative or indeterminate HIV antibody assay at diagnosis, symptoms of primary HIV infection, or a negative HIV test during the past 12 mo classified 195 infections (26.1% as recent (< or = 12 mo. Symptoms of CDC stages B or C classified 161 infections as older (21.5%, and 392 patients with no symptoms remained unclassified. BED-EIA ruled 65% of the 195 recent infections as recent and 80% of the 161 older infections as older. Two INNO-LIA algorithms showed 50% and 40% sensitivity combined with 95% and 99% specificity, respectively. Estimation of recent infection in the entire study population, based on actual results of the three tests and adjusted for a test's sensitivity and specificity, yielded 37% for BED-EIA compared to 35% and 33

  9. Assessment of recent HIV-1 infection by a line immunoassay for HIV-1/2 confirmation.

    Science.gov (United States)

    Schüpbach, Jörg; Gebhardt, Martin D; Tomasik, Zuzana; Niederhauser, Christoph; Yerly, Sabine; Bürgisser, Philippe; Matter, Lukas; Gorgievski, Meri; Dubs, Rolf; Schultze, Detlev; Steffen, Ingrid; Andreutti, Corinne; Martinetti, Gladys; Güntert, Bruno; Staub, Roger; Daneel, Synove; Vernazza, Pietro

    2007-12-01

    Knowledge of the number of recent HIV infections is important for epidemiologic surveillance. Over the past decade approaches have been developed to estimate this number by testing HIV-seropositive specimens with assays that discriminate the lower concentration and avidity of HIV antibodies in early infection. We have investigated whether this "recency" information can also be gained from an HIV confirmatory assay. The ability of a line immunoassay (INNO-LIA HIV I/II Score, Innogenetics) to distinguish recent from older HIV-1 infection was evaluated in comparison with the Calypte HIV-1 BED Incidence enzyme immunoassay (BED-EIA). Both tests were conducted prospectively in all HIV infections newly diagnosed in Switzerland from July 2005 to June 2006. Clinical and laboratory information indicative of recent or older infection was obtained from physicians at the time of HIV diagnosis and used as the reference standard. BED-EIA and various recency algorithms utilizing the antibody reaction to INNO-LIA's five HIV-1 antigen bands were evaluated by logistic regression analysis. A total of 765 HIV-1 infections, 748 (97.8%) with complete test results, were newly diagnosed during the study. A negative or indeterminate HIV antibody assay at diagnosis, symptoms of primary HIV infection, or a negative HIV test during the past 12 mo classified 195 infections (26.1%) as recent (EIA ruled 65% of the 195 recent infections as recent and 80% of the 161 older infections as older. Two INNO-LIA algorithms showed 50% and 40% sensitivity combined with 95% and 99% specificity, respectively. Estimation of recent infection in the entire study population, based on actual results of the three tests and adjusted for a test's sensitivity and specificity, yielded 37% for BED-EIA compared to 35% and 33% for the two INNO-LIA algorithms. Window-based estimation with BED-EIA yielded 41% (95% confidence interval 36%-46%). Recency information can be extracted from INNO-LIA-based confirmatory testing at

  10. C-peptide prevents hyperglycemia-induced endothelial apoptosis through inhibition of reactive oxygen species-mediated transglutaminase 2 activation

    National Research Council Canada - National Science Library

    Bhatt, Mahendra Prasad; Lim, Young-Cheol; Hwang, JongYun; Na, SungHun; Kim, Young-Myeong; Ha, Kwon-Soo

    2013-01-01

    .... We investigated the protective mechanism of C-peptide against hyperglycemia-induced apoptosis using human umbilical vein endothelial cells and streptozotocin diabetic mice. High glucose (33 mmol/L...

  11. Sex and gender differences in HIV-1 infection.

    Science.gov (United States)

    Griesbeck, Morgane; Scully, Eileen; Altfeld, Marcus

    2016-08-01

    The major burden of the human immunodeficiency (HIV) type 1 pandemic is nowadays carried by women from sub-Saharan Africa. Differences in the manifestations of HIV-1 infection between women and men have been long reported, and might be due to both socio-economic (gender) and biological (sex) factors. Several studies have shown that women are more susceptible to HIV-1 acquisition than men. Following HIV-1 infection, women have lower viral loads during acute infection and exhibit stronger antiviral responses than men, which may contribute to differences in the size of viral reservoirs. Oestrogen receptor signalling could represent an important mediator of sex differences in HIV-1 reservoir size and may represent a potential therapeutic target. Furthermore, immune activation, a hallmark of HIV-1 infection, is generally higher in women than in men and could be a central mechanism in the sex difference observed in the speed of HIV-1 disease progression. Here, we review the literature regarding sex-based differences in HIV-1 infection and discuss how a better understanding of the underlying mechanisms could improve preventive and therapeutic strategies. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  12. Correlates of HIV-1 genital shedding in Tanzanian women.

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    Clare Tanton

    2011-03-01

    Full Text Available Understanding the correlates of HIV shedding is important to inform strategies to reduce HIV infectiousness. We examined correlates of genital HIV-1 RNA in women who were seropositive for both herpes simplex virus (HSV-2 and HIV-1 and who were enrolled in a randomised controlled trial of HSV suppressive therapy (aciclovir 400 mg b.i.d vs. placebo in Tanzania.Samples, including a cervico-vaginal lavage, were collected and tested for genital HIV-1 and HSV and reproductive tract infections (RTIs at randomisation and 6, 12 and 24 months follow-up. Data from all women at randomisation and women in the placebo arm during follow-up were analysed using generalised estimating equations to determine the correlates of cervico-vaginal HIV-1 RNA detection and load.Cervico-vaginal HIV-1 RNA was detected at 52.0% of 971 visits among 482 women, and was independently associated with plasma viral load, presence of genital ulcers, pregnancy, bloody cervical or vaginal discharge, abnormal vaginal discharge, cervical ectopy, Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, an intermediate bacterial vaginosis score and HSV DNA detection. Similar factors were associated with genital HIV-1 RNA load.RTIs were associated with increased presence and quantity of genital HIV-1 RNA in this population. These results highlight the importance of integrating effective RTI treatment into HIV care services.

  13. The Complex Interaction Between Methamphetamine Abuse and HIV-1 Pathogenesis.

    Science.gov (United States)

    Passaro, Ryan Colby; Pandhare, Jui; Qian, Han-Zhu; Dash, Chandravanu

    2015-09-01

    The global HIV/AIDS pandemic has claimed the lives of an estimated 35 million people. A significant barrier for combating this global pandemic is substance use since it is associated with HIV transmission, delayed diagnosis/initiation of therapy, and poor adherence to therapy. Clinical studies also suggest a link between substance use and HIV-disease progression/AIDS-associated mortality. Methamphetamine (METH) use is one of the fastest-growing substance use problems in the world. METH use enhances high-risk sexual behaviors, therefore increases the likelihood of HIV-1 acquisition. METH use is also associated with higher viral loads, immune dysfunction, and antiretroviral resistance. Moreover, METH use has also been correlated with rapid progression to AIDS. However, direct effects of METH on HIV-1 disease progression remains poorly understood because use of METH and other illicit drugs is often associated with reduced/non adherence to ART. Nevertheless, in vitro studies demonstrate that METH increases HIV-1 replication in cell cultures and animal models. Thus, it has been proposed that METH's potentiating effects on HIV-1 replication may in part contribute to the worsening of HIV-1 pathogenesis. However, our recent data demonstrate that METH at physiologically relevant concentrations has no effect and at higher concentrations inhibits HIV-1 replication in CD4+ T cells. Thus, the goal of this review is to systematically examine the published literature to better understand the complex interaction between METH abuse and HIV-1 disease progression.

  14. Cell-Associated HIV-1 DNA and RNA Decay Dynamics During Early Combination Antiretroviral Therapy in HIV-1-Infected Infants.

    Science.gov (United States)

    Uprety, Priyanka; Chadwick, Ellen G; Rainwater-Lovett, Kaitlin; Ziemniak, Carrie; Luzuriaga, Katherine; Capparelli, Edmund V; Yenokyan, Gayane; Persaud, Deborah

    2015-12-15

    The decay of human immunodeficiency virus type 1 (HIV-1)-infected cells during early combination antiretroviral therapy (cART) in infected infants is not defined. HIV-1 DNA, including 2-long terminal repeat (2-LTR) circles, and multiply spliced (ms-) and unspliced (us-) HIV-1 RNA concentrations were measured at 0, 24, 48, and 96 weeks of cART in infants from the IMPAACT P1030 trial receiving lopinavir-ritonavir-based cART. The ratio of HIV-1 DNA concentrations to replication-competent genomes was also estimated. Linear mixed effects models with random intercept and linear splines were used to estimate patient-specific decay kinetics of HIV-1 DNA. The median HIV-1 DNA concentration before cART at a median age of 2 months was 3.2 log10 copies per million PBMC. With cART, the average estimated patient-specific change in HIV-1 DNA concentrations was -0.040 log10/week (95% confidence interval [CI], -.05, -.03) between 0 and 24 weeks and -0.017 log10/week between 24 and 48 weeks (95% CI, -.024, -.01). 2-LTR circles decreased with cART but remained detectable through 96 weeks. Pre-cART HIV-1 DNA concentration was correlated with time to undetectable plasma viral load and post-cART HIV-1 DNA at 96 weeks; although HIV-1 DNA concentrations exceeded replication-competent HIV-1 genomes by 148-fold. Almost all infants had ms- and usRNA detected pre-cART, with 75% having usRNA through 96 weeks of cART. By 2 months of age, a large pool of HIV-1-infected cells is established in perinatal infection, which influences time to undetectable viral load and reservoir size. This has implications for informing novel approaches aimed at early restriction of HIV-1 reservoirs to enable virologic remission and cure. © The Author 2015. 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.

  15. The effect of insulin administration on c-peptide in critically ill patients with type 2 diabetes.

    Science.gov (United States)

    Crisman, Marco; Lucchetta, Luca; Luethi, Nora; Cioccari, Luca; Lam, Que; Eastwood, Glenn M; Bellomo, Rinaldo; Mårtensson, Johan

    2017-12-01

    In critically ill patients with permissive hyperglycemia, it is uncertain whether exogenous insulin administration suppresses or enhances c-peptide secretion (a marker of pancreatic beta-cell response). We aimed to explore this effect in patients with type 2 diabetes. We prospectively enrolled a cohort of 45 critically ill patients with type 2 diabetes managed according to a liberal glucose protocol (target blood glucose 10-14 mmol/l). We recorded the administration of insulin and oral hypoglycemic agents and measured plasma c-peptide as surrogate marker of endogenous insulin secretion on the first two consecutive days in ICU. Overall, 20 (44.4%) patients required insulin to achieve target blood glucose. Insulin-treated patients had higher glycated hemoglobin A1c, more premorbid insulin-requiring type 2 diabetes, and greater blood glucose levels but lower c-peptide levels on admission. Premorbid insulin-requiring diabetes was independently associated with lower admission c-peptide, whereas greater plasma creatinine was independently associated with higher levels. Increases in c-peptide were positively correlated with an increase in blood glucose both in patients who did (r = 0.54, P = 0.01) and did not (r = 0.56, P = 0.004) receive insulin. However, insulin administration was independently associated with a greater increase in c-peptide (P = 0.04). This association was not modified by the use of oral insulin secretagogues. C-peptide, a marker of beta-cell response, responds to and is influenced by glycemia and renal function in critically ill patients with type 2 diabetes. In addition, in our cohort, exogenous insulin administration was associated with a greater increase in c-peptide in response to hyperglycemia. Trial Registration Australian New Zealand Clinical Trials Registry (ACTRN12615000216516).

  16. HIV-1 Replication and the Cellular Eukaryotic Translation Apparatus

    Directory of Open Access Journals (Sweden)

    Santiago Guerrero

    2015-01-01

    Full Text Available Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1 uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication.

  17. Sensitive non-radioactive detection of HIV-1

    DEFF Research Database (Denmark)

    Teglbjærg, Lars Stubbe; Nielsen, C; Hansen, J E

    1992-01-01

    to standard PCR for the detection of HIV-1 DNA. The assay described features the use of a simple and inexpensive sample preparation technique and a non-radioactive hybridization procedure for confirmation of results. To test the suitability of the assay for clinical purposes, we tested cell samples from 76......This report describes the use of the polymerase chain reaction (PCR) for the non-radioactive detection of HIV-1 proviral genomic sequences in HIV-1 infected cells. We have developed a sensitive assay, using three different sets of nested primers and our results show that this method is superior...

  18. Role of C-peptide in Altered Lipid Profile among Apparently Healthy Adults of Vijayapura City, Karnataka

    Directory of Open Access Journals (Sweden)

    Chandrahas M.Kulkarni

    2016-04-01

    Full Text Available Background: C-peptide is produced in equimolar concentration during insulin production as inactive molecule by beta islet cells of Langerhans. C-peptide is most useful biomarker of endogenous insulin production. Aim and Objectives: To predict metabolic syndrome in advance by estimation of C-peptide and lipid profile in healthy adults. Material and Methods: Serum C-peptide, fasting blood glucose and lipid profile of 128 healthy individuals were estimated. Adults in the age group of 18 to 60 years of both sexes were included in study. Results: C-peptide levels were increased in 27%, Serum cholesterol in 30%, LDL Cholesterol in 55% and triglyceride levels in 21% of healthy individuals. Significant correlation was observed between C peptide, age, serum cholesterol, LDL and cholesterol LDL ratio in male subjects only. In our study group most of the subjects (both males and females fell in overweight group. Conclusion: Cpeptide level and lipid profile may be considered as useful biomarkers to predict type 2 diabetes mellitus in advance, possibly due to insulin resistance.

  19. In vivo effects of methamphetamine on HIV-1 replication: A population-based study

    National Research Council Canada - National Science Library

    Jiang, Junjun; Wang, Minlian; Liang, Bingyu; Shi, Yi; Su, Qijian; Chen, Hui; Huang, Jiegang; Su, Jinming; Pan, Peijiang; Li, Yu; Wang, Hong; Chen, Rongfeng; Liu, Jie; Zhao, Fangning; Ye, Li; Liang, Hao

    2016-01-01

    Although a number of in vitro studies have shown that methamphetamine (METH) can increase HIV-1 replication in human immune cells, a direct link between METH use and HIV-1 pathogenesis remains to be determined among HIV-1 patients...

  20. Multiple HIV-1/M + HIV-1/O dual infections and new HIV-1/MO inter-group recombinant forms detected in Cameroon.

    Science.gov (United States)

    De Oliveira, Fabienne; Mourez, Thomas; Vessiere, Aurélia; Ngoupo, Paul-Alain; Alessandri-Gradt, Elodie; Simon, François; Rousset, Dominique; Plantier, Jean-Christophe

    2017-01-13

    Due to the prevalence of HIV-1 group M and the endemicity of HIV-1 group O infections in Cameroon, patients may be infected with both viruses and/or with HIV-1/MO recombinant forms. Such atypical infections may be deleterious in terms of diagnosis and therapeutic management due to the high divergence of HIV-1/O. The aim of this study was to identify prospectively such atypical infections in Cameroon. Based on serological screening by env-V3 serotyping and a molecular strategy using group-specific (RT)-PCRs, we identified 10 Cameroonian patients harboring three different profiles of infection: (1) 4 HIV-1/M + O dual infections without evidence of recombinant; (2) 5 recombinants associated with one or both parental strains; and (3) 1 new recombinant form without parental strains. This work highlights the dynamic co-evolution of these two HIV groups in Cameroon that could lead to the emergence of a circulating recombinant form MO, and the need for accurate identification of such atypical infections for precise diagnosis, virological monitoring and therapeutic management with adapted tools.

  1. HIV-1 tropism testing in subjects achieving undetectable HIV-1 RNA: diagnostic accuracy, viral evolution and compartmentalization.

    Science.gov (United States)

    Pou, Christian; Codoñer, Francisco M; Thielen, Alexander; Bellido, Rocío; Pérez-Álvarez, Susana; Cabrera, Cecilia; Dalmau, Judith; Curriu, Marta; Lie, Yolanda; Noguera-Julian, Marc; Puig, Jordi; Martínez-Picado, Javier; Blanco, Julià; Coakley, Eoin; Däumer, Martin; Clotet, Bonaventura; Paredes, Roger

    2013-01-01

    Technically, HIV-1 tropism can be evaluated in plasma or peripheral blood mononuclear cells (PBMCs). However, only tropism testing of plasma HIV-1 has been validated as a tool to predict virological response to CCR5 antagonists in clinical trials. The preferable tropism testing strategy in subjects with undetectable HIV-1 viremia, in whom plasma tropism testing is not feasible, remains uncertain. We designed a proof-of-concept study including 30 chronically HIV-1-infected individuals who achieved HIV-1 RNA evolution in PBMCs during viremia suppression and only found evolution of R5 viruses in one subject. No de novo CXCR4-using HIV-1 production was observed over time. Finally, Slatkin-Maddison tests suggested that plasma and cell-associated V3 forms were sometimes compartmentalized. The absence of tropism shifts during viremia suppression suggests that, when available, testing of stored plasma samples is generally safe and informative, provided that HIV-1 suppression is maintained. Tropism testing in PBMCs may not necessarily produce equivalent biological results to plasma, because the structure of viral populations and the diagnostic performance of tropism assays may sometimes vary between compartments. Thereby, proviral DNA tropism testing should be specifically validated in clinical trials before it can be applied to routine clinical decision-making.

