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Sample records for block hiv-1 replication

  1. Hyperthermia stimulates HIV-1 replication.

    OpenAIRE

    Ferdinand Roesch; Oussama Meziane; Anna Kula; Sébastien Nisole; Françoise Porrot; Ian Anderson; Fabrizio Mammano; Ariberto Fassati; Alessandro Marcello; Monsef Benkirane; Olivier Schwartz

    2012-01-01

    International audience HIV-infected individuals may experience fever episodes. Fever is an elevation of the body temperature accompanied by inflammation. It is usually beneficial for the host through enhancement of immunological defenses. In cultures, transient non-physiological heat shock (42-45°C) and Heat Shock Proteins (HSPs) modulate HIV-1 replication, through poorly defined mechanisms. The effect of physiological hyperthermia (38-40°C) on HIV-1 infection has not been extensively inve...

  2. Methylation: a regulator of HIV-1 replication?

    OpenAIRE

    Jeang Kuan-Teh; Yedavalli Venkat RK

    2007-01-01

    Abstract Recent characterizations of methyl transferases as regulators of cellular processes have spurred investigations into how methylation events might influence the HIV-1 life cycle. Emerging evidence suggests that protein-methylation can positively and negatively regulate HIV-1 replication. How DNA- and RNA- methylation might impact HIV-1 is also discussed.

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

    International Nuclear Information System (INIS)

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

  4. The anti-inflammatory activity of curcumin protects the genital mucosal epithelial barrier from disruption and blocks replication of HIV-1 and HSV-2.

    Directory of Open Access Journals (Sweden)

    Victor H Ferreira

    Full Text Available Inflammation is a known mechanism that facilitates HIV acquisition and the spread of infection. In this study, we evaluated whether curcumin, a potent and safe anti-inflammatory compound, could be used to abrogate inflammatory processes that facilitate HIV-1 acquisition in the female genital tract (FGT and contribute to HIV amplification. Primary, human genital epithelial cells (GECs were pretreated with curcumin and exposed to HIV-1 or HIV glycoprotein 120 (gp120, both of which have been shown to disrupt epithelial tight junction proteins, including ZO-1 and occludin. Pre-treatment with curcumin prevented disruption of the mucosal barrier by maintaining ZO-1 and occludin expression and maintained trans-epithelial electric resistance across the genital epithelium. Curcumin pre-treatment also abrogated the gp120-mediated upregulation of the proinflammatory cytokines tumor necrosis factor-α and interleukin (IL-6, which mediate barrier disruption, as well as the chemokines IL-8, RANTES and interferon gamma-induced protein-10 (IP-10, which are capable of recruiting HIV target cells to the FGT. GECs treated with curcumin and exposed to the sexually transmitted co-infecting microbes HSV-1, HSV-2 and Neisseria gonorrhoeae were unable to elicit innate inflammatory responses that indirectly induced activation of the HIV promoter and curcumin blocked Toll-like receptor (TLR-mediated induction of HIV replication in chronically infected T-cells. Finally, curcumin treatment resulted in significantly decreased HIV-1 and HSV-2 replication in chronically infected T-cells and primary GECs, respectively. All together, our results suggest that the use of anti-inflammatory compounds such as curcumin may offer a viable alternative for the prevention and/or control of HIV replication in the FGT.

  5. The anti-inflammatory activity of curcumin protects the genital mucosal epithelial barrier from disruption and blocks replication of HIV-1 and HSV-2.

    Science.gov (United States)

    Ferreira, Victor H; Nazli, Aisha; Dizzell, Sara E; Mueller, Kristen; Kaushic, Charu

    2015-01-01

    Inflammation is a known mechanism that facilitates HIV acquisition and the spread of infection. In this study, we evaluated whether curcumin, a potent and safe anti-inflammatory compound, could be used to abrogate inflammatory processes that facilitate HIV-1 acquisition in the female genital tract (FGT) and contribute to HIV amplification. Primary, human genital epithelial cells (GECs) were pretreated with curcumin and exposed to HIV-1 or HIV glycoprotein 120 (gp120), both of which have been shown to disrupt epithelial tight junction proteins, including ZO-1 and occludin. Pre-treatment with curcumin prevented disruption of the mucosal barrier by maintaining ZO-1 and occludin expression and maintained trans-epithelial electric resistance across the genital epithelium. Curcumin pre-treatment also abrogated the gp120-mediated upregulation of the proinflammatory cytokines tumor necrosis factor-α and interleukin (IL)-6, which mediate barrier disruption, as well as the chemokines IL-8, RANTES and interferon gamma-induced protein-10 (IP-10), which are capable of recruiting HIV target cells to the FGT. GECs treated with curcumin and exposed to the sexually transmitted co-infecting microbes HSV-1, HSV-2 and Neisseria gonorrhoeae were unable to elicit innate inflammatory responses that indirectly induced activation of the HIV promoter and curcumin blocked Toll-like receptor (TLR)-mediated induction of HIV replication in chronically infected T-cells. Finally, curcumin treatment resulted in significantly decreased HIV-1 and HSV-2 replication in chronically infected T-cells and primary GECs, respectively. All together, our results suggest that the use of anti-inflammatory compounds such as curcumin may offer a viable alternative for the prevention and/or control of HIV replication in the FGT. PMID:25856395

  6. Persistent HIV-1 replication during antiretroviral therapy

    OpenAIRE

    Martinez-Picado, Javier; Deeks, Steven G

    2016-01-01

    Purpose of review The present review will highlight some of the recent findings regarding the capacity of HIV-1 to replicate during antiretroviral therapy (ART). Recent findings Although ART is highly effective at inhibiting HIV replication, it is not curative. Several mechanisms contribute to HIV persistence during ART, including HIV latency, immune dysfunction, and perhaps persistent low-level spread of the virus to uninfected cells (replication). The success in curing HIV will depend on ef...

  7. Persistent HIV-1 replication maintains the tissue reservoir during therapy.

    Science.gov (United States)

    Lorenzo-Redondo, Ramon; Fryer, Helen R; Bedford, Trevor; Kim, Eun-Young; Archer, John; Kosakovsky Pond, Sergei L; Chung, Yoon-Seok; Penugonda, Sudhir; Chipman, Jeffrey G; Fletcher, Courtney V; Schacker, Timothy W; Malim, Michael H; Rambaut, Andrew; Haase, Ashley T; McLean, Angela R; Wolinsky, Steven M

    2016-02-01

    Lymphoid tissue is a key reservoir established by HIV-1 during acute infection. It is a site associated with viral production, storage of viral particles in immune complexes, and viral persistence. Although combinations of antiretroviral drugs usually suppress viral replication and reduce viral RNA to undetectable levels in blood, it is unclear whether treatment fully suppresses viral replication in lymphoid tissue reservoirs. Here we show that virus evolution and trafficking between tissue compartments continues in patients with undetectable levels of virus in their bloodstream. We present a spatial and dynamic model of persistent viral replication and spread that indicates why the development of drug resistance is not a foregone conclusion under conditions in which drug concentrations are insufficient to completely block virus replication. These data provide new insights into the evolutionary and infection dynamics of the virus population within the host, revealing that HIV-1 can continue to replicate and replenish the viral reservoir despite potent antiretroviral therapy. PMID:26814962

  8. Novel Approaches to Inhibiting HIV-1 Replication

    OpenAIRE

    Adamson, Catherine S.; Freed, Eric O.

    2009-01-01

    Considerable success has been achieved in the treatment of HIV-1 infection, and more than two-dozen antiretroviral drugs are available targeting several distinct steps in the viral replication cycle. However, resistance to these compounds emerges readily, even in the context of combination therapy. Drug toxicity, adverse drug-drug interactions, and accompanying poor patient adherence can also lead to treatment failure. These considerations make continued development of novel antiretroviral th...

  9. A conditionally replicating HIV-1 vector interferes with wild-type HIV-1 replication and spread.

    OpenAIRE

    Dropulić, B; Hĕrmánková, M; Pitha, P M

    1996-01-01

    Defective-interfering viruses are known to modulate virus pathogenicity. We describe conditionally replicating HIV-1 (crHIV) vectors that interfere with wild-type HIV-1 (wt-HIV) replication and spread. crHIV vectors are defective-interfering HIV genomes that do not encode viral proteins and replicate only in the presence of wt-HIV helper virus. In cells that contain both wt-HIV and crHIV genomes, the latter are shown to have a selective advantage for packaging into progeny virions because the...

  10. Persistent HIV-1 replication during antiretroviral therapy

    Science.gov (United States)

    Martinez-Picado, Javier; Deeks, Steven G.

    2016-01-01

    Purpose of review The present review will highlight some of the recent findings regarding the capacity of HIV-1 to replicate during antiretroviral therapy (ART). Recent findings Although ART is highly effective at inhibiting HIV replication, it is not curative. Several mechanisms contribute to HIV persistence during ART, including HIV latency, immune dysfunction, and perhaps persistent low-level spread of the virus to uninfected cells (replication). The success in curing HIV will depend on efficiently targeting these three aspects. The degree to which HIV replicates during ART remains controversial. Most studies have failed to find any evidence of HIV evolution in blood, even with samples collected over many years, although a recent very intensive study of three individuals suggested that the virus population does shift, at least during the first few months of therapy. Stronger but still not definitive evidence for replication comes from a series of studies in which standard regimens were intensified with an integration inhibitor, resulting in changes in episomal DNA (blood) and cell-associated RNA (tissue). Limited drug penetration within tissues and the presence of immune sanctuaries have been argued as potential mechanisms allowing HIV to spread during ART. Mathematical models suggest that HIV replication and evolution is possible even without the selection of fully drug-resistant variants. As persistent HIV replication could have clinical consequences and might limit the efficacy of curative interventions, determining if HIV replicates during ART and why, should remain a key focus of the HIV research community. Summary Residual viral replication likely persists in lymphoid tissues, at least in a subset of individuals. Abnormal levels of immune activation might contribute to sustain virus replication. PMID:27078619

  11. Novel approaches to inhibiting HIV-1 replication.

    Science.gov (United States)

    Adamson, Catherine S; Freed, Eric O

    2010-01-01

    Considerable success has been achieved in the treatment of HIV-1 infection, and more than two-dozen antiretroviral drugs are available targeting several distinct steps in the viral replication cycle. However, resistance to these compounds emerges readily, even in the context of combination therapy. Drug toxicity, adverse drug-drug interactions, and accompanying poor patient adherence can also lead to treatment failure. These considerations make continued development of novel antiretroviral therapeutics necessary. In this article, we highlight a number of steps in the HIV-1 replication cycle that represent promising targets for drug discovery. These include lipid raft microdomains, the RNase H activity of the viral enzyme reverse transcriptase, uncoating of the viral core, host cell machinery involved in the integration of the viral DNA into host cell chromatin, virus assembly, maturation, and budding, and the functions of several viral accessory proteins. We discuss the relevant molecular and cell biology, and describe progress to date in developing inhibitors against these novel targets. 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. PMID:19782103

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

    OpenAIRE

    Killian M

    2012-01-01

    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 t...

  13. Lipids and Membrane Microdomains in HIV-1 Replication

    OpenAIRE

    Waheed, Abdul A.; Freed, Eric O.

    2009-01-01

    Several critical steps in the replication cycle of human immunodeficiency virus type 1 (HIV-1) – entry, assembly and budding – are complex processes that take place at the plasma membrane of the host cell. A growing body of data indicates that these early and late steps in HIV-1 replication take place in specialized plasma membrane microdomains, and that many of the viral and cellular components required for entry, assembly, and budding are concentrated in these microdomains. In particular, a...

  14. Azasugar-Containing Phosphorothioate Oligonucleotide (AZPSON) DBM-2198 Inhibits Human Immunodeficiency Virus Type 1 (HIV-1) Replication by Blocking HIV-1 gp120 without Affecting the V3 Region

    OpenAIRE

    Lee, Jinjoo; Byeon, Se Eun; Jung, Ju Yeol; Kang, Myeong-Ho; Park, Yu-Jin; Jung, Kyeong-Eun; Bae, Yong-Soo

    2015-01-01

    DBM-2198, a six-membered azasugar nucleotide (6-AZN)-containing phosphorothioate (P = S) oligonucleotide (AZPSON), was described in our previous publication [Lee et al. (2005)] with regard to its antiviral activity against a broad spectrum of HIV-1 variants. This report describes the mechanisms underlying the anti-HIV-1 properties of DBM-2198. The LTR-mediated reporter assay indicated that the anti-HIV-1 activity of DBM-2198 is attributed to an extracellular mode of action rather than intrace...

  15. 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.

  16. Possible applications for replicating HIV 1 vectors

    OpenAIRE

    Das, Atze T.; Jeeninga, Rienk E.; Berkhout, Ben

    2010-01-01

    Since its discovery some 25 years ago, much has been learned about HIV type 1 and the molecular details of its replication cycle. This insight has been used to develop lentiviral vector systems that have advantages over conventional retroviral vector systems. For safety reasons, the lentiviral vector systems are replication incompetent and the risk of generating a replication competent virus has been minimized. Nevertheless, there may be certain applications for replication competent HIV base...

  17. The CD85j+ NK cell subset potently controls HIV-1 replication in autologous dendritic cells.

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    Daniel Scott-Algara

    Full Text Available Natural killer (NK cells and dendritic cells (DC are thought to play critical roles in the first phases of HIV infection. In this study, we examined changes in the NK cell repertoire and functions occurring in response to early interaction with HIV-infected DC, using an autologous in vitro NK/DC coculture system. We show that NK cell interaction with HIV-1-infected autologous monocyte-derived DC (MDDC modulates NK receptor expression. In particular, expression of the CD85j receptor on NK cells was strongly down-regulated upon coculture with HIV-1-infected MDDC. We demonstrate that CD85j(+ NK cells exert potent control of HIV-1 replication in single-round and productively HIV-1-infected MDDC, whereas CD85j(- NK cells induce a modest and transient decrease of HIV-1 replication. HIV-1 suppression in MDCC by CD85j(+ NK cells required cell-to-cell contact and did not appear mediated by cytotoxicity or by soluble factors. HIV-1 inhibition was abolished when NK-MDDC interaction through the CD85j receptor was blocked with a recombinant CD85j molecule, whereas inhibition was only slightly counteracted by blocking HLA class I molecules, which are known CD85j ligands. After masking HLA class I molecules with specific antibodies, a fraction of HIV-1 infected MDDC was still strongly stained by a recombinant CD85j protein. These results suggest that CD85j(+ NK cell inhibition of HIV-1 replication in MDDC is mainly mediated by CD85j interaction with an unknown ligand (distinct from HLA class I molecules preferentially expressed on HIV-1-infected MDDC.

  18. N-terminal Slit2 inhibits HIV-1 replication by regulating the actin cytoskeleton

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    Anand Appakkudal R

    2013-01-01

    Full Text Available Abstract Background Slit2 is a ~ 200 kDa secreted glycoprotein that has been recently shown to regulate immune functions. However, not much is known about its role in HIV (human immunodeficiency virus-1 pathogenesis. Results In the present study, we have shown that the N-terminal fragment of Slit2 (Slit2N (~120 kDa inhibits replication of both CXCR4 and CCR5-tropic HIV-1 viruses in T-cell lines and peripheral blood T-cells. Furthermore, we demonstrated inhibition of HIV-1 infection in resting CD4+ T-cells. In addition, we showed that Slit2N blocks cell-to-cell transmission of HIV-1. We have shown that Slit2N inhibits HIV-1 infection by blocking viral entry into T-cells. We also ruled out Slit2N-mediated inhibition of various other steps in the life cycle including binding, integration and viral transcription. Elucidation of the molecular mechanism revealed that Slit2N mediates its functional effects by binding to Robo1 receptor. Furthermore, we found that Slit2N inhibited Gp120-induced Robo1-actin association suggesting that Slit2N may inhibit cytoskeletal rearrangements facilitating HIV-1 entry. Studies into the mechanism of inhibition of HIV-1 revealed that Slit2N abrogated HIV-1 envelope-induced actin cytoskeletal dynamics in both T-cell lines and primary T-cells. We further showed that Slit2N specifically attenuated the HIV-1 envelope-induced signaling pathway consisting of Rac1, LIMK and cofilin that regulates actin polymerization. Conclusions Taken together, our results show that Slit2N inhibits HIV-1 replication through novel mechanisms involving modulation of cytoskeletal dynamics. Our study, thus, provides insights into the role of Slit2N in HIV-1 infection and underscores its potential in limiting viral replication in T-cells.

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

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    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.

  20. HIV-1 replication and the cellular eukaryotic translation apparatus.

    Science.gov (United States)

    Guerrero, Santiago; Batisse, Julien; Libre, Camille; Bernacchi, Serena; Marquet, Roland; Paillart, Jean-Christophe

    2015-01-01

    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. PMID:25606970

  1. The Anti-Inflammatory Activity of Curcumin Protects the Genital Mucosal Epithelial Barrier from Disruption and Blocks Replication of HIV-1 and HSV-2

    OpenAIRE

    Ferreira, Victor H; Nazli, Aisha; Dizzell, Sara E.; Mueller, Kristen; Kaushic, Charu

    2015-01-01

    Inflammation is a known mechanism that facilitates HIV acquisition and the spread of infection. In this study, we evaluated whether curcumin, a potent and safe anti-inflammatory compound, could be used to abrogate inflammatory processes that facilitate HIV-1 acquisition in the female genital tract (FGT) and contribute to HIV amplification. Primary, human genital epithelial cells (GECs) were pretreated with curcumin and exposed to HIV-1 or HIV glycoprotein 120 (gp120), both of which have been ...

  2. Restrictions to HIV-1 replication in resting CD4+T lymphocytes

    Institute of Scientific and Technical Information of China (English)

    Xiaoyu Pan; Hanna-Mari Baldauf; Oliver T Keppler; Oliver T Fackler

    2013-01-01

    CD4+ T lymphocytes represent the main target cell population of human immunodeficiency virus (HIV).In an activated state,CD4+ T cells residing in lymphoid organs are a major reservoir of ongoing HIV-1 replication in infected individuals.In contrast,resting CD4+ T cells are highly resistant to productive HIV-1 infection,yet are massively depleted during disease progression and represent a substantial latent reservoir for the virus in vivo.Barriers preventing replication of HIV-1 in resting CD4+ T cells include a rigid layer of cortical actin and,early after HIV-1entry,a block that limits reverse transcription of incoming viral RNA genomes.Defining the molecular bases of these restrictions has remained one of the central open questions in HIV research.Recent advances unraveled mechanisms by which HIV-1 bypasses the entry block and established the host cell restriction factor SAMHD1,a deoxynucleoside triphosphate triphosphohydrolase,as a central determinant of the cellular restriction to HIV-1 reverse transcription in resting CD4+ T cells.This review summarizes our current molecular and pathophysiological understanding of the multi-faceted interactions of HIV-1 with resting CD4+ T lymphocytes.

  3. Natural Plant Alkaloid (Emetine Inhibits HIV-1 Replication by Interfering with Reverse Transcriptase Activity

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    Ana Luiza Chaves Valadão

    2015-06-01

    Full Text Available Ipecac alkaloids are secondary metabolites produced in the medicinal plant Psychotria ipecacuanha. Emetine is the main alkaloid of ipecac and one of the active compounds in syrup of Ipecac with emetic property. Here we evaluated emetine’s potential as an antiviral agent against Human Immunodeficiency Virus. We performed in vitro Reverse Transcriptase (RT Assay and Natural Endogenous Reverse Transcriptase Activity Assay (NERT to evaluate HIV RT inhibition. Emetine molecular docking on HIV-1 RT was also analyzed. Phenotypic assays were performed in non-lymphocytic and in Peripheral Blood Mononuclear Cells (PBMC with HIV-1 wild-type and HIV-harboring RT-resistant mutation to Nucleoside Reverse Transcriptase Inhibitors (M184V. Our results showed that HIV-1 RT was blocked in the presence of emetine in both models: in vitro reactions with isolated HIV-1 RT and intravirion, measured by NERT. Emetine revealed a strong potential of inhibiting HIV-1 replication in both cellular models, reaching 80% of reduction in HIV-1 infection, with low cytotoxic effect. Emetine also blocked HIV-1 infection of RT M184V mutant. These results suggest that emetine is able to penetrate in intact HIV particles, and bind and block reverse transcription reaction, suggesting that it can be used as anti-HIV microbicide. Taken together, our findings provide additional pharmacological information on the potential therapeutic effects of emetine.

  4. Methamphetamine Inhibits HIV-1 Replication in CD4+ T Cells by Modulating Anti–HIV-1 miRNA Expression

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    Mantri, Chinmay K.; Mantri, Jyoti V.; Pandhare, Jui; Dash, Chandravanu

    2014-01-01

    Methamphetamine is the second most frequently used illicit drug in the United States. Methamphetamine abuse is associated with increased risk of HIV-1 acquisition, higher viral loads, and enhanced HIV-1 pathogenesis. Although a direct link between methamphetamine abuse and HIV-1 pathogenesis remains to be established in patients, methamphetamine has been shown to increase HIV-1 replication in macrophages, dendritic cells, and cells of HIV transgenic mice. Intriguingly, the effects of methamph...

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

    OpenAIRE

    Jeang Kuan-Teh; Luban Jeremy; Strebel Klaus

    2009-01-01

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

  6. Digoxin Suppresses HIV-1 Replication by Altering Viral RNA Processing

    OpenAIRE

    Wong, Raymond W; Ahalya Balachandran; Ostrowski, Mario A.; Alan Cochrane

    2013-01-01

    Author Summary Antiretroviral therapies (ART) for HIV/AIDS are successful in slowing disease progression by inhibiting viral proteins. However, the ability of HIV to adapt to ARTs has given rise to drug-resistant virus strains that now represent ≥16% of newly infected people. This development calls for the generation of new treatment strategies. Since HIV is dependent upon RNA processing under control of the host, we searched for compounds/drugs that inhibit HIV-1 replication at this step. We...

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

    International Nuclear Information System (INIS)

    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. - Highlights: ► We studied the role of Nup98 and Nup153 in HIV-1 infection. ► Nup98 binds the HIV-1 core and is involved in HIV-1 integration. ► Nup153 binds the HIV-1 core and is involved in HIV-1 nuclear import. ► Depletion of Nup153 decreased the integration of HIV-1 in transcriptionally active sites

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

    Energy Technology Data Exchange (ETDEWEB)

    Di Nunzio, Francesca, E-mail: francesca.di-nunzio@pasteur.fr [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Fricke, Thomas [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States); Miccio, Annarita [University of Modena e Reggio Emilia, Centro di Medicina Rigenerativa, Modena (Italy); Valle-Casuso, Jose Carlos; Perez, Patricio [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States); Souque, Philippe [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Rizzi, Ermanno; Severgnini, Marco [Institute of Biomedical Technologies, CNR, Milano (Italy); Mavilio, Fulvio [University of Modena e Reggio Emilia, Centro di Medicina Rigenerativa, Modena (Italy); Genethon, Evry (France); Charneau, Pierre [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Diaz-Griffero, Felipe, E-mail: felipe.diaz-griffero@einstein.yu.edu [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States)

    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. - Highlights: ► We studied the role of Nup98 and Nup153 in HIV-1 infection. ► Nup98 binds the HIV-1 core and is involved in HIV-1 integration. ► Nup153 binds the HIV-1 core and is involved in HIV-1 nuclear import. ► Depletion of Nup153 decreased the integration of HIV-1 in transcriptionally active sites.

  9. LEDGINs inhibit late stage HIV-1 replication by modulating integrase multimerization in the virions

    OpenAIRE

    Desimmie, Belete Ayele; Schrijvers, Rik; Demeulemeester, Jonas; Borrenberghs, Doortje; Weydert, Caroline; Thys, Wannes; Vets, Sofie; Van Remoortel, Barbara; Hofkens, Johan; De Rijck, Jan; Hendrix, Jelle; Bannert, Norbert; Gijsbers, Rik; Christ, Frauke; Debyser, Zeger

    2013-01-01

    Background: LEDGINs are novel allosteric HIV integrase (IN) inhibitors that target the lens epithelium-derived growth factor (LEDGF)/p75 binding pocket of IN. They block HIV-1 integration by abrogating the interaction between LEDGF/p75 and IN as well as by allosterically inhibiting the catalytic activity of IN. Results: Here we demonstrate that LEDGINs reduce the replication capacity of HIV particles produced in their presence. We systematically studied the molecular basis of this late...

  10. Ebselen, a Small-Molecule Capsid Inhibitor of HIV-1 Replication.

    Science.gov (United States)

    Thenin-Houssier, Suzie; de Vera, Ian Mitchelle S; Pedro-Rosa, Laura; Brady, Angela; Richard, Audrey; Konnick, Briana; Opp, Silvana; Buffone, Cindy; Fuhrmann, Jakob; Kota, Smitha; Billack, Blase; Pietka-Ottlik, Magdalena; Tellinghuisen, Timothy; Choe, Hyeryun; Spicer, Timothy; Scampavia, Louis; Diaz-Griffero, Felipe; Kojetin, Douglas J; Valente, Susana T

    2016-04-01

    The human immunodeficiency virus type 1 (HIV-1) capsid plays crucial roles in HIV-1 replication and thus represents an excellent drug target. We developed a high-throughput screening method based on a time-resolved fluorescence resonance energy transfer (HTS-TR-FRET) assay, using the C-terminal domain (CTD) of HIV-1 capsid to identify inhibitors of capsid dimerization. This assay was used to screen a library of pharmacologically active compounds, composed of 1,280in vivo-active drugs, and identified ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], an organoselenium compound, as an inhibitor of HIV-1 capsid CTD dimerization. Nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the direct interaction of ebselen with the HIV-1 capsid CTD and dimer dissociation when ebselen is in 2-fold molar excess. Electrospray ionization mass spectrometry revealed that ebselen covalently binds the HIV-1 capsid CTD, likely via a selenylsulfide linkage with Cys198 and Cys218. This compound presents anti-HIV activity in single and multiple rounds of infection in permissive cell lines as well as in primary peripheral blood mononuclear cells. Ebselen inhibits early viral postentry events of the HIV-1 life cycle by impairing the incoming capsid uncoating process. This compound also blocks infection of other retroviruses, such as Moloney murine leukemia virus and simian immunodeficiency virus, but displays no inhibitory activity against hepatitis C and influenza viruses. This study reports the use of TR-FRET screening to successfully identify a novel capsid inhibitor, ebselen, validating HIV-1 capsid as a promising target for drug development. PMID:26810656

  11. Positive Selection of Primate Genes that Promote HIV-1 Replication

    OpenAIRE

    Meyerson, Nicholas R.; Rowley, Paul A.; Swan, Christina H; Le, Dona T.; Wilkerson, Greg K; Sawyer, Sara L

    2014-01-01

    Evolutionary analyses have revealed that most host-encoded restriction factors against HIV-1 have experienced virus-driven selection during primate evolution. However, HIV also depends on the function of many human proteins, called host factors, for its replication. It is not clear whether virus-driven selection shapes the evolution of host factor genes to the extent that it is known to shape restriction factor genes. We show that 5 out of 40 HIV host factor genes (13%) analyzed do bear stron...

  12. Inhibiting Early-Stage Events in HIV-1 Replication by Small-Molecule Targeting of the HIV-1 Capsid

    OpenAIRE

    Kortagere, Sandhya; Madani, Navid; Mankowski, Marie K.; Schön, Arne; Zentner, Isaac; Swaminathan, Gokul; Princiotto, Amy; Anthony, Kevin; Oza, Apara; Sierra, Luz-Jeannette; Passic, Shendra R.; Wang, Xiaozhao; Jones, David M; Stavale, Eric; Fred C. Krebs

    2012-01-01

    The HIV-1 capsid (CA) protein plays essential roles in both early and late stages of virl replication and has emerged as a novel drug target. We report hybrid structure-based virtual screening to identify small molecules with the potential to interact with the N-terminal domain (NTD) of HIV-1 CA and disrupt early, preintegration steps of the HIV-1 replication cycle. The small molecule 4,4′-[dibenzo[b,d]furan-2,8-diylbis(5-phenyl-1H-imidazole-4,2-diyl)]dibenzoic acid (CK026), which had anti-HI...

  13. Inhibiting early-stage events in HIV-1 replication by small-molecule targeting of the HIV-1 capsid.

    Science.gov (United States)

    Kortagere, Sandhya; Madani, Navid; Mankowski, Marie K; Schön, Arne; Zentner, Isaac; Swaminathan, Gokul; Princiotto, Amy; Anthony, Kevin; Oza, Apara; Sierra, Luz-Jeannette; Passic, Shendra R; Wang, Xiaozhao; Jones, David M; Stavale, Eric; Krebs, Fred C; Martín-García, Julio; Freire, Ernesto; Ptak, Roger G; Sodroski, Joseph; Cocklin, Simon; Smith, Amos B

    2012-08-01

    The HIV-1 capsid (CA) protein plays essential roles in both early and late stages of virl replication and has emerged as a novel drug target. We report hybrid structure-based virtual screening to identify small molecules with the potential to interact with the N-terminal domain (NTD) of HIV-1 CA and disrupt early, preintegration steps of the HIV-1 replication cycle. The small molecule 4,4'-[dibenzo[b,d]furan-2,8-diylbis(5-phenyl-1H-imidazole-4,2-diyl)]dibenzoic acid (CK026), which had anti-HIV-1 activity in single- and multiple-round infections but failed to inhibit viral replication in peripheral blood mononuclear cells (PBMCs), was identified. Three analogues of CK026 with reduced size and better drug-like properties were synthesized and assessed. Compound I-XW-053 (4-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid) retained all of the antiviral activity of the parental compound and inhibited the replication of a diverse panel of primary HIV-1 isolates in PBMCs, while displaying no appreciable cytotoxicity. This antiviral activity was specific to HIV-1, as I-XW-053 displayed no effect on the replication of SIV or against a panel of nonretroviruses. Direct interaction of I-XW-053 was quantified with wild-type and mutant CA protein using surface plasmon resonance and isothermal titration calorimetry. Mutation of Ile37 and Arg173, which are required for interaction with compound I-XW-053, crippled the virus at an early, preintegration step. Using quantitative PCR, we demonstrated that treatment with I-XW-053 inhibited HIV-1 reverse transcription in multiple cell types, indirectly pointing to dysfunction in the uncoating process. In summary, we have identified a CA-specific compound that targets and inhibits a novel region in the NTD-NTD interface, affects uncoating, and possesses broad-spectrum anti-HIV-1 activity. PMID:22647699

  14. Toxoplasma gondii inhibits R5 HIV-1 replication in human lymphoid tissues ex vivo

    Science.gov (United States)

    Sassi, Atfa; Brichacek, Beda; Hieny, Sara; Yarovinsky, Felix; Golding, Hana; Grivel, Jean-Charles; Sher, Alan; Margolis, Leonid

    2016-01-01

    Critical events of HIV-1 pathogenesis occur in lymphoid tissues where HIV-1 is typically accompanied by infections with other pathogens (HIV co-pathogens). Co-pathogens greatly affect the clinical course of the disease and the transmission of HIV. The apicomplexan parasite Toxoplasma gondii is a common HIV co-pathogen associated with AIDS development. Here, we examined the interaction of T. gondii and HIV in coinfected human lymphoid tissue ex vivo. Both pathogens readily replicate in ex vivo infected blocks of human tonsillar tissue. Surprisingly, we found that live T. gondii preferentially inhibits R5 HIV-1 replication in coinfected tissues. This effect is reproduced by treatment of the tissue blocks with recombinant C-18, a T. gondii -encoded cyclophilin that binds to CCR5. These ex vivo findings raise the possibility that, in addition to being a co-factor in HIV disease, T. gondii may influence the outcome of viral infection by preferentially suppressing R5 variants. PMID:19671446

  15. Infected Cell Killing by HIV-1 Protease Promotes NF-κB Dependent HIV-1 Replication

    OpenAIRE

    Bren, Gary D.; Joe Whitman; Nathan Cummins; Brett Shepard; Rizza, Stacey A; Trushin, Sergey A.; Badley, Andrew D

    2008-01-01

    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 casp...

  16. Recruitment of a SAP18-HDAC1 complex into HIV-1 virions and its requirement for viral replication.

    Directory of Open Access Journals (Sweden)

    Masha Sorin

    2009-06-01

    Full Text Available HIV-1 integrase (IN is a virally encoded protein required for integration of viral cDNA into host chromosomes. INI1/hSNF5 is a component of the SWI/SNF complex that interacts with HIV-1 IN, is selectively incorporated into HIV-1 (but not other retroviral virions, and modulates multiple steps, including particle production and infectivity. To gain further insight into the role of INI1 in HIV-1 replication, we screened for INI1-interacting proteins using the yeast two-hybrid system. We found that SAP18 (Sin3a associated protein 18 kD, a component of the Sin3a-HDAC1 complex, directly binds to INI1 in yeast, in vitro and in vivo. Interestingly, we found that IN also binds to SAP18 in vitro and in vivo. SAP18 and components of a Sin3A-HDAC1 complex were specifically incorporated into HIV-1 (but not SIV and HTLV-1 virions in an HIV-1 IN-dependent manner. Using a fluorescence-based assay, we found that HIV-1 (but not SIV virion preparations harbour significant deacetylase activity, indicating the specific recruitment of catalytically active HDAC into the virions. To determine the requirement of virion-associated HDAC1 to HIV-1 replication, an inactive, transdominant negative mutant of HDAC1 (HDAC1(H141A was utilized. Incorporation of HDAC1(H141A decreased the virion-associated histone deacetylase activity. Furthermore, incorporation of HDAC1(H141A decreased the infectivity of HIV-1 (but not SIV virions. The block in infectivity due to virion-associated HDAC1(H141A occurred specifically at the early reverse transcription stage, while entry of the virions was unaffected. RNA-interference mediated knock-down of HDAC1 in producer cells resulted in decreased virion-associated HDAC1 activity and a reduction in infectivity of these virions. These studies indicate that HIV-1 IN and INI1/hSNF5 bind SAP18 and selectively recruit components of Sin3a-HDAC1 complex into HIV-1 virions. Furthermore, HIV-1 virion-associated HDAC1 is required for efficient early post

  17. A Symmetric Region of the HIV-1 Integrase Dimerization Interface Is Essential for Viral Replication

    Science.gov (United States)

    Serrao, Erik; Thys, Wannes; Demeulemeester, Jonas; Al-Mawsawi, Laith Q.; Christ, Frauke; Debyser, Zeger; Neamati, Nouri

    2012-01-01

    HIV-1 integrase (IN) is an important target for contemporary antiretroviral drug design research. Historically, efforts at inactivating the enzyme have focused upon blocking its active site. However, it has become apparent that new classes of allosteric inhibitors will be necessary to advance the antiretroviral field in light of the emergence of viral strains resistant to contemporary clinically used IN drugs. In this study we have characterized the importance of a close network of IN residues, distant from the active site, as important for the obligatory multimerization of the enzyme and viral replication as a whole. Specifically, we have determined that the configuration of six residues within a highly symmetrical region at the IN dimerization interface, composed of a four-tiered aromatic interaction flanked by two salt bridges, significantly contributes to proper HIV-1 replication. Additionally, we have utilized a quantitative luminescence assay to examine IN oligomerization and have determined that there is a very low tolerance for amino acid substitutions along this region. Even conservative residue substitutions negatively impacted IN multimerization, resulting in an inactive viral enzyme and a non-replicative virus. We have shown that there is a very low tolerance for amino acid variation at the symmetrical dimeric interface region characterized in this study, and therefore drugs designed to target the amino acid network detailed here could be expected to yield a significantly reduced number of drug-resistant escape mutations compared to contemporary clinically-evaluated antiretrovirals. PMID:23028829

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

    OpenAIRE

    Santiago Guerrero; Julien Batisse; Camille Libre; Serena Bernacchi; Roland Marquet; Jean-Christophe Paillart

    2015-01-01

    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 ta...

  19. TNPO3 is required for HIV-1 replication after nuclear import but prior to integration and binds the HIV-1 core.

    OpenAIRE

    Valle-Casuso, Jose Carlos; Di Nunzio, Francesca; Yang, Yang; Reszka, Natalia; Lienlaf, Maritza; Arhel, Nathalie; Perez, Patricio; Brass, Abraham L.; Diaz-Griffero, Felipe

    2012-01-01

    International audience TNPO3 is a nuclear importer required for HIV-1 infection. Here, we show that depletion of TNPO3 leads to an HIV-1 block after nuclear import but prior to integration. To investigate the mechanistic requirement of TNPO3 in HIV-1 infection, we tested the binding of TNPO3 to the HIV-1 core and found that TNPO3 binds to the HIV-1 core. Overall, this work suggests that TNPO3 interacts with the incoming HIV-1 core in the cytoplasm to assist a process that is important for ...

  20. Inhibitory effect of aqueous dandelion extract on HIV-1 replication and reverse transcriptase activity

    Directory of Open Access Journals (Sweden)

    Han Huamin

    2011-11-01

    Full Text Available Abstract Background Acquired immunodeficiency syndrome (AIDS, which is caused by the human immunodeficiency virus (HIV, is an immunosuppressive disease that results in life-threatening opportunistic infections. The general problems in current therapy include the constant emergence of drug-resistant HIV strains, adverse side effects and the unavailability of treatments in developing countries. Natural products from herbs with the abilities to inhibit HIV-1 life cycle at different stages, have served as excellent sources of new anti-HIV-1 drugs. In this study, we aimed to investigate the anti-HIV-1 activity of aqueous dandelion extract. Methods The pseudotyped HIV-1 virus has been utilized to explore the anti-HIV-1 activity of dandelion, the level of HIV-1 replication was assessed by the percentage of GFP-positive cells. The inhibitory effect of the dandelion extract on reverse transcriptase activity was assessed by the reverse transcriptase assay kit. Results Compared to control values obtained from cells infected without treatment, the level of HIV-1 replication and reverse transcriptase activity were decreased in a dose-dependent manner. The data suggest that dandelion extract has a potent inhibitory activity against HIV-1 replication and reverse transcriptase activity. The identification of HIV-1 antiviral compounds from Taraxacum officinale should be pursued. Conclusions The dandelion extract showed strong activity against HIV-1 RT and inhibited both the HIV-1 vector and the hybrid-MoMuLV/MoMuSV retrovirus replication. These findings provide additional support for the potential therapeutic efficacy of Taraxacum officinale. Extracts from this plant may be regarded as another starting point for the development of an antiretroviral therapy with fewer side effects.

  1. Phosphodiesterase 8a Supports HIV-1 Replication in Macrophages at the Level of Reverse Transcription

    Science.gov (United States)

    Booiman, Thijs; Cobos Jiménez, Viviana; van Dort, Karel A.; van 't Wout, Angélique B.; Kootstra, Neeltje A.

    2014-01-01

    Background HIV-1 infected macrophages play a key role in HIV-1 infection. Even during anti-retroviral treatment, macrophages keep producing virus due to suboptimal tissue penetration and reduced efficacy of antiretrovirals. It is therefore of major importance to understand which host factors are involved in HIV-1 replication in macrophages. Previously, we have shown that genetic polymorphisms in phosphodiesterase 8a (PDE8A) are strongly associated with HIV-1 replication in these cells. Here we analyzed the mechanism and regulation of PDE8A in HIV-1 replication in macrophages. Results PDE8A mRNA expression strongly increases upon differentiation of monocytes into macrophages, which corresponds to the increased susceptibility of mature macrophages to HIV-1. In parallel, expression of microRNA miR-145-5p, predicted to target PDE8A mRNA, strongly decreased. The interaction of miR-145-5p with the 3′ UTR of PDE8A mRNA could be experimentally validated, suggesting that indeed miR-145-5p can regulate PDE8A expression levels. Knockdown of PDE8A in macrophages resulted in a decrease in total HIV-1 replication and proviral DNA levels. These observations confirm that PDE8A regulates HIV-1 replication in macrophages and that this effect is mediated through early steps in the viral replication cycle. Conclusions PDE8A is highly expressed in macrophages, and its expression is regulated by miR-145-5p. Our findings strongly suggest that PDE8A supports HIV-1 replication in macrophages and that this effect is mediated at the level of reverse transcription. PMID:25295610

  2. Slower Uncoating Is Associated with Impaired Replicative Capability of Simian-Tropic HIV-1

    OpenAIRE

    Kono, Ken; Takeda, Eri; Tsutsui, Hiromi; Kuroishi, Ayumu; Hulme, Amy E.; Hope, Thomas J.; Nakayama, Emi E.; Shioda, Tatsuo

    2013-01-01

    Human immunodeficiency virus type 1 (HIV-1) productively infects only humans and chimpanzees, but not Old World monkeys, such as rhesus and cynomolgus (CM) monkeys. To establish a monkey model of HIV-1/AIDS, several HIV-1 derivatives have been constructed. We previously generated a simian-tropic HIV-1 that replicates efficiently in CM cells. This virus encodes a capsid protein (CA) with SIVmac239-derived loops between α-helices 4 and 5 (L4/5) and between α-helices 6 and 7 (L6/7), along with t...

  3. HIV-1 Induced Nuclear Factor I-B (NF-IB Expression Negatively Regulates HIV-1 Replication through Interaction with the Long Terminal Repeat Region

    Directory of Open Access Journals (Sweden)

    Sai Vikram Vemula

    2015-02-01

    Full Text Available Background: Retroviruses rely on host factors for cell entry, replication, transcription, and other major steps during their life cycle. Human Immunodeficiency Virus-1 (HIV-1 is well known for utilizing a plethora of strategies to evade the host immune response, including the establishment of latent infection within a subpopulation of susceptible cells. HIV-1 also manipulates cellular factors in latently infected cells and persists for long periods of time, despite the presence of successful highly active antiretroviral therapy (HAART. Results: In this study we demonstrate that Nuclear Factor-IB (NF-IB is induced during HIV-1 infection and its expression negatively impacts viral replication. During HIV-1 infection in peripheral blood mononuclear cells (PBMCs, and the T cell line, Jurkat or during induction of virus replication in latently infected cells, ACH2 and J1.1, we observed a time-dependent alteration in NF-IB expression pattern that correlated with HIV-1 viral expression. Using the Chip assay, we observed an association of NF-IB with the long terminal repeat region of HIV-1 (LTR (-386 to -453 nt, and this association negatively correlated with HIV-1 transcription. Furthermore, knock-down of NF-IB levels in J1.1 cells resulted in an increase of HIV-1 levels. Knock-down of NF-IB levels in J-Lat-Tat-GFP (A1, (a Jurkat cell GFP reporter model for latent HIV-1 infection resulted in an increase in GFP levels, indicating a potential negative regulatory role of NF-IB in HIV-1 replication. Conclusion: Overall, our results suggest that NF-IB may play a role in intrinsic antiretroviral defenses against HIV-1. These observations may offer new insights into the correlation of the latently infected host cell types and HIV-1, and help to define new therapeutic approaches for triggering the switch from latency to active replication thereby eliminating HIV-1 latent infection.

  4. Efficient Gene Transfer Mediated by HIV-1-based Defective Lentivector and Inhibition of HIV-1 Replication

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Lentiviral vectors have drawn considerable attention recently and show great promise to become important delivery vehicles for future gene transfer manipulation. In the present study we have optimized a protocol for preparation of human immunodeficiency virus type-1 (HIV-1)-based defective lentiviral vectors (DLV) and characterized these vectors in terms of their transduction of different cells. Transient co-transfection of 293T packaging cells with DNA plasmids encoding lentiviral vector constituents resulted in production of high-titer DLV (0.5-1.2 × 107IU/mL), which can be further concentrated over 100-fold through a single step ultracentrifugation. These vectors were capable of transducing a variety of cells from both primate and non-primate sources and high transduction efficiency was achieved using concentrated vectors. Assessment of potential generation of RCV revealed no detection of infection by infectious particles in DLV-transduced CEM, SupT-1 and MT-2 cells. Long-term culture of transduced cells showed a stable expression of transgenes without apparent alteration in cellular morphology and growth kinetics. Vector mobilization to untransduced cells mediated by wild-type HIV-1 infection was confirmed in this test. Challenge of transduced human T-lymphocytes with wild-type HIV-1 showed these cells are totally resistant to the viral infection. Considering the effective gene transfer and stable gene expression, safety and anti-HIV activity, these DLV vectors warrant further exploration for their potential use as a gene transfer vehicle in the development of gene therapy protocols.

  5. Nuclear localization of Vpr is crucial for the efficient replication of HIV-1 in primary CD4+ T cells

    International Nuclear Information System (INIS)

    The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpr appears to make a substantial contribution to the replication of HIV-1 in established T cell lines when HIV-1 is present at very low multiplicities of infection. However, the role of Vpr in viral replication in primary CD4+ T cells remains to be clarified. In this study, we generated a panel of viruses that encoded mutant forms of Vpr that lacked either the ability to accumulate in the nucleus and induce G2 arrest or the ability to induce apoptosis, which has been shown to occur independently of G2 arrest of the cell cycle. We demonstrate here that the nuclear localization of Vpr and consequent G2 arrest but not the induction of apoptosis by Vpr are important for viral replication in primary CD4+ T cells at both high and low multiplicities of infection. Viruses that encoded mutant forms of Vpr that failed to be imported into the nucleus in the presence of cytoplasmic extracts from primary CD4+ T cells in an in vitro nuclear import assay replicated at drastically reduced rates. Thus, Vpr might be a key regulator of the viral nuclear import process during infection in primary CD4+ T cells. By contrast, a mutant form of Vpr that exhibited diffuse cytosolic staining exclusively in an immunofluorescence assay of HeLa cells and was not imported into nucleus by the cytosol from HeLa cells was effectively imported into the nucleus by cytosol from primary CD4+ T cells. This Vpr mutant virus replicated well in primary CD4+ T cells, indicating that cellular factors in primary CD4+ T cells are indispensable for the accumulation of Vpr in the nucleus and, thus, for viral replication. Our results suggest that the nuclear import of Vpr might be a good target in efforts to block the early stages of replication of HIV-1

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

    Directory of Open Access Journals (Sweden)

    Giacaman Rodrigo A

    2008-07-01

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

  7. Discovery of Novel Small-Molecule HIV-1 Replication Inhibitors That Stabilize Capsid Complexes

    Science.gov (United States)

    Titolo, Steve; Lemke, Christopher T.; Goudreau, Nathalie; Mercier, Jean-François; Wardrop, Elizabeth; Shah, Vaibhav B.; von Schwedler, Uta K.; Langelier, Charles; Banik, Soma S. R.; Aiken, Christopher; Sundquist, Wesley I.

    2013-01-01

    The identification of novel antiretroviral agents is required to provide alternative treatment options for HIV-1-infected patients. The screening of a phenotypic cell-based viral replication assay led to the identification of a novel class of 4,5-dihydro-1H-pyrrolo[3,4-c]pyrazol-6-one (pyrrolopyrazolone) HIV-1 inhibitors, exemplified by two compounds: BI-1 and BI-2. These compounds inhibited early postentry stages of viral replication at a step(s) following reverse transcription but prior to 2 long terminal repeat (2-LTR) circle formation, suggesting that they may block nuclear targeting of the preintegration complex. Selection of viruses resistant to BI-2 revealed that substitutions at residues A105 and T107 within the capsid (CA) amino-terminal domain (CANTD) conferred high-level resistance to both compounds, implicating CA as the antiviral target. Direct binding of BI-1 and/or BI-2 to CANTD was demonstrated using isothermal titration calorimetry and nuclear magnetic resonance (NMR) chemical shift titration analyses. A high-resolution crystal structure of the BI-1:CANTD complex revealed that the inhibitor bound within a recently identified inhibitor binding pocket (CANTD site 2) between CA helices 4, 5, and 7, on the surface of the CANTD, that also corresponds to the binding site for the host factor CPSF-6. The functional consequences of BI-1 and BI-2 binding differ from previously characterized inhibitors that bind the same site since the BI compounds did not inhibit reverse transcription but stabilized preassembled CA complexes. Hence, this new class of antiviral compounds binds CA and may inhibit viral replication by stabilizing the viral capsid. PMID:23817385

  8. Stimulation of HIV-1 Replication in Immature Dendritic Cells in Contact with Primary CD4 T or B Lymphocytes

    OpenAIRE

    Holl, V.; Xu, K.; Peressin, M.; Lederle, A.; Biedma, M. E.; Delaporte, M.; Decoville, T.; Schmidt, S.; Laumond, G.; Aubertin, A. M.; Moog, C

    2010-01-01

    Sexual transmission is the major route of HIV-1 infection worldwide. Dendritic cells (DCs) from the mucosal layers are considered to be the initial targets of HIV-1 and probably play a crucial role in HIV-1 transmission. We investigated the role of cell-to-cell contact between HIV-1-exposed immature DCs and various lymphocyte subsets in the stimulation of HIV-1 replication. We found that HIV-1 replication and production in DCs were substantially enhanced by the coculture of DCs with primary C...

  9. Cocaine Enhances HIV-1 Replication in CD4+ T Cells by Down-Regulating MiR-125b

    OpenAIRE

    Mantri, Chinmay K.; Jui Pandhare Dash; Jyoti Velamarti Mantri; Dash, Chandravanu C. V.

    2012-01-01

    The main objective of this study was to examine effects of cocaine on HIV-1 replication in primary CD4+ T cells. Cocaine a commonly used drug among HIV-1 positive individuals serves as a cofactor for HIV-1 infection and progression to acquired immunodeficiency syndrome (AIDS). Accumulating evidence suggest that cocaine increases HIV-1 replication in cell cultures, peripheral blood mononuclear cells (PBMCs) and animal models. Intriguingly, there are no studies on cocaine-induced alterations in...

  10. Ring finger protein 39 genetic variants associate with HIV-1 plasma viral loads and its replication in cell culture

    OpenAIRE

    Lin, Ying-Ju; Chen, Chia-Yen; Jeang, Kuan-Teh; Liu, Xiang; Wang, Jen-Hsien; Hung, Chien-Hui; Tsang, Hsinyi; Lin, Ting-Hsu; Liao, Chiu-Chu; Huang, Shao-Mei; Lin, Cheng-Wen; Ho, Mao-Wang; Chien, Wen-Kuei; Chen, Jin-Hua; Ho, Tsung-Jung

    2014-01-01

    Background The human immunodeficiency virus (HIV-1) exploits host proteins to complete its life cycle. Genome-wide siRNA approaches suggested that host proteins affect HIV-1 replication. However, the results barely overlapped. RING finger protein 39 (RNF39) has been identified from genome-wide association studies. However, its function during HIV-1 replication remains unclear. Methods and results We investigated the relationship between common RNF39 genetic variants and HIV-1 viral loads. The...

  11. Characterization of Virus host-interactions that regulate HIV-1 replication

    OpenAIRE

    Votteler, Jörg

    2009-01-01

    Retroviruses like the human immunodeficiency virus type 1 (HIV-1) are obligate cellular parasites that depend on host cell factors for their replication. The aim of this study was to characterize two specific cases of these numerous virus-host interactions. First, the previously identified interaction between the cellular peptidyl-prolyl cis/trans isomerase cyclophilin A (CypA) and the HIV-1 accessory protein Vpr was investigated on the molecular level. HIV-1 Vpr induces G2 cell-cycle arrest ...

  12. CRISPR-Cas9 Can Inhibit HIV-1 Replication but NHEJ Repair Facilitates Virus Escape

    OpenAIRE

    Wang, Gang; Zhao, Na; Berkhout, Ben; Das, Atze T.

    2016-01-01

    Several recent studies demonstrated that the clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 can be used for guide RNA (gRNA)-directed, sequence-specific cleavage of HIV proviral DNA in infected cells. We here demonstrate profound inhibition of HIV-1 replication by harnessing T cells with Cas9 and antiviral gRNAs. However, the virus rapidly and consistently escaped from this inhibition. Sequencing of the HIV-1 escape variants revealed nucleotide...

  13. Stem-loop binding protein is a multifaceted cellular regulator of HIV-1 replication.

    Science.gov (United States)

    Li, Ming; Tucker, Lynne D; Asara, John M; Cheruiyot, Collins K; Lu, Huafei; Wu, Zhijin J; Newstein, Michael C; Dooner, Mark S; Friedman, Jennifer; Lally, Michelle A; Ramratnam, Bharat

    2016-08-01

    A rare subset of HIV-1-infected individuals is able to maintain plasma viral load (VL) at low levels without antiretroviral treatment. Identifying the mechanisms underlying this atypical response to infection may lead to therapeutic advances for treating HIV-1. Here, we developed a proteomic analysis to compare peripheral blood cell proteomes in 20 HIV-1-infected individuals who maintained either high or low VL with the aim of identifying host factors that impact HIV-1 replication. We determined that the levels of multiple histone proteins were markedly decreased in cohorts of individuals with high VL. This reduction was correlated with lower levels of stem-loop binding protein (SLBP), which is known to control histone metabolism. Depletion of cellular SLBP increased promoter engagement with the chromatin structures of the host gene high mobility group protein A1 (HMGA1) and viral long terminal repeat (LTR), which led to higher levels of HIV-1 genomic integration and proviral transcription. Further, we determined that TNF-α regulates expression of SLBP and observed that plasma TNF-α levels in HIV-1-infected individuals correlated directly with VL levels and inversely with cellular SLBP levels. Our findings identify SLBP as a potentially important cellular regulator of HIV-1, thereby establishing a link between histone metabolism, inflammation, and HIV-1 infection. PMID:27454292

  14. Discordance between Frequency of Human Immunodeficiency Virus Type 1 (HIV-1)-Specific Gamma Interferon-Producing CD4+ T Cells and HIV-1-Specific Lymphoproliferation in HIV-1-Infected Subjects with Active Viral Replication

    OpenAIRE

    Palmer, B. E.; Boritz, E; Blyveis, N.; Wilson, C C

    2002-01-01

    One hallmark of uncontrolled, chronic human immunodeficiency virus type 1 (HIV-1) infection is the absence of strong HIV-1-specific, CD4+ T-cell-proliferative responses, yet the mechanism underlying this T helper (Th)-cell defect remains controversial. To better understand the impact of HIV-1 replication on Th-cell function, we compared the frequency of CD4+ Th-cell responses based on production of gamma interferon to lymphoproliferative responses directed against HIV-1 proteins in HIV-1-infe...

  15. HIV-1-encoded antisense RNA suppresses viral replication for a prolonged period

    Directory of Open Access Journals (Sweden)

    Kobayashi-Ishihara Mie

    2012-05-01

    Full Text Available Abstract Background Recent evidence proposes a novel concept that mammalian natural antisense RNAs play important roles in cellular homeostasis by regulating the expression of several genes. Identification and characterization of retroviral antisense RNA would provide new insights into mechanisms of replication and pathogenesis. HIV-1 encoded-antisense RNAs have been reported, although their structures and functions remain to be studied. We have tried to identify and characterize antisense RNAs of HIV-1 and their function in viral infection. Results Characterization of transcripts of HEK293T cells that were transiently transfected with an expression plasmid with HIV-1NL4–3 DNA in the antisense orientation showed that various antisense transcripts can be expressed. By screening and characterizing antisense RNAs in HIV-1NL4–3-infected cells, we defined the primary structure of a major form of HIV-1 antisense RNAs, which corresponds to a variant of previously reported ASP mRNA. This 2.6 kb RNA was transcribed from the U3 region of the 3′ LTR and terminated at the env region in acutely or chronically infected cell lines and acutely infected human peripheral blood mononuclear cells. Reporter assays clearly demonstrated that the HIV-1 LTR harbours promoter activity in the reverse orientation. Mutation analyses suggested the involvement of NF-κΒ binding sites in the regulation of antisense transcription. The antisense RNA was localized in the nuclei of the infected cells. The expression of this antisense RNA suppressed HIV-1 replication for more than one month. Furthermore, the specific knockdown of this antisense RNA enhanced HIV-1 gene expression and replication. Conclusions The results of the present study identified an accurate structure of the major form of antisense RNAs expressed from the HIV-1NL4–3 provirus and demonstrated its nuclear localization. Functional studies collectively demonstrated a new role of the antisense RNA in viral

  16. Abasic phosphorothioate oligomers inhibit HIV-1 reverse transcription and block virus transmission across polarized ectocervical organ cultures.

    Science.gov (United States)

    Fraietta, Joseph A; Mueller, Yvonne M; Lozenski, Karissa L; Ratner, Deena; Boesteanu, Alina C; Hancock, Aidan S; Lackman-Smith, Carol; Zentner, Isaac J; Chaiken, Irwin M; Chung, Suhman; LeGrice, Stuart F J; Snyder, Beth A; Mankowski, Marie K; Jones, Natalie M; Hope, Jennifer L; Gupta, Phalguni; Anderson, Sharon H; Wigdahl, Brian; Katsikis, Peter D

    2014-12-01

    In the absence of universally available antiretroviral (ARV) drugs or a vaccine against HIV-1, microbicides may offer the most immediate hope for controlling the AIDS pandemic. The most advanced and clinically effective microbicides are based on ARV agents that interfere with the earliest stages of HIV-1 replication. Our objective was to identify and characterize novel ARV-like inhibitors, as well as demonstrate their efficacy at blocking HIV-1 transmission. Abasic phosphorothioate 2' deoxyribose backbone (PDB) oligomers were evaluated in a variety of mechanistic assays and for their ability to inhibit HIV-1 infection and virus transmission through primary human cervical mucosa. Cellular and biochemical assays were used to elucidate the antiviral mechanisms of action of PDB oligomers against both lab-adapted and primary CCR5- and CXCR4-utilizing HIV-1 strains, including a multidrug-resistant isolate. A polarized cervical organ culture was used to test the ability of PDB compounds to block HIV-1 transmission to primary immune cell populations across ectocervical tissue. The antiviral activity and mechanisms of action of PDB-based compounds were dependent on oligomer size, with smaller molecules preventing reverse transcription and larger oligomers blocking viral entry. Importantly, irrespective of molecular size, PDBs potently inhibited virus infection and transmission within genital tissue samples. Furthermore, the PDB inhibitors exhibited excellent toxicity and stability profiles and were found to be safe for vaginal application in vivo. These results, coupled with the previously reported intrinsic anti-inflammatory properties of PDBs, support further investigations in the development of PDB-based topical microbicides for preventing the global spread of HIV-1. PMID:25224013

  17. Role of RNA helicases in HIV-1 replication

    OpenAIRE

    Jeang, Kuan-Teh; Yedavalli, Venkat

    2006-01-01

    Viruses are replication competent genomes which are relatively gene-poor. Even the largest viruses (i.e. Herpesviruses) encode only slightly >200 open reading frames (ORFs). However, because viruses replicate obligatorily inside cells, and considering that evolution may be driven by a principle of economy of scale, it is reasonable to surmise that many viruses have evolved the ability to co-opt cell-encoded proteins to provide needed surrogate functions. An in silico survey of viral sequence ...

  18. Discovery of Novel Small-Molecule HIV-1 Replication Inhibitors That Stabilize Capsid Complexes

    OpenAIRE

    Lamorte, Louie; Titolo, Steve; Lemke, Christopher T.; Goudreau, Nathalie; Mercier, Jean-François; Wardrop, Elizabeth; Shah, Vaibhav B.; von Schwedler, Uta K.; Langelier, Charles; Banik, Soma S. R.; Aiken, Christopher; Sundquist, Wesley I.; Mason, Stephen W.

    2013-01-01

    The identification of novel antiretroviral agents is required to provide alternative treatment options for HIV-1-infected patients. The screening of a phenotypic cell-based viral replication assay led to the identification of a novel class of 4,5-dihydro-1H-pyrrolo[3,4-c]pyrazol-6-one (pyrrolopyrazolone) HIV-1 inhibitors, exemplified by two compounds: BI-1 and BI-2. These compounds inhibited early postentry stages of viral replication at a step(s) following reverse transcription but prior to ...