  2. HIV-1 infection of in vitro cultured human monocytes: early events and influence of anti HIV-1 antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Olofsson, S; Nielsen, Jens Ole

    1994-01-01

    To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (M phi s) we examined the susceptibility of in vitro cultured monocyte/M phi s to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera on this in......To characterize the role of the humoral immune response on HIV-1 infection of monocytes and macrophages (M phi s) we examined the susceptibility of in vitro cultured monocyte/M phi s to various HIV-1 isolates and the influence of heterologous and particularly autologous anti HIV-1 sera...... on this infection. Depending on the period of in vitro cultivation and the virus isolate used different patterns of susceptibility were detected. One week old monocyte/M phi s were highly susceptible to HIV-1 infection, in contrast to monocyte/M phi s cultured 4 weeks. The infection by virus isolated immediately...... after seroconversion lead to persistent infection with high level of antigen production in contrast to infection by homologous virus isolated later. MAb against the V3-IIIB loop and sCD4 inhibited the infection of monocyte/M phi s in a dose dependent manner, indicating that infection requires binding...

  3. Conserved epitopes on HIV-1, FIV and SIV p24 proteins are recognized by HIV-1 infected subjects.

    Science.gov (United States)

    Roff, Shannon R; Sanou, Missa P; Rathore, Mobeen H; Levy, Jay A; Yamamoto, Janet K

    2015-01-01

    Cross-reactive peptides on HIV-1 and FIV p24 protein sequences were studied using peripheral blood mononuclear cells (PBMC) from untreated HIV-1-infected long-term survivors (LTS; >10 y of infection without antiretroviral therapy, ART), short-term HIV-1 infected subjects not on ART, and ART-treated HIV-1 infected subjects. IFNγ-ELISpot and CFSE-proliferation analyses were performed with PBMC using overlapping HIV-1 and FIV p24 peptides. Over half of the HIV-1 infected subjects tested (22/31 or 71%) responded to one or more FIV p24 peptide pools by either IFNγ or T-cell proliferation analysis. PBMC and T cells from infected subjects in all 3 HIV(+) groups predominantly recognized one FIV p24 peptide pool (Fp14) by IFNγ production and one additional FIV p24 peptide pool (Fp9) by T-cell proliferation analysis. Furthermore, evaluation of overlapping SIV p24 peptide sequences identified conserved epitope(s) on the Fp14/Hp15-counterpart of SIV, Sp14, but none on Fp9-counterpart of SIV, Sp9. The responses to these FIV peptide pools were highly reproducible and persisted throughout 2-4 y of monitoring. Intracellular staining analysis for cytotoxins and phenotyping for CD107a determined that peptide epitopes from Fp9 and Fp14 pools induced cytotoxic T lymphocyte-associated molecules including perforin, granzyme B, granzyme A, and/or expression of CD107a. Selected FIV and corresponding SIV epitopes recognized by HIV-1 infected patients indicate that these protein sequences are evolutionarily conserved on both SIV and HIV-1 (e.g., Hp15:Fp14:Sp14). These studies demonstrate that comparative immunogenicity analysis of HIV-1, FIV, and SIV can identify evolutionarily-conserved T cell-associated lentiviral epitopes, which could be used as a vaccine for prophylaxis or immunotherapy.

  4. Achieving HIV-1 Control through RNA-Directed Gene Regulation

    Directory of Open Access Journals (Sweden)

    Vera Klemm

    2016-12-01

    Full Text Available HIV-1 infection has been transformed by combined anti-retroviral therapy (ART, changing a universally fatal infection into a controllable infection. However, major obstacles for an HIV-1 cure exist. The HIV latent reservoir, which exists in resting CD4+ T cells, is not impacted by ART, and can reactivate when ART is interrupted or ceased. Additionally, multi-drug resistance can arise. One alternate approach to conventional HIV-1 drug treatment that is being explored involves gene therapies utilizing RNA-directed gene regulation. Commonly known as RNA interference (RNAi, short interfering RNA (siRNA induce gene silencing in conserved biological pathways, which require a high degree of sequence specificity. This review will provide an overview of the silencing pathways, the current RNAi technologies being developed for HIV-1 gene therapy, current clinical trials, and the challenges faced in progressing these treatments into clinical trials.

  5. Purinergic Receptors: Key Mediators of HIV-1 infection and inflammation

    Directory of Open Access Journals (Sweden)

    Talia H Swartz

    2015-11-01

    Full Text Available Human immunodeficiency virus (HIV-1 causes a chronic infection that afflicts more than 38 million individuals worldwide. While the infection can be suppressed with potent anti-retroviral therapies, individuals infected with HIV have elevated levels of inflammation as indicated by increased T cell activation, soluble biomarkers, and associated morbidity and mortality. A single mechanism linking HIV pathogenesis to this inflammation has yet to be identified. Purinergic receptors are known to mediate inflammation and have been shown to be required for HIV-1 infection at the level of HIV-1 membrane fusion. Here we review the literature on the role of purinergic receptors in HIV-1 infection and associated inflammation and describe a role for these receptors as potential therapeutic targets.

  6. HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors

    DEFF Research Database (Denmark)

    Vanangamudi, Murugesan; Poongavanam, Vasanthanathan; Namasivayam, Vigneshwaran

    2017-01-01

    BACKGROUND: Design of inhibitors for HIV-1 reverse transcriptase inhibition (HIV-1 RT) is one of the successful chemotherapies for the treatment of HIV infection. Among the inhibitors available for HIV-1 RT, non-nucleoside reverse transcriptase inhibitors (NNRTIs) have shown to be very promising...... and clinically approved drugs. However, the efficiency of many of these drugs has been reduced by the drug-resistant variants of HIV-1 RT. The aim of the current review is to provide a summary of lead optimization strategies from the 3D-QSARs studies on NNRTI class from the past 21 years (1995 to 2016). METHODS......, formimidoester disulfides, thiocarbamate, thiazolidinone derivatives, etc. have been discussed in detail. In addition, we explore the position of the functional groups that drive the protein-ligand interaction. RESULTS: The structure-activity relationship (SAR) revealed from CoMFA and CoMSIA studies...

  7. GBV-C/HGV and HIV-1 coinfection

    Directory of Open Access Journals (Sweden)

    Maria Teresa Maidana

    Full Text Available An interesting interaction pattern has been found between HIV-1 and GBV-C/HGV, resulting in protection against progression to AIDS. The mechanisms involved in this interaction remain to be clarified. We examined the current knowledge concerning this coinfection and developed hypotheses to explain its effects. A better understanding of this interaction could result in new concepts, which may lead to new strategies to control HIV-1 replication and progression to AIDS.

  8. Epidermal Langerhans cells, HIV-1 infection and psoriasis.

    Science.gov (United States)

    Zemelman, V; Van Neer, F; Roberts, N; Patel, P; Langtry, J; Staughton, R C

    1994-03-01

    Langerhans cells (LCs) subserve an important antigen-presenting function in the skin immune system. They bear CD4 receptors, which make them potential targets for infection with the human immunodeficiency virus (HIV-1). The observation of reduced numbers of LCs in the skin of patients with the acquired immunodeficiency syndrome (AIDS), and the association of severe psoriasis with HIV-1 infection, raise interesting questions regarding the role of LCs in the skin of HIV-1-positive psoriatic patients. In this study, LCs were quantified in the lesional and non-lesional skin of seven HIV-1-positive psoriatic patients, and the results were compared with age-, sex- and site-matched HIV-1-negative psoriatic patients. The number of LCs was determined by staining skin sections with S-100 polyclonal antibody, using the three-step avidin-biotin immunoperoxidase method. The S-100-positive cells above the basal layer were quantified in two ways: cells/mm2 of epidermal area, and cells/mm of length of basement membrane. HIV-1-positive psoriatic patients showed a reduction in the number of epidermal LCs compared with HIV-1-negative psoriatic patients using both methods of quantification, in both lesional and non-lesional skin (P < 0.05, Mann-Whitney test). In addition, a reduction in the number of LCs in lesional compared with non-lesional skin was observed in both HIV-1-positive and -negative patients when LCs were quantified per mm2 of epidermal area (P < 0.05, Wilcoxon test).(ABSTRACT TRUNCATED AT 250 WORDS)

  9. The preparation and characterization of biological isolates of HIV-1

    OpenAIRE

    2012-01-01

    M.Sc. It is the widely accepted view that the human immunodeficiency virus (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS) and that South Africa harbors mainly HIV type 1 subtype C (HIV-1 C). Extensively characterized biological isolates (especially of HIV-1 subtype C) for use in HIV/AIDS vaccine and drug development are not readily available. This study evaluated three different protocols for the expansion of virus from infected PBMC's of 68 HIV/AIDS patients (de...

  10. Topological Analysis of HIV-1 Glycoproteins Expressed In Situ on Virus Surfaces Reveals Tighter Packing but Greater Conformational Flexibility than for Soluble gp120

    Science.gov (United States)

    Tong, Tommy; Osawa, Keiko; Robinson, James E.; Crooks, Ema T.

    2013-01-01

    In natural infection, antibodies interact with HIV-1 primarily through nonfunctional forms of envelope glycoproteins (Env), including uncleaved (UNC) gp160 and gp41 stumps. These antigens are important to fully characterize, as they may be decoys that promote nonneutralizing responses and may also be targets for nonneutralizing effector responses. In this study, we compared the antigenic properties of Env expressed in situ on pseudovirion virus-like particle (VLP) surfaces and soluble gp120 using harmonized enzyme-linked immunosorbent assays (ELISAs) and a panel of 51 monoclonal antibodies (MAbs). Only 32 of 46 soluble gp120-reactive MAbs recognized the primary UNC gp160 antigen of VLPs. Indeed, many epitopes were poorly exposed (C1, V2, C1-C4, C4, C4-V3, CD4 induced [CD4i], and PGT group 3) or obscured (C2, C5, and C1-C5) on VLPs. In further studies, VLP Env exhibited an increased degree of inter-MAb competition, the epicenter of which was the base of the V3 loop, where PGT, 2G12, V3, and CD4 binding site specificities competed. UNC gp160 also underwent more drastic soluble CD4 (sCD4)-induced conformational changes than soluble gp120, exposing CD4i, C1-C4, and V2 epitopes. A greater propensity of UNC gp160 to undergo conformational changes was also suggested by the induction of CD4i MAb binding to VLPs by a V3 MAb as well as by soluble CD4. The same effect was not observed for soluble gp120. Taken together, our data suggest that membrane-expressed UNC gp160 exists in a less “triggered” conformational state than soluble gp120 and that MAb binding to UNC gp160 tends to have greater conformational consequences. PMID:23740975

  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

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    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. Viral piracy: HIV-1 targets dendritic cells for transmission.

    Science.gov (United States)

    Lekkerkerker, Annemarie N; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2006-04-01

    Dendritic cells (DCs), the professional antigen presenting cells, are critical for host immunity by inducing specific immune responses against a broad variety of pathogens. Remarkably the human immunodeficiency virus-1 (HIV-1) subverts DC function leading to spread of the virus. At an early phase of HIV-1 transmission, DCs capture HIV-1 at mucosal surfaces and transmit the virus to T cells in secondary lymphoid tissues. Capture of the virus on DCs takes place via C-type lectins of which the dendritic cell-specific intercellular adhesion molecule-3 (ICAM-3) grabbing nonintegrin (DC-SIGN) is the best studied. DC-SIGN-captured HIV-1 particles accumulate in CD81(+) multivesicular bodies (MVBs) in DCs and are subsequently transmitted to CD4+ T cells resulting in infection of T cells. The viral cell-to-cell transmission takes place at the DC-T cell interface termed the infectious synapse. Recent studies demonstrate that direct infection of DCs contributes to the transmission to T cells at a later phase. Moreover, the infected DCs may function as cellular reservoirs for HIV-1. This review discusses the different processes that govern viral piracy of DCs by HIV-1, emphasizing the intracellular routing of the virus from capture on the cell surface to egress in the infectious synapse.

  13. SMYD2-Mediated Histone Methylation Contributes to HIV-1 Latency.

    Science.gov (United States)

    Boehm, Daniela; Jeng, Mark; Camus, Gregory; Gramatica, Andrea; Schwarzer, Roland; Johnson, Jeffrey R; Hull, Philip A; Montano, Mauricio; Sakane, Naoki; Pagans, Sara; Godin, Robert; Deeks, Steven G; Krogan, Nevan J; Greene, Warner C; Ott, Melanie

    2017-05-10

    Transcriptional latency of HIV is a last barrier to viral eradication. Chromatin-remodeling complexes and post-translational histone modifications likely play key roles in HIV-1 reactivation, but the underlying mechanisms are incompletely understood. We performed an RNAi-based screen of human lysine methyltransferases and identified the SET and MYND domain-containing protein 2 (SMYD2) as an enzyme that regulates HIV-1 latency. Knockdown of SMYD2 or its pharmacological inhibition reactivated latent HIV-1 in T cell lines and in primary CD4(+) T cells. SMYD2 associated with latent HIV-1 promoter chromatin, which was enriched in monomethylated lysine 20 at histone H4 (H4K20me1), a mark lost in cells lacking SMYD2. Further, we find that lethal 3 malignant brain tumor 1 (L3MBTL1), a reader protein with chromatin-compacting properties that recognizes H4K20me1, was recruited to the latent HIV-1 promoter in a SMYD2-dependent manner. We propose that a SMYD2-H4K20me1-L3MBTL1 axis contributes to HIV-1 latency and can be targeted with small-molecule SMYD2 inhibitors. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. DBR1 siRNA inhibition of HIV-1 replication

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    Naidu Yathi

    2005-10-01

    Full Text Available Abstract Background HIV-1 and all retroviruses are related to retroelements of simpler organisms such as the yeast Ty elements. Recent work has suggested that the yeast retroelement Ty1 replicates via an unexpected RNA lariat intermediate in cDNA synthesis. The putative genomic RNA lariat intermediate is formed by a 2'-5' phosphodiester bond, like that found in pre-mRNA intron lariats and it facilitates the minus-strand template switch during cDNA synthesis. We hypothesized that HIV-1 might also form a genomic RNA lariat and therefore that siRNA-mediated inhibition of expression of the human RNA lariat de-branching enzyme (DBR1 expression would specifically inhibit HIV-1 replication. Results We designed three short interfering RNA (siRNA molecules targeting DBR1, which were capable of reducing DBR1 mRNA expression by 80% and did not significantly affect cell viability. We assessed HIV-1 replication in the presence of DBR1 siRNA and found that DBR1 knockdown led to decreases in viral cDNA and protein production. These effects could be reversed by cotransfection of a DBR1 cDNA indicating that the inhibition of HIV-1 replication was a specific effect of DBR1 underexpression. Conclusion These data suggest that DBR1 function may be needed to debranch a putative HIV-1 genomic RNA lariat prior to completion of reverse transcription.

  15. HIV-1, Methamphetamine and Astrocytes at Neuroinflammatory crossroads

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    Kathleen eBorgmann

    2015-10-01

    Full Text Available As a popular psychostimulant, methamphetamine (METH use leads to long-lasting, strong euphoric effects. While METH abuse is common in the general population, between 10-15% of human immunodeficiency virus-1 (HIV-1 patients report having abused METH. METH exacerbates the severity and onset of HIV-1-associated neurocognitive disorders (HAND through direct and indirect mechanisms. Repetitive METH use decreases adherence to antiretroviral drug regimens, increasing the likelihood of HIV-1 disease progression towards AIDS. METH exposure also directly affects both innate and adaptive immunity, altering lymphocyte number and activity, cytokine signaling, phagocytic function, and CNS infiltration through the blood brain barrier. Further, METH triggers the neuronal dopamine reward pathway and leads to altered neuronal activity and direct toxicity. Concurrently, METH and HIV-1 alter the neuroimmune balance and induce neuroinflammation. Neuroinflammation modulates a wide range of brain functions including neuronal signaling and activity, glial activation, viral infection, oxidative stress and excitotoxicity. Pathologically, glial activation is a hallmark of both HIV-1 and METH-associated neuroinflammation. Significant commonality exists in the neurotoxic mechanisms for both METH and HAND; however, the pathways dysregulated in astroglia during METH exposure are less clear. Thus alterations in astrocyte intracellular signaling pathways, gene expression and function during METH and HIV-1 comorbidity, neuroinflammation and HAND are carefully reviewed. Interventions targeting astrocytes in HAND and METH are presented as potential novel therapeutic approaches.

  16. Current views on HIV-1 latency, persistence, and cure.

    Science.gov (United States)

    Melkova, Zora; Shankaran, Prakash; Madlenakova, Michaela; Bodor, Josef

    2017-01-01

    HIV-1 infection cannot be cured as it persists in latently infected cells that are targeted neither by the immune system nor by available therapeutic approaches. Consequently, a lifelong therapy suppressing only the actively replicating virus is necessary. The latent reservoir has been defined and characterized in various experimental models and in human patients, allowing research and development of approaches targeting individual steps critical for HIV-1 latency establishment, maintenance, and reactivation. However, additional mechanisms and processes driving the remaining low-level HIV-1 replication in the presence of the suppressive therapy still remain to be identified and targeted. Current approaches toward HIV-1 cure involve namely attempts to reactivate and purge HIV latently infected cells (so-called "shock and kill" strategy), as well as approaches involving gene therapy and/or gene editing and stem cell transplantation aiming at generation of cells resistant to HIV-1. This review summarizes current views and concepts underlying different approaches aiming at functional or sterilizing cure of HIV-1 infection.