  19. Evaluation of the effect of pyrimethamine, an anti-malarial drug, on HIV-1 replication

    OpenAIRE

    Oguariri, Raphael M.; Joseph W Adelsberger; Michael W Baseler; Imamichi, Tomozumi

    2010-01-01

    Co-infection of human immunodeficiency virus (HIV) with malaria is one of the pandemic problems in Africa and parts of Asia. Here we investigated the impact of PYR and two other clinical anti-malarial drugs (chloroquine [CQ] or artemisinin [ART]) on HIV-1 replication. Peripheral blood mononuclear cells (PBMCs) or MT-2 cells were infected with HIVNL4.3 strain and treated with different concentrations of the anti-malarial drugs. HIV-1 replication was measured using p24 ELISA. We show that 10 μM...

  20. A post-entry role for CD63 in early HIV-1 replication

    International Nuclear Information System (INIS)

    Macrophages and CD4+ lymphocytes are the major reservoirs for HIV-1 infection. CD63 is a tetraspanin transmembrane protein, which has been shown to play an essential role during HIV-1 replication in macrophages. In this study, we further confirm the requirement of CD63 in early HIV-1 replication events in both macrophages and a CD4+ cell line. Further analysis revealed that viral attachment and cell-cell fusion were unaffected by CD63 silencing. However, CD63-depleted macrophages showed a significant decrease in the initiation and completion of HIV-1 reverse transcription, affecting subsequent events of the HIV-1 life cycle. Integration of HIV-1 cDNA as well as the formation of 2-LTR circles was notably reduced. Reporter assays showed that CD63 down regulation reduced production of the early HIV protein Tat. In agreement, CD63 silencing also inhibited production of the late protein p24. These findings suggest that CD63 plays an early post-entry role prior to or at the reverse transcription step.

  1. Inhibition of HIV-1 replication in human monocyte-derived macrophages by parasite Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Guadalupe Andreani

    Full Text Available BACKGROUND: Cells of monocyte/macrophage lineage are one of the major targets of HIV-1 infection and serve as reservoirs for viral persistence in vivo. These cells are also the target of the protozoa Trypanosoma cruzi, the causative agent of Chagas disease, being one of the most important endemic protozoonoses in Latin America. It has been demonstrated in vitro that co-infection with other pathogens can modulate HIV replication. However, no studies at cellular level have suggested an interaction between T. cruzi and HIV-1 to date. METHODOLOGY/PRINCIPAL FINDINGS: By using a fully replicative wild-type virus, our study showed that T. cruzi inhibits HIV-1 antigen production by nearly 100% (p99% being stronger than HIV-T. cruzi (approximately 90% for BaL and approximately 85% for VSV-G infection. In MDM with established HIV-1 infection, T. cruzi significantly inhibited luciferate activity (p<0.01. By quantifying R-U5 and U5-gag transcripts by real time PCR, our study showed the expression of both transcripts significantly diminished in the presence of trypomastigotes (p<0.05. Thus, T. cruzi inhibits viral post-integration steps, early post-entry steps and entry into MDM. Trypomastigotes also caused a approximately 60-70% decrease of surface CCR5 expression on MDM. Multiplication of T. cruzi inside the MDM does not seem to be required for inhibiting HIV-1 replication since soluble factors secreted by trypomastigotes have shown similar effects. Moreover, the major parasite antigen cruzipain, which is secreted by the trypomastigote form, was able to inhibit viral production in MDM over 90% (p<0.01. CONCLUSIONS/SIGNIFICANCE: Our study showed that T. cruzi inhibits HIV-1 replication at several replication stages in macrophages, a major cell target for both pathogens.

  2. Modeling HIV-1 Latency in Primary T Cells Using a Replication-Competent Virus.

    Science.gov (United States)

    Martins, Laura J; Bonczkowski, Pawel; Spivak, Adam M; De Spiegelaere, Ward; Novis, Camille L; DePaula-Silva, Ana Beatriz; Malatinkova, Eva; Typsteen, Wim; Bosque, Alberto; Vanderkerckhove, Linos; Planelles, Vicente

    2016-02-01

    HIV-1 latently infected cells in vivo can be found in extremely low frequencies. Therefore, in vitro cell culture models have been used extensively for the study of HIV-1 latency. Often, these in vitro systems utilize defective viruses. Defective viruses allow for synchronized infections and circumvent the use of antiretrovirals. In addition, replication-defective viruses cause minimal cytopathicity because they fail to spread and usually do not encode env or accessory genes. On the other hand, replication-competent viruses encode all or most viral genes and better recapitulate the nuances of the viral replication cycle. The study of latency with replication-competent viruses requires the use of antiretroviral drugs in culture, and this mirrors the use of antiretroviral treatment (ART) in vivo. We describe a model that utilizes cultured central memory CD4(+) T cells and replication-competent HIV-1. This method generates latently infected cells that can be reactivated using latency reversing agents in the presence of antiretroviral drugs. We also describe a method for the removal of productively infected cells prior to viral reactivation, which takes advantage of the downregulation of CD4 by HIV-1, and the use of a GFP-encoding virus for increased throughput. PMID:26171776

  3. Modeling HIV-1 intracellular replication: two simulation approaches

    NARCIS (Netherlands)

    N. Zarrabi; E. Mancini; J. Tay; S. Shahand; P.M.A. Sloot

    2010-01-01

    Many mathematical and computational models have been developed to investigate the complexity of HIV dynamics, immune response and drug therapy. However, there are not many models which consider the dynamics of virus intracellular replication at a single level. We propose a model of HIV intracellular

  4. HIV-1 Nef Dimerization is required for Nef-Mediated Receptor Downregulation and Viral Replication

    OpenAIRE

    Poe, Jerrod A.; Smithgall, Thomas E

    2009-01-01

    Nef, an HIV-1 accessory factor capable of interaction with a diverse array of host cell signaling molecules, is essential for high-titer HIV replication and AIDS progression. Previous biochemical and structural studies have suggested that Nef may form homodimers and higher order oligomers in HIV-infected cells, which may be required for both immune and viral receptor downregulation as well as viral replication. Using bimolecular fluorescence complementation (BiFC), we provide the first direct...

  5. The Impact of Macrophage Nucleotide Pools on HIV-1 Reverse Transcription, Viral Replication, and the Development of Novel Antiviral Agents

    OpenAIRE

    Christina Gavegnano; Kennedy, Edward M.; Baek Kim; Schinazi, Raymond F.

    2012-01-01

    Macrophages are ubiquitous and represent a significant viral reservoir for HIV-1. Macrophages are nondividing, terminally differentiated cells, which have a unique cellular microenvironment relative to actively dividing T lymphocytes, all of which can impact HIV-1 infection/replication, design of inhibitors targeting viral replication in these cells, emergence of mutations within the HIV-1 genome, and disease progression. Scarce dNTPs drive rNTP incorporation into the proviral DNA in macropha...

  6. The local environment orchestrates mucosal decidual macrophage differentiation and substantially inhibits HIV-1 replication.

    Science.gov (United States)

    El Costa, H; Quillay, H; Marlin, R; Cannou, C; Duriez, M; Benjelloun, F; de Truchis, C; Rahmati, M; Ighil, J; Barré-Sinoussi, F; Nugeyre, M T; Menu, E

    2016-05-01

    Macrophages from the decidua basalis (dM), the main uterine mucosa during pregnancy, are weakly permissive to HIV-1 infection. Here, we investigated the mechanisms underlying this natural control. We show, by using freshly purified decidual macrophages and ex vivo human decidual explants, that the local decidual environment influences dM differentiation and naturally protects these cells from HIV-1 infection. Interferon (IFN)-γ, present in the decidual tissue, contributes to maintenance of the dM phenotype and restricts HIV-1 infection by mechanisms involving the cyclin-dependent kinase inhibitor p21Cip1/Waf1. We also found that activation of Toll-like receptors 7 and 8 expressed by dM reinforces the low permissivity of dM to HIV-1 by restricting viral replication and inducing secretion of cytokines in the decidual environment, including IFN-γ, that shape dM plasticity. A major challenge for HIV-1 eradication is to control infection of tissue-resident macrophages in the female reproductive tract. Our findings provide clues to the development of novel strategies to prevent HIV-1 macrophage infection. PMID:26349662

  7. 3-Phenylcoumarins as Inhibitors of HIV-1 Replication

    Directory of Open Access Journals (Sweden)

    José Alcamí

    2012-08-01

    Full Text Available We have synthesized fourteen 3-phenylcoumarin derivatives and evaluated their anti-HIV activity. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase gene as reporter. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein. Six compounds displayed NF-κB inhibition, four resulted Tat antagonists and three of them showed both activities. Three compounds inhibited HIV replication with IC50 values < 25 µM. The antiviral effect of the 4-hydroxycoumarin derivative 19 correlates with its specific inhibition of Tat functions, while compound 8, 3-(2-chlorophenylcoumarin, seems to act through a mechanism unrelated to the molecular targets considered in this research.

  8. HIV-1 Induced Nuclear Factor I-B (NF-IB) Expression Negatively Regulates HIV-1 Replication through Interaction with the Long Terminal Repeat Region

    OpenAIRE

    Sai Vikram Vemula; Ravichandran Veerasamy; Viswanath Ragupathy; Santanu Biswas; Krishnakumar Devadas; Indira Hewlett

    2015-01-01

    Background: Retroviruses rely on host factors for cell entry, replication, transcription, and other major steps during their life cycle. Human Immunodeficiency Virus-1 (HIV-1) is well known for utilizing a plethora of strategies to evade the host immune response, including the establishment of latent infection within a subpopulation of susceptible cells. HIV-1 also manipulates cellular factors in latently infected cells and persists for long periods of time, despite the presence of successful...

  9. Slower uncoating is associated with impaired replicative capability of simian-tropic HIV-1.

    Science.gov (United States)

    Kono, Ken; Takeda, Eri; Tsutsui, Hiromi; Kuroishi, Ayumu; Hulme, Amy E; Hope, Thomas J; Nakayama, Emi E; Shioda, Tatsuo

    2013-01-01

    Human immunodeficiency virus type 1 (HIV-1) productively infects only humans and chimpanzees, but not Old World monkeys, such as rhesus and cynomolgus (CM) monkeys. To establish a monkey model of HIV-1/AIDS, several HIV-1 derivatives have been constructed. We previously generated a simian-tropic HIV-1 that replicates efficiently in CM cells. This virus encodes a capsid protein (CA) with SIVmac239-derived loops between α-helices 4 and 5 (L4/5) and between α-helices 6 and 7 (L6/7), along with the entire vif from SIVmac239 (NL-4/5S6/7SvifS). These SIVmac239-derived sequences were expected to protect the virus from HIV-1 restriction factors in monkey cells. However, the replicative capability of NL-4/5S6/7SvifS in human cells was severely impaired. By long-term cultivation of human CEM-SS cells infected with NL-4/5S6/7SvifS, we succeeded in partially rescuing the impaired replicative capability of the virus in human cells. This adapted virus encoded a G-to-E substitution at the 116(th) position of the CA (NL-4/5SG116E6/7SvifS). In the work described here, we explored the mechanism by which the replicative capability of NL-4/5S6/7SvifS was impaired in human cells. Quantitative analysis (by real-time PCR) of viral DNA synthesis from infected cells revealed that NL-4/5S6/7SvifS had a major defect in nuclear entry. Mutations in CA are known to affect viral core stability and result in deleterious effects in HIV-1 infection; therefore, we measured the kinetics of uncoating of these viruses. The uncoating of NL-4/5S6/7SvifS was significantly slower than that of wild type HIV-1 (WT), whereas the uncoating of NL-4/5SG116E6/7SvifS was similar to that of WT. Our results suggested that the lower replicative capability of NL-4/5S6/7SvifS in human cells was, at least in part, due to the slower uncoating of this virus. PMID:23967315

  10. Early low-titer neutralizing antibodies impede HIV-1 replication and select for virus escape.

    Directory of Open Access Journals (Sweden)

    Katharine J Bar

    Full Text Available Single genome sequencing of early HIV-1 genomes provides a sensitive, dynamic assessment of virus evolution and insight into the earliest anti-viral immune responses in vivo. By using this approach, together with deep sequencing, site-directed mutagenesis, antibody adsorptions and virus-entry assays, we found evidence in three subjects of neutralizing antibody (Nab responses as early as 2 weeks post-seroconversion, with Nab titers as low as 1∶20 to 1∶50 (IC(50 selecting for virus escape. In each of the subjects, Nabs targeted different regions of the HIV-1 envelope (Env in a strain-specific, conformationally sensitive manner. In subject CH40, virus escape was first mediated by mutations in the V1 region of the Env, followed by V3. HIV-1 specific monoclonal antibodies from this subject mapped to an immunodominant region at the base of V3 and exhibited neutralizing patterns indistinguishable from polyclonal antibody responses, indicating V1-V3 interactions within the Env trimer. In subject CH77, escape mutations mapped to the V2 region of Env, several of which selected for alterations of glycosylation. And in subject CH58, escape mutations mapped to the Env outer domain. In all three subjects, initial Nab recognition was followed by sequential rounds of virus escape and Nab elicitation, with Nab escape variants exhibiting variable costs to replication fitness. Although delayed in comparison with autologous CD8 T-cell responses, our findings show that Nabs appear earlier in HIV-1 infection than previously recognized, target diverse sites on HIV-1 Env, and impede virus replication at surprisingly low titers. The unexpected in vivo sensitivity of early transmitted/founder virus to Nabs raises the possibility that similarly low concentrations of vaccine-induced Nabs could impair virus acquisition in natural HIV-1 transmission, where the risk of infection is low and the number of viruses responsible for transmission and productive clinical

  11. Retroviral restriction factors TRIM5α: therapeutic strategy to inhibit HIV-1 replication.

    Science.gov (United States)

    Zhang, Jing; Ge, Weiying; Zhan, Peng; De Clercq, Erik; Liu, Xinyong

    2011-01-01

    Tripartite motif protein 5-alpha (TRIM5α) is a cytoplasmic protein that efficiently recognizes the incoming capsid (CA) protein of retroviruses and potently inhibits virus infection in a species-specific manner. Through directly recognizing and interacting with HIV CA, TRIM5α is capable of disrupting the ordered process of viral uncoating, eventually interfering with HIV-1 reverse transcription and virus replication. TRIM5α protein contains four domains: RING domain, B-box 2 domain, coiled-coil domain, and B30.2 domain (SPRY) domain. All of the domains are necessary for efficient retrovirus restriction and the B30.2 domain has been shown to be the determinant of the specificity of restriction. Species-specific innate resistance against viral infections offers novel avenues for antiviral therapeutics. Various mutants of TRIM5α have been described which differently affect the HIV-1 reverse transcription process. This makes the establishment of new and improved models for HIV replication and AIDS pathogenesis by monitoring endogenous TRIM5α an attractive approach. TRIM5α-mediated restriction is modulated by the host protein Cyclophilin A (Cyp A) which could effectively interact with the CA of HIV-1. Here we will review the structure and roles of TRIM5α protein, the interaction between Cyp A and TRIM5α, as well as gene therapy strategies associated with TRIM5α to inhibit HIV-1 infection. PMID:21568899

  12. HIV-1 clade promoters strongly influence spatial and temporal dynamics of viral replication in vivo

    Science.gov (United States)

    Centlivre, Mireille; Sommer, Peter; Michel, Marie; Fang, Raphaël Ho Tsong; Gofflo, Sandrine; Valladeau, Jenny; Schmitt, Nathalie; Thierry, Françoise; Hurtrel, Bruno; Wain-Hobson, Simon; Sala, Monica

    2005-01-01

    Although the primary determinant of cell tropism is the interaction of viral envelope or capsid proteins with cellular receptors, other viral elements can strongly modulate viral replication. While the HIV-1 promoter is polymorphic for a variety of transcription factor binding sites, the impact of these polymorphisms on viral replication in vivo is not known. To address this issue, we engineered isogenic SIVmac239 chimeras harboring the core promoter/enhancer from HIV-1 clades B, C, and E. Here it is shown that the clade C and E core promoters/enhancers bear a noncanonical activator protein–1 (AP-1) binding site, absent from the corresponding clade B region. Relative ex vivo replication of chimeras was strongly dependent on the tissue culture system used. Notably, in thymic histocultures, replication of the clade C chimera was favored by IL-7 enrichment, which suggests that the clade C polymorphism in the AP-1 and NF-κB binding sites is involved. Simultaneous infection of rhesus macaques with the 3 chimeras revealed a strong predominance of the clade C chimera during primary infection. Thereafter, the B chimera dominated in all tissues. These data show that the clade C promoter is particularly adapted to sustain viral replication in primary viremia and that clade-specific promoter polymorphisms constitute a major determinant for viral replication. PMID:15690084

  13. HIV-1 Vpr increases HCV replication through VprBP in cell culture.

    Science.gov (United States)

    Yan, Yanling; Huang, Fang; Yuan, Ting; Sun, Binlian; Yang, Rongge

    2016-09-01

    Coinfection of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) occurs at a high frequency, in which HIV shows a promotion of HCV-derived liver diseases. However, the mechanism of how this occurs is not well understood. Our previous work has demonstrated that the HIV-1 accessory protein Vpr enhances HCV RNA replication in cell culture. Because Vpr performs most of its functions through host protein VprBP (DCAF1), the role of VprBP in the regulation of HCV by Vpr was investigated in this study. We found that the Vpr mutant Q65R, which is deficient in VprBP binding, could not enhance HCV replication. Furthermore, Vpr-mediated enhancement of HCV replication was severely diminished in VprBP knockdown cells. In addition, an inhibitor of Cullin RING E3 ligases, MLN4924, impaired the function of Vpr during HCV replication. Together, these results suggest that Vpr promotes HCV replication in a VprBP-dependent manner, and that the activity of Cullin RING E3 ligases is essential to this process. In conclusion, our findings demonstrate that HIV-1 Vpr makes the cellular environment more suitable for HCV replication, which might relate with the host ubiquitination system. PMID:27460548

  14. APOBEC3G restricts early HIV-1 replication in the cytoplasm of target cells

    International Nuclear Information System (INIS)

    Cellular APOBEC3G (A3G) protein is packaged into human immunodeficiency virus type 1 (HIV-1) virions in producer cells yet restricts viral replication in target cells. To characterize this restriction in target cells, the effect of A3G on generating various HIV-1 cDNA products was measured by quantitative real-time PCR. A3G decreased cDNA products from Vif-deficient HIV-1, with minor effects on early reverse transcripts and larger declines in late reverse transcripts. However, the greatest decline was typically observed in nuclear 2-LTR circles. Moreover, the magnitude of these declines varied with A3G dose. Adding integration inhibitor did not stop the A3G-mediated loss in 2-LTR circles. Moreover, obstructing HIV-1 nuclear entry using vesicular stomatitis virus matrix protein did not stop the A3G-mediated decline in late reverse transcripts. Collectively, these data suggest that A3G has important restriction activity in the cytoplasm and progressively diminishes viral cytoplasmic and nuclear cDNA forms with increasing magnitude during restriction

  15. 宿主细胞对HIV-1复制的限制性%The host restriction factors targeted HIV-1 replication

    Institute of Scientific and Technical Information of China (English)

    贾彦辉; 徐庆刚

    2013-01-01

    HIV-1感染的主要靶细胞是宿主的CD4+T淋巴细胞,使宿主的免疫机能下降.在HIV-1与宿主的长期进化中,它们之间逐渐形成了复杂的入侵与反入侵关系.人类已经进化出多种机制来抵制HIV-1的感染和复制.宿主细胞内的限制性因子是抑制HIV-1复制的主要机制之一,也是研究人员比较关注的一类机制.SAMHD1作为最新发现的一个限制性因子,成为一个研究热点.通过阐述SAMHD1,APOBEC3G/F,TRIM5α及Tetherin在HIV-1复制中的关键作用,了解宿主细胞对病毒感染的限制性,有助于理解宿主与病毒之间的抗衡关系,宿主抗病毒机制,为治疗HIV-1寻找新的靶点.%The CD4 + T cells are the most important targeted cells of HIV-1 infection leading to immunity dysfunction.A long history of human infection by HIV-1 has resulted in complicated relationship between human and HIV-1.Among the many mechanisms to inhibit HIV-1 infection and replication in human,the host restriction factors are an attentive mechanism.Recently,researchers pay much attention to SAMHD1 which is a new discovered restriction factor.This review mainly discussed the effect of SAMHD1,APOBEC3G/ F,TRIM5α and Tetherin on HIV-1 life cycle.Description of HIV-1 restriction in host cells helps us to understand viral pathogenesis and searching for a new antiviral strategy.

  16. Cocaine enhances HIV-1 replication in CD4+ T cells by down-regulating MiR-125b.

    Directory of Open Access Journals (Sweden)

    Chinmay K Mantri

    Full Text Available The main objective of this study was to examine effects of cocaine on HIV-1 replication in primary CD4+ T cells. Cocaine a commonly used drug among HIV-1 positive individuals serves as a cofactor for HIV-1 infection and progression to acquired immunodeficiency syndrome (AIDS. Accumulating evidence suggest that cocaine increases HIV-1 replication in cell cultures, peripheral blood mononuclear cells (PBMCs and animal models. Intriguingly, there are no studies on cocaine-induced alterations in HIV-1 replication in primary CD4+ T cells that serve as the main targets for HIV-1 replication in vivo. In this report, we demonstrate cocaine-induced enhancement of HIV-1 replication in primary CD4+ T cells isolated from human PBMCs. To decipher a potential mechanism, we examined whether cocaine targets the innate antiviral immunity of CD4+ T cells mediated by cellular microRNAs (miRNAs. This is because recently a network of anti-HIV miRNAs in CD4+ T cells is highlighted to suppress viral replication. Our genome wide miRNA expression analysis indicated downregulation of several anti-HIV miRNAs (miR-28, miR-125b, miR-150, miR-223, and miR-382 in cocaine treated CD4+ T cells. However, our real-time quantitative PCR analysis revealed significant downregulation of miR-125b only. Our results illustrated that miR-125b knockdown enhances HIV-1 replication, whereas overexpression of miR-125b decreases HIV-1 replication in these cells. Therefore, we believe miR-125b is a key player for the cocaine induced enhancement of HIV-1 replication in CD4+ T cells. Since, miR-125b targets the 3' UTR regions of HIV-1 transcripts and inhibits viral protein translation, our data suggest modulation of post entry steps of HIV-1 by cocaine. Given that a plethora of studies suggest that cocaine regulates HIV entry, our results implicate a potentially novel mechanism by which cocaine can increase viral replication in CD4+ T cells.

  17. Plasmacytoid Dendritic Cells Suppress HIV-1 Replication but Contribute to HIV-1 Induced Immunopathogenesis in Humanized Mice

    OpenAIRE

    Guangming Li; Menglan Cheng; Jun-Ichi Nunoya; Liang Cheng; Haitao Guo; Haisheng Yu; Yong-Jun Liu; Lishan Su; Liguo Zhang

    2014-01-01

    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 de...

  18. Deletions in the fifth alpha helix of HIV-1 matrix block virus release

    International Nuclear Information System (INIS)

    The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release

  19. Deletions in the fifth alpha helix of HIV-1 matrix block virus release

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, Bridget; Li, Yan; Maly, Connor J.; Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Chen, Han [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Zhou, You [Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE (United States); Nebraska Center for Virology, Lincoln, NE (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Nebraska Center for Virology, Lincoln, NE (United States)

    2014-11-15

    The matrix (MA) protein of HIV-1 is the N-terminal component of the Gag structural protein and is critical for the early and late stages of viral replication. MA contains five α-helices (α1–α5). Deletions in the N-terminus of α5 as small as three amino acids impaired virus release. Electron microscopy of one deletion mutant (MA∆96-120) showed that its particles were tethered to the surface of cells by membranous stalks. Immunoblots indicated all mutants were processed completely, but mutants with large deletions had alternative processing intermediates. Consistent with the EM data, MA∆96-120 retained membrane association and multimerization capability. Co-expression of this mutant inhibited wild type particle release. Alanine scanning mutation in this region did not affect virus release, although the progeny virions were poorly infectious. Combined, these data demonstrate that structural ablation of the α5 of MA inhibits virus release. - Highlights: • Deletions were identified in the C-terminus of matrix that block virus release. • These deletion mutants still multimerized and associated with membranes. • TEM showed the mutant particles were tethered to the cell surface. • Amino acid mutagenesis of the region did not affect release. • The data suggests that disruption of matrix structure blocks virus release.

  20. CRISPR/Cas9-Derived Mutations Both Inhibit HIV-1 Replication and Accelerate Viral Escape

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2016-04-01

    Full Text Available Cas9 cleaves specific DNA sequences with the assistance of a programmable single guide RNA (sgRNA. Repairing this broken DNA by the cell’s error-prone non-homologous end joining (NHEJ machinery leads to insertions and deletions (indels that often impair DNA function. Using HIV-1, we have now demonstrated that many of these indels are indeed lethal for the virus, but that others lead to the emergence of replication competent viruses that are resistant to Cas9/sgRNA. This unexpected contribution of Cas9 to the development of viral resistance is facilitated by some indels that are not deleterious for viral replication, but that are refractory to recognition by the same sgRNA as a result of changing the target DNA sequences. This observation illustrates two opposite outcomes of Cas9/sgRNA action, i.e., inactivation of HIV-1 and acceleration of viral escape, thereby potentially limiting the use of Cas9/sgRNA in HIV-1 therapy.

  1. HIV-1 Nef control of cell signalling molecules: multiple strategies to promote virus replication

    Indian Academy of Sciences (India)

    Alison L Greenway; Gavan Holloway; Dale A McPhee; Phoebe Ellis; Alyssa Cornall; Michael Lidman

    2003-04-01

    HIV-1 has at its disposal numerous proteins encoded by its genome which provide the required arsenal to establish and maintain infection in its host for a considerable number of years. One of the most important and enigmatic of these proteins is Nef. The Nef protein of HIV-1 plays a fundamental role in the virus life cycle. This small protein of approximately 27 kDa is required for maximal virus replication and disease progression. The mechanisms by which it is able to act as a positive factor during virus replication is an area of intense research and although some controversy surrounds Nef much has been gauged as to how it functions. Its ability to modulate the expression of key cellular receptors important for cell activation and control signal transduction elements and events by interacting with numerous cellular kinases and signalling molecules, including members of the Src family kinases, leading to an effect on host cell function is likely to explain at least in part its role during infection and represents a finely tuned mechanism where this protein assists HIV-1 to control its host.

  2. CRISPR-Cas9 Can Inhibit HIV-1 Replication but NHEJ Repair Facilitates Virus Escape

    Science.gov (United States)

    Wang, Gang; Zhao, Na; Berkhout, Ben; Das, Atze T

    2016-01-01

    Several recent studies demonstrated that the clustered regularly interspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 can be used for guide RNA (gRNA)-directed, sequence-specific cleavage of HIV proviral DNA in infected cells. We here demonstrate profound inhibition of HIV-1 replication by harnessing T cells with Cas9 and antiviral gRNAs. However, the virus rapidly and consistently escaped from this inhibition. Sequencing of the HIV-1 escape variants revealed nucleotide insertions, deletions, and substitutions around the Cas9/gRNA cleavage site that are typical for DNA repair by the nonhomologous end-joining pathway. We thus demonstrate the potency of CRISPR-Cas9 as an antiviral approach, but any therapeutic strategy should consider the viral escape implications. PMID:26796669

  3. Human Immunodeficiency Virus Type 1 (HIV-1)-Induced GRO-α Production Stimulates HIV-1 Replication in Macrophages and T Lymphocytes

    OpenAIRE

    Lane, Brian R.; Strieter, Robert M; Coffey, Michael J.; Markovitz, David M.

    2001-01-01

    We examined the early effects of infection by CCR5-using (R5 human immunodeficiency virus [HIV]) and CXCR4-using (X4 HIV) strains of HIV type 1 (HIV-1) on chemokine production by primary human monocyte-derived macrophages (MDM). While R5 HIV, but not X4 HIV, replicated in MDM, we found that the production of the C-X-C chemokine growth-regulated oncogene alpha (GRO-α) was markedly stimulated by X4 HIV and, to a much lesser extent, by R5 HIV. HIV-1 gp120 engagement of CXCR4 initiated the stimul...

  4. Effects of root, shoot, leaf and seed extracts of seven Artemisia species on HIV-1 replication and CD4 expression

    Directory of Open Access Journals (Sweden)

    Hassan Mohabatkar

    2015-12-01

    Full Text Available Objective: To investigate the effects of flower, leaf, shoot and root extracts of seven Artemisia species on peripheral blood mononuclear cells (PBMCs toxicity and HIV-1 replication. Methods: The studied Artemisia species were Artemisia absinthium, Artemisia khorasanica, Artemisia deserti, Artemisia fragrans, Artemisia aucheri, Artemisia sieberi and Artemisia vulgaris. The activity of these plant extracts on HIV-1 replication and CD4 expression was performed by HIV-1 p24 antigen kit and flow cytometry respectively. Results: The results demonstrated that flower extracts of all species increased PBMCs number more than shoot, leaf and root extracts. However, the frequency of CD4 expression in PBMC was not increased in the presence of all flower extracts. The flower extracts of all species had inhibitory effect on HIV-1 replication. Conclusions: In conclusion, the results demonstrated that flower extracts of Artemisia species are good candidates for further studies as anticancer agents.

  5. LEDGF/p75-independent HIV-1 replication demonstrates a role for HRP-2 and remains sensitive to inhibition by LEDGINs.

    Directory of Open Access Journals (Sweden)

    Rik Schrijvers

    Full Text Available Lens epithelium-derived growth factor (LEDGF/p75 is a cellular cofactor of HIV-1 integrase (IN that interacts with IN through its IN binding domain (IBD and tethers the viral pre-integration complex to the host cell chromatin. Here we report the generation of a human somatic LEDGF/p75 knockout cell line that allows the study of spreading HIV-1 infection in the absence of LEDGF/p75. By homologous recombination the exons encoding the LEDGF/p75 IBD (exons 11 to 14 were knocked out. In the absence of LEDGF/p75 replication of laboratory HIV-1 strains was severely delayed while clinical HIV-1 isolates were replication-defective. The residual replication was predominantly mediated by the Hepatoma-derived growth factor related protein 2 (HRP-2, the only cellular protein besides LEDGF/p75 that contains an IBD. Importantly, the recently described IN-LEDGF/p75 inhibitors (LEDGINs remained active even in the absence of LEDGF/p75 by blocking the interaction with the IBD of HRP-2. These results further support the potential of LEDGINs as allosteric integrase inhibitors.

  6. LEDGF/p75-Independent HIV-1 Replication Demonstrates a Role for HRP-2 and Remains Sensitive to Inhibition by LEDGINs

    Science.gov (United States)

    Schrijvers, Rik; De Rijck, Jan; Demeulemeester, Jonas; Adachi, Noritaka; Vets, Sofie; Ronen, Keshet; Christ, Frauke; Bushman, Frederic D.; Debyser, Zeger; Gijsbers, Rik

    2012-01-01

    Lens epithelium–derived growth factor (LEDGF/p75) is a cellular cofactor of HIV-1 integrase (IN) that interacts with IN through its IN binding domain (IBD) and tethers the viral pre-integration complex to the host cell chromatin. Here we report the generation of a human somatic LEDGF/p75 knockout cell line that allows the study of spreading HIV-1 infection in the absence of LEDGF/p75. By homologous recombination the exons encoding the LEDGF/p75 IBD (exons 11 to 14) were knocked out. In the absence of LEDGF/p75 replication of laboratory HIV-1 strains was severely delayed while clinical HIV-1 isolates were replication-defective. The residual replication was predominantly mediated by the Hepatoma-derived growth factor related protein 2 (HRP-2), the only cellular protein besides LEDGF/p75 that contains an IBD. Importantly, the recently described IN-LEDGF/p75 inhibitors (LEDGINs) remained active even in the absence of LEDGF/p75 by blocking the interaction with the IBD of HRP-2. These results further support the potential of LEDGINs as allosteric integrase inhibitors. PMID:22396646

  7. Inhibition of HIV Replication by Cyclic and Hairpin PNAs Targeting the HIV-1 TAR RNA Loop

    Directory of Open Access Journals (Sweden)

    Gregory Upert

    2012-01-01

    Full Text Available Human immunodeficiency virus-1 (HIV-1 replication and gene expression entails specific interaction of the viral protein Tat with its transactivation responsive element (TAR, to form a highly stable stem-bulge-loop structure. Previously, we described triphenylphosphonium (TPP cation-based vectors that efficiently deliver nucleotide analogs (PNAs into the cytoplasm of cells. In particular, we showed that the TPP conjugate of a linear 16-mer PNA targeting the apical stem-loop region of TAR impedes Tat-mediated transactivation of the HIV-1 LTR in vitro and also in cell culture systems. In this communication, we conjugated TPP to cyclic and hairpin PNAs targeting the loop region of HIV-1 TAR and evaluated their antiviral efficacy in a cell culture system. We found that TPP-cyclic PNAs containing only 8 residues, showed higher antiviral potency compared to hairpin PNAs of 12 or 16 residues. We further noted that the TPP-conjugates of the 8-mer cyclic PNA as well as the 16-mer linear PNA displayed similar antiviral efficacy. However, cyclic PNAs were shown to be highly specific to their target sequences. This communication emphasizes on the importance of small constrained cyclic PNAs over both linear and hairpin structures for targeting biologically relevant RNA hairpins.

  8. Trypanosoma cruzi (Chagas' disease agent reduces HIV-1 replication in human placenta

    Directory of Open Access Journals (Sweden)

    Cappa Stella

    2008-07-01

    Full Text Available Abstract Background Several factors determine the risk of HIV mother-to-child transmission (MTCT, such as coinfections in placentas from HIV-1 positive mothers with other pathogens. Chagas' disease is one of the most endemic zoonoses in Latin America, caused by the protozoan Trypanosoma cruzi. The purpose of the study was to determine whether T. cruzi modifies HIV infection of the placenta at the tissue or cellular level. Results Simple and double infections were carried out on a placental histoculture system (chorionic villi isolated from term placentas from HIV and Chagas negative mothers and on the choriocarcinoma BeWo cell line. Trypomastigotes of T. cruzi (VD lethal strain, either purified from mouse blood or from Vero cell cultures, 24 h-supernatants of blood and cellular trypomastigotes, and the VSV-G pseudotyped HIV-1 reporter virus were used for the coinfections. Viral transduction was evaluated by quantification of luciferase activity. Coinfection with whole trypomastigotes, either from mouse blood or from cell cultures, decreased viral pseudotype luciferase activity in placental histocultures. Similar results were obtained from BeWo cells. Supernatants of stimulated histocultures were used for the simultaneous determination of 29 cytokines and chemokines with the Luminex technology. In histocultures infected with trypomastigotes, as well as in coinfected tissues, IL-6, IL-8, IP-10 and MCP-1 production was significantly lower than in controls or HIV-1 transducted tissue. A similar decrease was observed in histocultures treated with 24 h-supernatants of blood trypomastigotes, but not in coinfected tissues. Conclusion Our results demonstrated that the presence of an intracellular pathogen, such as T. cruzi, is able to impair HIV-1 transduction in an in vitro system of human placental histoculture. Direct effects of the parasite on cellular structures as well as on cellular/viral proteins essential for HIV-1 replication might influence

  9. Primary T-cells from human CD4/CCR5-transgenic rats support all early steps of HIV-1 replication including integration, but display impaired viral gene expression

    Directory of Open Access Journals (Sweden)

    Hermann Volker

    2007-07-01

    Full Text Available Abstract Background In vivo studies on HIV-1 pathogenesis and testing of antiviral strategies have been hampered by the lack of an immunocompetent small animal model that is highly susceptible to HIV-1 infection. Since native rodents are non-permissive, we developed transgenic rats that selectively express the HIV-1 receptor complex, hCD4 and hCCR5, on relevant target cells. These animals display a transient low-level plasma viremia after HIV-1YU-2 infection, demonstrating HIV-1 susceptibility in vivo. However, unlike macrophages, primary CD4 T-cells from double-transgenic animals fail to support viral spread ex vivo. To identify quantitative limitations or absolute blocks in this rodent species, we quantitatively assessed the efficiency of key steps in the early phase of the viral replication cycle in a side-by-side comparison in infected cell lines and primary T-cells from hCD4/hCCR5-transgenic rats and human donors. Results Levels of virus entry, HIV-1 cDNA synthesis, nuclear import, and integration into the host genome were shown to be remarkably similar in cell lines and, where technically accessible, in primary T-cells from both species. In contrast, a profound impairment at the level of early HIV gene expression was disclosed at the single-cell level in primary rat T-cells and most other rat-derived cells. Macrophages were a notable exception, possibly reflecting the unique transcriptional milieu in this evolutionarily conserved target cell of all lentiviruses. Importantly, transient trans-complementation by ex vivo nucleofection with the Tat-interacting protein Cyclin T1 of human origin markedly elevated HIV gene expression in primary rat T-cells. Conclusion This is the first study that has quantitatively determined the efficiency of consecutive steps in the HIV-1 replication cycle in infected primary HIV target cells from a candidate transgenic small animal and compared it to human cells. Unlike cells derived from mice or rabbits, rat

  10. The cellular TAR RNA binding protein, TRBP, promotes HIV-1 replication primarily by inhibiting the activation of double-stranded RNA-dependent kinase PKR.

    Science.gov (United States)

    Sanghvi, Viraj R; Steel, Laura F

    2011-12-01

    The TAR RNA binding protein, TRBP, is a cellular double-stranded RNA (dsRNA) binding protein that can promote the replication of HIV-1 through interactions with the viral TAR element as well as with cellular proteins that affect the efficiency of translation of viral transcripts. The structured TAR element, present on all viral transcripts, can impede efficient translation either by sterically blocking access of translation initiation factors to the 5'-cap or by activating the dsRNA-dependent kinase, PKR. Several mechanisms by which TRBP can facilitate translation of viral transcripts have been proposed, including the binding and unwinding of TAR and the suppression of PKR activation. Further, TRBP has been identified as a cofactor of Dicer in the processing of microRNAs (miRNAs), and sequestration of TRBP by TAR in infected cells has been proposed as a viral countermeasure to potential host cell RNA interference-based antiviral activities. Here, we have addressed the relative importance of these various roles for TRBP in HIV-1 replication. Using Jurkat T cells, primary human CD4(+) T cells, and additional cultured cell lines, we show that depletion of TRBP has no effect on viral replication when PKR activation is otherwise blocked. Moreover, the presence of TAR-containing mRNAs does not affect the efficacy of cellular miRNA silencing pathways. These results establish that TRBP, when expressed at physiological levels, promotes HIV-1 replication mainly by suppressing the PKR-mediated antiviral response, while its contribution to HIV-1 replication through PKR-independent pathways is minimal. PMID:21937648

  11. Inhibition of HIV-1 integrase nuclear import and replication by a peptide bearing integrase putative nuclear localization signal

    Directory of Open Access Journals (Sweden)

    Waigmann Elisabeth

    2009-12-01

    Full Text Available Abstract Background The integrase (IN of human immunodeficiency virus type 1 (HIV-1 has been implicated in different steps during viral replication, including nuclear import of the viral pre-integration complex. The exact mechanisms underlying the nuclear import of IN and especially the question of whether it bears a functional nuclear localization signal (NLS remain controversial. Results Here, we studied the nuclear import pathway of IN by using multiple in vivo and in vitro systems. Nuclear import was not observed in an importin α temperature-sensitive yeast mutant, indicating an importin α-mediated process. Direct interaction between the full-length IN and importin α was demonstrated in vivo using bimolecular fluorescence complementation assay (BiFC. Nuclear import studies in yeast cells, with permeabilized mammalian cells, or microinjected cultured mammalian cells strongly suggest that the IN bears a NLS domain located between residues 161 and 173. A peptide bearing this sequence -NLS-IN peptide- inhibited nuclear accumulation of IN in transfected cell-cycle arrested cells. Integration of viral cDNA as well as HIV-1 replication in viral cell-cycle arrested infected cells were blocked by the NLS-IN peptide. Conclusion Our present findings support the view that nuclear import of IN occurs via the importin α pathway and is promoted by a specific NLS domain. This import could be blocked by NLS-IN peptide, resulting in inhibition of viral infection, confirming the view that nuclear import of the viral pre-integration complex is mediated by viral IN.

  12. The role of Vif oligomerization and RNA chaperone activity in HIV-1 replication.

    Science.gov (United States)

    Batisse, Julien; Guerrero, Santiago; Bernacchi, Serena; Sleiman, Dona; Gabus, Caroline; Darlix, Jean-Luc; Marquet, Roland; Tisné, Carine; Paillart, Jean-Christophe

    2012-11-01

    The viral infectivity factor (Vif) is essential for the productive infection and dissemination of HIV-1 in non-permissive cells that involve most natural HIV-1 target cells. Vif counteracts the packaging of two cellular cytidine deaminases named APOBEC3G (A3G) and A3F by diverse mechanisms including the recruitment of an E3 ubiquitin ligase complex and the proteasomal degradation of A3G/A3F, the inhibition of A3G mRNA translation or by a direct competition mechanism. In addition, Vif appears to be an active partner of the late steps of viral replication by participating in virus assembly and Gag processing, thus regulating the final stage of virion formation notably genomic RNA dimerization and by inhibiting the initiation of reverse transcription. Vif is a small pleiotropic protein with multiple domains, and recent studies highlighted the importance of Vif conformation and flexibility in counteracting A3G and in binding RNA. In this review, we will focus on the oligomerization and RNA chaperone properties of Vif and show that the intrinsic disordered nature of some Vif domains could play an important role in virus assembly and replication. Experimental evidence demonstrating the RNA chaperone activity of Vif will be presented. PMID:22728817

  13. A study of the topoisomerase II activity in HIV-1 replication using the ferrocene derivatives as probes.

    Science.gov (United States)

    Kondapi, Anand K; Satyanarayana, Nathamu; Saikrishna, A D

    2006-06-15

    Human Topoisomerase II is present in two isoforms, 170KDa alpha and 180KDa beta. Both the isoforms play a crucial role in maintenance of topological changes during DNA replication and recombination. It has been shown that Topoisomerase II activity is required for HIV-1 replication and the enzyme is phosphorylated during early time points of HIV-1 replication. In the present study, we have studied the molecular action of Topoisomerase II inhibitors, azalactone ferrocene (AzaFecp), Thiomorpholide amido methyl ferrocene (ThioFecp), and Ruthenium benzene amino pyridine (Ru(ben)Apy) on cell proliferation and also on various events of HIV-1 replication cycle. The Topoisomerase II beta over-expressing neuroblastoma cell line shows a higher sensitivity to these compounds compared to the Sup-T1 cell line. All the three Topoisomerase II inhibitors show significant anti-HIV activity at nanomolar concentrations against an Indian isolate of HIV-1(93IN101) in Sup-T1 cell line. An analysis of action of these compounds on proviral DNA synthesis at 5h of post-infection shows that they inhibit proviral DNA synthesis as well as the formation of pre-integration complexes completely. Further analysis, using polymerase chain reaction and western blot, showed that both the Topoisomerase II alpha and beta isoforms are present in the pre-integration complexes, suggesting their significant role in HIV-1 replication. PMID:16712776

  14. Protease inhibitors effectively block cell-to-cell spread of HIV-1 between T cells

    OpenAIRE

    Titanji, Boghuma; Aasa-Chapman, Marlen; Pillay, Deenan; Jolly, Clare

    2013-01-01

    Background; The Human Immunodeficiency Virus type-1 (HIV-1) spreads by cell-free diffusion and by direct cell-to-cell transfer, the latter being a significantly more efficient mode of transmission. Recently it has been suggested that cell-to-cell spread may permit ongoing virus replication in the presence of antiretroviral therapy (ART) based on studies performed using Reverse Transcriptase Inhibitors (RTIs). Protease Inhibitors (PIs) constitute an important component of ART; however whether ...

  15. 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...

  16. Replication and drug resistant mutation of HIV-1 subtype B' (Thailand B variants isolated from HAART treatment individuals in China

    Directory of Open Access Journals (Sweden)

    Yuan Lin

    2009-11-01

    Full Text Available Abstract Background Drug resistant HIV-1 variants were emergent more and more in AIDS individuals with highly active antiretroviral therapy (HAART treatment. Understanding the replication and drug resistant mutation of HIV-1 variants isolated from HAART treatment individuals of China could help to design appropriate therapeutic strategies for these individuals. Methods Use GHOST cell lines to analysis the coreceptor usage of HIV-1 variants. Coculture with PBMCs to analysis the replication capacity. Use RT-PCR to analysis the drug resistant mutation of pol gene. Results 13 HIV-1 variants experienced HAART were included in this study. 5 HIV-1 variants used CCR5 coreceptor (R5, while 8 use both CCR5 and CXCR4 coreceptor (R5X4. The replication capacity of R5X4 variants was no difference with R5 variants in vitro without antiretroviral drugs. Compare the drug resistant mutation between first HIV-1 variants and fourth variants; there were 37 drug resistant mutations in first variants and 32 drug resistant mutations in fourth variants. Only 7 drug resistance mutations were lost after coculture for 4 weeks, and 2 drug resistance mutations were emerged. Conclusion These data suggested that the drug resistant level could not reduce in vitro in absence of antiretroviral drugs in few weeks. And maybe helpful for these HAART experienced individuals when change antiretroviral drugs.

  17. Relief of preintegration inhibition and characterization of additional blocks for HIV replication in primary mouse T cells.

    Directory of Open Access Journals (Sweden)

    Jing-xin Zhang

    Full Text Available Development of a small animal model to study HIV replication and pathogenesis has been hampered by the failure of the virus to replicate in non-primate cells. Most studies aimed at achieving replication in murine cells have been limited to fibroblast cell lines, but generating an appropriate model requires overcoming blocks to viral replication in primary T cells. We have studied HIV-1 replication in CD4(+ T cells from human CD4/CCR5/Cyclin T1 transgenic mice. Expression of hCD4 and hCCR5 in mouse CD4(+ T cells enabled efficient entry of R5 strain HIV-1. In mouse T cells, HIV-1 underwent reverse transcription and nuclear import as efficiently as in human T cells. In contrast, chromosomal integration of HIV-1 proviral DNA was inefficient in activated mouse T cells. This process was greatly enhanced by providing a secondary T cell receptor (TCR signal after HIV-1 infection, especially between 12 to 24 h post infection. This effect was specific for primary mouse T cells. The pathways involved in HIV replication appear to be PKCtheta-, CARMA1-, and WASp-independent. Treatment with Cyclosporin A (CsA further relieved the pre-integration block. However, transcription of HIV-1 RNA was still reduced in mouse CD4(+ T cells despite expression of the hCyclin T1 transgene. Additional post-transcriptional defects were observed at the levels of Gag expression, Gag processing, Gag release and virus infectivity. Together, these post-integration defects resulted in a dramatically reduced yield of infectious virus (300-500 fold after a single cycle of HIV-1 replication. This study implies the existence of host factors, in addition to those already identified, that are critical for HIV-1 replication in mouse cells. This study also highlights the differences between primary T cells and cell lines regarding pre-integration steps in the HIV-1 replication cycle.

  18. Cellular specificity of HIV-1 replication can be controlled by LTR sequences

    International Nuclear Information System (INIS)

    Two well-established determinants of retroviral tropism are envelope sequences that regulate entry and LTR sequences that can regulate viral expression in a cell-specific manner. Studies with human immunodeficiency virus-1 (HIV-1) have demonstrated that tropism of this virus maps primarily to variable envelope sequences. Studies have demonstrated that T cell and macrophage-specific transcription factor binding motifs exist in the upstream region of the LTR U3; however, the ability of the core enhancer/promoter proximal elements (two NF-κB and three Sp1 sites) to function well in macrophages and T cells have led many to conclude that HIV LTR sequences are not primary determinants of HIV tropism. To determine if cellular specificity could be imparted to HIV by the core enhancer elements, the enhancer/promoter proximal region of the HIV LTR was substituted with motifs that control gene expression in a myeloid-specific manner. The enhancer region from equine infectious anemia virus (EIAV) when substituted for the HIV enhancer/promoter proximal region was found to drive expression in a macrophage-specific manner and was responsive to HIV Tat. The addition of a 5' methylation-dependent binding site (MDBP) and a promoter proximal Sp1 motif increased expression without altering cellular specificity. Spacing between the promoter proximal region and the TATA box was also found to influence LTR activity. Infectivity studies using chimeric LTRs within the context of a dual-tropic infectious molecular clone established that these LTRs directed HIV replication and production of infectious virions in macrophages but not primary T cells or T cell lines. This investigation demonstrates that cellular specificity can be imparted onto HIV-1 replication at the level of viral transcription and not entry

  19. Effect of morphine on replication of HIV-1 in MT-2 cells%吗啡对HIV-1在MT2细胞内复制影响

    Institute of Scientific and Technical Information of China (English)

    梁冰玉; 庄道民; 蒋俊俊; 刘思扬; 苏齐鉴; 李敬云; 梁浩

    2011-01-01

    with HIV-1 on the 3rd,4th,5th,and 6th day,the expressions of HTV-1 p24 antigen in 10-12mol/L,10-10mol/L and 10-8mol/L concentration of morphine treatment group were increased significantly compared to those of the control(P 0. 05 for all). When MT-2 cells infected with HIV-1 on the 3rd,4th,5th,and 6th,the p24 antigen expressions were enhanced remarkably with significant difference among different concentration morphine treatment groups ( P < 0. 05). There were significant differences for different infection time in the p24 antigen expressions of three concentration of morphine treatment groups( P <0. 05) ,with an increase trend with the duration HIV-1 infection. Conclusion Morphine has the ability to enhance HIV-1 replication in MT-2 cell and the enhancement increases with the duration of HIV-1 infection. The morphine-mediated increase of HIV-1 p24 antigen expression could be blocked by the opiate receptor antagonist (naloxone).

  20. Function of ubiquitin (Ub) specific protease 15 (USP15) in HIV-1 replication and viral protein degradation.

    Science.gov (United States)

    Pyeon, Dohun; Timani, Khalid Amine; Gulraiz, Fahad; He, Johnny J; Park, In-Woo

    2016-09-01

    HIV-1 Nef is necessary and may be sufficient for HIV-1-associated AIDS pathogenicity, in that knockout of Nef alone can protect HIV-infected patients from AIDS. We therefore investigated the feasibility of physical knockout of Nef, using the host ubiquitin proteasome system in HIV-1-infected cells. Our co-immunoprecipitation analysis demonstrated that Nef interacted with ubiquitin specific protease 15 (USP15), and that USP15, which is known to stabilize cellular proteins, degraded Nef. Nef could also cause decay of USP15, although Nef-mediated degradation of USP15 was weaker than USP15-mediated Nef degradation. Direct interaction between Nef and USP15 was essential for the observed reciprocal decay of the proteins. Further, USP15 degraded not only Nef but also HIV-1 structural protein, Gag, thereby substantially inhibiting HIV-1 replication. However, Gag did not degrade USP15, indicating that the Nef and USP15 complex, in distinction to other viral proteins, play an integral role in coordinating viral protein degradation and hence HIV-1 replication. Moreover, Nef and USP15 globally suppressed ubiquitylation of cellular proteins, indicating that these proteins are major determinants for the stability of cellular as well as viral proteins. Taken together, these data indicate that Nef and USP15 are vital in regulating degradation of viral and cellular proteins and thus HIV-1 replication, and specific degradation of viral, not cellular proteins, by USP15 points to USP15 as a candidate therapeutic agent to combat AIDS by eliminating viral proteins from the infected cells via USP15-mediated proteosomal degradation. PMID:27460547

  1. Two Retroviruses Packaged in One Cell Line can Combined Inhibit the Replication of HIV-1 in TZM-bl Cells

    Institute of Scientific and Technical Information of China (English)

    Zhipin Liang; Zhiyuan Guo; Xin Wang; Xiaohong Kong; Chang Liu

    2012-01-01

    The cellular protein tetherin tethers the HIV-1 viral particles on the cellular membrane to inhibit the replication of HIV-1.However,the HIV-1 accessory protein Vpu counteracts the antiviral function of tetherin.In this study,two retroviral vector plasmids were constructed.One inhibited the vpu gene expression; the other one over-expressed the tetherin.Both retroviral vector plasmids could be packaged in the packaging cell line PT67 to obtain the corresponding retroviruses.The retroviral vector plasmids'functions of tetherin over-expression or vpu-RNAi were detected at the cell level.Retroviral vector plasmids were transfected to PT67 cells at different ratios from 0T3V to 3T0V,and then mixed retroviruses were harvested.The antiviral functions of mixed retroviruses were detected in HIV-1 infected TZM-bl cells.The results showed that packaged mixed retroviruses could repress the replication of HIV-1 in TZM-bl cells.

  2. The Cellular TAR RNA Binding Protein, TRBP, Promotes HIV-1 Replication Primarily by Inhibiting the Activation of Double-Stranded RNA-Dependent Kinase PKR▿

    OpenAIRE

    Sanghvi, Viraj R.; Steel, Laura F

    2011-01-01

    The TAR RNA binding protein, TRBP, is a cellular double-stranded RNA (dsRNA) binding protein that can promote the replication of HIV-1 through interactions with the viral TAR element as well as with cellular proteins that affect the efficiency of translation of viral transcripts. The structured TAR element, present on all viral transcripts, can impede efficient translation either by sterically blocking access of translation initiation factors to the 5′-cap or by activating the dsRNA-dependent...

  3. Data in support of NFκB and JNK pathways involvement in TLR3-mediated HIV-1 transactivation, expression of IL-6 and transcription factors associated with HIV-1 replication

    OpenAIRE

    Biju Bhargavan; Woollard, Shawna M.; Kanmogne, Georgette D

    2015-01-01

    In the present article, using human monocyte-derived macrophages and cell lines containing integrated copies of the HIV-1 promoter, we show the effects of TLR3 ligands on the pro-inflammatory cytokine IL-6. We further show the effects of TLR3 ligands on HIV-1 transactivation and transcription factors involved in HIV-1 replication. This article complements the data reported by the authors, “Toll-Like receptor-3 mediates HIV-1 transactivation via NFκB and JNK pathways, and histone acetylation, ...

  4. NF-IL6 (C/EBPβ) induces HIV-1 replication by inhibiting cytidine deaminase APOBEC3G

    OpenAIRE

    Shigemi M Kinoshita; Taguchi, Shizuka

    2008-01-01

    T cell activation is crucial for the productive HIV-1 infection of primary T cells; however, little is known about the host molecules involved in this process. We show that the host transcription factor NF-IL6 (also called C/EBPβ) renders primary CD4+ T cells highly permissive for HIV-1 replication. NF-IL6 facilitates reverse transcription of the virus by binding to and inhibiting the antiviral cytidine deaminase APOBEC3G. A mutation in NF-IL6 at Ser-288 weakened its binding to APOBEC3G and s...

  5. Inhibition of HIV-1 replication by chimeric phosphorothioate oligodeoxynucleotides applied in free solution

    DEFF Research Database (Denmark)

    Lund, O S; Hansen, J E

    1998-01-01

    Oligodeoxynucleotides (ODNs) containing a variable number of 3' and 5' terminal phosphorothioate linkages were applied in free solution to cells infected by HIV-1. ODNs of 28 nt length were applied at up to 5 microM concentration. The ODNs were found to inhibit HIV-1 infection in a dose dependent...... manner, which correlated with the number of modified linkages (4, 8 and 12, respectively). A target sequence in the HIV-1 rev mRNA, previously reported as sensitive to antisense inhibition by full length phosphorothioate ODNs, only revealed non-sequence dependent inhibition of HIV-1, when tested by these...

  6. Significantly reduced CCR5-tropic HIV-1 replication in vitro in cells from subjects previously immunized with Vaccinia Virus

    Directory of Open Access Journals (Sweden)

    Alibek Kenneth

    2010-05-01

    Full Text Available Abstract Background At present, the relatively sudden appearance and explosive spread of HIV throughout Africa and around the world beginning in the 1950s has never been adequately explained. Theorizing that this phenomenon may be somehow related to the eradication of smallpox followed by the cessation of vaccinia immunization, we undertook a comparison of HIV-1 susceptibility in the peripheral blood mononuclear cells from subjects immunized with the vaccinia virus to those from vaccinia naive donors. Results Vaccinia immunization in the preceding 3-6 months resulted in an up to 5-fold reduction in CCR5-tropic but not in CXCR4-tropic HIV-1 replication in the cells from vaccinated subjects. The addition of autologous serum to the cell cultures resulted in enhanced R5 HIV-1 replication in the cells from unvaccinated, but not vaccinated subjects. There were no significant differences in the concentrations of MIP-1α, MIP-1β and RANTES between the cell cultures derived from vaccinated and unvaccinated subjects when measured in culture medium on days 2 and 5 following R5 HIV-1 challenge. Discussion Since primary HIV-1 infections are caused almost exclusively by the CCR5-tropic HIV-1 strains, our results suggest that prior immunization with vaccinia virus might provide an individual with some degree of protection to subsequent HIV infection and/or progression. The duration of such protection remains to be determined. A differential elaboration of MIP-1α, MIP-1β and RANTES between vaccinated and unvaccinated subjects, following infection, does not appear to be a mechanism in the noted protection.

  7. LMP-420, a small-molecule inhibitor of TNF-alpha, reduces replication of HIV-1 and Mycobacterium tuberculosis in human cells

    Directory of Open Access Journals (Sweden)

    Tangsinmankong Nutthapong

    2006-03-01

    Full Text Available Abstract Background Co-infections of human immunodeficiency virus (HIV and Mycobacterium tuberculosis (M. Tb are steadily increasing and represent a major health crisis in many developing countries. Both pathogens individually stimulate tumor necrosis factor-alpha (TNF release from infected cells and TNF, in turn, enhances the replication of each. A recent report on a Phase I clinical trial suggested that etanercept (soluble TNF receptor might be beneficial in treating HIV/M. Tb co-infected patients. We sought to determine if a small molecule inhibitor of TNF synthesis and activity could block replication of either organism and thus be a potential adjunct to existing drugs targeting these agents. Results LMP-420, a novel anti-inflammatory agent that inhibits TNF, was tested for HIV-1 inhibition both alone and in combination with AZT (3' -azido-3-deoxythymidine. LMP-420 alone was tested against M. Tb. HIV-1 infected human peripheral blood mononuclear cells (PBMC or M. Tb-infected human alveolar macrophages (AM were treated with a single dose of LMP-420 and viral or bacterial replication determined after 7 or 5 days respectively. Viral replication was determined from supernatant p24 levels measured by ELISA. M. Tb replication was determined by bacterial culture of macrophage lysates. LMP-420 alone inhibited HIV replication over 7 days with an IC50 of ~300 nM. Combination of LMP-420 with AZT doubled the level of HIV inhibition observed with AZT alone. LMP-420 alone inhibited the replication of virulent M. Tb by >80%, more than that observed with anti-TNF antibody alone. Conclusion Inhibition of TNF with inexpensive, small-molecule, orally-active drugs may represent a useful strategy for enhancing the activity of currently-available antiviral and anti-M. Tb agents, particularly in those areas where co-infections with these pathogens act to synergistically enhance each other.

  8. Non-catalytic site HIV-1 integrase inhibitors disrupt core maturation and induce a reverse transcription block in target cells.

    Directory of Open Access Journals (Sweden)

    Mini Balakrishnan

    Full Text Available HIV-1 integrase (IN is the target for two classes of antiretrovirals: i the integrase strand-transfer inhibitors (INSTIs and ii the non-catalytic site integrase inhibitors (NCINIs. NCINIs bind at the IN dimer interface and are thought to interfere primarily with viral DNA (vDNA integration in the target cell by blocking IN-vDNA assembly as well as the IN-LEDGF/p75 interaction. Herein we show that treatment of virus-producing cells, but not of mature virions or target cells, drives NCINI antiviral potency. NCINIs target an essential late-stage event in HIV replication that is insensitive to LEDGF levels in the producer cells. Virus particles produced in the presence of NCINIs displayed normal Gag-Pol processing and endogenous reverse transcriptase activity, but were defective at initiating vDNA synthesis following entry into the target cell. NCINI-resistant virus carrying a T174I mutation in the IN dimer interface was less sensitive to the compound-induced late-stage effects, including the reverse transcription block. Wild-type, but not T174I virus, produced in the presence of NCINIs exhibited striking defects in core morphology and an increased level of IN oligomers that was not observed upon treatment of mature cell-free particles. Collectively, these results reveal that NCINIs act through a novel mechanism that is unrelated to the previously observed inhibition of IN activity or IN-LEDGF interaction, and instead involves the disruption of an IN function during HIV-1 core maturation and assembly.