  17. Identification of benzazole compounds that induce HIV-1 transcription.

    Directory of Open Access Journals (Sweden)

    Jason D Graci

    Full Text Available Despite advances in antiretroviral therapy, HIV-1 infection remains incurable in patients and continues to present a significant public health burden worldwide. While a number of factors contribute to persistent HIV-1 infection in patients, the presence of a stable, long-lived reservoir of latent provirus represents a significant hurdle in realizing an effective cure. One potential strategy to eliminate HIV-1 reservoirs in patients is reactivation of latent provirus with latency reversing agents in combination with antiretroviral therapy, a strategy termed "shock and kill". This strategy has shown limited clinical effectiveness thus far, potentially due to limitations of the few therapeutics currently available. We have identified a novel class of benzazole compounds effective at inducing HIV-1 expression in several cellular models. These compounds do not act via histone deacetylase inhibition or T cell activation, and show specificity in activating HIV-1 in vitro. Initial exploration of structure-activity relationships and pharmaceutical properties indicates that these compounds represent a potential scaffold for development of more potent HIV-1 latency reversing agents.

  18. Preserved C-peptide levels in overweight or obese compared with underweight children upon diagnosis of type 1 diabetes mellitus

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    Hyeoh Won Yu

    2015-06-01

    Full Text Available PurposeWe hypothesized that overweight or obese children might develop type 1 diabetes mellitus (T1DM early despite residual beta-cell function. Factors independently associated with preservation of C-peptide level were analyzed.MethodsWe retrospectively reviewed the medical data of 135 children aged 2.1-16.5 years with autoimmune T1DM. Body mass index (BMI, pubertal stage, and glycosylated hemoglobin (HbA1c and C-peptide levels were evaluated. Patients were assigned to underweight (22.2%, normal weight (63.7%, and overweight or obese (14.1% groups according to their BMI.ResultsPreservation of serum C-peptide levels (≥0.6 ng/mL was found in 43.0% of subjects. With increasing BMI, the proportions of children with preserved C-peptide levels increased from 33.3% to 41.9% to 63.2%, with marginal significance (P=0.051. Interaction analysis indicated no effect of BMI score on age at onset associated with serum C-peptide levels. The lower the C-peptide level, the younger the age of onset (P<0.001, after adjustment for BMI z-score and HbA1c level. However, no significant relationship between BMI z-score or category and onset age was evident. Upon multivariate-adjusted modeling, the odds that the C-peptide level was preserved increased by 1.2 fold (P=0.001 per year of life, by 3.1 folds (P=0.015 in children presenting without (compared to with ketoacidosis, and by 5.0 folds (P=0.042 in overweight or obese (compared to underweight children.ConclusionOverweight or obese children had slightly more residual beta-cell function than did underweight children. However, we found no evidence that obesity temporally accelerates T1DM presentation.

  19. Development of pyridine dicoumarols as potent anti HIV-1 leads, targeting HIV-1 associated topoisomeraseIIβ kinase.

    Science.gov (United States)

    Kammari, Kurumurthy; Devaraya, Kiran; Bommakanti, Akhila; Kondapi, Anand K

    2017-09-01

    A structural study of a series of pyridine dicoumarol derivatives with potential activity against a novel Topoisomerase IIβ kinase which was identified in the HIV-1 viral lysate, compounds were designed and synthesized based on a 3D-QSAR study. Based on QSAR model we have designed and synthesized a series of pyridine dicoumarol derivatives and characterized by spectral studies, all the molecules are biologically evaluated by kinase assay, cytotoxicity assay, ELISA and PCR method. We demonstrated the achievement of water soluble disodium pyridine dicoumarate derivatives showing high anti-HIV-1 activity (IC50 HIV-1-associated topoisomerase IIβ kinase inhibitors for clinical application against AIDS. A new class of anti-HIV-1 lead compounds have been designed and tested. Further studies would result in development of  novel and potential drugs.

  20. Successful increase in contraceptive uptake among Kenyan HIV-1-serodiscordant couples enrolled in an HIV-1 prevention trial.

    Science.gov (United States)

    Ngure, Kenneth; Heffron, Renee; Mugo, Nelly; Irungu, Elizabeth; Celum, Connie; Baeten, Jared M

    2009-11-01

    To evaluate a multipronged approach to promote dual contraceptive use by women within heterosexual HIV-1-serodiscordant partnerships. For 213 HIV-1-serodiscordant couples in Thika, Kenya, participating in an HIV-1 prevention clinical trial, contraceptive promotion was initiated through a multipronged intervention that included staff training, couples family planning sessions, and free provision of hormonal contraception on-site. Contraceptive use and pregnancy incidence were compared between two time periods (before versus after June 2007, when the intervention was initiated) and between Thika and other Kenyan trial sites (Eldoret, Kisumu, and Nairobi). Generalized estimating equations and Andersen-Gill proportional hazards modeling were used. Nonbarrier contraceptive use increased after implementation of the intervention: from 31.5 to 64.7% of visits among HIV-1-seropositive women [odds ratio 4.0, 95% confidence interval (CI) 3.0-5.3] and from 28.6 to 46.7% of visits among HIV-1-seronegative women (odds ratio 2.2, 95% CI 1.4-3.5). In comparison, at the other Kenyan sites, where the intervention was not implemented, contraceptive use changed minimally, from 15.6 to 22.3% of visits for HIV-1-seropositive women and from 13.6 to 12.7% among HIV-1-seronegative women. Self-reported condom use remained high during follow-up. Pregnancy incidence at the Thika was significantly lower after compared with before June 2007 (hazard ratio 0.2, 95% CI 0.1-0.6) and was approximately half that at other Kenyan sites during the intervention period (hazard ratio 0.5, 95% CI 0.3-0.8). A multipronged family planning intervention can lead to high nonbarrier contraceptive uptake and reduced pregnancy incidence among women in HIV-1-serodiscordant partnerships.

  1. Successful increase in contraceptive uptake among Kenyan HIV-1 serodiscordant couples enrolled in an HIV-1 prevention trial

    Science.gov (United States)

    Ngure, Kenneth; Heffron, Renee; Mugo, Nelly; Irungu, Elizabeth; Celum, Connie; Baeten, Jared

    2016-01-01

    Objective To evaluate a multi-pronged approach to promote dual contraceptive use by women within heterosexual HIV-1 serodiscordant partnerships. Methods For 213 HIV-1 serodiscordant couples in Thika, Kenya participating in an HIV-1 prevention clinical trial, contraceptive promotion was initiated through a multi-pronged intervention that included staff training, couples family planning sessions, and free provision of hormonal contraception on-site. Contraceptive use and pregnancy incidence were compared between two time periods (before versus after June 2007, when the intervention was initiated) and between Thika and other Kenyan trial sites (Eldoret, Kisumu, and Nairobi). Generalized estimating equations and Andersen-Gill proportional hazards modeling were used. Results Non-barrier contraceptive use increased after implementation of the intervention: from 31.5% to 64.7% of visits among HIV-1 seropositive women (odds ratio [OR] 4.0, 95% confidence interval [CI] 3.0–5.3) and from 28.6% to 46.7% of visits among HIV-1 seronegative women (OR 2.2, 95% CI 1.4–3.5). In comparison, at the other Kenyan sites, where the intervention was not implemented, contraceptive use changed minimally, from 15.6% to 22.3% of visits for HIV-1 seropositive women and from 13.6% to 12.7% among HIV-1 seronegative women. Self-reported condom use remained high during follow-up. Pregnancy incidence at the Thika was significantly lower after compared with before June 2007 (hazard ratio [HR] 0.2, 95% CI 0.1–0.6), and was approximately half that at other Kenyan sites during the intervention period (HR 0.5, 95% CI 0.3–0.8). Conclusions A multi-pronged family planning intervention can lead to high non-barrier contraceptive uptake and reduced pregnancy incidence among women in HIV-1 serodiscordant partnerships. PMID:20081393

  2. Development and evaluation of HIV-1 subtype RNA panels for the standardization of HIV-1 NAT assays.

    Science.gov (United States)

    Lee, Sherwin; Wood, Owen; Taffs, Rolf E; Hu, Jinjie; Machuca, Ana; Vallejo, Alejandro; Hewlett, Indira

    2006-11-01

    Multiple nucleic acid-based techniques (NAT) have been implemented for testing blood and plasma donors for HIV-1 RNA which may be detected at an earlier stage of infection when HIV antigen or antibody is absent or below the limit of detection of current assays. The available NAT assays are based on different technologies. In order to evaluate the performance of nucleic acid-based techniques (NAT assays) and to allow accurate comparisons of results from different assays, it is essential to have well characterized specimens with known copy numbers as a standard. For this purpose, a comprehensive study was conducted to develop two HIV-1 RNA reference panels. The first (Panel 1) was prepared using a single specimen from the HIV-1 group M subtype B and consists of panel members with a wide range of HIV-1 RNA copy numbers. Panel 2 consists of 26 members representing HIV-1 group M subtypes A, C, D, E, F, G and groups O and N. For accurate determination of HIV-1 RNA copy numbers of each member of Panel 2, they were analyzed using various testing platforms/technologies available through the cooperation of five independent laboratories participating in the study. A consensus value for HIV RNA copy number was assigned to each member of Panel 2 based on statistical analysis of the data provided by the participants. Both panels could serve as reference panels to be used by manufacturers of HIV NAT tests to evaluate the sensitivity limits of their assays.

  3. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Kee Suk [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1983-03-15

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean+-S.D. of Group I was 91.1+-3.2 mg%, while that of Group II is 82.5+-4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean+-S.D. of 14.7+-3.0 muU/ml while Group II shows that of 7.0+-2.6 muU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7+-10.8 muU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  4. Clinical performance of the Multispot HIV-1/HIV-2 rapid test to correctly differentiate HIV-2 from HIV-1 infection in screening algorithms using third and fourth generation assays and to identify cross reactivity with the HIV-1 Western Blot.

    Science.gov (United States)

    Ramos, Eric M; Harb, Socorro; Dragavon, Joan; Coombs, Robert W

    2013-12-01

    An accurate and rapid serologic method to differentiate HIV-2 from HIV-1 infection is required since the confirmatory HIV-1 Western Blot (WB) may demonstrate cross-reactivity with HIV-2 antibodies. To evaluate the performance of the Bio-Rad Multispot HIV-1/HIV-2 rapid assay as a supplemental test to correctly identify HIV-2 infection and identify HIV-1 WB cross-reactivity with HIV-2 in clinical samples tested at an academic medical center. Between August 2008 and July 2012, clinical samples were screened for HIV using either 3rd- or 4th-generation HIV-1/2 antibody or combination antibody and HIV-1 p24 antigen assays, respectively. All repeatedly reactive samples were reflexed for Multispot rapid testing. Multispot HIV-2 and HIV-1 and HIV-2-reactive samples were further tested using an HIV-2 immunoblot assay and HIV-1 or HIV-2 RNA assays when possible. The HIV-1 WB was performed routinely for additional confirmation and to assess for HIV-2 antibody cross-reactivity. Of 46,061 samples screened, 890 (89.6%) of 993 repeatedly reactive samples were also Multispot-reactive: 882 for HIV-1; three for only HIV-2; and five for both HIV-1 and HIV-2. All three HIV-2-only Multispot-positives along with a single dually reactive HIV-1/2 Multispot-positive were also HIV-2 immunoblot-positive; the latter was HIV-1 RNA negative and HIV-2 RNA positive. The Multispot rapid test performed well as a supplemental test for HIV-1/2 diagnostic testing. Four new HIV-2 infections (0.45%) were identified from among 890 Multispot-reactive tests. The use of HIV-1 WB alone to confirm HIV-1/2 screening assays may underestimate the true prevalence of HIV-2 infection in the United States. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. HIV-1 evades innate immune recognition through specific cofactor recruitment

    Science.gov (United States)

    Rasaiyaah, Jane; Tan, Choon Ping; Fletcher, Adam J.; Price, Amanda J.; Blondeau, Caroline; Hilditch, Laura; Jacques, David A.; Selwood, David L.; James, Leo C.; Noursadeghi, Mahdad; Towers, Greg J.

    2013-11-01

    Human immunodeficiency virus (HIV)-1 is able to replicate in primary human macrophages without stimulating innate immunity despite reverse transcription of genomic RNA into double-stranded DNA, an activity that might be expected to trigger innate pattern recognition receptors. We reasoned that if correctly orchestrated HIV-1 uncoating and nuclear entry is important for evasion of innate sensors then manipulation of specific interactions between HIV-1 capsid and host factors that putatively regulate these processes should trigger pattern recognition receptors and stimulate type 1 interferon (IFN) secretion. Here we show that HIV-1 capsid mutants N74D and P90A, which are impaired for interaction with cofactors cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and cyclophilins (Nup358 and CypA), respectively, cannot replicate in primary human monocyte-derived macrophages because they trigger innate sensors leading to nuclear translocation of NF-κB and IRF3, the production of soluble type 1 IFN and induction of an antiviral state. Depletion of CPSF6 with short hairpin RNA expression allows wild-type virus to trigger innate sensors and IFN production. In each case, suppressed replication is rescued by IFN-receptor blockade, demonstrating a role for IFN in restriction. IFN production is dependent on viral reverse transcription but not integration, indicating that a viral reverse transcription product comprises the HIV-1 pathogen-associated molecular pattern. Finally, we show that we can pharmacologically induce wild-type HIV-1 infection to stimulate IFN secretion and an antiviral state using a non-immunosuppressive cyclosporine analogue. We conclude that HIV-1 has evolved to use CPSF6 and cyclophilins to cloak its replication, allowing evasion of innate immune sensors and induction of a cell-autonomous innate immune response in primary human macrophages.

  6. Phylodynamics of the HIV-1 epidemic in Cuba.

    Science.gov (United States)

    Delatorre, Edson; Bello, Gonzalo

    2013-01-01

    Previous studies have shown that the HIV-1 epidemic in Cuba displayed a complex molecular epidemiologic profile with circulation of several subtypes and circulating recombinant forms (CRF); but the evolutionary and population history of those viral variants remains unknown. HIV-1 pol sequences of the most prevalent Cuban lineages (subtypes B, C and G, CRF18_cpx, CRF19_cpx, and CRFs20/23/24_BG) isolated between 1999 and 2011 were analyzed. Maximum-likelihood analyses revealed multiple introductions of subtype B (n≥66), subtype C (n≥10), subtype G (n≥8) and CRF18_cpx (n≥2) viruses in Cuba. The bulk of HIV-1 infections in this country, however, was caused by dissemination of a few founder strains probably introduced from North America/Europe (clades B(CU-I) and B(CU-II)), east Africa (clade C(CU-I)) and central Africa (clades G(CU), CRF18(CU) and CRF19(CU)), or locally generated (clades CRFs20/23/24_BG). Bayesian-coalescent analyses show that the major HIV-1 founder strains were introduced into Cuba during 1985-1995; whereas the CRFs_BG strains emerged in the second half of the 1990s. Most HIV-1 Cuban clades appear to have experienced an initial period of fast exponential spread during the 1990s and early 2000s, followed by a more recent decline in growth rate. The median initial growth rate of HIV-1 Cuban clades ranged from 0.4 year⁻¹ to 1.6 year⁻¹. Thus, the HIV-1 epidemic in Cuba has been a result of the successful introduction of a few viral strains that began to circulate at a rather late time of the AIDS pandemic, but then were rapidly disseminated through local transmission networks.

  7. Increased genetic diversity of HIV-1 circulating in Hong Kong.

    Directory of Open Access Journals (Sweden)

    Jonathan Hon-Kwan Chen

    Full Text Available HIV-1 group M strains are characterized into 9 pure subtypes and 48 circulating recombinant forms (CRFs. Recent studies have identified the presence of new HIV-1 recombinants in Hong Kong and their complexity continues to increase. This study aims to characterize the HIV-1 genetic diversity in Hong Kong. Phylogenetic analyses were performed by using HIV-1 pol sequences including protease and partial reverse transcriptase isolated from 1045 local patients in Hong Kong from 2003 to 2008. For the pol sequences with unassigned genotype, the evidence of recombination was determined by using sliding-window based bootscan plots and their env C2V3 region were also sequenced. Epidemiological background of these patients was further collected. The pol phylogenetic analyses highlighted the extent of HIV-1 genetic diversity in Hong Kong. Subtype B (450/1045; 43.1% and CRF01_AE (469/1045; 44.9% variants were clearly predominant. Other genotypes (126/1045; 12.1% including 3 defined subtypes, 10 CRFs, 1 unassigned subtype and 33 recombinants with 11 different mosaic patterns were observed. Recombinants of subtype B and CRF01_AE were mainly found among local Chinese MSM throughout 2004 to 2008, while the CRF02_AG and subtype G recombinants were circulating among non-Chinese Asian population in Hong Kong through heterosexual transmission starting from 2008. Our study demonstrated the complex recombination of HIV-1 in Hong Kong and the need in developing surveillance system for tracking the distribution of new HIV-1 genetic variants.

  8. HIV-1 viral load measurement in venous blood and fingerprick blood using Abbott RealTime HIV-1 DBS assay.

    Science.gov (United States)

    Tang, Ning; Pahalawatta, Vihanga; Frank, Andrea; Bagley, Zowie; Viana, Raquel; Lampinen, John; Leckie, Gregor; Huang, Shihai; Abravaya, Klara; Wallis, Carole L

    2017-07-01

    HIV RNA suppression is a key indicator for monitoring success of antiretroviral therapy. From a logistical perspective, viral load (VL) testing using Dried Blood Spots (DBS) is a promising alternative to plasma based VL testing in resource-limited settings. To evaluate the analytical and clinical performance of the Abbott RealTime HIV-1 assay using a fully automated one-spot DBS sample protocol. Limit of detection (LOD), linearity, lower limit of quantitation (LLQ), upper limit of quantitation (ULQ), and precision were determined using serial dilutions of HIV-1 Virology Quality Assurance stock (VQA Rush University), or HIV-1-containing armored RNA, made in venous blood. To evaluate correlation, bias, and agreement, 497 HIV-1 positive adult clinical samples were collected from Ivory Coast, Uganda and South Africa. For each HIV-1 participant, DBS-fingerprick, DBS-venous and plasma sample results were compared. Correlation and bias values were obtained. The sensitivity and specificity were analyzed at a threshold of 1000 HIV-1 copies/mL generated using the standard plasma protocol. The Abbott HIV-1 DBS protocol had an LOD of 839 copies/mL, a linear range from 500 to 1×107 copies/mL, an LLQ of 839 copies/mL, a ULQ of 1×107 copies/mL, and an inter-assay SD of ≤0.30 log copies/mL for all tested levels within this range. With clinical samples, the correlation coefficient (r value) was 0.896 between DBS-fingerprick and plasma and 0.901 between DBS-venous and plasma, and the bias was -0.07 log copies/mL between DBS-fingerprick and plasma and -0.02 log copies/mL between DBS-venous and plasma. The sensitivity of DBS-fingerprick and DBS-venous was 93%, while the specificity of both DBS methods was 95%. The results demonstrated that the Abbott RealTime HIV-1 assay with DBS sample protocol is highly sensitive, specific and precise across a wide dynamic range and correlates well with plasma values. The Abbott RealTime HIV-1 assay with DBS sample protocol provides an

  9. HIV-1 Continues To Replicate and Evolve in Patients with Natural Control of HIV Infection

    DEFF Research Database (Denmark)

    Mens, Helene; Kearney, Mary; Wiegand, Ann

    2010-01-01

    Elucidating mechanisms leading to the natural control of HIV-1 infection is of great importance for vaccine design and for understanding viral pathogenesis. Rare HIV-1-infected individuals, termed HIV-1 controllers, have plasma HIV-1 RNA levels below the limit of detection by standard clinical...

  10. War and peace between microbes: HIV-1 interactions with coinfecting viruses.

    Science.gov (United States)

    Lisco, Andrea; Vanpouille, Christophe; Margolis, Leonid

    2009-11-19

    HIV-1 disrupts the homeostatic equilibrium between the host and coinfecting microbes, facilitating reactivation of persistent viruses and invasion by new viruses. These viruses usually accelerate HIV disease but occasionally create conditions detrimental for HIV-1. Understanding these phenomena may lead to anti-HIV-1 strategies that specifically target interactions between HIV-1 and coinfecting viruses.

  11. Human immature Langerhans cells restrict CXCR4-using HIV-1 transmission

    NARCIS (Netherlands)

    Sarrami-Forooshani, Ramin; Mesman, Annelies W.; van Teijlingen, Nienke H.; Sprokholt, Joris K.; van der Vlist, Michiel; Ribeiro, Carla M. S.; Geijtenbeek, Teunis B. H.

    2014-01-01

    Sexual transmission is the main route of HIV-1 infection and the CCR5-using (R5) HIV-1 is predominantly transmitted, even though CXCR4-using (X4) HIV-1 is often abundant in chronic HIV-1 patients. The mechanisms underlying this tropism selection are unclear. Mucosal Langerhans cells (LCs) are the

  12. Impaired production of cytokines is an independent predictor of mortality in HIV-1-infected patients

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Gerstoft, Jan; Pedersen, Bente K

    2003-01-01

    With regard to the natural history of HIV-1 infection this study investigated whether whole-blood culture cytokine production was associated with mortality in HIV-1-infected patients.......With regard to the natural history of HIV-1 infection this study investigated whether whole-blood culture cytokine production was associated with mortality in HIV-1-infected patients....

  13. Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

    Science.gov (United States)

    Yilmaz, Aylin; Gisslén, Magnus; Spudich, Serena; Lee, Evelyn; Jayewardene, Anura; Aweeka, Francesca; Price, Richard W

    2009-09-01

    Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing this drug. Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma. Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0). The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180). CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations. Approximately 50% of the CSF specimens exceeded the IC(95) levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

  14. Raltegravir cerebrospinal fluid concentrations in HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Aylin Yilmaz

    Full Text Available INTRODUCTION: Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF and plasma in subjects receiving antiretroviral treatment regimens containing this drug. METHODS: Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma. RESULTS: Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0. The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180. CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations. CONCLUSIONS: Approximately 50% of the CSF specimens exceeded the IC(95 levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

  15. Functional role of Alix in HIV-1 replication.

    Science.gov (United States)

    Fujii, Ken; Munshi, Utpal M; Ablan, Sherimay D; Demirov, Dimiter G; Soheilian, Ferri; Nagashima, Kunio; Stephen, Andrew G; Fisher, Robert J; Freed, Eric O

    2009-09-01

    Retroviral Gag proteins encode small peptide motifs known as late domains that promote the release of virions from infected cells by interacting directly with host cell factors. Three types of retroviral late domains, with core sequences P(T/S)AP, YPX(n)L, and PPPY, have been identified. HIV-1 encodes a primary P(T/S)AP-type late domain and an apparently secondary late domain sequence of the YPX(n)L type. The P(T/S)AP and YPX(n)L motifs interact with the endosomal sorting factors Tsg101 and Alix, respectively. Although biochemical and structural studies support a direct binding between HIV-1 p6 and Alix, the physiological role of Alix in HIV-1 biology remains undefined. To elucidate the function of the p6-Alix interaction in HIV-1 replication, we introduced a series of mutations in the p6 Alix binding site and evaluated the effects on virus particle production and virus replication in a range of cell types, including physiologically relevant primary T cells and macrophages. We also examined the effects of the Alix binding site mutations on virion morphogenesis and single-cycle virus infectivity. We determined that the p6-Alix interaction plays an important role in HIV-1 replication and observed a particularly severe impact of Alix binding site mutations when they were combined with mutational inactivation of the Tsg101 binding site.

  16. HIV-1 integrase inhibitory substances from Coleus parvifolius.

    Science.gov (United States)

    Tewtrakul, Supinya; Miyashiro, Hirotsugu; Nakamura, Norio; Hattori, Masao; Kawahata, Takuya; Otake, Toru; Yoshinaga, Tomokazu; Fujiwara, Tamio; Supavita, Tanomjit; Yuenyongsawad, Supreeya; Rattanasuwon, Pranee; Dej-Adisai, Sukanya

    2003-03-01

    For the purpose of discovering anti-HIV-1 agents from natural sources, water and EtOH extracts of 50 Thai plants were screened for their inhibitory activity against HIV-1 integrase (IN), an enzyme essential for viral replication. Of these plants, an EtOH extract of Coleus parvifolius Benth. (aerial parts) showed potent activity against HIV-1 IN with an IC50 value of 9.2 microg/mL. From this extract, 11 compounds were isolated and identified as luteolin 5-O-beta-d-glucopyranoside (1), luteolin (2), luteolin 7-methyl ether (3), luteolin 5-O-beta-d-glucuronide (4), 5-O-beta-d-glucopyranosyl-luteolin 7-methyl ether (5), rosmarinic acid (6), rosmarinic acid methyl ester (7), daucosterol (8), a mixture of alpha- and beta-amyrin (9, 10) and phytol (11). Of these compounds, rosmarinic acid methyl ester (7), rosmarinic acid (6), luteolin (2) and luteolin 7-methyl ether (3) exhibited inhibitory activities against HIV-1 IN with IC50 values of 3.1, 5.0, 11.0 and 11.0 microM, respectively. Among rosmarinic acid derivatives, the HIV-1 IN inhibitory activity increased in turn for a dimer (IC50 = 5.0 microM), a trimer (IC50 = 1.4 microM), and a tetramer (IC50 = 1.0 microM). Copyright 2003 John Wiley & Sons, Ltd.

  17. Antimalarial activity of HIV-1 protease inhibitor in chromone series.

    Science.gov (United States)

    Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

    2014-12-01

    Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Impact of Cocaine Abuse on HIV-1 Pathogenesis

    Directory of Open Access Journals (Sweden)

    Sabyasachi eDash

    2015-10-01

    Full Text Available Over 1.2 million people in the United States are infected with the human immunodeficiency virus (HIV. Tremendous progress has been made over the past three decades on many fronts in the prevention and treatment of HIV-1 disease. However, HIV-1 infection is incurable and antiretroviral drugs continue to remain the only effective treatment option for HIV infected patients. Unfortunately, only three out of ten HIV-1 infected individuals in the US have the virus under control. Thus, majority of HIV-1 infected individuals in the US are either unaware of their infection status or not connected/retained to care or are non-adherent to antiretroviral therapy (ART. This national public health crisis, as well as the ongoing global HIV/AIDS pandemic, is further exacerbated by substance abuse, which serves as a powerful cofactor at every stage of HIV/AIDS including transmission, diagnosis, pathogenesis, and treatment. Clinical studies indicate that substance abuse may increase viral load, accelerate disease progression and worsen AIDS-related mortality even among ART adherent patients. However, confirming a direct causal link between substance abuse and HIV/AIDS in human patients remains a highly challenging endeavor. In this review we will discuss the recent and past developments in clinical and basic science research on the effects of cocaine abuse on HIV-1 pathogenesis.

  19. Molecular typing of the local HIV-1 epidemic in Serbia.

    Science.gov (United States)

    Siljic, Marina; Salemovic, Dubravka; Jevtovic, Djordje; Pesic-Pavlovic, Ivana; Zerjav, Sonja; Nikolic, Valentina; Ranin, Jovan; Stanojevic, Maja

    2013-10-01

    Worldwide HIV-1 pandemic is becoming increasingly complex, with growing heterogeneity of subtypes and recombinant viruses. Previous studies have documented HIV-1 subtype B as the predominant one in Serbia, with limited presence and genetic diversity of non B subtypes. In recent years, MSM transmission has become the most frequently reported risk for HIV infection among newly diagnosed patients in Serbia, but very little is known of the network structure and dynamics of viral transmission in this and other risk groups. To gain insight about the HIV-1 subtypes distribution pattern as well as characteristics of HIV-1 transmission clusters in Serbia, we analyzed the genetic diversity of the pol gene segment in 221 HIV-1-infected patients sampled during 2002-2011. Subtype B was found to still be the most prevalent one in Serbia, accounting for over 90% of samples, while greater diversity of other subtypes was found than previously reported, including subtypes G, C, A, F, CRF01 and CRF02. In total, 41.3% of analyzed subtype B sequences were found associated in transmission clusters/network, that are highly related with MSM transmission route. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. HIV-1 subtype B: Traces of a pandemic.

    Science.gov (United States)

    Junqueira, Dennis Maletich; Almeida, Sabrina Esteves de Matos

    2016-08-01

    Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration. After localized dispersion, the virus was brought to the United States of America via homosexual/bisexual contact around 1969. Inside USA, the incidence of HIV-1B infection increased exponentially and it became established in the population, affecting not only homosexual individuals but also heterosexual individuals and injecting drug users. Soon after, the virus was disseminated and became established in other regions, including Europe, Asia, Latin America, and Australia. Recent studies suggest that, in addition to this pandemic clade, several lineages have emerged from Haiti and reached other Caribbean and Latin American countries via short-distance dissemination. Different subtype B genetic variants have also been detected in these epidemics. Four genetic variants have been described to date: subtype B', which mainly circulates in Thailand and other Asian countries; a specific variant mainly found in Trinidad and Tobago; the GPGS variant, which is primarily detected in Korea; and the GWGR variant, which is mainly detected in Brazil. This paper reviews the evolution of HIV-1B and its impact on the human population. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Functional Role of Alix in Hiv-1 Replication

    Science.gov (United States)

    Fujii, Ken; Munshi, Utpal M.; Ablan, Sherimay D.; Demirov, Dimiter G.; Soheilian, Ferri; Nagashima, Kunio; Stephen, Andrew G.; Fisher, Robert J.; Freed, Eric O.

    2009-01-01

    Retroviral Gag proteins encode small peptide motifs known as late domains that promote the release of virions from infected cells by interacting directly with host cell factors. Three types of retroviral late domains, with core sequences P(T/S)AP, YPXnL, and PPPY, have been identified. HIV-1 encodes a primary P(T/S)AP-type late domain and an apparently secondary late domain sequence of the YPXnL type. The P(T/S)AP and YPXnL motifs interact with the endosomal sorting factors Tsg101 and Alix, respectively. Although biochemical and structural studies support a direct binding between HIV-1 p6 and Alix, the physiological role of Alix in HIV-1 biology remains undefined. To elucidate the function of the p6–Alix interaction in HIV-1 replication, we introduced a series of mutations in the p6 Alix binding site and evaluated the effects on virus particle production and virus replication in a range of cell types, including physiologically relevant primary T cells and macrophages. We also examined the effects of the Alix binding site mutations on virion morphogenesis and single-cycle virus infectivity. We determined that the p6–Alix interaction plays an important role in HIV-1 replication and observed a particularly severe impact of Alix binding site mutations when they were combined with mutational inactivation of the Tsg101 binding site. PMID:19596386

  2. HIV-1, human interaction database: current status and new features.

    Science.gov (United States)

    Ako-Adjei, Danso; Fu, William; Wallin, Craig; Katz, Kenneth S; Song, Guangfeng; Darji, Dakshesh; Brister, J Rodney; Ptak, Roger G; Pruitt, Kim D

    2015-01-01

    The 'Human Immunodeficiency Virus Type 1 (HIV-1), Human Interaction Database', available through the National Library of Medicine at http://www.ncbi.nlm.nih.gov/genome/viruses/retroviruses/hiv-1/interactions, serves the scientific community exploring the discovery of novel HIV vaccine candidates and therapeutic targets. Each HIV-1 human protein interaction can be retrieved without restriction by web-based downloads and ftp protocols and includes: Reference Sequence (RefSeq) protein accession numbers, National Center for Biotechnology Information Gene identification numbers, brief descriptions of the interactions, searchable keywords for interactions and PubMed identification numbers (PMIDs) of journal articles describing the interactions. In addition to specific HIV-1 protein-human protein interactions, included are interaction effects upon HIV-1 replication resulting when individual human gene expression is blocked using siRNA. A total of 3142 human genes are described participating in 12,786 protein-protein interactions, along with 1316 replication interactions described for each of 1250 human genes identified using small interfering RNA (siRNA). Together the data identifies 4006 human genes involved in 14,102 interactions. With the inclusion of siRNA interactions we introduce a redesigned web interface to enhance viewing, filtering and downloading of the combined data set. Published by Oxford University Press on behalf of Nucleic Acids Research 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  3. Dynamics of HIV-1 recombination in its natural target cells.

    Science.gov (United States)

    Levy, David N; Aldrovandi, Grace M; Kutsch, Olaf; Shaw, George M

    2004-03-23

    Genetic recombination is believed to assist HIV-1 diversification and escape from host immunity and antiviral therapies, yet this process remains largely unexamined within the natural target-cell populations. We developed a method for measuring HIV-1 recombination directly that employs reporter viruses bearing functional enhanced yellow fluorescent protein (YFP) and enhanced cyan fluorescent protein (CFP) genes in which recombination produces a modified GFP gene and GFP fluorescence in the infected cells. These reporter viruses allow simultaneous quantification of the dynamics of HIV-1 infection, coinfection, and recombination in cell culture and in animal models by flow-cytometric analysis. Multiround infection assays revealed that productive cellular coinfection was subject to little functional inhibition. As a result, generation of recombinants proceeded according to the square of the infection rate during HIV-1 replication in T lymphocytes and within human thymic grafts in severe combined immunodeficient (SCID)-hu (Thy/Liv) mice. These results suggest that increases in viral load may confer a compounding risk of virus escape by means of recombinational diversification. A single round of replication in T lymphocytes in culture generated an average of nine recombination events per virus, and infection of macrophages led to approximately 30 crossover events, making HIV-1 up to an order of magnitude more recombinogenic than recognized previously and demonstrating that the infected cell exerts a profound influence on the frequency of recombination.

  4. Metabolic risk profiles in diabetes stratified according to age at onset, islet autoimmunity and fasting C-peptide

    DEFF Research Database (Denmark)

    Wod, Mette; Yderstræde, Knud B; Halekoh, Ulrich

    2017-01-01

    OBJECTIVE: Islet autoimmunity, age at onset and time to insulin treatment are often used to define subgroups of diabetes. However, the latter criterion is not clinical useful. Here, we examined whether an unbiased stratification of diabetes according to age at onset, fasting C-peptide and GAD......, fasting C-peptide above or below 300 pmol/l (CPEPhigh or CPEPlow), and presence or absence of GADab (GADpos or GADneg). HbA1c, BMI, blood pressure (BP), lipid profile, alanine aminotransferase (ALT) and creatinine were evaluated. RESULTS: GADab were present in 13% of the cohort. Age at onset...... as GADposCPEPhigh; n=327) and patients with type 2 diabetes (GADnegCPEPhigh; n=3,544). Patients with LADA defined an intermediate group with higher HbA1c but otherwise lower cardiometabolic risk than patients with type 2 diabetes. CONCLUSIONS: Our results demonstrate that fasting C-peptide and GADab status...

  5. Association of IL-1ra and adiponectin with C-peptide and remission in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Pfleger, C.; Hansen, L.; Herder, C.