  9. Non-catalytic site HIV-1 integrase inhibitors disrupt core maturation and induce a reverse transcription block in target cells.

    Science.gov (United States)

    Balakrishnan, Mini; Yant, Stephen R; Tsai, Luong; O'Sullivan, Christopher; Bam, Rujuta A; Tsai, Angela; Niedziela-Majka, Anita; Stray, Kirsten M; Sakowicz, Roman; Cihlar, Tomas

    2013-01-01

    HIV-1 integrase (IN) is the target for two classes of antiretrovirals: i) the integrase strand-transfer inhibitors (INSTIs) and ii) the non-catalytic site integrase inhibitors (NCINIs). NCINIs bind at the IN dimer interface and are thought to interfere primarily with viral DNA (vDNA) integration in the target cell by blocking IN-vDNA assembly as well as the IN-LEDGF/p75 interaction. Herein we show that treatment of virus-producing cells, but not of mature virions or target cells, drives NCINI antiviral potency. NCINIs target an essential late-stage event in HIV replication that is insensitive to LEDGF levels in the producer cells. Virus particles produced in the presence of NCINIs displayed normal Gag-Pol processing and endogenous reverse transcriptase activity, but were defective at initiating vDNA synthesis following entry into the target cell. NCINI-resistant virus carrying a T174I mutation in the IN dimer interface was less sensitive to the compound-induced late-stage effects, including the reverse transcription block. Wild-type, but not T174I virus, produced in the presence of NCINIs exhibited striking defects in core morphology and an increased level of IN oligomers that was not observed upon treatment of mature cell-free particles. Collectively, these results reveal that NCINIs act through a novel mechanism that is unrelated to the previously observed inhibition of IN activity or IN-LEDGF interaction, and instead involves the disruption of an IN function during HIV-1 core maturation and assembly. PMID:24040198

  10. Screening of Potential HIV-1 Inhibitors/Replication Blockers Using Secure Lentiviral in Vitro System

    OpenAIRE

    Prokofjeva, M.; Spirin, P.; Yanvarev, D.; Ivanov, A.; M Novikov; Stepanov, O.; Gottikh, M.; Kochetkov, S.; Fehse, B; Stocking, C; Prassolov, V

    2011-01-01

    The development and usage of safe cell systems for testing agents which possess anti-HIV activity is a very important factor in the design of new drugs. We have described in detail a system we designed that is based on lentiviral vectors (Prokofjeva et. al., Antiviral Therapy, in print) for swift and completely safe screening of potential HIV-1 replication inhibitors. The system enables one to test the efficiency of the inhibitory activity of compounds whose action is directed towards either ...

  11. Pharmacokinetics and brain uptake of HIV-1 replication inhibitor DB213 in Sprague-Dawley rats.

    Science.gov (United States)

    Wang, Qianwen; Zhang, Yufeng; Qian, Shuai; Peng, Shaohong; Zhang, Qian; Wong, Chun-Ho; Chan, H Y Edwin; Zuo, Zhong

    2016-06-01

    The current study aims to investigate the pharmacokinetics and brain uptake of HIV-1 replication inhibitor DB213 via a developed LC/MS/MS analytical method. A sensitive, selective, accurate and reliable LC/MS/MS method for determination and quantification of DB213 in rat plasma and brain was developed and validated. A triple quadrupole mass spectrometer equipped with electrospray ionization (ESI) source was applied for the detection of DB213 and benzamidine (Internal Standard). The analytes were quantified by using multiple reaction monitoring (MRM) mode with m/z 333.4→86.1 and m/z 121.2→104 for DB213 and benzamidine respectively. Chromatographic separation of DB213 and benzamidine was achieved on a SunFire C8 (4.6×250mm, i.d. 5μm) analytical column with gradient elution of a mobile phase consisted of acetonitrile and 20mM ammonium formate buffer (containing 0.5% formic acid). The method achieved good linearity from 1.95∼1000ng/ml (r(2)=0.999) in plasma and 0.98∼125ng/ml (r(2)=0.999) in brain. The validated method was successfully applied to plasma pharmacokinetics (PK) and brain uptake of intravenous administration of DB213 water solution (1mg/kg) to Sprague-Dawley rats. It was found that the area under the plasma concentration-time curve from 0 to 360min (AUC0→360min) was 184422.1±42450.8ngmin/ml and the elimination half-life of DB213 after intravenous administration was 70.9±16.1min. In addition, DB213 has demonstrated a potential to cross the blood-brain barrier via intravenous administration with a brain tissue concentration of 11.3±3.6ng/g peaked at 30min post-dosing. PMID:26999321

  12. HIV-1 replication through hHR23A-mediated interaction of Vpr with 26S proteasome.

    Directory of Open Access Journals (Sweden)

    Ge Li

    Full Text Available HIV-1 Vpr is a virion-associated protein. Its activities link to viral pathogenesis and disease progression of HIV-infected patients. In vitro, Vpr moderately activates HIV-1 replication in proliferating T cells, but it is required for efficient viral infection and replication in vivo in non-dividing cells such as macrophages. How exactly Vpr contributes to viral replication remains elusive. We show here that Vpr stimulates HIV-1 replication at least in part through its interaction with hHR23A, a protein that binds to 19S subunit of the 26S proteasome and shuttles ubiquitinated proteins to the proteasome for degradation. The Vpr-proteasome interaction was initially discovered in fission yeast, where Vpr was shown to associate with Mts4 and Mts2, two 19S-associated proteins. The interaction of Vpr with the 19S subunit of the proteasome was further confirmed in mammalian cells where Vpr associates with the mammalian orthologues of fission yeast Mts4 and S5a. Consistently, depletion of hHR23A interrupts interaction of Vpr with proteasome in mammalian cells. Furthermore, Vpr promotes hHR23A-mediated protein-ubiquitination, and down-regulation of hHR23A using RNAi significantly reduced viral replication in non-proliferating MAGI-CCR5 cells and primary macrophages. These findings suggest that Vpr-proteasome interaction might counteract certain host restriction factor(s to stimulate viral replication in non-dividing cells.

  13. Roles of HIV-1 capsid in viral replication and immune evasion.

    Science.gov (United States)

    Le Sage, Valerie; Mouland, Andrew J; Valiente-Echeverría, Fernando

    2014-11-26

    The primary roles of the human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein are to encapsidate and protect the viral RNA genome. It is becoming increasing apparent that HIV-1 CA is a multifunctional protein that acts early during infection to coordinate uncoating, reverse transcription, nuclear import of the pre-integration complex and integration of double stranded viral DNA into the host genome. Additionally, numerous recent studies indicate that CA is playing a crucial function in HIV-1 immune evasion. Here we summarize the current knowledge on HIV-1 CA and its interactions with the host cell to promote infection. The fact that CA engages in a number of different protein-protein interactions with the host makes it an interesting target for the development of new potent antiviral agents. PMID:25036886

  14. A DEAD box protein facilitates HIV-1 replication as a cellular co-factor of Rev

    International Nuclear Information System (INIS)

    HIV-1 Rev escorts unspliced viral mRNAs out of the nucleus of infected cells, which allows formation of infectious HIV-1 virions. We have identified a putative DEAD box (Asp-Glu-Ala-Asp) RNA helicase, DDX1, as a cellular co-factor of Rev, through yeast and mammalian two-hybrid systems using the N-terminal motif of Rev as 'bait'. DDX1 is not a functional homolog of HIV-1 Rev, but down-regulation of DDX1 resulted in an alternative splicing pattern of Rev-responsive element (RRE)-containing mRNA, and attenuation of Gag p24 antigen production from HLfb rev(-) cells rescued by exogenous Rev. Co-transfection of a DDX1 expression vector with HIV-1 significantly increased viral production. DDX1 binding to Rev, as well as to the RRE, strongly suggest that DDX1 affects Rev function through the Rev-RRE axis. Moreover, down-regulation of DDX1 altered the steady state subcellular distribution of Rev, from nuclear/nucleolar to cytoplasmic dominance. These findings indicate that DDX1 is a critical cellular co-factor for Rev function, which maintains the proper subcellular distribution of this lentiviral regulatory protein. Therefore, alterations in DDX1-Rev interactions could induce HIV-1 persistence and targeting DDX1 may lead to rationally designed and novel anti-HIV-1 strategies and therapeutics

  15. A Haplotype Block Model for Fine Mapping of Quantitative Trait Loci Regulating HIV-1 Pathogenesis

    OpenAIRE

    Zhu, Yun; Hou, Wei; Wu, Rongling

    2003-01-01

    The dynamic change of human immunodeficiency virus type-1 (HIV-1) particles that cause AIDS displays considerable variation from patients to patients. It is likely that such variation in HIV-1 pathogenesis is correlated with the genetic architecture of hosts. Traditional genetic analysis of HIV-1 infection is based on various biochemical approaches, but it has been little successful because HIV-1 dynamics, as a complex trait, is under polygenic control and sensitive to environmental changes. ...

  16. McCoy cell line as a possible model containing CD4+ receptors for the study of HIV-1 replication

    Directory of Open Access Journals (Sweden)

    Nogueira Yeda L.

    2003-01-01

    Full Text Available Several studies have recently shown the use of recombinant rabies virus as potential vector-viral vaccine for HIV-1. The sequence homology between gp 120 and rabies virus glycoprotein has been reported. The McCoy cell line has therefore been used to show CD4+ or CD4+ like receptors. Samples of HIV-1 were isolated, when plasma of HIV-1 positive patients was inoculated in the McCoy cell line. The virus infection was then studied during successive virus passages. The proteins released in the extra cellular medium were checked for protein activity, by exposure to SDS Electrophoresis and blotting to nitro-cellulose filter, then reacting with sera of HIV positive and negative patients. Successive passages were performed, and showed viral replication, membrane permeabilization, the syncytium formation, and the cellular lysis (cytopathic effect. Flow cytometry analysis shows clear evidence that CD4+ receptors are present in this cell line, which enhances the likelihood of easy isolation and replication of HIV. The results observed allow the use of this cell line as a possible model for isolating HIV, as well as for carrying out studies of the dynamics of viral infection in several situations, including exposure to drugs in pharmacological studies, and possibly studies and analyses of the immune response in vaccine therapies.

  17. Nef functions in BLT mice to enhance HIV-1 replication and deplete CD4+CD8+ thymocytes

    Directory of Open Access Journals (Sweden)

    Zou Wei

    2012-05-01

    Full Text Available Abstract Background The outcome of untreated HIV-1 infection is progression to AIDS and death in nearly all cases. Some important exceptions are the small number of patients infected with HIV-1 deleted for the accessory gene, nef. With these infections, disease progression is entirely suppressed or greatly delayed. Whether Nef is critical for high levels of replication or is directly cytotoxic remains controversial. The major problem in determining the role of Nef in HIV/AIDS has been the lack of tractable in vivo models where Nef’s complex pathogenic phenotype can be recapitulated. Results Intravenous inoculation (3000 to 600,000 TCIU of BLT humanized mice with HIV-1LAI reproducibly establishes a systemic infection. HIV-1LAI (LAI replicates to high levels (peak viral load in blood 8,200,000 ± 1,800,000 copies of viral RNA/ml, range 3,600,000 to 20,400,000; n = 9 and exhaustively depletes CD4+ T cells in blood and tissues. CD4+CD8+ thymocytes were also efficiently depleted but CD4+CD8- thymocytes were partially resistant to cell killing by LAI. Infection with a nef-deleted LAI (LAINefdd gave lower peak viral loads (1,220,000 ± 330,000, range 27,000 to 4,240,000; n = 17. For fourteen of seventeen LAINefdd-infected mice, there was little to no loss of either CD4+ T cells or thymocytes. Both LAI- and LAINefdd-infected mice had about 8% of total peripheral blood CD8+ T cells that were CD38+HLA-DR+ compared dd-infected mice that lost CD4+ T cells received 600,000 TCIU. All three exhibited peak viral loads over 3,000,000 copies of LAINefdd RNA/ml. Over an extended time course, substantial systemic CD4+ T cell loss was observed for the three mice, but there was no loss of CD4+CD8+ or CD4+CD8- thymocytes. Conclusion We conclude Nef is necessary for elevated viral replication and as a result indirectly contributes to CD4+ T cell killing. Further, Nef was not necessary for the activation of peripheral blood CD8+ T cells following

  18. Inhibition of hepatitis B virus and human immunodeficiency virus (HIV-1) replication by Warscewiczia coccinea (Vahl) Kl. (Rubiaceae) ethanol extract.

    Science.gov (United States)

    Quintero, A; Fabbro, R; Maillo, M; Barrios, M; Milano, M B; Fernández, A; Williams, B; Michelangeli, F; Rangel, H R; Pujol, F H

    2011-09-01

    The primary objective of this study was to search for natural products capable of inhibiting hepatitis B virus (HBV) replication. The research design, methods and procedures included testing hydro-alcoholic extracts (n = 66) of 31 species from the Venezuelan Amazonian rain forest on the cell line HepG2 2.2.15, which constitutively produces HBV. The main outcomes and results were as follows: the species Euterpe precatoria, Jacaranda copaia, Jacaranda obtusifolia, Senna silvestris, Warscewiczia coccinea and Vochysia glaberrima exerted some degree of inhibition on HBV replication. The leaves of W. coccinea showed a significant antiviral activity: 80% inhibition with 100 µg mL⁻¹ of extract. This extract also exerted inhibition on covalently closed circular deoxyribonucleic acid (cccDNA) production and on HIV-1 replication in MT4 cells (more than 90% inhibition with 50 µg mL⁻¹ of extract). Initial fractionation using organic solvents of increasing polarity and water showed that the ethanol fraction was responsible for most of the antiviral inhibitory activities of both the viruses. It was concluded that Warscewiczia coccinea extract showed inhibition of HBV and HIV-1 replication. Bioassay-guided purification of this fraction may allow the isolation of an antiviral compound with inhibitory activity against both viruses. PMID:21827337

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

    Directory of Open Access Journals (Sweden)

    Rekosh David

    2008-05-01

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

  20. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells

    OpenAIRE

    Mouhssin Oufir; Bisset, Leslie R.; Hoffmann, Stefan R. K.; Gongda Xue; Stephan Klauser; Bianca Bergamaschi; Alain Gervaix; Jürg Böni; Jörg Schüpbach; Bernd Gutte

    2011-01-01

    An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 r...

  1. Diminished transmission of drug resistant HIV-1 variants with reduced replication capacity in a human transmission model

    OpenAIRE

    Pingen, Marieke; Sarrami-Forooshani, Ramin; Wensing, Annemarie MJ; van Ham, Petra; Drewniak, Agata; Boucher, Charles Ab; Geijtenbeek, Teunis BH; Nijhuis, Monique

    2014-01-01

    Background Different patterns of drug resistance are observed in treated and therapy naïve HIV-1 infected populations. Especially the NRTI-related M184I/V variants, which are among the most frequently encountered mutations in treated patients, are underrepresented in the antiretroviral naïve population. M184I/V mutations are known to have a profound effect on viral replication and tend to revert over time in the new host. However it is debated whether a diminished transmission efficacy of HIV...

  2. Site-directed mutagenesis of HIV-1 vpu gene demonstrates two clusters of replication-defective mutants with distinct ability to down-modulate cell surface CD4 and tetherin

    Directory of Open Access Journals (Sweden)

    Masako Nomaguchi

    2010-11-01

    Full Text Available HIV-1 Vpu acts positively on viral infectivity by mediating CD4 degradation in endoplasmic reticulum and enhances virion release by counteracting a virion release restriction factor, tetherin. In order to define the impact of Vpu activity on HIV-1 replication, we have generated a series of site-specific proviral vpu mutants. Of fifteen mutants examined, seven exhibited a replication-defect similar to that of a vpu-deletion mutant in a lymphocyte cell line H9. These mutations clustered in narrow regions within transmembrane domain (TMD and cytoplasmic domain (CTD. Replication-defective mutants displayed the reduced ability to enhance virion release from a monolayer cell line HEp2 without exception. Upon transfection with Vpu expression vectors, neither TMD mutants nor CTD mutants blocked CD4 expression at the cell surface in another monolayer cell line MAGI. While TMD mutants were unable to down-modulate cell surface tetherin in HEp2 cells, CTD mutants did quite efficiently. Confocal microscopy analysis revealed the difference of intracellular localization between TMD and CTD mutants. In total, replication capability of HIV-1 carrying vpu mutations correlates well with the ability of Vpu to enhance virion release and to impede the cell surface expression of CD4 but not with the ability to down-modulate cell surface tetherin. Our results here suggest that efficient viral replication requires not only down-regulation of cell surface tetherin but also its degradation.

  3. Inhibitory effect of aqueous dandelion extract on HIV-1 replication and reverse transcriptase activity

    OpenAIRE

    Han Huamin; He Wen; Wang Wei; Gao Bin

    2011-01-01

    Abstract Background Acquired immunodeficiency syndrome (AIDS), which is caused by the human immunodeficiency virus (HIV), is an immunosuppressive disease that results in life-threatening opportunistic infections. The general problems in current therapy include the constant emergence of drug-resistant HIV strains, adverse side effects and the unavailability of treatments in developing countries. Natural products from herbs with the abilities to inhibit HIV-1 life cycle at different stages, hav...

  4. Tannin inhibits HIV-1 entry by targeting gp41

    Institute of Scientific and Technical Information of China (English)

    Lin L(U); Shu-wen LIU; Shi-bo JIANG; Shu-guang WU

    2004-01-01

    AIM: To investigate the mechanism by which tannin inhibits HIV-1 entry into target cells. METHODS: The inhibitory activity of tannin on HIV-1 replication and entry was detected by p24 production and HIV-1-mediated cell fusion, respectively. The inhibitory activity on the gp41 six-helix bundle formation was determined by an improved sandwich ELISA. RESULTS: Tannins from different sources showed potent inhibitory activity on HIV-1 replication,HIV-1-mediated cell fusion, and the gp4 six-helix bundle formation. CONCLUSION: Tannin inhibits HIV-1 entry into target cells by interfering with the gp41 six-helix bundle formation, thus blocking HIV-1 fusion with the target cell.

  5. Optimized Replicating Renilla Luciferase Reporter HIV-1 Utilizing Novel Internal Ribosome Entry Site Elements for Native Nef Expression and Function.

    Science.gov (United States)

    Alberti, Michael O; Jones, Jennifer J; Miglietta, Riccardo; Ding, Haitao; Bakshi, Rakesh K; Edmonds, Tara G; Kappes, John C; Ochsenbauer, Christina

    2015-12-01

    We previously developed replication-competent reporter HIV-1 (referred to herein as LucR.T2A reporter viruses), utilizing a "ribosome skipping" T2A peptide strategy to link Renilla luciferase (LucR) with Nef expression. The demonstrated utility for HIV-1 vaccine and transmission study applications included measurement of neutralizing antibody (NAb) activity in vaccine sera, improved cell-mediated virus inhibition assays, such as T cell-mediated virus inhibition and antibody-dependent cell-mediated cytotoxicity (ADCC) assays, and humanized mouse models. Herein, we extend our prior work and introduce reporter virus technology for applications that require fully functional Nef. We demonstrate that in CD4(+) T cells productively infected with LucR.T2A reporter viruses, T2A peptide-driven Nef expression and function, such as down-regulation of surface CD4 and MHC-I, were impaired. We overcame this limitation of LucR.T2A reporter viruses and achieved physiological Nef expression and function by engineering novel LucR reporter HIV-1 comprising 11 different internal ribosome entry site (IRES) elements chosen for size and relative activity. A range of Nef expression was observed in 293T cells transfected with the different LucR.IRES reporter virus constructs. Iteratively, we identified IRES reporter genomes that expressed Nef closest to physiological levels and produced virus with infectivity, titers, and replication kinetics similar to nonreporter viruses. Our results demonstrated that LucR reporter activity was stable over multiple replication cycles in peripheral blood mononuclear cells (PBMCs). Furthermore, we analyzed Nef functionality, i.e., down-modulation of MHC-I and CD4, following infection of T cell lines and PBMCs. Unlike LucR.T2A reporter virus, one of the redesigned LucR.IRES reporter viruses [containing the modified encephalomyocarditis virus (EMCV) 6ATR IRES element, "6ATRi"] demonstrated Nef expression and function similar to parental "nonreporter" virus

  6. Secondary mutations in viruses resistant to HIV-1 integrase inhibitors that restore viral infectivity and replication kinetics.

    Science.gov (United States)

    Nakahara, Koichiro; Wakasa-Morimoto, Chiaki; Kobayashi, Masanori; Miki, Shigeru; Noshi, Takeshi; Seki, Takahiro; Kanamori-Koyama, Mikiko; Kawauchi, Shinobu; Suyama, Akemi; Fujishita, Toshio; Yoshinaga, Tomokazu; Garvey, Edward P; Johns, Brian A; Foster, Scott A; Underwood, Mark R; Sato, Akihiko; Fujiwara, Tamio

    2009-02-01

    Passage of HIV-1 in the presence of integrase inhibitors (INIs) generates resistant viruses that have mutations in the integrase region. Integrase-resistant mutations Q148K and Q148R were identified as primary mutations with the passage of HIV-1 IIIB in the presence of INIs S-1360 or S/GSK-364735, respectively. Secondary amino acid substitutions E138K or G140S were observed when passage with INI was continued. The role of these mutations was investigated with molecular clones. Relative to Q148K alone, Q148K/E138K had 2- and >6-fold increases in resistance to S-1360 and S/GSK-364735, respectively, and the double mutant had slightly better infectivity and replication kinetics. In contrast, Q148K/G140S and Q148R/E138K had nearly equivalent or slightly reduced fold resistance to the INI compared with their respective Q148 primary mutants, and had increases in infectivity and replication kinetics. Recovery of these surrogates of viral fitness coincided with the recovery of integration efficiency of viral DNA into the host cell chromosome for these double mutants. These data show that recovery of viral integration efficiency can be an important factor for the emergence and maintenance of INI-resistant mutations. PMID:19027039

  7. Direct Evidence of Lower Viral Replication Rates In Vivo in Human Immunodeficiency Virus Type 2 (HIV-2) Infection than in HIV-1 Infection

    OpenAIRE

    MacNeil, Adam; Sarr, A. D.; Sankalé, J.-L.; Meloni, S.; Mboup, S.; Kanki, Phyllis Jean

    2007-01-01

    Studies have shown that human immunodeficiency virus type 2 (HIV-2) is less pathogenic than HIV-1, with a lower rate of disease progression. Similarly, plasma viral loads are lower in HIV-2 infection, suggesting that HIV-2 replication is restricted in vivo in comparison to that of HIV-1. However, to date, in vivo studies characterizing replication intermediates in the viral life cycle of HIV-2 have been limited. In order to test the hypothesis that HIV-2 has a lower replication rate in vivo t...

  8. Fluorescent reporter signals, EGFP and DsRed, encoded in HIV-1 facilitate the detection of productively infected cells and cell-associated viral replication levels

    Directory of Open Access Journals (Sweden)

    Kazutaka eTerahara

    2012-01-01

    Full Text Available Flow cytometric analysis is a reliable and convenient method for investigating molecules at the single cell level. Previously, recombinant human immunodeficiency virus type 1 (HIV-1 strains were constructed that express a fluorescent reporter, either enhanced green fluorescent protein or DsRed, which allow the monitoring of HIV-1-infected cells by flow cytometry. The present study further investigated the potential of these recombinant viruses in terms of whether the HIV-1 fluorescent reporters would be helpful in evaluating viral replication based on fluorescence intensity. When primary CD4+ T cells were infected with recombinant viruses, the fluorescent reporter intensity measured by flow cytometry was associated with the level of CD4 downmodulation and Gag p24 expression in infected cells. Interestingly, some HIV-1-infected cells, in which CD4 was only moderately downmodulated, were reporter-positive but Gag p24-negative. Furthermore, when the activation status of primary CD4+ T cells was modulated by T cell receptor-mediated stimulation, we confirmed the preferential viral production upon strong stimulation and showed that the intensity of the fluorescent reporter within a proportion of HIV-1-infected cells was correlated with the viral replication level. These findings indicate that a fluorescent reporter encoded within HIV-1 is useful for the sensitive detection of productively-infected cells at different stages of infection and for evaluating cell-associated viral replication at the single cell level.

  9. Interleukin-27 is a potent inhibitor of cis HIV-1 replication in monocyte-derived dendritic cells via a type I interferon-independent pathway.

    Directory of Open Access Journals (Sweden)

    Qian Chen

    Full Text Available IL-27, a member of the IL-12 family of cytokines, plays an important and diverse role in the function of the immune system. Whilst generally recognized as an anti-inflammatory cytokine, in addition IL-27 has been found to have broad anti-viral effects. Recently, IL-27 has been shown to be a potent inhibitor of HIV-1 infection in CD4+ T cells and macrophages. The main objective of this study was to see whether IL-27 has a similar inhibitory effect on HIV-1 replication in dendritic cells (DCs. Monocytes were differentiated into immature DCs (iDCs and mature DCs (mDCs with standard techniques using a combination of GM-CSF, IL-4 and LPS. Following differentiation, iDCs were infected with HIV-1 and co-cultured in the presence or absence of IL-27. IL-27 treated DCs were shown to be highly potent inhibitors of cis HIV-1, particularly of CCR5 tropic strains. Of note, other IL-12 family members (IL-12, IL-23 and IL-35 had no effect on HIV-1 replication. Microarray studies of IL-27 treated DCs showed no up-regulation of Type I (IFN gene expression. Neutralization of the Type-I IFN receptor had no impact on the HIV inhibition. Lastly, IL-27 mediated inhibition was shown to act post-viral entry and prior to completion of reverse transcription. These results show for the first time that IL-27 is a potent inhibitor of cis HIV-1 infection in DCs by a Type I IFN independent mechanism. IL-27 has previously been reported to inhibit HIV-1 replication in CD4+ T cells and macrophages, thus taken together, this cytokine is a potent anti-HIV agent against all major cell types targeted by the HIV-1 virus and may have a therapeutic role in the future.

  10. Proteomic analyses associate cystatin B with restricted HIV-1 replication in placental macrophages

    OpenAIRE

    Luciano-Montalvo, Claribel; Ciborowski, Pawel; Duan, Fenghai; Gendelman, Howard E.; Meléndez, Loyda M.

    2008-01-01

    Mononuclear phagocytes (MP; monocytes, tissue macrophages, and dendritic cells) are reservoirs, vehicles of dissemination, and targets for persistent HIV infection. However, not all MP populations equally support viral growth. Such differential replication is typified by the greater ability of placental macrophages (PM), as compared with monocyte-derived macrophages (MDM), to restrict viral replication. Since cytosolic protein patterns can differentiate macrophage subtypes, we used a proteomi...

  11. Quantifying the Antiviral Effect of IFN on HIV-1 Replication in Cell Culture

    Science.gov (United States)

    Ikeda, Hiroki; Godinho-Santos, Ana; Rato, Sylvie; Vanwalscappel, Bénédicte; Clavel, François; Aihara, Kazuyuki; Iwami, Shingo; Mammano, Fabrizio

    2015-06-01

    Type-I interferons (IFNs) induce the expression of hundreds of cellular genes, some of which have direct antiviral activities. Although IFNs restrict different steps of HIV replication cycle, their dominant antiviral effect remains unclear. We first quantified the inhibition of HIV replication by IFN in tissue culture, using viruses with different tropism and growth kinetics. By combining experimental and mathematical analyses, we determined quantitative estimates for key parameters of HIV replication and inhibition, and demonstrate that IFN mainly inhibits de novo infection (33% and 47% for a X4- and a R5-strain, respectively), rather than virus production (15% and 6% for the X4 and R5 strains, respectively). This finding is in agreement with patient-derived data analyses.

  12. Developing strategies for HIV-1 eradication

    OpenAIRE

    Durand, Christine M.; Blankson, Joel N.; Siliciano, Robert F.

    2012-01-01

    Highly active antiretroviral therapy (HAART) suppresses HIV-1 replication, transforming the outlook for infected patients. However, reservoirs of replication-competent forms of the virus persist during HAART, and when treatment is stopped, high rates of HIV-1 replication return. Recent insights into HIV-1 latency, as well as a report that HIV-1 infection was eradicated in one individual, have renewed interest in finding a cure for HIV-1 infection. Strategies for HIV-1 eradication include gene...

  13. GB Virus C Proteins interfere with the Replication of HIV-1

    OpenAIRE

    Jung, Susan

    2010-01-01

    GB Virus C (GBV-C) was discovered in 1995 within the search for new hepatitis viruses. The human apathogenic enveloped RNA virus belongs to the family of the Flaviviridae and replicates primarily in lymphocytes. Transmission occurs mainly by sexual or parenteral exposure. In developed countries up to 6% of the healthy population and up to 40% of multiply exposed individuals, such as HIV patients, are viremic for GBV-C. Since the late 1990s, GBV-C has been investigated in the context of HIV. U...

  14. Potent and selective inhibition of human immunodeficiency virus (HIV)-1 and HIV-2 replication by a class of bicyclams interacting with a viral uncoating event.

    OpenAIRE

    De Clercq, E; Yamamoto, N; Pauwels, R; Baba, M.; Schols, D; Nakashima, H.; Balzarini, J.; Debyser, Z.; Murrer, B A; Schwartz, D.