    2008-01-01

    with recent-onset type 1 diabetes. RESEARCH DESIGN AND METHODS: Serum was obtained from 256 newly diagnosed patients (122 males and 134 females, median age 9.6 years). Stimulated C-peptide, blood glucose, and A1C were determined in addition to circulating concentration of cytokines at 1, 6, and 12 months...... after diagnosis. Analyses were adjusted for sex, age, and BMI percentile. RESULTS: Anti-inflammatory IL-1ra was positively associated with C-peptide after 6 (P = 0.0009) and 12 (P = 0.009) months. The beneficial association of IL-1ra on beta-cell function was complemented by the negative association...... of IL-1 beta with C-peptide after 1 month (P = 0.009). In contrast, anti-inflammatory adiponectin was elevated in patients with poor metabolic control after 6 and 12 months (P

  6. No evidence of association between HIV-1 and malaria in populations with low HIV-1 prevalence.

    Directory of Open Access Journals (Sweden)

    Diego F Cuadros

    Full Text Available BACKGROUND: The geographic overlap between HIV-1 and malaria has generated much interest in their potential interactions. A variety of studies have evidenced a complex HIV-malaria interaction within individuals and populations that may have dramatic effects, but the causes and implications of this co-infection at the population level are still unclear. In a previous publication, we showed that the prevalence of malaria caused by the parasite Plasmodium falciparum is associated with HIV infection in eastern sub-Saharan Africa. To complement our knowledge of the HIV-malaria co-infection, the objective of this work was to assess the relationship between malaria and HIV prevalence in the western region of sub-Saharan Africa. METHODOLOGY/PRINCIPAL FINDINGS: Population-based cross-sectional data were obtained from the HIV/AIDS Demographic and Health Surveys conducted in Burkina Faso, Ghana, Guinea, Mali, Liberia and Cameroon, and the malaria atlas project. Using generalized linear mixed models, we assessed the relationship between HIV-1 and Plasmodium falciparum parasite rate (PfPR adjusting for important socio-economic and biological cofactors. We found no evidence that individuals living in areas with stable malaria transmission (PfPR>0.46 have higher odds of being HIV-positive than individuals who live in areas with PfPR≤0.46 in western sub-Saharan Africa (estimated odds ratio 1.14, 95% confidence interval 0.86-1.50. In contrast, the results suggested that PfPR was associated with being infected with HIV in Cameroon (estimated odds ratio 1.56, 95% confidence interval 1.23-2.00. CONCLUSION/SIGNIFICANCE: Contrary to our previous research on eastern sub-Saharan Africa, this study did not identify an association between PfPR and infection with HIV in western sub-Saharan Africa, which suggests that malaria might not play an important role in the spread of HIV in populations where the HIV prevalence is low. Our work highlights the importance of

  7. Amniotic fluid insulin and C-peptide as predictive markers for fetal macrosomia, birth injuries, and delivery complications?

    Science.gov (United States)

    Stein, Roland Gregor; Meinusch, Malgorzata; Diessner, Joachim; Dietl, Johannes; Hönig, Arnd; Zollner, Ursula

    2014-01-15

    Gestational diabetes mellitus (GDM) occurs in 3-5% of all pregnancies. GDM increases both maternal and fetal risks, causes fetal macrosomia, and hence increases the rates of caesarean sections and delivery complications such as shoulder dystocia. An early predictive marker and consequent early treatment could be beneficial, so amniotic fluid insulin and C-peptide have been examined in several studies. Increased amniotic fluid insulin in early amniocentesis between the 14th and 20th gestational week predicted a later GDM. A potential direct association with fetal macrosomia remains to be determined. This retrospective study investigated amniotic fluid insulin/C-peptide from amniocenteses between 14 and 20 weeks of gestation in correlation with fetal birth weight, type of delivery, and complications. To focus on effects of fetal hyperinsulinism apart from therapeutic confounders, we included patients who did not participate in GDM screening. Insulin and C-peptide were measured in 144 samples of frozen amniotic fluid. Birth weight, type of delivery, complications, and birth injuries were noted. Birth weights ranged from 760 g to 4410 g with a mean weight of 3424 g at an average of 40 weeks gestation. The mean amniotic fluid insulin was 4.36 U/ml and the mean C-peptide concentration was 0.076 ng/ml. There was no correlation between amniotic fluid insulin or C peptide and birth weight, type of delivery, complications, and birth injuries. Amniotic fluid insulin and C-peptide are unsuitable as predictive marker for fetal macrosomia, type of delivery, complications, or birth injuries.

  8. Types of pediatric diabetes mellitus defined by anti-islet autoimmunity and random C-peptide at diagnosis.

    Science.gov (United States)

    Redondo, Maria J; Rodriguez, Luisa M; Escalante, Mirna; Smith, E O'Brian; Balasubramanyam, Ashok; Haymond, Morey W

    2013-08-01

    To test the hypothesis that anti-islet autoantibody expression and random serum C-peptide obtained at diagnosis define phenotypes of pediatric diabetes with distinct clinical features. We analyzed 607 children aged diabetes after exclusion of 13% of cases with secondary diabetes (e.g., cystic fibrosis related, steroid induced) and 7.3% of cases lacking measurement of C-peptide and/or autoantibodies. Autoantibody positivity (A+) was defined as ≥ 1 positive out of GAD65, insulin, and ICA512 antibodies. Preserved beta-cell function (β+) was defined as random serum C-peptide at diagnosis ≥ 0.6 ng/mL. Body mass index (BMI) was measured at median 1.2 months after diagnosis. Characteristics at diagnosis and 2 yr (range 18-30 months) after diagnosis were compared among groups. Autoantibody expression and C-peptide at diagnosis defined the following groups: A+β- (52.1% of the children), A+β+ (32.8%), A-β+ (12.5%), and A-β- (2.6%). These four groups differed in gender, race/ethnicity, and clinical characteristics at diagnosis [i.e., age, pubertal development, obesity/overweight, diabetic ketoacidosis, glycemia, and hemoglobin A1c (HbA1c)] and at 2 yr (i.e., clinical diagnosis, treatment, and HbA1c) (all p 2 ng/mL was associated with lower HbA1c at onset (p = 0.0001) and, in the A+β+ subgroup, with higher frequency of achieving HbA1c diabetes (maturity onset diabetes of the young, MODY) were A-β+ with C-peptide between 0.6 and 2 ng/mL. Anti-islet autoantibodies status and serum random C-peptide at diagnosis define four distinct phenotypes of pediatric diabetes with prognostic value. © 2013 John Wiley & Sons A/S.

  9. Sensitivity and reproducibility of urinary C-peptide as estimate of islet B-cell function in insulin-treated diabetes

    DEFF Research Database (Denmark)

    Gjessing, H J; Matzen, L E; Faber, O K

    1989-01-01

    The aims of the present study were to evaluate the ability of urinary C-peptide determination to demonstrate presence of residual insulin secretion, and to evaluate the reproducibility of urinary C-peptide excretion in 125 insulin-treated diabetic patients. C-peptide was determined in two...... of 125 patients were without residual insulin secretion. In contrast to this, only 7 patients were diagnosed as C-peptide nonsecretors using the analytical detection limit of urinary C-peptide. Eighty-four per cent of patients considered to have Type 1 (insulin-dependent) diabetes with a duration...... of diabetes of more than 15 years had detectable C-peptide in the urine.(ABSTRACT TRUNCATED AT 250 WORDS)...

  10. Copy number variation of KIR genes influences HIV-1 control

    DEFF Research Database (Denmark)

    Pelak, Kimberly; Need, Anna C; Fellay, Jacques

    2011-01-01

    A genome-wide screen for large structural variants showed that a copy number variant (CNV) in the region encoding killer cell immunoglobulin-like receptors (KIR) associates with HIV-1 control as measured by plasma viral load at set point in individuals of European ancestry. This CNV encompasses...... the KIR3DL1-KIR3DS1 locus, encoding receptors that interact with specific HLA-Bw4 molecules to regulate the activation of lymphocyte subsets including natural killer (NK) cells. We quantified the number of copies of KIR3DS1 and KIR3DL1 in a large HIV-1 positive cohort, and showed that an increase in KIR3...... amounts of these activating and inhibitory KIR play a role in regulating the peripheral expansion of highly antiviral KIR3DS1+ NK cells, which may determine differences in HIV-1 control following infection....

  11. Anti - HIV-1 integrase activity of Thai Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Kingkan Bunluepuech

    2009-08-01

    Full Text Available For the purpose of discovering anti-HIV-1 agents from natural sources, the aqueous and EtOH extracts of eight Thaiplants including Clerodendron indicum (whole plant, Tiliacora triandra (stem, Capparis micracantha (wood, Harrissoniaperforata (wood, Ficus glomerata (wood, Diospyros decandra (wood, Dracaena loureiri (heartwood, and Tinospora crispa (stem were screened for their inhibitory activities against HIV-1 integrase (IN using the multiplate integration assay(MIA. Of the EtOH extracts, Ficus glomerata (wood was the most potent with an IC50 value of 7.8 g/ml; whereas the water extract of Harrisonia perforata (wood was the most potent aqueous extract with an IC50 value of 2.3 g/ml. The isolation of active principles against HIV-1 IN from Ficus glomerata is now actively pursued.

  12. Cellular and molecular mechanisms of HIV-1 integration targeting.

    Science.gov (United States)

    Engelman, Alan N; Singh, Parmit K

    2018-02-07

    Integration is central to HIV-1 replication and helps mold the reservoir of cells that persists in AIDS patients. HIV-1 interacts with specific cellular factors to target integration to interior regions of transcriptionally active genes within gene-dense regions of chromatin. The viral capsid interacts with several proteins that are additionally implicated in virus nuclear import, including cleavage and polyadenylation specificity factor 6, to suppress integration into heterochromatin. The viral integrase protein interacts with transcriptional co-activator lens epithelium-derived growth factor p75 to principally position integration within gene bodies. The integrase additionally senses target DNA distortion and nucleotide sequence to help fine-tune the specific phosphodiester bonds that are cleaved at integration sites. Research into virus-host interactions that underlie HIV-1 integration targeting has aided the development of a novel class of integrase inhibitors and may help to improve the safety of viral-based gene therapy vectors.

  13. Genetic Consequences of Antiviral Therapy on HIV-1

    Directory of Open Access Journals (Sweden)

    Miguel Arenas

    2015-01-01

    Full Text Available A variety of enzyme inhibitors have been developed in combating HIV-1, however the fast evolutionary rate of this virus commonly leads to the emergence of resistance mutations that finally allows the mutant virus to survive. This review explores the main genetic consequences of HIV-1 molecular evolution during antiviral therapies, including the viral genetic diversity and molecular adaptation. The role of recombination in the generation of drug resistance is also analyzed. Besides the investigation and discussion of published works, an evolutionary analysis of protease-coding genes collected from patients before and after treatment with different protease inhibitors was included to validate previous studies. Finally, the review discusses the importance of considering genetic consequences of antiviral therapies in models of HIV-1 evolution that could improve current genotypic resistance testing and treatments design.

  14. HIV-1 Ribonuclease H Inhibitory Phenolic Glycosides from Eugenia hyemalis

    Science.gov (United States)

    Bokesch, Heidi R.; Wamiru, Antony; Le Grice, Stuart F. J.; Beutler, John A.; McKee, Tawnya C.; McMahon, James B.

    2008-01-01

    Three new galloyl arbutins, hyemalosides A–C (1–3), along with nine known compounds were isolated from the evergreen tree Eugenia hyemalis. The structures of compounds 1–3 were determined by analysis of NMR and MS data. Compounds 1–3 inhibited HIV-1 RNase H in vitro with IC50 values of 1.46, >18, and 1.19 μM, respectively. However, in a XTT-based cell viability assay using the human T-cell line CEM-SS infected with HIV-1RT, none of the compounds inhibited the cytopathic effect of HIV-1 infection at the highest dose tested (20 μg/mL). PMID:18763827

  15. Cytokine expression during syphilis infection in HIV-1-infected individuals

    DEFF Research Database (Denmark)

    Knudsen, Andreas; Benfield, Thomas; Kofoed, Kristian

    2009-01-01

    BACKGROUND: Little is known about cytokine responses to syphilis infection in HIV-1-infected individuals. METHODS: We retrospectively identified patients with HIV-1 and Treponema pallidum coinfection. Plasma samples from before, during, and after coinfection were analyzed for interleukin (IL)-2, IL...... syphilis.IL-10 and TNF-alpha levels correlated positively with plasma HIV RNA values at the time of diagnosis (r = 0.38, P = 0.023, and r = 0.64, P HIV-1 and early...... infection to 46.7 pg/mL (IQR, 28.4-78.9) at the time of diagnosis (P = 0.027) and decreased to 13.0 pg/mL (IQR, 6.2-19.4) after treatment of syphilis (P

  16. Are T cells the only HIV-1 reservoir?

    Science.gov (United States)

    Kandathil, Abraham Joseph; Sugawara, Sho; Balagopal, Ashwin

    2016-12-20

    Current antiretroviral therapies have improved the duration and quality of life of people living with HIV-1. However, viral reservoirs impede complete eradication of the virus. Although there are many strategies to eliminate infectious virus, the most actively pursued are latency reversing agents in conjunction with immune modulation. This strategy, known as "shock and kill", has been tested primarily against the most widely recognized HIV-1 latent reservoir found in resting memory CD4+ T cells. This is in part because of the dearth of conclusive evidence about the existence of non-T cell reservoirs. Studies of non-T cell reservoirs have been difficult to interpret because of technical and biological issues that have hampered a better understanding. This review considers the current knowledge of non-T cell reservoirs, the challenges encountered in a better understanding of these populations, and their implications for HIV-1 cure research.

  17. Stable assembly of HIV-1 export complexes occurs cotranscriptionally

    DEFF Research Database (Denmark)

    Nawroth, Isabel; Mueller, Florian; Basyuk, Eugenia

    2014-01-01

    The HIV-1 Rev protein mediates export of unspliced and singly spliced viral transcripts by binding to the Rev response element (RRE) and recruiting the cellular export factor CRM1. Here, we investigated the recruitment of Rev to the transcription sites of HIV-1 reporters that splice either post......- or cotranscriptionally. In both cases, we observed that Rev localized to the transcription sites of the reporters and recruited CRM1. Rev and CRM1 remained at the reporter transcription sites when cells were treated with the splicing inhibitor Spliceostatin A (SSA), showing that the proteins associate with RNA prior...... to or during early spliceosome assembly. Fluorescence recovery after photobleaching (FRAP) revealed that Rev and CRM1 have similar kinetics as the HIV-1 RNA, indicating that Rev, CRM1, and RRE-containing RNAs are released from the site of transcription in one single export complex. These results suggest...

  18. Oral and systemic manifestations in HIV-1 patients

    Directory of Open Access Journals (Sweden)

    Tatiany Oliveira de Alencar Menezes

    2015-02-01

    Full Text Available INTRODUCTION: This study aimed to estimate the prevalence of the most frequent oral and systemic manifestations in human immunodeficiency virus-1 (HIV-1-positive patients. METHODS: The study was conducted on 300 HIV-1 patients attending the Reference Unit Specialized in Special Infectious Parasitic Diseases in Belém, Pará, Brazil. RESULTS: The most prevalent oral conditions were caries (32.6%, candidiasis (32%, and periodontal disease (17%. Among the systemic manifestations, hepatitis (29.2%, gastritis (16%, arterial hypertension (14.7%, and tuberculosis (12% were the most commonly observed. CONCLUSIONS: We here reported on the most prevalent oral and systemic conditions in HIV-1-positive patients. The healthcare professional's knowledge of the various manifestations among these patients is fundamental to ensure prompt and accurate diagnosis and treatment, and for improving the quality of life of these patients.

  19. HIV-1 induces DCIR expression in CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Alexandra A Lambert

    2010-11-01

    Full Text Available The C-type lectin receptor DCIR, which has been shown very recently to act as an attachment factor for HIV-1 in dendritic cells, is expressed predominantly on antigen-presenting cells. However, this concept was recently challenged by the discovery that DCIR can also be detected in CD4(+ T cells found in the synovial tissue from rheumatoid arthritis (RA patients. Given that RA and HIV-1 infections share common features such as a chronic inflammatory condition and polyclonal immune hyperactivation status, we hypothesized that HIV-1 could promote DCIR expression in CD4(+ T cells. We report here that HIV-1 drives DCIR expression in human primary CD4(+ T cells isolated from patients (from both aviremic/treated and viremic/treatment naive persons and cells acutely infected in vitro (seen in both virus-infected and uninfected cells. Soluble factors produced by virus-infected cells are responsible for the noticed DCIR up-regulation on uninfected cells. Infection studies with Vpr- or Nef-deleted viruses revealed that these two viral genes are not contributing to the mechanism of DCIR induction that is seen following acute infection of CD4(+ T cells with HIV-1. Moreover, we report that DCIR is linked to caspase-dependent (induced by a mitochondria-mediated generation of free radicals and -independent intrinsic apoptotic pathways (involving the death effector AIF. Finally, we demonstrate that the higher surface expression of DCIR in CD4(+ T cells is accompanied by an enhancement of virus attachment/entry, replication and transfer. This study shows for the first time that HIV-1 induces DCIR membrane expression in CD4(+ T cells, a process that might promote virus dissemination throughout the infected organism.

  20. HIV-1 Induces DCIR Expression in CD4+ T Cells

    Science.gov (United States)

    Lambert, Alexandra A.; Imbeault, Michaël; Gilbert, Caroline; Tremblay, Michel J.

    2010-01-01

    The C-type lectin receptor DCIR, which has been shown very recently to act as an attachment factor for HIV-1 in dendritic cells, is expressed predominantly on antigen-presenting cells. However, this concept was recently challenged by the discovery that DCIR can also be detected in CD4+ T cells found in the synovial tissue from rheumatoid arthritis (RA) patients. Given that RA and HIV-1 infections share common features such as a chronic inflammatory condition and polyclonal immune hyperactivation status, we hypothesized that HIV-1 could promote DCIR expression in CD4+ T cells. We report here that HIV-1 drives DCIR expression in human primary CD4+ T cells isolated from patients (from both aviremic/treated and viremic/treatment naive persons) and cells acutely infected in vitro (seen in both virus-infected and uninfected cells). Soluble factors produced by virus-infected cells are responsible for the noticed DCIR up-regulation on uninfected cells. Infection studies with Vpr- or Nef-deleted viruses revealed that these two viral genes are not contributing to the mechanism of DCIR induction that is seen following acute infection of CD4+ T cells with HIV-1. Moreover, we report that DCIR is linked to caspase-dependent (induced by a mitochondria-mediated generation of free radicals) and -independent intrinsic apoptotic pathways (involving the death effector AIF). Finally, we demonstrate that the higher surface expression of DCIR in CD4+ T cells is accompanied by an enhancement of virus attachment/entry, replication and transfer. This study shows for the first time that HIV-1 induces DCIR membrane expression in CD4+ T cells, a process that might promote virus dissemination throughout the infected organism. PMID:21085612

  1. Flail arm-like syndrome associated with HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Nalini A

    2009-01-01

    Full Text Available During the last 20 years at least 23 cases of motor neuron disease have been reported in HIV-1 seropositive patients. In this report we describe the clinical picture of a young man with HIV-1 clade C infection and flail arm-like syndrome, who we were able to follow-up for a long period. We investigated and prospectively monitored a 34-year-old man with features of flail arm syndrome, who developed the weakness and wasting 1 year after being diagnosed with HIV-1 infection after a routine blood test. He presented in 2003 with progressive, symmetrical wasting and weakness of the proximal muscles of the upper limb of 2 years′ duration. He had severe wasting and weakness of the shoulder and arm muscles. There were no pyramidal signs. He has been on HAART for the last 4 years and the weakness or wasting has not worsened. At the last follow-up in July 2007, the patient had the same neurological deficit and no other symptoms or signs of HIV-1 infection. MRI of the spinal cord in 2007 showed characteristic T2 hyperintense signals in the central part of the spinal cord, corresponding to the central gray matter. Thus, our patient had HIV-1 clade C infection associated with a ′flail arm-like syndrome.′ The causal relationship between HIV-1 infection and amyotrophic lateral sclerosis (ALS-like syndrome is still uncertain. The syndrome usually manifests as a lower motor neuron syndrome, as was seen in our young patient. It is known that treatment with antiretroviral therapy (ART stabilizes/improves the condition. In our patient the weakness and atrophy remained stable over a period of 3.5 years after commencing HAART regimen.

  2. Genotypic and functional properties of early infant HIV-1 envelopes

    Directory of Open Access Journals (Sweden)

    Sullivan John L

    2011-08-01

    Full Text Available Abstract Background Understanding the properties of HIV-1 variants that are transmitted from women to their infants is crucial to improving strategies to prevent transmission. In this study, 162 full-length envelope (env clones were generated from plasma RNA obtained from 5 HIV-1 Clade B infected mother-infant pairs. Following extensive genotypic and phylogenetic analyses, 35 representative clones were selected for functional studies. Results Infant quasispecies were highly homogeneous and generally represented minor maternal variants, consistent with transmission across a selective bottleneck. Infant clones did not differ from the maternal in env length, or glycosylation. All infant variants utilized the CCR5 co-receptor, but were not macrophage tropic. Relatively high levels (IC50 ≥ 100 μg/ml of autologous maternal plasma IgG were required to neutralize maternal and infant viruses; however, all infant viruses were neutralized by pooled sera from HIV-1 infected individuals, implying that they were not inherently neutralization-resistant. All infant viruses were sensitive to the HIV-1 entry inhibitors Enfuvirtide and soluble CD4; none were resistant to Maraviroc. Sensitivity to human monoclonal antibodies 4E10, 2F5, b12 and 2G12 varied. Conclusions This study provides extensive characterization of the genotypic and functional properties of HIV-1 env shortly after transmission. We present the first detailed comparisons of the macrophage tropism of infant and maternal env variants and their sensitivity to Maraviroc, the only CCR5 antagonist approved for therapeutic use. These findings may have implications for improving approaches to prevent mother-to-child HIV-1 transmission.

  3. Exosomes from uninfected cells activate transcription of latent HIV-1.

    Science.gov (United States)

    Barclay, Robert A; Schwab, Angela; DeMarino, Catherine; Akpamagbo, Yao; Lepene, Benjamin; Kassaye, Seble; Iordanskiy, Sergey; Kashanchi, Fatah

    2017-07-14

    HIV-1 infection causes AIDS, infecting millions worldwide. The virus can persist in a state of chronic infection due to its ability to become latent. We have previously shown a link between HIV-1 infection and exosome production. Specifically, we have reported that exosomes transport viral proteins and RNA from infected cells to neighboring uninfected cells. These viral products could then elicit an innate immune response, leading to activation of the Toll-like receptor and NF-κB pathways. In this study, we asked whether exosomes from uninfected cells could activate latent HIV-1 in infected cells. We observed that irrespective of combination antiretroviral therapy, both short- and long-length viral transcripts were increased in wild-type HIV-1-infected cells exposed to purified exosomes from uninfected cells. A search for a possible mechanism for this finding revealed that the exosomes increase RNA polymerase II loading onto the HIV-1 promoter in the infected cells. These viral transcripts, which include trans-activation response (TAR) RNA and a novel RNA that we termed TAR-gag, can then be packaged into exosomes and potentially be exported to neighboring uninfected cells, leading to increased cellular activation. To better decipher the exosome release pathways involved, we used siRNA to suppress expression of ESCRT (endosomal sorting complex required for transport) proteins and found that ESCRT II and IV significantly control exosome release. Collectively, these results imply that exosomes from uninfected cells activate latent HIV-1 in infected cells and that true transcriptional latency may not be possible in vivo, especially in the presence of combination antiretroviral therapy.

  4. HIV-1 protease-substrate coevolution in nelfinavir resistance.

    Science.gov (United States)

    Kolli, Madhavi; Ozen, Ayşegül; Kurt-Yilmaz, Nese; Schiffer, Celia A

    2014-07-01

    Resistance to various human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. The virus accumulates mutations within the protease (PR) that render the PIs less potent. Occasionally, Gag sequences also coevolve with mutations at PR cleavage sites contributing to drug resistance. In this study, we investigated the structural basis of coevolution of the p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations by determining crystal structures of wild-type and NFV-resistant HIV-1 protease in complex with p1-p6 substrate peptide variants with L449F and/or S451N. Alterations of residue 30's interaction with the substrate are compensated by the coevolving L449F and S451N cleavage site mutations. This interdependency in the PR-p1-p6 interactions enhances intermolecular contacts and reinforces the overall fit of the substrate within the substrate envelope, likely enabling coevolution to sustain substrate recognition and cleavage in the presence of PR resistance mutations. Resistance to human immunodeficiency virus type 1 (HIV-1) protease inhibitors challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. Mutations in HIV-1 protease selected under the pressure of protease inhibitors render the inhibitors less potent. Occasionally, Gag sequences also mutate and coevolve with protease, contributing to maintenance of viral fitness and to drug resistance. In this study, we investigated the structural basis of coevolution at the Gag p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations. Our structural analysis reveals the interdependency of protease-substrate interactions and how coevolution may restore substrate recognition and cleavage in the presence of protease drug resistance mutations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. Trichomonas vaginalis treatment reduces vaginal HIV-1 shedding.

    Science.gov (United States)

    Kissinger, Patricia; Amedee, Angela; Clark, Rebecca A; Dumestre, Jeanne; Theall, Katherine P; Myers, Leann; Hagensee, Michael E; Farley, Thomas A; Martin, David H

    2009-01-01

    Vaginal HIV-1 shedding has been associated with Trichomonas vaginalis (TV) infection and could play a role in HIV transmission. The purpose of the study was to examine if effective TV treatment reduces the presence of vaginal HIV-1 RNA. TV+ women attending an HIV outpatient clinic in New Orleans, LA, who resolved infection (n = 58) and TV-negative controls (n = 92), matched on antiretroviral therapy (ART) were examined and interviewed at baseline, 1, and 3 months. TV status was tested by culture and the amount of cell free HIV-1 RNA in the vaginal fluids was determined by the Amplicor HIV-1 Monitor ultrasensitive assay. : Most women (81.3%) were black and the mean age was 37.5 (SD 8.7). At baseline, 46.0% had plasma HIV-1 RNA >/=10,000 copies/mL, 26.4% had CD4<200 cells/muL, 54.7% were taking ART, and only 26.0% had detectable HIV-1 RNA in their vaginal fluids. TV-positive women who were effectively treated for TV were less likely to shed HIV vaginally at 3-months post-treatment compared to baseline (R.R. 0.34, 95% CI: 0.12-0.92, P = 0.03), whereas there was no change for TV-negative women. This study provides additional support that reducing TV infection among HIV-positive women may have an impact on the prevention of HIV transmission. Reasons for the delayed treatment effect and the effect on cervical shedding need further investigation.

  6. Reverse Transcription Mechanically Initiates HIV-1 Capsid Disassembly.

    Science.gov (United States)

    Rankovic, Sanela; Varadarajan, Janani; Ramalho, Ruben; Aiken, Christopher; Rousso, Itay

    2017-06-15

    The HIV-1 core consists of the viral genomic RNA and several viral proteins encased within a conical capsid. After cell entry, the core disassembles in a process termed uncoating. Although HIV-1 uncoating has been linked to reverse transcription of the viral genome in target cells, the mechanism by which uncoating is initiated is unknown. Using time-lapse atomic force microscopy, we analyzed the morphology and physical properties of isolated HIV-1 cores during the course of reverse transcription in vitro We found that, during an early stage of reverse transcription the pressure inside the capsid increases, reaching a maximum after 7 h. High-resolution mechanical mapping reveals the formation of a stiff coiled filamentous structure underneath the capsid surface. Subsequently, this coiled structure disappears, the stiffness of the capsid drops precipitously to a value below that of a pre-reverse transcription core, and the capsid undergoes partial or complete rupture near the narrow end of the conical structure. We propose that the transcription of the relatively flexible single-stranded RNA into a more rigid filamentous structure elevates the pressure within the core, which triggers the initiation of capsid disassembly.IMPORTANCE For successful infection, the HIV-1 genome, which is in the form of a single-stranded RNA enclosed inside a capsid shell, must be reverse transcribed into double-stranded DNA and released from the capsid (in a process known as uncoating) before it can be integrated into the target cell genome. The mechanism that triggers uncoating is a pivotal question of long standing. By using atomic force microscopy, we found that during reverse transcription the pressure inside the capsid increases until the internal stress exceeds the strength of the capsid structure and the capsid breaks open. The application of AFM technologies to study purified HIV-1 cores represents a new experimental platform for elucidating additional aspects of capsid

  7. Confirmation of Putative HIV-1 Group P in Cameroon▿

    OpenAIRE

    Vallari, Ana; Holzmayer, Vera; Harris, Barbara; Yamaguchi, Julie; Ngansop, Charlotte; Makamche, Florence; Mbanya, Dora; Kaptué, Lazare; Ndembi, Nicaise; Gürtler, Lutz; Devare, Sushil; Brennan, Catherine A.

    2010-01-01

    We report the second human immunodeficiency virus (HIV) belonging to the new HIV type 1 (HIV-1) group P lineage that is closely related to the simian immunodeficiency virus found in gorillas. This virus was identified in an HIV-seropositive male hospital patient in Cameroon, confirming that the group P virus is circulating in humans. Results from screening 1,736 HIV-seropositive specimens collected in Cameroon indicate that HIV-1 group P infections are rare, accounting for only 0.06% of HIV i...

  8. Dual neonate vaccine platform against HIV-1 and M. tuberculosis.

    Directory of Open Access Journals (Sweden)

    Richard Hopkins

    Full Text Available Acquired immunodeficiency syndrome and tuberculosis (TB are two of the world's most devastating diseases. The first vaccine the majority of infants born in Africa receive is Mycobacterium bovis bacillus Calmette-Guérin (BCG as a prevention against TB. BCG protects against disseminated disease in the first 10 years of life, but provides a variable protection against pulmonary TB and enhancing boost delivered by recombinant modified vaccinia virus Ankara (rMVA expressing antigen 85A (Ag85A of M. tuberculosis is currently in phase IIb evaluation in African neonates. If the newborn's mother is positive for human immunodeficiency virus type 1 (HIV-1, the baby is at high risk of acquiring HIV-1 through breastfeeding. We suggested that a vaccination consisting of recombinant BCG expressing HIV-1 immunogen administered at birth followed by a boost with rMVA sharing the same immunogen could serve as a strategy for prevention of mother-to-child transmission of HIV-1 and rMVA expressing an African HIV-1-derived immunogen HIVA is currently in phase I trials in African neonates. Here, we aim to develop a dual neonate vaccine platform against HIV-1 and TB consisting of BCG.HIVA administered at birth followed by a boost with MVA.HIVA.85A. Thus, mMVA.HIVA.85A and sMVA.HIVA.85A vaccines were constructed, in which the transgene transcription is driven by either modified H5 or short synthetic promoters, respectively, and tested for immunogenicity alone and in combination with BCG.HIVA(222. mMVA.HIVA.85A was produced markerless and thus suitable for clinical manufacture. While sMVA.HIVA.85A expressed higher levels of the immunogens, it was less immunogenic than mMVA.HIVA.85A in BALB/c mice. A BCG.HIVA(222-mMVA.HIVA.85A prime-boost regimen induced robust T cell responses to both HIV-1 and M. tuberculosis. Therefore, proof-of-principle for a dual anti-HIV-1/M. tuberculosis infant vaccine platform is established. Induction of immune responses against these pathogens

  9. Novel Acylguanidine-Based Inhibitor of HIV-1

    Science.gov (United States)

    Mwimanzi, Philip; Tietjen, Ian; Miller, Scott C.; Shahid, Aniqa; Cobarrubias, Kyle; Kinloch, Natalie N.; Baraki, Bemuluyigza; Richard, Jonathan; Finzi, Andrés; Fedida, David; Brumme, Zabrina L.

    2016-01-01

    ABSTRACT The emergence of transmissible HIV-1 strains with resistance to antiretroviral drugs highlights a continual need for new therapies. Here we describe a novel acylguanidine-containing compound, 1-(2-(azepan-1-yl)nicotinoyl)guanidine (or SM111), that inhibits in vitro replication of HIV-1, including strains resistant to licensed protease, reverse transcriptase, and integrase inhibitors, without major cellular toxicity. At inhibitory concentrations, intracellular p24Gag production was unaffected, but virion release (measured as extracellular p24Gag) was reduced and virion infectivity was substantially impaired, suggesting that SM111 acts at a late stage of viral replication. SM111-mediated inhibition of HIV-1 was partially overcome by a Vpu I17R mutation alone or a Vpu W22* truncation in combination with Env N136Y. These mutations enhanced virion infectivity and Env expression on the surface of infected cells in the absence and presence of SM111 but also impaired Vpu's ability to downregulate CD4 and BST2/tetherin. Taken together, our results support acylguanidines as a class of HIV-1 inhibitors with a distinct mechanism of action compared to that of licensed antiretrovirals. Further research on SM111 and similar compounds may help to elucidate knowledge gaps related to Vpu's role in promoting viral egress and infectivity. IMPORTANCE New inhibitors of HIV-1 replication may be useful as therapeutics to counteract drug resistance and as reagents to perform more detailed studies of viral pathogenesis. SM111 is a small molecule that blocks the replication of wild-type and drug-resistant HIV-1 strains by impairing viral release and substantially reducing virion infectivity, most likely through its ability to prevent Env expression at the infected cell surface. Partial resistance to SM111 is mediated by mutations in Vpu and/or Env, suggesting that the compound affects host/viral protein interactions that are important during viral egress. Further characterization of

  10. Prediction of the secondary structure of HIV-1 gp120

    DEFF Research Database (Denmark)

    Hansen, J E; Lund, O; Nielsen, Jens Ole

    1996-01-01

    The secondary structure of HIV-1 gp120 was predicted using multiple alignment and a combination of two independent methods based on neural network and nearest-neighbor algorithms. The methods agreed on the secondary structure for 80% of the residues in BH10 gp120. Six helices were predicted in HIV...... strain BH10 gp120, as well as in 27 other HIV-1 strains examined. Two helical segments were predicted in regions displaying profound sequence variation, one in a region suggested to be critical for CD4 binding. The predicted content of helix, beta-strand, and coil was consistent with estimates from...... of future HIV subunit vaccine candidates....

  11. Prediction of the Secondary Structure of HIV-1 gp120

    DEFF Research Database (Denmark)

    Hansen, Jan; Lund, Ole; Nielsen, Jens O.

    1996-01-01

    The secondary structure of HIV-1 gp120 was predicted using multiple alignment and a combination of two independent methods based on neural network and nearest-neighbor algorithms. The methods agreed on the secondary structure for 80% of the residues in BH10 gp120. Six helices were predicted in HIV...... strain BH10 gp120, as well as in 27 other HIV-1 strains examined. Two helical seqments were predicted in regions displaying profound sequence variation, one in a region suggested to be critical for CD4 biding. The predicted content of helix, beta-strand, and coil was consistent with estimates from...... of future HIV sub-unit vaccine candidates....