    1992-01-01

    A series of bicyclams have been shown to be potent and selective inhibitors of human immunodeficiency virus (HIV). The compounds are inhibitory to the replication of various HIV-1 and HIV-2 strains in various human T-cell systems, including peripheral blood lymphocytes, at 0.14-1.4 microM, without being toxic to the host cells at 2.2 mM. The bicyclam JM2763 is active against 3'-azido-3'-deoxythymidine (zidovudine; AZT)-resistant HIV-1 strains and acts additively with AZT. Mechanism of action ...

  15. Differential response of primary and immortalized CD4+ T cells to Neisseria gonorrhoeae-induced cytokines determines the effect on HIV-1 replication.

    Directory of Open Access Journals (Sweden)

    Wendy N Dobson-Belaire

    Full Text Available To compare the effect of gonococcal co-infection on immortalized versus primary CD4(+ T cells the Jurkat cell line or freshly isolated human CD4(+ T cells were infected with the HIV-1 X4 strain NL4-3. These cells were exposed to whole gonococci, supernatants from gonococcal-infected PBMCs, or N. gonorrhoeae-induced cytokines at varying levels. Supernatants from gonococcal-infected PBMCs stimulated HIV-1 replication in Jurkat cells while effectively inhibiting HIV-1 replication in primary CD4(+ T cells. ELISA-based analyses revealed that the gonococcal-induced supernatants contained high levels of proinflammatory cytokines that promote HIV-1 replication, as well as the HIV-inhibitory IFNα. While all the T cells responded to the HIV-stimulatory cytokines, albeit to differing degrees, the Jurkat cells were refractory to IFNα. Combined, these results indicate that N. gonorrhoeae elicits immune-modulating cytokines that both activate and inhibit HIV-production; the outcome of co-infection depending upon the balance between these opposing signals.

  16. Effects of root, shoot, leaf and seed extracts of sevenArtemisia species on HIV-1 replication and CD4 expression

    Institute of Scientific and Technical Information of China (English)

    Hassan Mohabatkar; Mandana Behbahani; Mohammad Reza Rahimi Nejad

    2015-01-01

    Objective:To investigate the effects of flower, leaf, shoot and root extracts of sevenArtemisia species on peripheral blood mononuclear cells (PBMCs) toxicity andHIV-1 replication. Methods:The studiedArtemisia species wereArtemisia absinthium, Artemisia khorasanica, Artemisia deserti, Artemisia fragrans, Artemisia aucheri, Artemisia sieberi andArtemisia vulgaris. The activity of these plant extracts onHIV-1 replication andCD4 expression was performed byHIV-1 p24 antigen kit and flow cytometry respectively. Results: The results demonstrated that flower extracts of all species increasedPBMCs number more than shoot, leaf and root extracts. However, the frequency ofCD4 expression inPBMC was not increased in the presence of all flower extracts. The flower extracts of all species had inhibitory effect onHIV-1 replication. Conclusions:In conclusion, the results demonstrated that flower extracts ofArtemisia species are good candidates for further studies as anticancer agents.

  17. Construction and characterisation of a full-length infectious molecular clone from a fast replicating, X4-tropic HIV-1 CRF02.AG primary isolate

    International Nuclear Information System (INIS)

    Based on our previous analysis of HIV-1 isolates from Cameroon, we constructed a full-length infectious molecular clone from a primary isolate belonging to the CRF02.AG group of recombinant viruses which dominate the HIV-epidemic in West and Central Africa. The virus derived by transfection of the proviral clone pBD6-15 replicated with similar efficiency compared to its parental isolate and used CXCR4 as coreceptor as well. Furthermore, HIV-1 BD6-15 exhibited similar replication properties and virus yield as the reference B-type HIV-1 strain NL4-3. Sequence analysis revealed open reading frames for all structural and accessory genes apart from vpr. Phylogenetic and bootscanning analyses confirmed that BD6-15 clusters with CRF02.AG recombinant strains from West and Central Africa with similar cross-over points as described for the CRF02.AG prototype strain lbNG. Thus, pBD6-15 represents the first non-subtype B infectious molecular clone of a fast replicating, high producer, X4-tropic primary HIV-1 isolate, which had only been briefly passaged in primary cells

  18. A mouse model based on replication-competent Tiantan vaccinia expressing luciferase/HIV-1 Gag fusion protein for the evaluation of protective efficacy of HIV vaccine

    Institute of Scientific and Technical Information of China (English)

    HUANG Yang; QIU Chao; LIU Lian-xing; FENG Yan-meng; ZHU Ting; XU Jian-qing

    2009-01-01

    Background Developing an effective vaccine against human immunodeficiency virus type 1 (HIV-1) remains a grand challenge after more than two decades of intensive effort. It is partially due to the lack of suitable animal models for screening and prioritizing vaccine candidates. In this study, we aim to develop a mice model to test HIV-1 vaccine efficacy. Methods We constructed a recombinant vaccinia expressing firefly luciferase and HIV-1 Gag fusion protein based on Tiantan strain, an attenuated but replication-competent poxvirus (rTTV-lucgag). By quantifying the luciferase activity as its read out, we defined the biodistribution of Tiantan strain poxvirus in mice inoculated intraperitoneally and attempted to apply this model to evaluate the HIV-1 vaccine efficacy. Results Our data demonstrated that the rTTV-lucgag was able to express high level of luciferase (≤106 relative luciferase units (RLU)/mg protein) and HIV-1 Gag (>3 folds increase comparing to the control). After intraperitoneal inoculation, this virus had dominant replication in the ovary, uterus, and cervix of mice and the luciferase activities in those organs are significantly correlated with viral titers (r2=0.71, P <0.01). Pre-immunization with an HIV gag DNA vaccine reduced the luciferase activity in ovary from (6006+3141) RLU/mg protein in control group to (1538±463) RLU/mg protein in vaccine group (P=0.1969). Conclusions The luciferase activity in ovary could represent viral replication in vivo;, this rTTV-lucgag/mice model may be suitable to assess the protective efficacy of cytotoxic T-cell responses to HIV Gag with less tedious work and high through-put.

  19. HbAHP-25, an In-Silico Designed Peptide, Inhibits HIV-1 Entry by Blocking gp120 Binding to CD4 Receptor.

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    Tahir Bashir

    Full Text Available Human Immunodeficiency Virus (HIV-1 poses a serious threat to the developing world and sexual transmission continues to be the major source of new infections. Therefore, the development of molecules, which prevent new HIV-1 infections, is highly warranted. In the present study, a panel of human hemoglobin (Hb-α subunit derived peptides and their analogues, with an ability to bind gp120, were designed in-silico and their anti-HIV-1 activity was evaluated. Of these peptides, HbAHP-25, an analogue of Hb-α derived peptide, demonstrated significant anti-HIV-1 activity. HbAHP-25 was found to be active against CCR5-tropic HIV-1 strains (ADA5 and BaL and CXCR4-tropic HIV-1 strains (IIIB and NL4-3. Surface plasmon resonance (SPR and ELISA revealed direct interaction between HbAHP-25 and HIV-1 envelope protein, gp120. The peptide prevented binding of CD4 to gp120 and blocked subsequent steps leading to entry and/or fusion or both. Anti-HIV activity of HbAHP-25 appeared to be specific as it failed to inhibit the entry of HIV-1 pseudotyped virus (HIV-1 VSV. Further, HbAHP-25 was found to be non-cytotoxic to TZM-bl cells, VK2/E6E7 cells, CEM-GFP cells and PBMCs, even at higher concentrations. Moreover, HbAHP-25 retained its anti-HIV activity in presence of seminal plasma and vaginal fluid. In brief, the study identified HbAHP-25, a novel anti-HIV peptide, which directly interacts with gp120 and thus has a potential to inhibit early stages of HIV-1 infection.

  20. The Structure-Specific Recognition Protein 1 Associates with Lens Epithelium-Derived Growth Factor Proteins and Modulates HIV-1 Replication.

    Science.gov (United States)

    Lopez, Angelica P; Kugelman, Jeffrey R; Garcia-Rivera, Jose; Urias, Eduardo; Salinas, Sandra A; Fernandez-Zapico, Martin E; Llano, Manuel

    2016-07-17

    The lens epithelium-derived growth factor p75 (LEDGF/p75) is a chromatin-bound protein essential for efficient lentiviral integration. Genome-wide studies have located LEDGF/p75 inside actively transcribed genes where it mediates lentiviral integration. Although its role in HIV-1 integration is clearly established, the role of LEDGF/p75-associated proteins in HIV-1 infection remains unexplored. Using protein-protein interaction assays, we demonstrated that LEDGF/p75 complexes with a chromatin-remodeling complex facilitates chromatin transcription (FACT), a heterodimer of the structure-specific recognition protein 1 (SSRP1) and the human homolog of suppressor of Ty 16 (hSpt16). Detailed analysis of the interaction of LEDGF/p75 with the FACT complex indicates that LEDGF/p75 interacts with SSRP1 in an hSpt16-independent manner that requires the PWWP domain of LEDGF proteins and the HMG domain of SSRP1. Functional characterizations demonstrate a LEDGF/p75-independent role of SSRP1 in the regulation of HIV-1 replication. shRNA-mediated partial knockdown of SSRP1 reduces HIV-1 infection, but not Murine Leukemia Virus, in human CD4(+) T cells. Similarly, SSRP1 knockdown affects infection by HIV-1-derived viruses that express genes from the viral LTR but not from an internal immediate-early CMV promoter, suggesting a role of SSRP1 in LTR-driven gene expression but not in viral DNA integration. Together, our data demonstrate for the first time the association of LEDGF proteins with the FACT complex and give further support to a role of SSRP1 in HIV-1 infection. PMID:27216501

  1. Centrosomal pre-integration latency of HIV-1 in quiescent cells

    Directory of Open Access Journals (Sweden)

    Emiliani Stéphane

    2007-09-01

    Full Text Available Abstract Human immunodeficiency virus type 1 (HIV-1 efficiently replicates in dividing and non-dividing cells. However, HIV-1 infection is blocked at an early post-entry step in quiescent CD4+ T cells in vitro. The molecular basis of this restriction is still poorly understood. Here, we show that in quiescent cells, incoming HIV-1 sub-viral complexes concentrate and stably reside at the centrosome for several weeks. Upon cell activation, viral replication resumes leading to viral gene expression. Thus, HIV-1 can persist in quiescent cells as a stable, centrosome-associated, pre-integration intermediate.

  2. A novel mode of human immunodeficiency virus type 1 (HIV-1) activation: ligation of CD28 alone induces HIV-1 replication in naturally infected lymphocytes.

    OpenAIRE

    1993-01-01

    Induction of human immunodeficiency virus (HIV) replication in infected CD4+ T lymphocytes requires cellular activation. The ligation of CD28, a signal-transducing receptor with a natural ligand on activated B cells and antigen-presenting cells, provides a costimulating signal for interleukin 2 production and T-cell proliferation as well as coactivation of the transfected HIV long terminal repeat in Jurkat cells. The aim of the present study was to investigate the ability of CD28 ligation to ...

  3. Molecular dynamics simulations of HIV-1 protease complexed with saquinavir

    OpenAIRE

    Watson, S. J.

    2009-01-01

    Inhibition of the Human Immunode�ficiency virus type-1 (HIV-1) protease enzyme blocks HIV-1 replication. Protease inhibitor drugs have successfully been used as a therapy for HIV-infected individuals to reduce their viral loads and slow the progression to Acquired Immune Defi�ciency Syndrome (AIDS). However, mutations readily and rapidly accrue in the protease gene resulting in a reduced sensitivity of the protein to the inhibitor. In this thesis, molecular dynamics simulations (MDS)...

  4. HIV-protease inhibitors block the replication of both vesicular stomatitis and influenza viruses at an early post-entry replication step

    International Nuclear Information System (INIS)

    The inhibitors of HIV-1 protease (PIs) have been designed to block the activity of the viral aspartyl-protease. However, it is now accepted that this family of inhibitors can also affect the activity of cell proteases. Since the replication of many virus species requires the activity of host cell proteases, investigating the effects of PIs on the life cycle of viruses other than HIV would be of interest. Here, the potent inhibition induced by saquinavir and nelfinavir on the replication of both vesicular stomatitis and influenza viruses is described. These are unrelated enveloped RNA viruses infecting target cells upon endocytosis and intracellular fusion. The PI-induced inhibition was apparently a consequence of a block at the level of the fusion between viral envelope and endosomal membranes. These findings would open the way towards the therapeutic use of PIs against enveloped RNA viruses other than HIV.

  5. HIV-1 Antiretroviral Drug Therapy

    OpenAIRE

    Arts, Eric J.; Hazuda, Daria J.

    2012-01-01

    The most significant advance in the medical management of HIV-1 infection has been the treatment of patients with antiviral drugs, which can suppress HIV-1 replication to undetectable levels. The discovery of HIV-1 as the causative agent of AIDS together with an ever-increasing understanding of the virus replication cycle have been instrumental in this effort by providing researchers with the knowledge and tools required to prosecute drug discovery efforts focused on targeted inhibition with ...

  6. Iron(II) supramolecular helicates interfere with the HIV-1 Tat–TAR RNA interaction critical for viral replication

    Science.gov (United States)

    Malina, Jaroslav; Hannon, Michael J.; Brabec, Viktor

    2016-07-01

    The interaction between the HIV-1 transactivator protein Tat and TAR (transactivation responsive region) RNA, plays a critical role in HIV-1 transcription. Iron(II) supramolecular helicates were evaluated for their in vitro activity to inhibit Tat–TAR RNA interaction using UV melting studies, electrophoretic mobility shift assay, and RNase A footprinting. The results demonstrate that iron(II) supramolecular helicates inhibit Tat-TAR interaction at nanomolar concentrations by binding to TAR RNA. These studies provide a new insight into the biological potential of metallosupramolecular helicates.

  7. Iron(II) supramolecular helicates interfere with the HIV-1 Tat–TAR RNA interaction critical for viral replication

    Science.gov (United States)

    Malina, Jaroslav; Hannon, Michael J.; Brabec, Viktor

    2016-01-01

    The interaction between the HIV-1 transactivator protein Tat and TAR (transactivation responsive region) RNA, plays a critical role in HIV-1 transcription. Iron(II) supramolecular helicates were evaluated for their in vitro activity to inhibit Tat–TAR RNA interaction using UV melting studies, electrophoretic mobility shift assay, and RNase A footprinting. The results demonstrate that iron(II) supramolecular helicates inhibit Tat-TAR interaction at nanomolar concentrations by binding to TAR RNA. These studies provide a new insight into the biological potential of metallosupramolecular helicates. PMID:27405089

  8. Novel branched isocyanides as useful building blocks in the Passerini-amine deprotection-acyl migration (PADAM) synthesis of potential HIV-1 protease inhibitors

    OpenAIRE

    Gravestock, David; Lourens, Anna C. U.; Rousseau, Amanda L.; Hoppe, Heinrich C; Nkabinde, Lindiwe A.; Bode, Moira L.

    2012-01-01

    Novel branched isocyanides have been prepared from L-serine and used as building blocks in the Passerini- amine deprotection-acyl migration (PADAM) sequence for the preparation of compounds with activity against HIV-1 protease. http://www.journals.elsevier.com/tetrahedron-letters/ The authors wish to thank the Innovation Fund (now the Technology Innovation Agency, South Africa) for financial support

  9. NLRX1 Sequesters STING to Negatively Regulate the Interferon Response, Thereby Facilitating the Replication of HIV-1 and DNA Viruses.

    Science.gov (United States)

    Guo, Haitao; König, Renate; Deng, Meng; Riess, Maximilian; Mo, Jinyao; Zhang, Lu; Petrucelli, Alex; Yoh, Sunnie M; Barefoot, Brice; Samo, Melissa; Sempowski, Gregory D; Zhang, Aiping; Colberg-Poley, Anamaris M; Feng, Hui; Lemon, Stanley M; Liu, Yong; Zhang, Yanping; Wen, Haitao; Zhang, Zhigang; Damania, Blossom; Tsao, Li-Chung; Wang, Qi; Su, Lishan; Duncan, Joseph A; Chanda, Sumit K; Ting, Jenny P-Y

    2016-04-13

    Understanding the negative regulators of antiviral immune responses will be critical for advancing immune-modulated antiviral strategies. NLRX1, an NLR protein that negatively regulates innate immunity, was previously identified in an unbiased siRNA screen as required for HIV infection. We find that NLRX1 depletion results in impaired nuclear import of HIV-1 DNA in human monocytic cells. Additionally, NLRX1 was observed to reduce type-I interferon (IFN-I) and cytokines in response to HIV-1 reverse-transcribed DNA. NLRX1 sequesters the DNA-sensing adaptor STING from interaction with TANK-binding kinase 1 (TBK1), which is a requisite for IFN-1 induction in response to DNA. NLRX1-deficient cells generate an amplified STING-dependent host response to cytosolic DNA, c-di-GMP, cGAMP, HIV-1, and DNA viruses. Accordingly, Nlrx1(-/-) mice infected with DNA viruses exhibit enhanced innate immunity and reduced viral load. Thus, NLRX1 is a negative regulator of the host innate immune response to HIV-1 and DNA viruses. PMID:27078069

  10. Diminished transmission of drug resistant HIV-1 variants with reduced replication capacity in a human transmission model

    NARCIS (Netherlands)

    M. Pingen (Marieke); R. Sarrami-Forooshani (Ramin); A.M.J. Wensing (Annemarie); P. van Ham (Petra); A. Drewniak (Agata); C.A.B. Boucher (Charles); T.B.H. Geijtenbeek (Teunis); M. Nijhuis (Monique)

    2014-01-01

    textabstractBackground: Different patterns of drug resistance are observed in treated and therapy naïve HIV-1 infected populations. Especially the NRTI-related M184I/V variants, which are among the most frequently encountered mutations in treated patients, are underrepresented in the antiretroviral

  11. Human HERC5 restricts an early stage of HIV-1 assembly by a mechanism correlating with the ISGylation of Gag

    Directory of Open Access Journals (Sweden)

    Woods Matthew W

    2011-11-01

    Full Text Available Abstract Background The identification and characterization of several interferon (IFN-induced cellular HIV-1 restriction factors, defined as host cellular proteins or factors that restrict or inhibit the HIV-1 life cycle, have provided insight into the IFN response towards HIV-1 infection and identified new therapeutic targets for HIV-1 infection. To further characterize the mechanism underlying restriction of the late stages of HIV-1 replication, we assessed the ability of IFNbeta-induced genes to restrict HIV-1 Gag particle production and have identified a potentially novel host factor called HECT domain and RCC1-like domain-containing protein 5 (HERC5 that blocks a unique late stage of the HIV-1 life cycle. Results HERC5 inhibited the replication of HIV-1 over multiple rounds of infection and was found to target a late stage of HIV-1 particle production. The E3 ligase activity of HERC5 was required for blocking HIV-1 Gag particle production and correlated with the post-translational modification of Gag with ISG15. HERC5 interacted with HIV-1 Gag and did not alter trafficking of HIV-1 Gag to the plasma membrane. Electron microscopy revealed that the assembly of HIV-1 Gag particles was arrested at the plasma membrane, at an early stage of assembly. The mechanism of HERC5-induced restriction of HIV-1 particle production is distinct from the mechanism underlying HIV-1 restriction by the expression of ISG15 alone, which acts at a later step in particle release. Moreover, HERC5 restricted murine leukemia virus (MLV Gag particle production, showing that HERC5 is effective in restricting Gag particle production of an evolutionarily divergent retrovirus. Conclusions HERC5 represents a potential new host factor that blocks an early stage of retroviral Gag particle assembly. With no apparent HIV-1 protein that directly counteracts it, HERC5 may represent a new candidate for HIV/AIDS therapy.

  12. The Tat protein of human immunodeficiency virus-1 enhances hepatitis C virus replication through interferon gamma-inducible protein-10

    Directory of Open Access Journals (Sweden)

    Qu Jing

    2012-04-01

    Full Text Available Abstract Background Co-infection with human immunodeficiency virus-1 (HIV-1 and hepatitis C virus (HCV is associated with faster progression of liver disease and an increase in HCV persistence. However, the mechanism by which HIV-1 accelerates the progression of HCV liver disease remains unknown. Results HIV-1/HCV co-infection is associated with increased expression of interferon gamma-induced protein-10 (IP-10 mRNA in peripheral blood mononuclear cells (PBMCs. HCV RNA levels were higher in PBMCs of patients with HIV-1/HCV co-infection than in patients with HCV mono-infection. HIV-1 Tat and IP-10 activated HCV replication in a time-dependent manner, and HIV-1 Tat induced IP-10 production. In addition, the effect of HIV-1 Tat on HCV replication was blocked by anti-IP-10 monoclonal antibody, demonstrating that the effect of HIV-1 Tat on HCV replication depends on IP-10. Taken together, these results suggest that HIV-1 Tat protein activates HCV replication by upregulating IP-10 production. Conclusions HIV-1/HCV co-infection is associated with increased expression of IP-10 mRNA and replication of HCV RNA. Furthermore, both HIV-1 Tat and IP-10 activate HCV replication. HIV-1 Tat activates HCV replication by upregulating IP-10 production. These results expand our understanding of HIV-1 in HCV replication and the mechanism involved in the regulation of HCV replication mediated by HIV-1 during co-infection.

  13. Mutations in the TΨC Loop of E. coli tRNALys,3 Have Varied Effects on In Trans Complementation of HIV-1 Replication

    Directory of Open Access Journals (Sweden)

    Morrow Casey D

    2007-01-01

    Full Text Available Abstract Background Human immunodeficiency virus (HIV-1 exclusively selects and utilizes tRNALys,3 as the primer for initiation of reverse transcription. Several elements within the TΨC stem loop of tRNALys,3 are postulated to be important for selection and use in reverse transcription. The post-transcriptional modification at nucleotide 58 could play a role during plus-strand synthesis to stop reverse transcriptase from re-copying the tRNA primer. Nucleotides 53 and 54 within the TΨC stem loop of the tRNA have been shown to be important to form the complex between tRNA and the HIV-1 viral genome during initiation of reverse transcription. Results To further delineate the features of the TΨC stem loop of tRNALys,3 in reverse transcription, we have developed a complementation system in which E. coli tRNALys,3 is provided in trans to an HIV-1 genome in which the PBS is complementary to this tRNA. Successful selection and use of E. coli tRNALys,3 results in the production of infectious virus. We have used this single round infectious system to ascertain the effects that different mutants in the TΨC stem loop of tRNALys,3 have on complementation. Mutants were designed within the TΨC loop (nucleotide 58 and within the stem and loop of the TΨC loop (nucleotides 53 and 54. Analysis of the expression of E. coli tRNALys,3 mutants revealed differences in the capacity for aminoacylation, which is an indication of intracellular stability of the tRNA. Alteration of nucleotide 58 from A to U (A58U, T54G and TG5453CC all resulted in tRNALys,3 that was aminoacylated when expressed in cells, while a T54C mutation resulted in a tRNALys,3 that was not aminoacylated. Both the A58U and T54G mutated tRNALys,3 complemented HIV-1 replication similar to wild type E. coli tRNALys,3. In contrast, the TG5453CC tRNALys,3 mutant did not complement replication. Conclusion The results demonstrate that post-transcriptional modification of nucleotide 58 in tRNALys,3 is not

  14. Modulation of HIV-1 Gag NC/p1 cleavage efficiency affects protease inhibitor resistance and viral replicative capacity

    Czech Academy of Sciences Publication Activity Database

    Maarseveen van, N. M.; Andersson, Dan; Lepšík, Martin; Fun, A.; Schipper, P. J.; Jong de, D.; Boucher, Ch. A. B.; Nijhuis, M.

    2012-01-01

    Roč. 9, č. 29 (2012), s. 1-7. ISSN 1742-4690 EU Projects: European Commission(XE) 37693 - HIV PI RESISTANCE Grant ostatní: Dutch AIDS Fund(XE) 2006028; (NWO) VIDI(XE) 91796349 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV -1 * protease * Gag * resistance * cleavage Subject RIV: CE - Biochemistry Impact factor: 5.657, year: 2012

  15. Sargassum fusiforme fraction is a potent and specific inhibitor of HIV-1 fusion and reverse transcriptase

    Directory of Open Access Journals (Sweden)

    Thornber Carol

    2008-01-01

    Full Text Available Abstract Sargassum fusiforme (Harvey Setchell has been shown to be a highly effective inhibitor of HIV-1 infection. To identify its mechanism of action, we performed bioactivity-guided fractionation on Sargassum fusiforme mixture. Here, we report isolation of a bioactive fraction SP4-2 (S. fusiforme, which at 8 μg/ml inhibited HIV-1 infection by 86.9%, with IC50 value of 3.7 μg. That represents 230-fold enhancement of antiretroviral potency as compared to the whole extract. Inhibition was mediated against both CXCR4 (X4 and CCR5 (R5 tropic HIV-1. Specifically, 10 μg/ml SP4-2 blocked HIV-1 fusion and entry by 53%. This effect was reversed by interaction of SP4-2 with sCD4, suggesting that S. fusiforme inhibits HIV-1 infection by blocking CD4 receptor, which also explained observed inhibition of both X4 and R5-tropic HIV-1. SP4-2 also inhibited HIV-1 replication after virus entry, by directly inhibiting HIV-1 reverse transcriptase (RT in a dose dependent manner by up to 79%. We conclude that the SP4-2 fraction contains at least two distinct and biologically active molecules, one that inhibits HIV-1 fusion by interacting with CD4 receptor, and another that directly inhibits HIV-1 RT. We propose that S. fusiforme is a lead candidate for anti-HIV-1 drug development.

  16. Mechanisms of inhibition of HIV replication by nonnucleoside reverse transcriptase inhibitors

    OpenAIRE

    Sluis-Cremer, Nicolas; Tachedjian, Gilda

    2008-01-01

    The nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) are a therapeutic class of compounds that are routinely used, in combination with other antiretroviral drugs, to treat HIV-1 infection. NNRTIs primarily block HIV-1 replication by preventing RT from completing reverse transcription of the viral single-stranded RNA genome into DNA. However, some NNRTIs, such as efavirenz, have been shown to inhibit the late stages of HIV-1 replication by interfering with HIV-1 Gag-Pol polyprotein...

  17. Adenovirus Vectors Block Human Immunodeficiency Virus–1 Replication in Human Alveolar Macrophages by Inhibition of the Long Terminal Repeat

    OpenAIRE

    Kaner, Robert J.; Santiago, Francisco; Rahaghi, Franck; Michaels, Elizabeth; Moore, John P.; Crystal, Ronald G.

    2009-01-01

    Heterologous viruses may transactivate or suppress human immunodeficiency virus (HIV)–1 replication. An adenovirus type 5 gene transfer vector (Ad5) HIV-1 vaccine was recently evaluated in a clinical trial, without efficacy. In this context, it is relevant to ask what effect Ad vectors have on HIV-1 replication, particularly in cells that are part of the innate immune system. Infection of HIV-1–infected human alveolar macrophages (AMs) obtained from HIV-1+ individuals with an Ad vector contai...

  18. The predominance of Human Immunodeficiency Virus type 1 (HIV-1 circulating recombinant form 02 (CRF02_AG in West Central Africa may be related to its replicative fitness

    Directory of Open Access Journals (Sweden)

    Butel Christelle

    2006-07-01

    Full Text Available Abstract Background CRF02_AG is the predominant HIV strain circulating in West and West Central Africa. The aim of this study was to test whether this predominance is associated with a higher in vitro replicative fitness relative to parental subtype A and G viruses. Primary HIV-1 isolates (10 CRF02_AG, 5 subtype A and 5 subtype G were obtained from a well-described Cameroonian cohort. Growth competition experiments were carried out at equal multiplicity of infection in activated T cells and monocyte-derived dendritic cells (MO-DC in parallel. Results Dual infection/competition experiments in activated T cells clearly indicated that CRF02_AG isolates had a significant replication advantage over the subtype A and subtype G viruses. The higher fitness of CRF02_AG was evident for isolates from patients with CD4+ T cell counts >200 cells/μL (non-AIDS or CD4+ T cell counts Conclusion We observed a higher ex vivo replicative fitness of CRF02_AG isolates compared to subtype A and G viruses from the same geographic region and showed that this was independent of the co-receptor tropism and irrespective of high or low CD4+ T cell count. This advantage in replicative fitness may contribute to the dominant spread of CRF02_AG over A and G subtypes in West and West Central Africa.

  19. Superior control of HIV-1 replication by CD8+ T cells targeting conserved epitopes: implications for HIV vaccine design.

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    Pratima Kunwar

    Full Text Available A successful HIV vaccine will likely induce both humoral and cell-mediated immunity, however, the enormous diversity of HIV has hampered the development of a vaccine that effectively elicits both arms of the adaptive immune response. To tackle the problem of viral diversity, T cell-based vaccine approaches have focused on two main strategies (i increasing the breadth of vaccine-induced responses or (ii increasing vaccine-induced responses targeting only conserved regions of the virus. The relative extent to which set-point viremia is impacted by epitope-conservation of CD8(+ T cell responses elicited during early HIV-infection is unknown but has important implications for vaccine design. To address this question, we comprehensively mapped HIV-1 CD8(+ T cell epitope-specificities in 23 ART-naïve individuals during early infection and computed their conservation score (CS by three different methods (prevalence, entropy and conseq on clade-B and group-M sequence alignments. The majority of CD8(+ T cell responses were directed against variable epitopes (p<0.01. Interestingly, increasing breadth of CD8(+ T cell responses specifically recognizing conserved epitopes was associated with lower set-point viremia (r = - 0.65, p = 0.009. Moreover, subjects possessing CD8(+ T cells recognizing at least one conserved epitope had 1.4 log10 lower set-point viremia compared to those recognizing only variable epitopes (p = 0.021. The association between viral control and the breadth of conserved CD8(+ T cell responses may be influenced by the method of CS definition and sequences used to determine conservation levels. Strikingly, targeting variable versus conserved epitopes was independent of HLA type (p = 0.215. The associations with viral control were independent of functional avidity of CD8(+ T cell responses elicited during early infection. Taken together, these data suggest that the next-generation of T-cell based HIV-1 vaccines should focus

  20. Identification of a novel sulfonamide non-nucleoside reverse transcriptase inhibitor by a phenotypic HIV-1 full replication assay.

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    Tae-Hee Kim

    Full Text Available Classical target-based, high-throughput screening has been useful for the identification of inhibitors for known molecular mechanisms involved in the HIV life cycle. In this study, the development of a cell-based assay that uses a phenotypic drug discovery approach based on automated high-content screening is described. Using this screening approach, the antiviral activity of 26,500 small molecules from a relevant chemical scaffold library was evaluated. Among the selected hits, one sulfonamide compound showed strong anti-HIV activity against wild-type and clinically relevant multidrug resistant HIV strains. The biochemical inhibition, point resistance mutations and the activity of structural analogs allowed us to understand the mode of action and propose a binding model for this compound with HIV-1 reverse transcriptase.

  1. Identification of a novel sulfonamide non-nucleoside reverse transcriptase inhibitor by a phenotypic HIV-1 full replication assay.

    Science.gov (United States)

    Kim, Tae-Hee; Ko, Yoonae; Christophe, Thierry; Cechetto, Jonathan; Kim, Junwon; Kim, Kyoung-Ae; Boese, Annette S; Garcia, Jean-Michel; Fenistein, Denis; Ju, Moon Kyeong; Kim, Junghwan; Han, Sung-Jun; Kwon, Ho Jeong; Brondani, Vincent; Sommer, Peter

    2013-01-01

    Classical target-based, high-throughput screening has been useful for the identification of inhibitors for known molecular mechanisms involved in the HIV life cycle. In this study, the development of a cell-based assay that uses a phenotypic drug discovery approach based on automated high-content screening is described. Using this screening approach, the antiviral activity of 26,500 small molecules from a relevant chemical scaffold library was evaluated. Among the selected hits, one sulfonamide compound showed strong anti-HIV activity against wild-type and clinically relevant multidrug resistant HIV strains. The biochemical inhibition, point resistance mutations and the activity of structural analogs allowed us to understand the mode of action and propose a binding model for this compound with HIV-1 reverse transcriptase. PMID:23874756

  2. Development of an HIV-1 Microbicide Based on Caulobacter crescentus: Blocking Infection by High-Density Display of Virus Entry Inhibitors.

    Science.gov (United States)

    Farr, Christina; Nomellini, John F; Ailon, Evan; Shanina, Iryna; Sangsari, Sassan; Cavacini, Lisa A; Smit, John; Horwitz, Marc S

    2013-01-01

    The HIV/AIDS pandemic remains an enormous global health concern. Despite effective prevention options, 2.6 million new infections occur annually, with women in developing countries accounting for more than half of these infections. New prevention strategies that can be used by women are urgently needed. Topical microbicides specific for HIV-1 represent a promising prevention strategy. Conceptually, using harmless bacteria to display peptides or proteins capable of blocking entry provides an inexpensive approach to microbicide development. To avoid the potential pitfalls of engineering commensal bacteria, our strategy is to genetically display infection inhibitors on a non-native bacterium and rely on topical application of stabilized bacteria before potential virus exposure. Due to the high density cell-surface display capabilities and the inherent low toxicity of the bacterium, the S-layer mediated protein display capabilities of the non-pathogenic bacterium Caulobacter crescentus has been exploited for this approach. We have demonstrated that C. crescentus displaying MIP1α or CD4 interfered with the virus entry pathway and provided significant protection from HIV-1 pseudovirus representing clade B in a standard single cycle infection assay. Here we have expanded our C. crescentus based microbicide approach with additional and diverse classes of natural and synthetic inhibitors of the HIV-1 entry pathway. All display constructs provided variable but significant protection from HIV-1 infection; some with protection as high as 70%. Further, we describe protection from infection with additional viral clades. These findings indicate the significant potential for engineering C. crescentus to be an effective and readily adaptable HIV-1 microbicide platform. PMID:23840383

  3. Development of an HIV-1 Microbicide Based on Caulobacter crescentus: Blocking Infection by High-Density Display of Virus Entry Inhibitors.

    Directory of Open Access Journals (Sweden)

    Christina Farr

    Full Text Available The HIV/AIDS pandemic remains an enormous global health concern. Despite effective prevention options, 2.6 million new infections occur annually, with women in developing countries accounting for more than half of these infections. New prevention strategies that can be used by women are urgently needed. Topical microbicides specific for HIV-1 represent a promising prevention strategy. Conceptually, using harmless bacteria to display peptides or proteins capable of blocking entry provides an inexpensive approach to microbicide development. To avoid the potential pitfalls of engineering commensal bacteria, our strategy is to genetically display infection inhibitors on a non-native bacterium and rely on topical application of stabilized bacteria before potential virus exposure. Due to the high density cell-surface display capabilities and the inherent low toxicity of the bacterium, the S-layer mediated protein display capabilities of the non-pathogenic bacterium Caulobacter crescentus has been exploited for this approach. We have demonstrated that C. crescentus displaying MIP1α or CD4 interfered with the virus entry pathway and provided significant protection from HIV-1 pseudovirus representing clade B in a standard single cycle infection assay. Here we have expanded our C. crescentus based microbicide approach with additional and diverse classes of natural and synthetic inhibitors of the HIV-1 entry pathway. All display constructs provided variable but significant protection from HIV-1 infection; some with protection as high as 70%. Further, we describe protection from infection with additional viral clades. These findings indicate the significant potential for engineering C. crescentus to be an effective and readily adaptable HIV-1 microbicide platform.

  4. Differential effect of CLK SR Kinases on HIV-1 gene expression: potential novel targets for therapy

    Directory of Open Access Journals (Sweden)

    Dobson Wendy

    2011-06-01

    Full Text Available Abstract Background RNA processing plays a critical role in the replication of HIV-1, regulated in part through the action of host SR proteins. To explore the impact of modulating SR protein activity on virus replication, the effect of increasing or inhibiting the activity of the Cdc2-like kinase (CLK family of SR protein kinases on HIV-1 expression and RNA processing was examined. Results Despite their high homology, increasing individual CLK expression had distinct effects on HIV-1, CLK1 enhancing Gag production while CLK2 inhibited the virus. Parallel studies on the anti-HIV-1 activity of CLK inhibitors revealed a similar discrepant effect on HIV-1 expression. TG003, an inhibitor of CLK1, 2 and 4, had no effect on viral Gag synthesis while chlorhexidine, a CLK2, 3 and 4 inhibitor, blocked virus production. Chlorhexidine treatment altered viral RNA processing, decreasing levels of unspliced and single spliced viral RNAs, and reduced Rev accumulation. Subsequent experiments in the context of HIV-1 replication in PBMCs confirmed the capacity of chlorhexidine to suppress virus replication. Conclusions Together, these findings establish that HIV-1 RNA processing can be targeted to suppress virus replication as demonstrated by manipulating individual CLK function and identified chlorhexidine as a lead compound in the development of novel anti-viral therapies.

  5. Mother-to-Child HIV-1 Transmission Events Are Differentially Impacted by Breast Milk and Its Components from HIV-1-Infected Women.

    Directory of Open Access Journals (Sweden)

    Ruizhong Shen

    Full Text Available Breast milk is a vehicle of infection and source of protection in post-natal mother-to-child HIV-1 transmission (MTCT. Understanding the mechanism by which breast milk limits vertical transmission will provide critical insight into the design of preventive and therapeutic approaches to interrupt HIV-1 mucosal transmission. However, characterization of the inhibitory activity of breast milk in human intestinal mucosa, the portal of entry in postnatal MTCT, has been constrained by the limited availability of primary mucosal target cells and tissues to recapitulate mucosal transmission ex vivo. Here, we characterized the impact of skimmed breast milk, breast milk antibodies (Igs and non-Ig components from HIV-1-infected Ugandan women on the major events of HIV-1 mucosal transmission using primary human intestinal cells and tissues. HIV-1-specific IgG antibodies and non-Ig components in breast milk inhibited the uptake of Ugandan HIV-1 isolates by primary human intestinal epithelial cells, viral replication in and transport of HIV-1- bearing dendritic cells through the human intestinal mucosa. Breast milk HIV-1-specific IgG and IgA, as well as innate factors, blocked the uptake and transport of HIV-1 through intestinal mucosa. Thus, breast milk components have distinct and complementary effects in reducing HIV-1 uptake, transport through and replication in the intestinal mucosa and, therefore, likely contribute to preventing postnatal HIV-1 transmission. Our data suggests that a successful preventive or therapeutic approach would require multiple immune factors acting at multiple steps in the HIV-1 mucosal transmission process.

  6. Factors secreted by human T lymphotropic virus type I (HTLV-I)-infected cells can enhance or inhibit replication of HIV-1 in HTLV-I-uninfected cells: implications for in vivo coinfection with HTLV-I and HIV-1.

    Science.gov (United States)

    Moriuchi, H; Moriuchi, M; Fauci, A S

    1998-05-18

    It remains controversial whether human T lymphotropic virus type I (HTLV-I) coinfection leads to more rapid progression of human immunodeficiency virus (HIV) disease in dually infected individuals. To investigate whether HTLV-I infection of certain cells can modulate HIV-1 infection of surrounding cells, primary CD4(+) T cells were treated with cell-free supernatants from HTLV-I-infected MT-2 cell cultures. The primary CD4+ T cells became resistant to macrophage (M)-tropic HIV-1 but highly susceptible to T cell (T)-tropic HIV-1. The CC chemokines RANTES (regulated on activation, normal T cell expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta in the MT-2 cell supernatants were identified as the major suppressive factors for M-tropic HIV-1 as well as the enhancers of T-tropic HIV-1 infection, whereas soluble Tax protein increased susceptibility to both M- and T-tropic HIV-1. The effect of Tax or CC chemokines on T-tropic HIV-1 was mediated, at least in part, by increasing HIV Env-mediated fusogenicity. Our data suggest that the net effect of HTLV-I coinfection in HIV-infected individuals favors the transition from M- to T-tropic HIV phenotype, which is generally indicative of progressive HIV disease. PMID:9584147

  7. Alterations in the expression of DEAD-box and other RNA binding proteins during HIV-1 replication

    OpenAIRE

    Zeichner Steven L; Krishnan Vyjayanthi

    2004-01-01

    Abstract Recent results showed that certain DEAD box protein RNA helicases, DDX3 and DDX1, play an important role in the HIV infection cycle by facilitating the export of long, singly spliced or unspliced HIV RNAs from the nucleus via the CRM1-Rev pathway. Close examination of an extensive microarray expression profiling dataset obtained from cells latently infected with HIV induced to undergo lytic viral replication indicated that additional DEAD box proteins, beyond DDX3 and DDX1, exhibit d...

  8. Pin1 liberates the human immunodeficiency virus type-1 (HIV-1): Must we stop it?

    Science.gov (United States)

    Hou, Hai; Wang, Jing-Zhang; Liu, Bao-Guo; Zhang, Ting

    2015-07-01

    Acquired immune deficiency syndrome (AIDS) is mainly caused by the human immunodeficiency virus type-1 (HIV-1). To our knowledge, this is the first review focusing on the vital role of Pin1 in the infection of HIV-1 and the development of AIDS. We and others have demonstrated that Pin1, the only known cis-to-trans isomerase recognizing the pThr/pSer-Pro motifs in proteins, plays striking roles in several human diseases. Interestingly, recent evidence gradually indicates that Pin1 regulates several key steps of the life cycle of HIV-1, including the uncoating of the HIV-1 core, the reverse transcription of the RNA genome of HIV-1, and the integration of the HIV-1 cDNA into human chromosomes. Whereas inhibiting Pin1 suppresses all of these key steps and attenuates the replication of HIV-1, at the same time different PIN1 gene variants are correlated with the susceptibility to HIV-1 infection. Furthermore, Pin1 potentially promotes HIV-1 infection by activating multiple oncogenes and inactivating multiple tumor suppressors, extending the life span of HIV-infected cells. These descriptions suggest Pin1 as a promising therapeutic target for the prevention of HIV-1 and highlight the possibility of blocking the development of AIDS by Pin1 inhibitors. PMID:25913034

  9. Computer-aided design of novel HIV-1 entry inhibitors blocking the virus envelope gp120 V3 loop

    Directory of Open Access Journals (Sweden)

    Tuzikov A. V.

    2012-12-01

    Full Text Available Aim. The object of this study was to implement computer-aided design of the water-soluble analog of glycolipid β -galactosylceramide (β-GalCer, which presents a potential HIV-1 entry inhibitor, by the analysis of intermolecular interactions of β-GalCer with the central region of the virus envelope gp120 V3 loop followed by synthesis of this glycolipid derivative and testing for antiviral activity. Methods. To reach the object of view, computer modeling procedures, such as quantum chemical calculations, molecular docking, molecular dynamics and free energy simulations, were involved in the studies in conjunction with chemical synthesis and anti-HIV-1 assay methods. Results. As a result, the high probability of exhibiting of antiviral activity was predicted for the designed β-GalCer analog. The data of molecular modeling were confirmed by those of primary medical trials of the synthesized compound. Conclusions. In the light of the findings obtained, the designed analog of β-GalCer may be considered as the basic structure for simulation of its more potent structural forms and for posterior selection of drug candidates most promising for synthesis and anti-HIV-1 assays.

  10. Importin α1与HIV-1整合酶相互作用及其对病毒复制的影响%Importin α1 interacts with HIV-1 integrase and plays a role in viral replication

    Institute of Scientific and Technical Information of China (English)

    敖竹君; Kallesh Danappa Jayappa; 姚小剑

    2014-01-01

    目的 研究HIV-1整合酶与细胞蛋白Importin α1(Impα1)的相互作用及其对HIV-1复制的影响.方法 采用化学发光免疫共沉淀系统定量检测细胞内HIV-1整合酶与Impα1蛋白的相互作用,同时利用基因沉默技术下调CD4+C8166 T细胞中Impα1的表达,以研究Impα/β入核转运途径对HIV 1复制的影响.结果 当T细胞内Impα1表达下降时,HIV 1对其感染性显著减弱.Real time PCR分析结果显示,尽管病毒逆转录未受到影响,但其2 LTR DNA(入核指标)及整合DNA的形成受到了抑制,提示Impα1的下调明显影响HIV-1入核转运过程.结论 该研究为HIV-1整合酶与Impα1蛋白之间的相互作用及其在病毒感染中的影响提供了重要的实验依据.

  11. Role of HIV-1 subtype C envelope V3 to V5 regions in viral entry, coreceptor utilization and replication efficiency in primary T-lymphocytes and monocyte-derived macrophages

    Directory of Open Access Journals (Sweden)

    Gopalan Sarla

    2007-11-01

    Full Text Available Abstract Background Several subtypes of HIV-1 circulate in infected people worldwide, including subtype B in the United States and subtype C in Africa and India. To understand the biological properties of HIV-1 subtype C, including cellular tropism, virus entry, replication efficiency and cytopathic effects, we reciprocally inserted our previously characterized envelope V3–V5 regions derived from 9 subtype C infected patients from India into a subtype B molecular clone, pNL4-3. Equal amounts of the chimeric viruses were used to infect T-lymphocyte cell lines (A3.01 and MT-2, coreceptor cell lines (U373-MAGI-CCR5/CXCR4, primary blood T-lymphocytes (PBL and monocyte-derived macrophages (MDM. Results We found that subtype C envelope V3–V5 region chimeras failed to replicate in T-lymphocyte cell lines but replicated in PBL and MDM. In addition, these chimeras were able to infect U373MAGI-CD4+-CCR5+ but not U373MAGI-CD4+-CXCR4+ cell line, suggesting CCR5 coreceptor utilization and R5 phenotypes. These subtype C chimeras were unable to induce syncytia in MT-2 cells, indicative of non-syncytium inducing (NSI phenotypes. More importantly, the subtype C envelope chimeras replicated at higher levels in PBL and MDM compared with subtype B chimeras and isolates. Furthermore, the higher levels subtype C chimeras replication in PBL and MDM correlated with increased virus entry in U373MAGI-CD4+-CCR5+. Conclusion Taken together, these results suggest that the envelope V3 to V5 regions of subtype C contributed to higher levels of HIV-1 replication compared with subtype B chimeras, which may contribute to higher viral loads and faster disease progression in subtype C infected individuals than other subtypes as well as rapid HIV-1 subtype C spread in India.

  12. Harnessing the CRISPR/Cas9 system to disrupt latent HIV-1 provirus

    OpenAIRE

    Hirotaka Ebina; Naoko Misawa; Yuka Kanemura; Yoshio Koyanagi

    2013-01-01

    Even though highly active anti-retroviral therapy is able to keep HIV-1 replication under control, the virus can lie in a dormant state within the host genome, known as a latent reservoir, and poses a threat to re-emerge at any time. However, novel technologies aimed at disrupting HIV-1 provirus may be capable of eradicating viral genomes from infected individuals. In this study, we showed the potential of the CRISPR/Cas9 system to edit the HIV-1 genome and block its expression. When LTR-targ...

  13. Production of Interferons and β-Chemokines by Placental Trophoblasts of HIV-1-Infected Women

    OpenAIRE

    Reuben, James M.; Shearer, William T; Mary Paul; Claudia Kozinetz; Stanley Cron; Popek, Edwina J; Hunter Hammill; Bang-Ning Lee

    2001-01-01

    Objective: The mechanism whereby the placental cells of a human immunodeficiency virus (HIV)-1-infected mother protect the fetus from HIV-1 infection is unclear. Interferons (IFNs) inhibit the replication of viruses by acting at various stages of the life cycle and may play a role in protecting against vertical transmission of HIV-1. In addition the β-chemokines RANTES (regulated on activation T cell expressed and secreted), macrophage inflammatory protein-1-α (MIP-1α), and MIP-1β can block H...

  14. NFAT5 regulates HIV-1 in primary monocytes via a highly conserved long terminal repeat site.

    Directory of Open Access Journals (Sweden)

    Shahin Ranjbar

    2006-12-01

    Full Text Available To replicate, HIV-1 capitalizes on endogenous cellular activation pathways resulting in recruitment of key host transcription factors to its viral enhancer. RNA interference has been a powerful tool for blocking key checkpoints in HIV-1 entry into cells. Here we apply RNA interference to HIV-1 transcription in primary macrophages, a major reservoir of the virus, and specifically target the transcription factor NFAT5 (nuclear factor of activated T cells 5, which is the most evolutionarily divergent NFAT protein. By molecularly cloning and sequencing isolates from multiple viral subtypes, and performing DNase I footprinting, electrophoretic mobility shift, and promoter mutagenesis transfection assays, we demonstrate that NFAT5 functionally interacts with a specific enhancer binding site conserved in HIV-1, HIV-2, and multiple simian immunodeficiency viruses. Using small interfering RNA to ablate expression of endogenous NFAT5 protein, we show that the replication of three major HIV-1 viral subtypes (B, C, and E is dependent upon NFAT5 in human primary differentiated macrophages. Our results define a novel host factor-viral enhancer interaction that reveals a new regulatory role for NFAT5 and defines a functional DNA motif conserved across HIV-1 subtypes and representative simian immunodeficiency viruses. Inhibition of the NFAT5-LTR interaction may thus present a novel therapeutic target to suppress HIV-1 replication and progression of AIDS.

  15. Screening of HIV-1 replication inhibitors by using pseudotyped virus system%应用假病毒技术研究HIV-1复制抑制剂

    Institute of Scientific and Technical Information of China (English)

    曹颖莉; 郭颖

    2008-01-01

    建立以HIV-1复制为靶点的细胞水平假病毒药理筛选模型,并运用该模型筛选化合物库中随机选取的化合物.细胞水平的HIV-1假病毒药理筛选模型是应用水泡性口膜炎病毒的外壳糖蛋白(vesicular stomatitis virus glycoprotein,VSV-G)包装HIV-1核心建立的,简称VSVG/HIV模型.细胞被VSVG/HIV感染后,病毒携带的报告基因的表达水平(荧光素酶活性或GFP阳性细胞比例)反映了HIV-1的复制水平.对HIV-1复制有抑制作用的化合物应用VSVG/MLV模型对其特异性地进一步检测.被感染细胞中报告基因的表达水平与病毒稀释度呈显著的剂量依赖效应.阳性药物齐多夫定(zidovudine,AZT)、拉米夫定(lamivudine,3TC)、去羟基苷(didanosine,DDI)可剂量依赖性地抑制HIV-1的复制,其IC50分别为48.5 nmol·L-1、 0.13 μmol·L-1和1.73 μmol·L-1,与文献报道一致.在随机筛选的500个化合物中有3个化合物可以抑制HIV-1的复制,IC50分别为1.92、 5.38和3.39 μmol·L-1,而对MLV的复制无影响.VSVG/HIV假病毒系统是一种安全、有效的针对HIV-1复制的药理筛选模型.当将此模型与VSVG/MLV模型联合使用时,可判断化合物作用的特异性.实验表明:3个化合物,2-甲硫基-5-(4-甲基苯并)酰胺基-1,3,4-噻二唑(化合物A)、N-(3-羟基苯基)-2-(4-异丁基苯基)丙酰胺(化合物B)和N-(4-甲基吡啶基)-4-甲基苯磺酰胺(化合物C)可以特异性抑制HIV-1的复制.

  16. Comparative molecular surface analysis (CoMSA) for virtual combinatorial library screening of styrylquinoline HIV-1 blocking agents.

    Science.gov (United States)

    Niedbala, Halina; Polanski, Jaroslaw; Gieleciak, Rafal; Musiol, Robert; Tabak, Dominik; Podeszwa, Barbara; Bak, Andrzej; Palka, Anna; Mouscadet, Jean-Francois; Gasteiger, Johann; Le Bret, Marc

    2006-12-01

    We used comparative molecular surface analysis to design molecules for the synthesis as part of the search for new HIV-1 integrase inhibitors. We analyzed the virtual combinatorial library (VCL) constituted from various moieties of styrylquinoline and styrylquinazoline inhibitors. Since imines can be applied in a strategy of dynamic combinatorial chemistry (DCC), we also tested similar compounds in which the -C=N- or -N=C- linker connected the heteroaromatic and aromatic moieties. We then used principal component analysis (PCA) or self-organizing maps (SOM), namely, the Kohonen neural networks to obtain a clustering plot analyzing the diversity of the VCL formed. Previously synthesized compounds of known activity, used as molecular probes, were projected onto this plot, which provided a set of promising virtual drugs. Moreover, we further modified the above mentioned VCL to include the single bond linker -C-N- or -N-C-. This allowed increasing compound stability but expanded also the diversity between the available molecular probes and virtual targets. The application of the CoMSA with SOM indicated important differences between such compounds and active molecular probes. We synthesized such compounds to verify the computational predictions. PMID:17168681

  17. Knockdown of MAP4 and DNAL1 produces a post-fusion and pre-nuclear translocation impairment in HIV-1 replication

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Daniel E., E-mail: d-gallo@northwestern.edu; Hope, Thomas J., E-mail: thope@northwestern.edu

    2012-01-05

    DNAL1 and MAP4 are both microtubule-associated proteins. These proteins were identified as HIV-1 dependency factors in a screen with wild-type HIV-1. In this study we demonstrate that knockdown using DNAL1 and MAP4 siRNAs and shRNAs inhibits HIV-1 infection regardless of envelope. Using a fusion assay, we show that DNAL1 and MAP4 do not impact fusion. By assaying for late reverse transcripts and 2-LTR circles, we show that DNAL1 and MAP4 inhibit both by approximately 50%. These results demonstrate that DNAL1 and MAP4 impact reverse transcription but not nuclear translocation. DNAL1 and MAP4 knockdown cells do not display cytoskeletal defects. Together these experiments indicate that DNAL1 and MAP4 may exert their functions in the HIV life cycle at reverse transcription, prior to nuclear translocation.

  18. Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

    Directory of Open Access Journals (Sweden)

    Li Yun-Yao

    2001-09-01

    Full Text Available Abstract Background Cellulose acetate phthalate (CAP, a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1 and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1 and 2 (HSV-2 and the major nonviral sexually transmitted disease (STD pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. Methods Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. Results 1 CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2 this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3 CAP binding to HIV-1 virions impairs their infectivity; 4 these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. Conclusions These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection.

  19. Demonstration of a Novel HIV-1 Restriction Phenotype from a Human T Cell Line

    OpenAIRE

    Han, Yanxing; Xiaojun WANG; Dang, Ying; Zheng, Yong-Hui

    2008-01-01

    Background Although retroviruses may invade host cells, a productive infection can be established only after the virus counteracts inhibition from different types of host restriction factors. Fv1, APOBEC3G/F, TRIM5α, ZAP, and CD317 inhibit the replication of different retroviruses by interfering with viral uncoating, reverse transcription, nuclear import, RNA stability, and release. In humans, although APOBEC3G/3F and CD317 block HIV-1 replication, their antiviral activities are neutralized b...

  20. Structure-functional analysis of human immunodeficiency virus type 1 (HIV-1) Vpr: role of leucine residues on Vpr-mediated transactivation and virus replication

    International Nuclear Information System (INIS)

    HIV-1 Vpr has been shown to transactivate LTR-directed expression through its interaction with several proteins of cellular origin including the glucocorticoid receptor (GR). Upon activation, steroid receptors bind to proteins containing the signature motif LxxLL, translocate into the nucleus, bind to their response element, and activate transcription. The presence of such motifs in HIV-1 Vpr has prompted us to undertake the analysis of the role of specific leucine residue(s) involved in Vpr-GR interaction, subcellular localization and its effect on Vpr-GR-mediated transactivation. The individual leucine residues present in H I, II, and III were mutated in the Vpr molecule and evaluated for their ability to interact with GR, transactivate GRE and HIV-1 LTR promoters, and their colocalization with GR. While Vpr mutants L42 and L67 showed reduced activation, substitutions at L20, L23, L26, L39, L64, and L68 exhibited a similar and slightly higher level of activation compared to Vprwt. Interestingly, a substitution at residue L22 resulted in a significantly higher GRE and HIV-1 LTR transactivation (8- to 11-fold higher) in comparison to wild type. Confocal microscopy indicated that Vpr L22A exhibited a distinct condensed nuclear localization pattern different from the nuclear/perinuclear pattern noted with Vprwt. Further, electrophoretic mobility shift assay (EMSA) revealed that the VprL22A-GR complex had higher DNA-binding activity when compared to the wild type Vpr-GR complex. These results suggest a contrasting role for the leucine residues on HIV-1 LTR-directed transactivation dependent upon their location in Vpr

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

    Directory of Open Access Journals (Sweden)

    Barré-Sinoussi Françoise

    2009-05-01

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

  2. UvrD controls the access of recombination proteins to blocked replication forks

    OpenAIRE

    Lestini, Roxane; Michel, Bénédicte

    2007-01-01

    Blocked replication forks often need to be processed by recombination proteins prior to replication restart. In Escherichia coli, the UvrD repair helicase was recently shown to act at inactivated replication forks, where it counteracts a deleterious action of RecA. Using two mutants affected for different subunits of the polymerase III holoenzyme (Pol IIIh), we show here that the anti-RecA action of UvrD at blocked forks reflects two different activities of this enzyme. A defective UvrD mutan...

  3. PVP-coated silver nanoparticles block the transmission of cell-free and cell-associated HIV-1 in human cervical culture

    Directory of Open Access Journals (Sweden)

    Rodriguez-Padilla Cristina

    2010-07-01

    Full Text Available Abstract Background Previous in vitro studies have demonstrated that polyvinylpyrrolidone coated silver nanoparticles (PVP-coated AgNPs have antiviral activity against HIV-1 at non-cytotoxic concentrations. These particles also demonstrate broad spectrum virucidal activity by preventing the interaction of HIV-1 gp120 and cellular CD4, thereby inhibiting fusion or entry of the virus into the host cell. In this study, we evaluated the antiviral activity of PVP-coated AgNPs as a potential topical vaginal microbicide to prevent transmission of HIV-1 infection using human cervical culture, an in vitro model that simulates in vivo conditions. Results When formulated into a non-spermicidal gel (Replens at a concentration of 0.15 mg/mL, PVP-coated AgNPs prevented the transmission of cell-associated HIV-1 and cell-free HIV-1 isolates. Importantly, PVP-coated AgNPs were not toxic to the explant, even when the cervical tissues were exposed continuously to 0.15 mg/mL of PVP-coated AgNPs for 48 h. Only 1 min of PVP-coated AgNPs pretreatment to the explant was required to prevent transmission of HIV-1. Pre-treatment of the cervical explant with 0.15 mg/mL PVP-coated AgNPs for 20 min followed by extensive washing prevented the transmission of HIV-1 in this model for 48 h. Conclusions A formulation of PVP-coated AgNPs homogenized in Replens gel acts rapidly to inhibit HIV-1 transmission after 1 min and offers long-lasting protection of the cervical tissue from infection for 48 h, with no evidence of cytotoxicity observed in the explants. Based on this data, PVP-coated AgNPs are a promising microbicidal candidate for use in topical vaginal/cervical agents to prevent HIV-1 transmission, and further research is warranted.

  4. Vaccine-induced plasma IgA specific for the C1 region of the HIV-1 envelope blocks binding and effector function of IgG

    OpenAIRE

    Tomaras, Georgia D.; Ferrari, Guido; Shen, Xiaoying; Alam, S. Munir; Liao, Hua-Xin; Pollara, Justin; Bonsignori, Mattia; Moody, M. Anthony; Fong, Youyi; Chen, Xi; Poling, Brigid; Nicholson, Cindo O.; Zhang, Ruijun; Lu, Xiaozhi; Parks, Robert,

    2013-01-01

    Analysis of correlates of risk of infection in the RV144 HIV-1 vaccine efficacy trial demonstrated that plasma IgG against the HIV-1 envelope (Env) variable region 1 and 2 inversely correlated with risk, whereas HIV-1 Env-specific plasma IgA responses directly correlated with risk. In the secondary analysis, antibody-dependent cellular cytotoxicity (ADCC) was another inverse correlate of risk, but only in the presence of low plasma IgA Env-specific antibodies. Thus, we investigated the hypoth...