  12. Cold denaturation of the HIV-1 protease monomer

    DEFF Research Database (Denmark)

    Rösner, Heike Ilona; Caldarini, Martina; Prestel, Andreas

    2017-01-01

    The HIV-1-protease is a complex protein which in its active form adopts a homodimer dominated by -sheet structures. We have discovered a cold-denatured state of the monomeric subunit of HIV-1-protease which is populated above 0ºC and therefore directly accessible to various spectroscopic...... approaches. From NMR secondary chemical shifts, temperature coefficients and protein dynamics we suggest that the cold denatured state populates a compact wet globule containing transient non-native-like -helical elements. From the linearity of the temperature coefficients and the hydrodynamic radii, we...

  13. German-Austrian recommendations for HIV1-therapy in pregnancy and in HIV1-exposed newborn, update 2008.

    Science.gov (United States)

    Buchholz, Bernd; Beichert, Matthias; Marcus, Ulrich; Grubert, Thomas; Gingelmaier, Andrea; Haberl, Annette; Schmied, Brigitte

    2009-11-03

    In Germany during the last years about 200-250 HIV1-infected pregnant women delivered a baby each year, a number that is currently increasing. To determine the HIV-status early in pregnancy voluntary HIV-testing of all pregnant women is recommended in Germany and Austria as part of prenatal care. In those cases, where HIV1-infection was known during pregnancy, since 1995 the rate of vertical transmission of HIV1 was reduced to 1-2%. - This low transmission rate has been achieved by the combination of anti-retroviral therapy of pregnant women, caesarean section scheduled before onset of labour, anti-retroviral post exposition prophylaxis in the newborn and refraining from breast-feeding by the HIV1-infected mother. To keep pace with new results in research, approval of new anti-retroviral drugs and changes in the general treatment recommendations for HIV1-infected adults, in 1998, 2001, 2003 and 2005 an interdisciplinary consensus meeting was held. Gynaecologists, infectious disease specialists, paediatricians, pharmacologists, virologists and members of the German AIDS Hilfe (NGO) were participating in this conference to update the prevention strategies. A fifth update became necessary in 2008. The updating process was started in January 2008 and was terminated in September 2008. The guidelines provide new recommendations on the indication and the starting point for HIV-therapy in pregnancies without complications, drugs and drug combinations to be used preferably in these pregnancies and updated information on adverse effects of anti-retroviral drugs. Also the procedures for different scenarios and risk constellations in pregnancy have been specified again. - With these current guidelines in Germany and Austria the low rate of vertical HIV1-transmission should be further maintained.

  14. Recognition of HIV-1 peptides by host CTL is related to HIV-1 similarity to human proteins.

    Directory of Open Access Journals (Sweden)

    Morgane Rolland

    Full Text Available BACKGROUND: While human immunodeficiency virus type 1 (HIV-1-specific cytotoxic T lymphocytes preferentially target specific regions of the viral proteome, HIV-1 features that contribute to immune recognition are not well understood. One hypothesis is that similarities between HIV and human proteins influence the host immune response, i.e., resemblance between viral and host peptides could preclude reactivity against certain HIV epitopes. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the extent of similarity between HIV-1 and the human proteome. Proteins from the HIV-1 B consensus sequence from 2001 were dissected into overlapping k-mers, which were then probed against a non-redundant database of the human proteome in order to identify segments of high similarity. We tested the relationship between HIV-1 similarity to host encoded peptides and immune recognition in HIV-infected individuals, and found that HIV immunogenicity could be partially modulated by the sequence similarity to the host proteome. ELISpot responses to peptides spanning the entire viral proteome evaluated in 314 individuals showed a trend indicating an inverse relationship between the similarity to the host proteome and the frequency of recognition. In addition, analysis of responses by a group of 30 HIV-infected individuals against 944 overlapping peptides representing a broad range of individual HIV-1B Nef variants, affirmed that the degree of similarity to the host was significantly lower for peptides with reactive epitopes than for those that were not recognized. CONCLUSIONS/SIGNIFICANCE: Our results suggest that antigenic motifs that are scarcely represented in human proteins might represent more immunogenic CTL targets not selected against in the host. This observation could provide guidance in the design of more effective HIV immunogens, as sequences devoid of host-like features might afford superior immune reactivity.

  15. Types of pediatric diabetes mellitus defined by anti-islet autoimmunity and random C-peptide at diagnosis

    Science.gov (United States)

    The objective of this study was to test the hypothesis that anti-islet autoantibody expression and random serum C-peptide obtained at diagnosis define phenotypes of pediatric diabetes with distinct clinical features. We analyzed 607 children aged diabetes after ex...

  16. Ethnic differences in C-peptide levels and anti-GAD antibodies in South African patients with diabetic ketoacidosis.

    Science.gov (United States)

    Rheeder, P; Stolk, R P; Grobbee, D E

    2001-01-01

    To determine differences between Black and White South Africans with diabetic ketoacidosis (DKA) and between Black patients on insulin vs. those on oral agents presenting with DKA, post stabilization fasting C-peptide levels and anti-glutamic acid decarboxylase (GAD) antibodies were measured together with serum glucose, acid base and urine ketones on admission. Of 60 patients with diabetic ketoacidosis (DKA) (76 admissions), the 43 Black patients had a higher BMI (23.1 vs. 20.0 kg/m(2), p=0.05) than did the 17 White patients, were more often newly diagnosed (37% vs. 1%, p=0.03), and a greater proportion of Black patients had fasting C-peptide levels >0.3 nmol/l (28% (10/36) vs. 0%, p=0.03). Of these 10 Black patients, eight were anti-GAD-negative. Thirteen Black patients (33%) were anti-GAD-positive vs. 10 (67%) White patients (p=0.03). There was no statistically significant difference in anti-GAD positivity between Black patients on oral agents or those on insulin. Most patients (5/7) admitted on oral agents had negative C-peptide levels after stabilization. Our results suggest that in patients presenting with DKA, a quarter of Black South Africans have C-peptide levels regarded as being indicative of type 2 DM and are less frequently anti-GAD-antibody-positive than are White South Africans.

  17. C-Peptide Versus Insulin: Relationships with Risk Biomarkers of Cardiovascular Disease in Metabolic Syndrome in Young Arab Females

    Directory of Open Access Journals (Sweden)

    A. Abdullah

    2012-01-01

    Full Text Available Background. Obesity is a major health concern and is associated with metabolic syndrome (MetS that increases the risk for cardiovascular disease (CVD. Since little is known about the relationships between MetS components and CVD in overweight/obese young Arab females, our study aimed at examining these relationships and further to explore the associations between connecting peptide (C-peptide and insulin with these biomarkers. Subjects and Methods. In this cross-sectional study, 80 apparently healthy young Arab females were recruited and grouped by their body mass index (BMI into normal-weight (GI and overweight/obese (GII groups. Results. The two groups significantly differed in BMI, waist circumference (WC and values of biomarkers, namely, leptin, fasting insulin, uric acid (UA, insulin resistance (HOMA-IR, C-peptide, high-sensitivity C-reactive protein (hs-CRP, high-density lipoprotein cholesterol (HDL-C, systolic blood pressure (SBP, and diastolic blood pressure (DBP. C-peptide significantly correlated with WC, leptin, UA, and HDL-C and was predicted by three biomarkers; UA, WC and HDL-C. Whereas, insulin significantly correlated with only two biomarkers including leptin and DBP and was predicted by UA and DBP. Conclusions. The present study highlighted the association between MetS and CVD in young Arab females and the possible role of C-peptide in the prediction of CVD.

  18. Ethnic differences in C-peptide levels and anti-GAD antibodies in South African patients with diabetic ketoacidosis

    NARCIS (Netherlands)

    Rheeder, P; Stolk, RP; Grobbee, DE

    To determine differences between Black and White South Africans with diabetic ketoacidosis (DKA) and between Black patients on insulin vs. those on oral agents presenting with DKA, post stabilization fasting C-peptide levels and anti-glutamic acid decarboxylase (GAD) antibodies were measured

  19. Effects of human SAMHD1 polymorphisms on HIV-1 susceptibility

    Energy Technology Data Exchange (ETDEWEB)

    White, Tommy E.; Brandariz-Nuñez, Alberto; Valle-Casuso, Jose Carlos [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, 1301 Morris Park – Price Center 501, New York, NY 10461 (United States); Knowlton, Caitlin; Kim, Baek [Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642 (United States); Sawyer, Sara L. [Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712 (United States); Diaz-Griffero, Felipe, E-mail: Felipe.Diaz-Griffero@einstein.yu.edu [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, 1301 Morris Park – Price Center 501, New York, NY 10461 (United States)

    2014-07-15

    SAMHD1 is a human restriction factor that prevents efficient infection of macrophages, dendritic cells and resting CD4+ T cells by HIV-1. Here we explored the antiviral activity and biochemical properties of human SAMHD1 polymorphisms. Our studies focused on human SAMHD1 polymorphisms that were previously identified as evolving under positive selection for rapid amino acid replacement during primate speciation. The different human SAMHD1 polymorphisms were tested for their ability to block HIV-1, HIV-2 and equine infectious anemia virus (EIAV). All studied SAMHD1 variants block HIV-1, HIV-2 and EIAV infection when compared to wild type. We found that these variants did not lose their ability to oligomerize or to bind RNA. Furthermore, all tested variants were susceptible to degradation by Vpx, and localized to the nuclear compartment. We tested the ability of human SAMHD1 polymorphisms to decrease the dNTP cellular levels. In agreement, none of the different SAMHD1 variants lost their ability to reduce cellular levels of dNTPs. Finally, we found that none of the tested human SAMHD1 polymorphisms affected the ability of the protein to block LINE-1 retrotransposition. - Highlights: • Human SAMHD1 single-nucleotide polymorphisms block HIV-1 and HIV-2 infection. • SAMHD1 polymorphisms do not affect its ability to block LINE-1 retrotransposition. • SAMHD1 polymorphisms decrease the cellular levels of dNTPs.

  20. Inhibitory constituents against HIV-1 protease from Agastache rugosa.

    Science.gov (United States)

    Min, B S; Hattori, M; Lee, H K; Kim, Y H

    1999-02-01

    Two diterpenoid compounds, agastanol (1) and agastaquinone (2), were isolated from the roots of Agastache rugosa (Labiatae). Compound 1 and 2 showed significant inhibitory effects against human immunodeficiency virus type 1 (HIV-1) protease activity with IC50 values of 360 and 87 microM, respectively.

  1. Progress and perspectives on HIV-1 microbicide development

    CSIR Research Space (South Africa)

    Alexandre, KB

    2016-10-01

    Full Text Available is the use of microbicides. In this review we provide a summary of the progress made toward the discovery of affordable and effective HIV-1 microbicides and suggest future directions. We show that there is a wide range of compounds that have been proposed...

  2. APOBEC3G inhibits elongation of HIV-1 reverse transcripts.

    Directory of Open Access Journals (Sweden)

    Kate N Bishop

    2008-12-01

    Full Text Available APOBEC3G (A3G is a host cytidine deaminase that, in the absence of Vif, restricts HIV-1 replication and reduces the amount of viral DNA that accumulates in cells. Initial studies determined that A3G induces extensive mutation of nascent HIV-1 cDNA during reverse transcription. It has been proposed that this triggers the degradation of the viral DNA, but there is now mounting evidence that this mechanism may not be correct. Here, we use a natural endogenous reverse transcriptase assay to show that, in cell-free virus particles, A3G is able to inhibit HIV-1 cDNA accumulation not only in the absence of hypermutation but also without the apparent need for any target cell factors. We find that although reverse transcription initiates in the presence of A3G, elongation of the cDNA product is impeded. These data support the model that A3G reduces HIV-1 cDNA levels by inhibiting synthesis rather than by inducing degradation.

  3. Stepping toward a Macaque Model of HIV-1 Induced AIDS

    Directory of Open Access Journals (Sweden)

    Jason T. Kimata

    2014-09-01

    Full Text Available HIV-1 exhibits a narrow host range, hindering the development of a robust animal model of pathogenesis. Past studies have demonstrated that the restricted host range of HIV-1 may be largely due to the inability of the virus to antagonize and evade effector molecules of the interferon response in other species. They have also guided the engineering of HIV-1 clones that can replicate in CD4 T-cells of Asian macaque species. However, while replication of these viruses in macaque hosts is persistent, it has been limited and without progression to AIDS. In a new study, Hatziioannou et al., demonstrate for the first time that adapted macaque-tropic HIV-1 can persistently replicate at high levels in pigtailed macaques (Macaca nemestrina, but only if CD8 T-cells are depleted at the time of inoculation. The infection causes rapid disease and recapitulates several aspects of AIDS in humans. Additionally, the virus undergoes genetic changes to further escape innate immunity in association with disease progression. Here, the importance of these findings is discussed, as they relate to pathogenesis and model development.

  4. Analysis of dinucleotide signatures in HIV-1 subtype B genomes

    Indian Academy of Sciences (India)

    Keywords. genome signature; DRAP; HIV-1; chaos game representation. Abstract. Dinucleotide usage is known to vary in the genomes of organisms. The dinucleotide usage profiles or genome signatures are similar for sequence samples taken from the same genome, but are different for taxonomically distant species.

  5. Innate immune factors associated with HIV-1 transmission

    NARCIS (Netherlands)

    Pollakis, Georgios; Stax, Martijn J.; Paxton, William A.

    2011-01-01

    Relatively little is known with regards to the mechanisms of HIV-1 transmission across a mucosal surface and more specifically what effects host factors have on influencing infection and early viral dissemination. The purpose of this review is to summarize which factors of the innate immune response

  6. Broadly neutralizing antibodies against HIV-1: templates for a vaccine

    NARCIS (Netherlands)

    van Gils, Marit J.; Sanders, Rogier W.

    2013-01-01

    The need for an effective vaccine to prevent the global spread of human immunodeficiency virus type 1 (HIV-1) is well recognized. Passive immunization and challenge studies in non-human primates testify that broadly neutralizing antibodies (BrNAbs) can accomplish protection against infection. In

  7. Viral dynamics of HIV-1 infection | Martin | Southern African Journal ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (2002) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Viral dynamics of HIV-1 infection. D Martin ...

  8. [Hematological changes associated with human immunodeficiency virus (HIV-1) infection].

    Science.gov (United States)

    Møller, T; Hasselbalch, H C

    1993-05-10

    Infection with human immunodeficiency virus type 1 (HIV-1) primarily involves a subgroup of T-lymphocytic cells, but other cell types are also invaded by the virus, including cell lines within the haematopoietic system. Together with infectious, inflammatory and neoplasic processes, invasion of haematopoietic tissue explains the haematological alterations which are seen during the course of infection with HIV-1. Anaemia develops in the large proportion of patients. Thrombocytopenia frequently occurs during the course of the disease, but may be seen in some patients already at the time of diagnosis, where the condition may be misdiagnosed as "idiopathic" thrombocytopenic purpura. Neutropenia is seen in all disease stages, but is most severe in patients with advanced disease. Bone marrow changes include varying degrees of dysplasia in one or more cell lines, which in some patients may mimic a myelodysplastic syndrome. The number of plasma cells is always increased. In many patients the bone marrow stroma exhibits an increased amount of reticular fibres. HIV-1 infection is associated with an increased risk of non-Hodgkin malignant lymphoma. Acute myelogenous leukaemia and myelomatosis have been described in patients with advanced disease. Treatment of the above mentioned haematological abnormalities aims primarily at reducing replication of HIV-1, thereby diminishing suppression of haematopoiesis by the virus infection, and at controlling the opportunistic infections during the course of the disease. Specific antiviral therapy (AZT) is most successful in correcting thrombocytopenia. The possibility of bone marrow suppression mediated by a toxic drug effect should always be considered in this patient group.

  9. Acute and Early HIV1 Infection in Childbearing Women during ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Acute and Early HIV1 Infection in Childbearing Women during Pregnancy and Postpartum Period in Tanzania, Zambia, and Botswana. National HIV prevention programs in Tanzania, Zambia, and Botswana must effectively address the infection rate among childbearing women during pregnancy and the postpartum period.

  10. The Immune Interaction between HIV-1 Infection and Mycobacterium tuberculosis.

    Science.gov (United States)

    Du Bruyn, Elsa; Wilkinson, Robert John

    2016-12-01

    The modulation of tuberculosis (TB)-induced immunopathology caused by human immunodeficiency virus (HIV)-1 coinfection remains incompletely understood but underlies the change seen in the natural history, presentation, and prognosis of TB in such patients. The deleterious combination of these two pathogens has been dubbed a "deadly syndemic," with each favoring the replication of the other and thereby contributing to accelerated disease morbidity and mortality. HIV-1 is the best-recognized risk factor for the development of active TB and accounts for 13% of cases globally. The advent of combination antiretroviral therapy (ART) has considerably mitigated this risk. Rapid roll-out of ART globally and the recent recommendation by the World Health Organization (WHO) to initiate ART for everyone living with HIV at any CD4 cell count should lead to further reductions in HIV-1-associated TB incidence because susceptibility to TB is inversely proportional to CD4 count. However, it is important to note that even after successful ART, patients with HIV-1 are still at increased risk for TB. Indeed, in settings of high TB incidence, the occurrence of TB often remains the first presentation of, and thereby the entry into, HIV care. As advantageous as ART-induced immune recovery is, it may also give rise to immunopathology, especially in the lower-CD4-count strata in the form of the immune reconstitution inflammatory syndrome. TB-immune reconstitution inflammatory syndrome will continue to impact the HIV-TB syndemic.

  11. HIV-1 integrase inhibitors as new components of antiviral therapy

    Energy Technology Data Exchange (ETDEWEB)

    Prikazchikova, T A; Aleksandrov, D A; Gottikh, M B [A. N. Belozersky Institute of Physico-Chemical Biology, M. V. Lomonosov Moscow State University, Moscow (Russian Federation); Sycheva, A M; Agapkina, Y Y [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2008-05-31

    Structural and functional features of HIV-1 integrase are considered and the state of the art in the quest for effective inhibitors of this enzyme is reported. The major classes of integrase inhibitors with known mechanisms of action as well as their in vitro and in vivo inhibitory activities are presented.

  12. Evaluation of the HIV-1 reverse transcriptase inhibitory properties of ...

    African Journals Online (AJOL)

    remedies in Kenya were screened for activity against the HIV-1 reverse transcriptase.“ ... drugs at present have fallen short of expectation in many ways. ..... effective doses: aromatic polycyclic diones hypericin and pseudhypericin. Proceedings of the National Academy of. Science of the USA. 1988; 85: 5230-. 5234. Tang J ...

  13. On the early dynamics and spread of HIV-1.

    Science.gov (United States)

    Rife, Brittany; Salemi, Marco

    2015-01-01

    Until recently, the origin of the HIV-1 group M pandemic largely remained a scientific mystery. The use of comprehensive evolutionary analyses has revealed a unique story regarding viral migration, starting in the 1920s in Kinshasa, and the social and infrastructural changes associated with the early spread of this deadly virus. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Immunological Response to Antiretroviral Therapy in HIV-1 Infected ...

    African Journals Online (AJOL)

    Objective: To describe the immunological response to ART in HIV-1 infected ART naïve patients in relation to age, sex, baseline CD4+ T cell counts and generic ART regimens at Muhimbili Nation Hospital, in Dar es Salaam, Tanzania. Methods: Retrospective analysis of data from patients enrolled in the pilot ART program ...

  15. Risk factors for perinatal HIV-1 transmission in pregnant women ...

    African Journals Online (AJOL)

    Objectives. To estimate the infant HIV-1 transmission rate and to evaluate risk factors for transmission in pregnant women at an Eastern Cape tertiary hospital requiring lifelong antiretroviral therapy (ART). Methods. Pregnant women who initiated lifelong ART during pregnancy and others who conceived on lifelong ART ...

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

    Indian Academy of Sciences (India)

    Keywords. HIV-1 resistance polymorphism; chemokine receptor; stromal-derived factor-1; Andhra Pradesh; AIDS. ... The estimated relative hazard values for the populations, computed from the three-locus genotype data, are comparable to those from Africa and Southeast Asia, where AIDS is known to be widespread.

  17. Immunological and Virological Response to HAART in HIV-1 ...

    African Journals Online (AJOL)

    Background: Among the countries highly endemic for viral hepatitis, Nigeria is found. Information on how triple infected persons (HIV, HBV, and HCV) fare on HAART in the country is lacking. Laboratory based investigation was carried out to assess the virological and immunological parameters of HIV-1 infected patients ...

  18. Inhibition of HIV-1 by a natural compound

    CSIR Research Space (South Africa)

    Van den Berg, N

    2011-06-01

    Full Text Available CSIR Biosciences investigated the anti-HIV properties of a plant indigenous to the Eastern Cape, commonly used by traditional healers. A natural compound isolated from the plant, coded BP36, inhibited infectivity of HIV-1 pseudoviruses. The data...

  19. Progress and perspectives on HIV-1 microbicide development

    CSIR Research Space (South Africa)

    Alexandre, Kabamba B

    2016-10-01

    Full Text Available The majority of HIV-1 infections occur via sexual intercourse. Women are the most affected by the epidemic, particularly in developing countries, due to their socio-economic dependence on men and the fact that they are often victims of gender based...

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

    Indian Academy of Sciences (India)

    Unknown

    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 ...

  1. Host genetic factors in susceptibility to HIV-1 infection and ...

    Indian Academy of Sciences (India)

    to influence the rate of AIDS progression in HIV-1 infected individuals. The candidate host genes suspected to influence the rate of progression from HIV to AIDS can be divided into three categories: (i) genes encoding cell-surface receptors or lig- ands for these proteins; (ii) genes within human leukocyte antigens (HLA) that ...

  2. Inhibition of HIV-1 lentiviral particles infectivity by Gynostemma ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... infections with claims of efficacy against HIV-1 infections were screened. These claims motivated the study in which the inhibition of viral vector infectivity of HeLa cells was assessed flow cytometrically by measuring the expression of green fluorescent protein (GFP) transgene incorporated in the lentiviral.

  3. The HIV-1 Nef protein and phagocyte NADPH oxidase activation

    DEFF Research Database (Denmark)

    Vilhardt, Frederik; Plastre, Olivier; Sawada, Makoto

    2002-01-01

    Nef, a multifunctional HIV protein, activates the Vav/Rac/p21-activated kinase (PAK) signaling pathway. Given the potential role of this pathway in the activation of the phagocyte NADPH oxidase, we have investigated the effect of the HIV-1 Nef protein on the phagocyte respiratory burst. Microglia...

  4. Elite controllers: understanding natural suppressive control of HIV-1 ...

    African Journals Online (AJOL)

    at the transcript and/or protein level also needs to be considered in genetic studies. Understanding the mechanisms responsible for this untreated, spontaneous and exceptional control of HIV-1 infection may be crucial to the development of HIV vaccines that provide protection from disease progression, and for the.

  5. Frequency of Cryptococcal Meningitis in HIV-1 Infected Patients in ...

    African Journals Online (AJOL)

    Methods: A cross sectional study was carried out at the Jos University Teaching Hospital (JUTH), A total of 100 HIV-1 infected patients suspected of having meningitis or meningoencephalitis were subjected to cerebrospinal fluid (CSF) analysis (including Indian ink preparation and fungal culture by conventional methods) ...

  6. GBV-C/HIV-1 coinfection is associated with low HIV-1 viral load and high CD4(+) T lymphocyte count.

    Science.gov (United States)

    de Miranda, Bárbara Katharine Barbosa; de Sá, Keyla Santos Guedes; da Silva, Andrea Nazaré Rangel; Feitosa, Rosimar Neris Martins; Cayres-Vallinoto, Izaura Maria Vieira; Ishak, Ricardo; Vallinoto, Antonio Carlos Rosário

    2017-11-01

    GB virus C (GBV-C) is a lymphotropic virus with a low level or non-existent replication in the liver. The interaction between HIV-1 and GBV-C apparently reduces the progression of HIV-1 infection to AIDS and improves the quality of life of HIV-1 infected individuals. A cross-sectional study was established to determine the possible effect of HIV-1/GBV-C coinfection on HIV-1 viral load and CD4(+) T lymphocyte counts. Samples from 313 HIV-1 infected persons from the Virus Laboratory of the Federal University of Pará as well as demographic and clinical information were obtained from medical records. This study used a nested PCR method to determine GBV-C viremia. The prevalence of HIV-1/GBV-C coinfection was 17%. There were no significant differences in the distribution according to age, sex or ethnicity between the groups. The differences in HIV-1 viral load and CD4(+) T lymphocyte count between the HIV-1 and HIV-1/GBV-C groups were highly significant, indicating that coinfection results in lower viral loads and higher CD4(+) T lymphocyte counts compared to HIV-1 mono-infection. The results indicate a protective effect among coinfected individuals.

  7. Impact of HIV-1, HIV-2, and HIV-1+2 dual infection on the outcome of tuberculosis.

    Science.gov (United States)

    Wejse, C; Patsche, C B; Kühle, A; Bamba, F J V; Mendes, M S; Lemvik, G; Gomes, V F; Rudolf, F

    2015-03-01

    HIV-1 infection has been shown to impact the outcome of patients with tuberculosis (TB), but data regarding the impact of HIV-2 on TB outcomes are limited. The aim of this study was to assess the impact of HIV types on mortality among TB patients in Guinea-Bissau and to examine the predictive ability of the TBscoreII, a clinical score used to assess disease severity. In a prospective follow-up study, we examined the prevalence of HIV-1, HIV-2, and HIV-1+2 co-infection in TB patients in Guinea-Bissau, and the impact on outcomes at 12 months of follow-up. We included all adult TB patients in an observational TB cohort at the Bandim Health Project (BHP) in Guinea-Bissau between 2003 and 2013 and assessed survival status at 12 months after the start of treatment. A total 1312 patients were included; 499 (38%) were female (male/female ratio 1.6). Three hundred and seventy-nine patients were HIV-infected: 241 had HIV-1, 93 had HIV-2, and 45 were HIV-1+2 dual infected. The HIV type-associated risk of TB was 6-fold higher for HIV-1, 7-fold higher for HIV-1+2 dual infection, and 2-fold higher for HIV-2 compared with the HIV-uninfected. Of the patients included, 144 (11%) died, 62 (12%) among females and 82 (9%) among males (hazard ratio (HR) 0.91, 95% confidence interval (CI) 0.64-1.30; p=0.596). Compared to male patients, female patients were younger (1 year younger, 95% CI 0.5-2; p=0.04), reported a longer duration of symptoms (14 days longer, 95% CI 4-25; p=0.003), and had a higher TBscoreII (0.5 points more, 95% CI 0.3-0.7; pHIV-infected (36% vs. 25%; pHIV infection increased the mortality risk, with HIV-1 infection displaying the highest HR (5.0, 95% CI 3.5-7.1), followed by HIV-1+2 (HR 4.2, 95% CI 2.2-7.8) and HIV-2 (HR 2.1, 95% CI 1.2-3.8). A TBscoreII ≥4 was associated with increased mortality (HR 2.2, 95% CI 1.5-3.1). Significantly increased HRs were found for signs of wasting; a BMI HIV type-associated risk of TB was much higher for HIV-1 patients and higher but

  8. Characterizing HIV-1 Splicing by Using Next-Generation Sequencing.

    Science.gov (United States)

    Emery, Ann; Zhou, Shuntai; Pollom, Elizabeth; Swanstrom, Ronald

    2017-03-15

    Full-length human immunodeficiency virus type 1 (HIV-1) RNA serves as the genome or as an mRNA, or this RNA undergoes splicing using four donors and 10 acceptors to create over 50 physiologically relevant transcripts in two size classes (1.8 kb and 4 kb). We developed an assay using Primer ID-tagged deep sequencing to quantify HIV-1 splicing. Using the lab strain NL4-3, we found that A5 (env/nef) is the most commonly used acceptor (about 50%) and A3 (tat) the least used (about 3%). Two small exons are made when a splice to acceptor A1 or A2 is followed by activation of donor D2 or D3, and the high-level use of D2 and D3 dramatically reduces the amount of vif and vpr transcripts. We observed distinct patterns of temperature sensitivity of splicing to acceptors A1 and A2. In addition, disruption of a conserved structure proximal to A1 caused a 10-fold reduction in all transcripts that utilized A1. Analysis of a panel of subtype B transmitted/founder viruses showed that splicing patterns are conserved, but with surprising variability of usage. A subtype C isolate was similar, while a simian immunodeficiency virus (SIV) isolate showed significant differences. We also observed transsplicing from a downstream donor on one transcript to an upstream acceptor on a different transcript, which we detected in 0.3% of 1.8-kb RNA reads. There were several examples of splicing suppression when the env intron was retained in the 4-kb size class. These results demonstrate the utility of this assay and identify new examples of HIV-1 splicing regulation. IMPORTANCE During HIV-1 replication, over 50 conserved spliced RNA variants are generated. The splicing assay described here uses new developments in deep-sequencing technology combined with Primer ID-tagged cDNA primers to efficiently quantify HIV-1 splicing at a depth that allows even low-frequency splice variants to be monitored. We have used this assay to examine several features of HIV-1 splicing and to identify new examples of

  9. In vitro nuclear interactome of the HIV-1 Tat protein.

    LENUS (Irish Health Repository)

    Gautier, Virginie W

    2009-01-01

    BACKGROUND: One facet of the complexity underlying the biology of HIV-1 resides not only in its limited number of viral proteins, but in the extensive repertoire of cellular proteins they interact with and their higher-order assembly. HIV-1 encodes the regulatory protein Tat (86-101aa), which is essential for HIV-1 replication and primarily orchestrates HIV-1 provirus transcriptional regulation. Previous studies have demonstrated that Tat function is highly dependent on specific interactions with a range of cellular proteins. However they can only partially account for the intricate molecular mechanisms underlying the dynamics of proviral gene expression. To obtain a comprehensive nuclear interaction map of Tat in T-cells, we have designed a proteomic strategy based on affinity chromatography coupled with mass spectrometry. RESULTS: Our approach resulted in the identification of a total of 183 candidates as Tat nuclear partners, 90% of which have not been previously characterised. Subsequently we applied in silico analysis, to validate and characterise our dataset which revealed that the Tat nuclear interactome exhibits unique signature(s). First, motif composition analysis highlighted that our dataset is enriched for domains mediating protein, RNA and DNA interactions, and helicase and ATPase activities. Secondly, functional classification and network reconstruction clearly depicted Tat as a polyvalent protein adaptor and positioned Tat at the nexus of a densely interconnected interaction network involved in a range of biological processes which included gene expression regulation, RNA biogenesis, chromatin structure, chromosome organisation, DNA replication and nuclear architecture. CONCLUSION: We have completed the in vitro Tat nuclear interactome and have highlighted its modular network properties and particularly those involved in the coordination of gene expression by Tat. Ultimately, the highly specialised set of molecular interactions identified will

  10. HIV-1 genetic variants in the Russian Far East.

    Science.gov (United States)

    Kazennova, Elena; Laga, Vita; Lapovok, Ilya; Glushchenko, Nataliya; Neshumaev, Dmitry; Vasilyev, Alexander; Bobkova, Marina

    2014-08-01

    A molecular analysis of HIV-1 subtypes and recombinants circulating in cities in the Russian Far East was performed. The study included samples from 201 outpatients from Vladivostok, Khabarovsk, and Blagoveshchensk. In most parts of Russia, patients are infected with HIV-1 subtype A, known as the IDU-A variant. Subtype B, including the IDU-B variant, is rare in Russia but widespread in the Ukraine, and the CRF02_AG is prevalent in Central Asian countries and Siberia, Russia. One of the challenges of this study in the Far East was to determine whether the molecular landscape of HIV infection in this region is influenced by the bordering countries, including China and Japan, where a distinct set of HIV subtypes is circulating, such as B', C, and CRF01_AE. The distribution of HIV-1 genetic variants in the cities studied was as follows: subtype A (IDU-A), 55.7%; subtype B, 25.3% (IDU-B variant-24.3%); subtype C, 10.0%; CRF02_AG, 1.5%; and CRF63_02A1, 7.5%. A phylogenetic analysis confirmed the relationship of subtype A viruses with the IDU-A variant predominating in Ukraine, Russia and other former Soviet Union (FSU) countries, of subtype B viruses with IDU-B in the Ukraine and of CRF02_AG variants with variants in Uzbekistan, Russia, and other former USSR countries. Subtype C sequences were not uniform, and most clustered between each other and HIV-1 sequences originating from Africa; there was only one sample possibly related to Chinese variants. Thus, despite close cultural and commercial relationships among Russia, China, and Japan, the distribution of HIV-1 subtypes in the Russian Far East is still primarily influenced by contacts with the countries of the former USSR.

  11. Characteristics of HIV-1 discordant couples enrolled in a trial of HSV-2 suppression to reduce HIV-1 transmission: the partners study.

    Directory of Open Access Journals (Sweden)

    Jairam R Lingappa

    Full Text Available The Partners HSV-2/HIV-1 Transmission Study (Partners Study is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2 suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort.HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count >or=250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed.Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the HIV-1 infected partners were women. Couples had cohabitated for a median of 5 years (range 2-9 with 28% reporting unprotected sex in the month prior to enrollment. Among HIV-1 susceptible participants, 86% of women and 59% of men were HSV-2 seropositive. Other laboratory-diagnosed sexually transmitted infections were uncommon (500 relative to <350, respectively, p<0.001.The Partners Study successfully enrolled a cohort of 3408 heterosexual HIV-1 serodiscordant couples in Africa at high risk for HIV-1 transmission. Follow-up of this cohort will evaluate the efficacy of acyclovir for HSV-2 suppression in preventing HIV-1 transmission and provide insights into biological and behavioral factors determining heterosexual HIV-1 transmission.ClinicalTrials.gov NCT00194519.

  12. Characteristics of HIV-1 Discordant Couples Enrolled in a Trial of HSV-2 Suppression to Reduce HIV-1 Transmission: The Partners Study

    Science.gov (United States)

    Lingappa, Jairam R.; Kahle, Erin; Mugo, Nelly; Mujugira, Andrew; Magaret, Amalia; Baeten, Jared; Bukusi, Elizabeth A.; Cohen, Craig R.; Katabira, Elly; Ronald, Allan; Kiarie, James; Farquhar, Carey; Stewart, Grace John; Makhema, Joseph; Essex, M.; Were, Edwin; Fife, Kenneth; deBruyn, Guy; Gray, Glenda; McIntyre, James; Manongi, Rachel; Kapiga, Saidi; Coetzee, David; Allen, Susan; Inambao, Mubiana; Kayitenkore, Kayitesi; Karita, Etienne; Kanweka, William; Delany, Sinead; Rees, Helen; Vwalika, Bellington; Coombs, Robert W.; Morrow, Rhoda; Whittington, William; Corey, Lawrence; Wald, Anna; Celum, Connie

    2009-01-01

    Background The Partners HSV-2/HIV-1 Transmission Study (Partners Study) is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2) suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort. Methods HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count ≥250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed. Results Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the