  5. HIV-1逆转录酶H221Y突变对Y181C突变株复制能力影响研究%Impact of HIV-1 reverse transcriptase H221Y mutation on replication capacity of Y181C mutant viral strain

    Institute of Scientific and Technical Information of China (English)

    殷丽丽; 韩晓旭; 赵彬; 张旻; 安明晖; 吉阳涛; 欧阳金鸣; 尚红

    2013-01-01

    Objective To explore the development of Y181C and H221Y mutations among HIV-1 infected patients upon antiretroviral therapy in China and to investigate the impact of H221Y mutation on replication capacity of Y181C mutant.Methods Three HIV-1 subtype B' infected patients with Y181C and H221Y mutations upon highly active antiretroviral therapy from Henan province were enrolled in this study.Follow-up blood samples collected every six months from the patients after therapy between 2004 to 2006 were detected for viral load evaluation.Fragments of pol gene were amplified by nested PCR.The purified PCR products were ligated into pMD18-T vector to construct recombinant plasmids,which were further sequenced and compared with the HIV reference strain from Stanford HIVDB for analyzing the development of Y181C and H221Y mutations.Plasmids containing Y181C mutation alone and plasmids containing Y181C and H221Y double mutations were constructed and cotransfected respectively with envelope-expression plasmid pVSV-G into HEK 293T cells to obtain HIV-1 pseudotyped viruses.Replication capacity of each pseudotyped virus was analyzed after a single-cycle infection in TZM-bl cells.Results A total of 57 TA cloned sequences from six follow-up blood samples of three patients were obtained.Y181C mutation alone was found in 46 clones and Y181C and H221Y mutations were found in 35 clones.Moreover,H221Y mutation was only found in clones in which Y181C mutation had already developed.Between two pairs of pseudotyped virus from two patients,replication capacity of those viruses containing Y181C and H221Y mutations were 1.42 and 1.62 fold higher than the viruses containing Y181C mutation alone,respectively.Conclusion H221Y mutation might be a compensatory mutation of Y181C mutation occurred to improve the replication capacity of viral strains with Y181C mutant in HIV-1 subtype B' infected patients upon antiretroviral therapy.The finding suggests that it's significantly important to further

  6. Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120

    OpenAIRE

    Li Yun-Yao; Strick Nathan; Neurath A Robert; Debnath Asim K

    2001-01-01

    Abstract Background Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. Met...

  7. Curcumin inhibits HIV-1 by promoting Tat protein degradation

    Science.gov (United States)

    Ali, Amjad; Banerjea, Akhil C.

    2016-01-01

    HIV-1 Tat is an intrinsically unfolded protein playing a pivotal role in viral replication by associating with TAR region of viral LTR. Unfolded proteins are degraded by 20S proteasome in an ubiquitin independent manner. Curcumin is known to activate 20S proteasome and promotes the degradation of intrinsically unfolded p53 tumor suppressor protein. Since HIV-1 Tat protein is largerly unfolded, we hypothesized that Tat may also be targeted through this pathway. Curcumin treated Tat transfected HEK-293T cells showed a dose and time dependent degradation of Tat protein. Contrary to this HIV-1 Gag which is a properly folded protein, remained unaffected with curcumin. Semi-quantitative RT-PCR analysis showed that curcumin treatment did not affect Tat gene transcription. Curcumin increased the rate of Tat protein degradation as shown by cycloheximide (CHX) chase assay. Degradation of the Tat protein is accomplished through proteasomal pathway as proteasomal inhibitor MG132 blocked Tat degradation. Curcumin also decreased Tat mediated LTR promoter transactivation and inhibited virus production from HIV-1 infected cells. Taken together our study reveals a novel observation that curcumin causes potent degradation of Tat which may be one of the major mechanisms behind its anti HIV activity. PMID:27283735

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

    Directory of Open Access Journals (Sweden)

    Li Huang

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

  9. APOBEC3G-UBA2 fusion as a potential strategy for stable expression of APOBEC3G and inhibition of HIV-1 replication

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    Li Lin

    2008-08-01

    Full Text Available Abstract Background Although APOBEC3G protein is a potent and innate anti-HIV-1 cellular factor, HIV-1 Vif counteracts the effect of APOBEC3G by promoting its degradation through proteasome-mediated proteolysis. Thus, any means that could prevent APOBEC3G degradation could potentially enhance its anti-viral effect. The UBA2 domain has been identified as an intrinsic stabilization signal that protects protein from proteasomal degradation. In this pilot study, we tested whether APOBEC3G, when it is fused with UBA2, can resist Vif-mediated proteasomal degradation and further inhibit HIV-1 infection. Results APOBEC3G-UBA2 fusion protein is indeed more resistant to Vif-mediated degradation than APOBEC3G. The ability of UBA2 domain to stabilize APOBEC3G was diminished when polyubiquitin was over-expressed and the APOBEC3G-UBA2 fusion protein was found to bind less polyubiquitin than APOBEC3G, suggesting that UBA2 stabilizes APOBEC3G by preventing ubiquitin chain elongation and proteasome-mediated proteolysis. Consistently, treatment of cells with a proteasome inhibitor MG132 alleviated protein degradation of APOBEC3G and APOBEC3G-UBA2 fusion proteins. Analysis of the effect of APOBEC3G-UBA2 fusion protein on viral infectivity indicated that infection of virus packaged from HEK293 cells expressing APOBEC3G-UBA2 fusion protein is significantly lower than those packaged from HEK293 cells over-producing APOBEC3G or APOBEC3G-UBA2 mutant fusion proteins. Conclusion Fusion of UBA2 to APOBEC3G can make it more difficult to be degraded by proteasome. Thus, UBA2 could potentially be used to antagonize Vif-mediated APOBEC3G degradation by preventing polyubiquitination. The stabilized APOBEC3G-UBA2 fusion protein gives stronger inhibitory effect on viral infectivity than APOBEC3G without UBA2.

  10. Interferon-induced HERC5 is evolving under positive selection and inhibits HIV-1 particle production by a novel mechanism targeting Rev/RRE-dependent RNA nuclear export

    OpenAIRE

    Woods, Matthew William; Tong, Jessica Gayle; Tom, Sean Kevin; Szabo, Peter Anthony; Cavanagh, Peter Craig; Dikeakos, Jimmy Dimitrios; Haeryfar, SM Mansour; Barr, Stephen Dominic

    2014-01-01

    Background Type I interferon (IFN) inhibits virus replication by activating multiple antiviral mechanisms and pathways. It has long been recognized that type I IFNs can potently block HIV-1 replication in vitro; as such, HIV-1 has been used as a system to identify and characterize IFN-induced antiviral proteins responsible for this block. IFN-induced HERC5 contains an amino-terminal Regulator of Chromosome Condensation 1 (RCC1)-like domain and a carboxyl-terminal Homologous to the E6-AP Carbo...

  11. APOBEC3G inhibits HIV-1 RNA elongation by inactivating the viral trans-activation response element.

    Science.gov (United States)

    Nowarski, Roni; Prabhu, Ponnandy; Kenig, Edan; Smith, Yoav; Britan-Rosich, Elena; Kotler, Moshe

    2014-07-29

    Deamination of cytidine residues in viral DNA is a major mechanism by which APOBEC3G (A3G) inhibits vif-deficient human immunodeficiency virus type 1 (HIV-1) replication. dC-to-dU transition following RNase-H activity leads to viral cDNA degradation, production of non-functional proteins, formation of undesired stop codons and decreased viral protein synthesis. Here, we demonstrate that A3G provides an additional layer of defense against HIV-1 infection dependent on inhibition of proviral transcription. HIV-1 transcription elongation is regulated by the trans-activation response (TAR) element, a short stem-loop RNA structure required for elongation factors binding. Vif-deficient HIV-1-infected cells accumulate short viral transcripts and produce lower amounts of full-length HIV-1 transcripts due to A3G deamination of the TAR apical loop cytidine, highlighting the requirement for TAR loop integrity in HIV-1 transcription. We further show that free single-stranded DNA (ssDNA) termini are not essential for A3G activity and a gap of CCC motif blocked with juxtaposed DNA or RNA on either or 3'+5' ends is sufficient for A3G deamination. These results identify A3G as an efficient mutator and that deamination of (-)SSDNA results in an early block of HIV-1 transcription. PMID:24859335

  12. Porphyromonas gingivalis induces CCR5-dependent transfer of infectious HIV-1 from oral keratinocytes to permissive cells

    Directory of Open Access Journals (Sweden)

    Dietrich Elizabeth A

    2008-03-01

    Full Text Available Abstract Background Systemic infection with HIV occurs infrequently through the oral route. The frequency of occurrence may be increased by concomitant bacterial infection of the oral tissues, since co-infection and inflammation of some cell types increases HIV-1 replication. A putative periodontal pathogen, Porphyromonas gingivalis selectively up-regulates expression of the HIV-1 coreceptor CCR5 on oral keratinocytes. We, therefore, hypothesized that P. gingivalis modulates the outcome of HIV infection in oral epithelial cells. Results Oral and tonsil epithelial cells were pre-incubated with P. gingivalis, and inoculated with either an X4- or R5-type HIV-1. Between 6 and 48 hours post-inoculation, P. gingivalis selectively increased the infectivity of R5-tropic HIV-1 from oral and tonsil keratinocytes; infectivity of X4-tropic HIV-1 remained unchanged. Oral keratinocytes appeared to harbor infectious HIV-1, with no evidence of productive infection. HIV-1 was harbored at highest levels during the first 6 hours after HIV exposure and decreased to barely detectable levels at 48 hours. HIV did not appear to co-localize with P. gingivalis, which increased selective R5-tropic HIV-1 trans infection from keratinocytes to permissive cells. When CCR5 was selectively blocked, HIV-1 trans infection was reduced. Conclusion P. gingivalis up-regulation of CCR5 increases trans infection of harbored R5-tropic HIV-1 from oral keratinocytes to permissive cells. Oral infections such as periodontitis may, therefore, increase risk for oral infection and dissemination of R5-tropic HIV-1.

  13. β-catenin/TCF-4 signaling regulates susceptibility of macrophages and resistance of monocytes to HIV-1 productive infection

    OpenAIRE

    Aljawai, Yosra; Richards, Maureen H.; Seaton, Melanie S.; Narasipura, Srinivas D.; Al-Harthi, Lena

    2014-01-01

    Cells of the monocyte/macrophage lineage are an important target for HIV-1 infection. They are often at anatomical sites linked to HIV-1 transmission and are an important vehicle for disseminating HIV-1 throughout the body, including the central nervous system. Monocytes do not support extensive productive HIV-1 replication, but they become more susceptible to HIV-1 infection as they differentiate into macrophages. The mechanisms guiding susceptibility of HIV-1 replication in monocytes versus...

  14. HIV-1 induces IL-10 production in human monocytes via a CD4-independent pathway.

    Science.gov (United States)

    Ji, Jiaxiang; Sahu, Gautam K; Braciale, Vivian L; Cloyd, Miles W

    2005-06-01

    In HIV-infected patients, increased levels of IL-10, mainly produced by virally infected monocytes, were reported to be associated with impaired cell-mediated immune responses. In this study, we investigated how HIV-1 induces IL-10 production in human monocytes. We found that CD14(+) monocytes infected by either HIV-1(213) (X4) or HIV-1(BaL) (R5) produced IL-10, IL-6, tumor necrosis factor-alpha (TNF-alpha), and to a lesser extent, IFN-gamma. However, the capacity of HIV-1 to induce these cytokines was not dependent on virus replication since UV-inactivated HIV-1 induced similar levels of these cytokines. In addition, soluble HIV-1 gp160 could induce CD14(+) monocytes to produce IL-10 but at lower levels. Cross-linking CD4 molecules (XLCD4) with anti-CD4 mAbs and goat anti-mouse IgG (GAM) resulted in high levels of IL-6, TNF-alpha and IFN-gamma but no IL-10 production by CD14(+) monocytes. Interestingly, neither anti-CD4 mAbs nor recombinant soluble CD4 (sCD4) receptor could block IL-10 secretion induced by HIV-1(213), HIV-1(BaL) or HIV-1 gp160 in CD14(+) monocytes, whereas anti-CD4 mAb or sCD4 almost completely blocked the secretion of the other cytokines. Furthermore, HIV-1(213) could induce IL-10 mRNA expression in CD14(+) monocytes while XLCD4 by anti-CD4 mAb and GAM failed to do so. As with IL-10 protein levels, HIV-1(213)-induced IL-10 mRNA expression in CD14(+) monocytes could not be inhibited by anti-CD4 mAb or sCD4. Taken together, HIV-1 binding to CD14(+) monocytes can induce CD4-independent IL-10 production at both mRNA and protein levels. This finding suggests that HIV induces the immunosuppressive IL-10 production in monocytes and is not dependent on CD4 molecules and that interference with HIV entry through CD4 molecules may have no impact on counteracting the effects of IL-10 during HIV infection. PMID:15937058

  15. Small-Molecule Inhibitors of the LEDGF/p75 Binding Site of Integrase Block HIV Replication and Modulate Integrase Multimerization

    Science.gov (United States)

    Christ, Frauke; Shaw, Stephen; Demeulemeester, Jonas; Desimmie, Belete A.; Marchand, Arnaud; Butler, Scott; Smets, Wim; Chaltin, Patrick; Westby, Mike

    2012-01-01

    Targeting the HIV integrase (HIV IN) is a clinically validated approach for designing novel anti-HIV therapies. We have previously described the discovery of a novel class of integration inhibitors, 2-(quinolin-3-yl)acetic acid derivatives, blocking HIV replication at a low micromolar concentration through binding in the LEDGF/p75 binding pocket of HIV integrase, hence referred to as LEDGINs. Here we report the detailed characterization of their mode of action. The design of novel and more potent analogues with nanomolar activity enabled full virological evaluation and a profound mechanistic study. As allosteric inhibitors, LEDGINs bind to the LEDGF/p75 binding pocket in integrase, thereby blocking the interaction with LEDGF/p75 and interfering indirectly with the catalytic activity of integrase. Detailed mechanism-of-action studies reveal that the allosteric mode of inhibition is likely caused by an effect on HIV-1 integrase oligomerization. The multimodal inhibition by LEDGINs results in a block in HIV integration and in a replication deficiency of progeny virus. The allosteric nature of LEDGINs leads to synergy in combination with the clinically approved active site HIV IN strand transfer inhibitor (INSTI) raltegravir, and cross-resistance profiling proves the distinct mode of action of LEDGINs and INSTIs. The allosteric nature of inhibition and compatibility with INSTIs underline an interest in further (clinical) development of LEDGINs. PMID:22664975

  16. In vitro anti-HIV-1 activities of resveratrol derivatives%白藜芦醇衍生物体外抗HIV-1活性的初步研究

    Institute of Scientific and Technical Information of China (English)

    黄宁; 杨柳萌; 王睿睿; 朱海亮; 郑永唐

    2012-01-01

    Objective; To study the in vitro anti-HIV-1 activities of resveratrol derivatives and the mechanisms. Methods; The cytotoxicities of compounds were tested by MTT assay. The anti-HIV activities of compounds in acute infection were evaluated by cytopathogenic effect (CPE) assay. The inhibition of HIV-lKm018 replication in PBMC was evaluated by p24 antigen expression. The fusion between of HIV-1 infected and uninfected cells was e-valuated by CPE. The inhibition of HIV-1 recombinant reverse transcriptase activity, HIV-1 recombinant protease activity and direct HIV-1 virus killing were used to determine the mechanism. Results; IFB-1 and IFB-9 from resveratrol derivatives markedly inhibited syncytium formation with selective indexes of 16. 16 and 230.27 , respectively. IFB-1 and IFB-9 suppressed HIV-1 p24 antigen production in acutely HIV-111IB-infected C8166 cells with EC50, of 14.57 and 0.23 μg·mL-1 , respectively. They also inhibited HIV-lKM018 replication in PBMC. IFB-1 and IFB-9 blocked the fusion between normal cells and chronically HIV-1-infected cells, but did not inhibit recombinant RT, PR activities and did not directly kill HIV-1. Conclusions; IFB-1 and IFB-9 show potential anti-HIV-1 activities and the mechanism might be associated with inhibition virus entry.%目的:检测白藜芦醇衍生物IFB-1和IFB-9的体外抗HIV-1活性,并对其进行抗HIV-1作用机制的初步研究.方法:采用MTT比色法检测白藜芦醇衍生物IFB-1和IFB-9的细胞毒性;细胞病变法检测化合物对HIV-1急性感染的抑制活性;采用HIV-1 p24抗原ELISA方法检测临床分离株HIV-1KM018在PBMC中复制的抑制实验;采用细胞病变法检测HIV-1感染和未感染细胞之间的融合;采用HIV-1重组逆转录酶活性抑制实验,HIV-1重组蛋白酶活性抑制实验以及直接杀病毒实验来研究化合物体外抗HIV-1机制.结果:白藜芦醇衍生物IFB-1和IFB-9对HIV-1 ⅢB诱导的合胞体形成抑制的选择指数分别为16

  17. In vitro anti-HIV-1 activities of Qishile, a Chinese medicine effective fraction formula%中药有效部位复方奇士乐体外抗HIV-1活性研究

    Institute of Scientific and Technical Information of China (English)

    杨柳萌; 王睿睿; 张高红; 张兴杰; 陈纪军; 郑永唐

    2011-01-01

    目的 评价有效部位复方奇士乐(QSL)的体外抗HIV-1药效学.方法 通过合胞体抑制、HIV-1感染细胞保护、HIV-1 p24抗原测定等方法检测急性感染中QSL对HIV-1实验株、临床分离株、耐药株的抑制作用和对慢性感染细胞中病毒复制的影响;通过ELISA方法和荧光法分别检测了QSL体外抑制HIV-1逆转录酶和蛋白酶活性作用.结果 有效部位复方制剂QSL能有效地抑制HIV-1ⅢB诱导淋巴细胞病变、保护HIV-1ⅢB感染MT-4细胞死亡、阻断HIV-1ⅢB慢性感染H9细胞与C8166细胞间融合的作用.QSL对HIV-1实验株HIV-1ⅢB、临床分离株HIV-1KM018、耐药株HIV-174V的病毒复制也有较好的抑制作用.QSL抑制HIV活性的作用机制可能为多靶点,主要是抑制HIV逆转录酶、蛋白酶和病毒进入细胞.结论 QSL是具有较好体外抗HIV-1活性的中药有效部位复方.%Aim To evaluate the anti-HIV-1 activities of Qishile ( QSL) in vitro , a Chinese medicine effective fraction formula. Methods The inhibition of syncytia formation induced by HIV -1 was determined under microscopy. The protection of HIV-1 induced MT-4 cell lytic effects was measured by MTT assay . The level of HIV-1 p24 antigen in acute and chronic HIV-1 infection was assayed by ELISA. HIV-1 reverse transcriptase and protease activites in vitro were tested by ELISA and FRET, respectively. Results QSL markedly inhibited syncytium formation induced by HIV-1 ⅢB , protected HIV-1 ⅢB induced MT-4 cell lytic effects and blocked cell-to-cell fusion. It also showed obviously inhibitory effect on the clinical strain HIV-1KM018 ancl drug resistant strain HIV-174V replication.QSL maybe inhibited HIV-I replication through multiple targets, including reverse transcriptase , protease and virus entry. Conclusion QSL is a Chinese medicine effective fraction formula with potent anti-HIV-1 activities.

  18. Modification of a loop sequence between α-helices 6 and 7 of virus capsid (CA protein in a human immunodeficiency virus type 1 (HIV-1 derivative that has simian immunodeficiency virus (SIVmac239 vif and CA α-helices 4 and 5 loop improves replication in cynomolgus monkey cells

    Directory of Open Access Journals (Sweden)

    Adachi Akio

    2009-08-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 productively infects only humans and chimpanzees but not cynomolgus or rhesus monkeys while simian immunodeficiency virus isolated from macaque (SIVmac readily establishes infection in those monkeys. Several HIV-1 and SIVmac chimeric viruses have been constructed in order to develop an animal model for HIV-1 infection. Construction of an HIV-1 derivative which contains sequences of a SIVmac239 loop between α-helices 4 and 5 (L4/5 of capsid protein (CA and the entire SIVmac239 vif gene was previously reported. Although this chimeric virus could grow in cynomolgus monkey cells, it did so much more slowly than did SIVmac. It was also reported that intrinsic TRIM5α restricts the post-entry step of HIV-1 replication in rhesus and cynomolgus monkey cells, and we previously demonstrated that a single amino acid in a loop between α-helices 6 and 7 (L6/7 of HIV type 2 (HIV-2 CA determines the susceptibility of HIV-2 to cynomolgus monkey TRIM5α. Results In the study presented here, we replaced L6/7 of HIV-1 CA in addition to L4/5 and vif with the corresponding segments of SIVmac. The resultant HIV-1 derivatives showed enhanced replication capability in established T cell lines as well as in CD8+ cell-depleted primary peripheral blood mononuclear cells from cynomolgus monkey. Compared with the wild type HIV-1 particles, the viral particles produced from a chimeric HIV-1 genome with those two SIVmac loops were less able to saturate the intrinsic restriction in rhesus monkey cells. Conclusion We have succeeded in making the replication of simian-tropic HIV-1 in cynomolgus monkey cells more efficient by introducing into HIV-1 the L6/7 CA loop from SIVmac. It would be of interest to determine whether HIV-1 derivatives with SIVmac CA L4/5 and L6/7 can establish infection of cynomolgus monkeys in vivo.

  19. Inhibition of highly productive HIV-1 infection in T cells, primary human macrophages, microglia, and astrocytes by Sargassum fusiforme

    Directory of Open Access Journals (Sweden)

    Veille Jean-Claude

    2006-05-01

    Full Text Available Abstract Background The high rate of HIV-1 mutation and increasing resistance to currently available antiretroviral (ART therapies highlight the need for new antiviral agents. Products derived from natural sources have been shown to inhibit HIV-1 replication during various stages of the virus life cycle, and therefore represent a potential source of novel therapeutic agents. To expand our arsenal of therapeutics against HIV-1 infection, we investigated aqueous extract from Sargassum fusiforme (S. fusiforme for ability to inhibit HIV-1 infection in the periphery, in T cells and human macrophages, and for ability to inhibit in the central nervous system (CNS, in microglia and astrocytes. Results S. fusiforme extract blocked HIV-1 infection and replication by over 90% in T cells, human macrophages and microglia, and it also inhibited pseudotyped HIV-1 (VSV/NL4-3 infection in human astrocytes by over 70%. Inhibition was mediated against both CXCR4 (X4 and CCR5 (R5-tropic HIV-1, was dose dependant and long lasting, did not inhibit cell growth or viability, was not toxic to cells, and was comparable to inhibition by the nucleoside analogue 2', 3'-didoxycytidine (ddC. S. fusiforme treatment blocked direct cell-to-cell infection spread. To investigate at which point of the virus life cycle this inhibition occurs, we infected T cells and CD4-negative primary human astrocytes with HIV-1 pseudotyped with envelope glycoprotein of vesicular stomatitis virus (VSV, which bypasses the HIV receptor requirements. Infection by pseudotyped HIV-1 (VSV/NL4-3 was also inhibited in a dose dependant manner, although up to 57% less, as compared to inhibition of native NL4-3, indicating post-entry interferences. Conclusion This is the first report demonstrating S. fusiforme to be a potent inhibitor of highly productive HIV-1 infection and replication in T cells, in primary human macrophages, microglia, and astrocytes. Results with VSV/NL4-3 infection, suggest inhibition

  20. Discovery of dual inhibitors targeting both HIV-1 capsid and human cyclophilin A to inhibit the assembly and uncoating of the viral capsid.

    Science.gov (United States)

    Li, Jiebo; Tan, Zhiwu; Tang, Shixing; Hewlett, Indira; Pang, Ruifang; He, Meizi; He, Shanshan; Tian, Baohe; Chen, Kan; Yang, Ming

    2009-04-15

    HIV-1 assembly and disassembly (uncoating) processes are critical for the HIV-1 replication. HIV-1 capsid (CA) and human cyclophilin A (CypA) play essential roles in these processes. We designed and synthesized a series of thiourea compounds as HIV-1 assembly and disassembly dual inhibitors targeting both HIV-1 CA protein and human CypA. The SIV-induced syncytium antiviral evaluation indicated that all of the inhibitors displayed antiviral activities in SIV-infected CEM cells at the concentration of 0.6-15.8 microM for 50% of maximum effective rate. Their abilities to bind CA and CypA were determined by ultraviolet spectroscopic analysis, fluorescence binding affinity and PPIase inhibition assay. Assembly studies in vitro demonstrated that the compounds could potently disrupt CA assembly with a dose-dependent manner. All of these molecules could bind CypA with binding affinities (Kd values) of 51.0-512.8 microM. Fifteen of the CypA binding compounds showed potent PPIase inhibitory activities (IC(50) valuesHIV-1 Protease or to HIV-1 Integrase in the enzyme assays. These results suggested that 15 compounds could block HIV-1 replication by inhibiting the PPIase activity of CypA to interfere with capsid disassembly and disrupting CA assembly. PMID:19328002

  1. LEDGF dominant interference proteins demonstrate prenuclear exposure of HIV-1 integrase and synergize with LEDGF depletion to destroy viral infectivity.

    Science.gov (United States)

    Meehan, Anne M; Saenz, Dyana T; Morrison, James; Hu, Chunling; Peretz, Mary; Poeschla, Eric M

    2011-04-01

    Target cell overexpression of the integrase binding domain (IBD) of LEDGF/p75 (LEDGF) inhibits HIV-1 replication. The mechanism and protein structure requirements for this dominant interference are unclear. More generally, how and when HIV-1 uncoating occurs postentry is poorly defined, and it is unknown whether integrase within the evolving viral core becomes accessible to cellular proteins prior to nuclear entry. We used LEDGF dominant interference to address the latter question while characterizing determinants of IBD antiviral activity. Fusions of green fluorescent protein (GFP) with multiple C-terminal segments of LEDGF inhibited HIV-1 replication substantially, but minimal chimeras of either polarity (GFP-IBD or IBD-GFP) were most effective. Combining GFP-IBD expression with LEDGF depletion was profoundly antiviral. CD4(+) T cell lines were rendered virtually uninfectable, with single-cycle HIV-1 infectivity reduced 4 logs and high-input (multiplicity of infection = 5.0) replication completely blocked. We restricted GFP-IBD to specific intracellular locations and found that antiviral activity was preserved when the protein was confined to the cytoplasm or directed to the nuclear envelope. The life cycle block triggered by the cytoplasm-restricted protein manifested after nuclear entry, at the level of integration. We conclude that integrase within the viral core becomes accessible to host cell protein interaction in the cytoplasm. LEDGF dominant interference and depletion impair HIV-1 integration at distinct postentry stages. GFP-IBD may trigger premature or improper integrase oligomerization. PMID:21270171

  2. Blocking rolling circle replication with a UV lesion creates a deletion hotspot.

    Science.gov (United States)

    Seigneur, M; Ehrlich, S D; Michel, B

    1997-11-01

    UV light irradiation increases genetic instability by causing mutations and deletions. The mechanism of UV-induced rearrangements was investigated making use of deletion-prone plasmids. Chimeric plasmids carrying pBR322 and M13 replication origins undergo deletions that join the M13 replication origin to a random nucleotide. A restriction fragment was UV irradiated, introduced into such a hybrid plasmid and deletions formed at the M13 origin were analysed. In most of the deletant molecules, the M13 replication nick site was linked to a nucleotide in the irradiated fragment, showing that UV lesions are deletion hotspots. These deletions were independent of the UvrABC excision repair proteins, suggesting that the deletogenic structure is the lesion itself and not a repair intermediate. They were not found in the absence of M13 replication, indicating that they result from the encounter of the M13 replication fork with the UV lesion. Furthermore, UV-induced deletions occurred independently of pBR322 replication. We conclude that, in contrast to pBR322 replication forks, M13 replication forks blocked by UV lesions are deletion prone. We propose that the deletion-prone properties of a UV-arrested polymerase depend on the associated helicase. PMID:9402026

  3. Inhibition of HIV-1 entry by extracts derived from traditional Chinese medicinal herbal plants

    Directory of Open Access Journals (Sweden)

    Song Xinming

    2009-08-01

    Full Text Available Abstract Background Highly active anti-retroviral therapy (HAART is the current HIV/AIDS treatment modality. Despite the fact that HAART is very effective in suppressing HIV-1 replication and reducing the mortality of HIV/AIDS patients, it has become increasingly clear that HAART does not offer an ultimate cure to HIV/AIDS. The high cost of the HAART regimen has impeded its delivery to over 90% of the HIV/AIDS population in the world. This reality has urgently called for the need to develop inexpensive alternative anti-HIV/AIDS therapy. This need has further manifested by recent clinical trial failures in anti-HIV-1 vaccines and microbicides. In the current study, we characterized a panel of extracts of traditional Chinese medicinal herbal plants for their activities against HIV-1 replication. Methods Crude and fractionated extracts were prepared from various parts of nine traditional Chinese medicinal herbal plants in Hainan Island, China. These extracts were first screened for their anti-HIV activity and cytotoxicity in human CD4+ Jurkat cells. Then, a single-round pseudotyped HIV-luciferase reporter virus system (HIV-Luc was used to identify potential anti-HIV mechanisms of these extracts. Results Two extracts, one from Euphorbiaceae, Trigonostema xyphophylloides (TXE and one from Dipterocarpaceae, Vatica astrotricha (VAD inhibited HIV-1 replication and syncytia formation in CD4+ Jurkat cells, and had little adverse effects on host cell proliferation and survival. TXE and VAD did not show any direct inhibitory effects on the HIV-1 RT enzymatic activity. Treatment of these two extracts during the infection significantly blocked infection of the reporter virus. However, pre-treatment of the reporter virus with the extracts and treatment of the extracts post-infection had little effects on the infectivity or gene expression of the reporter virus. Conclusion These results demonstrate that TXE and VAD inhibit HIV-1 replication likely by blocking

  4. Nuclear retention of multiply spliced HIV-1 RNA in resting CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Kara G Lassen

    2006-07-01

    Full Text Available HIV-1 latency in resting CD4+ T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART. We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4+ T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4+ T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4+ T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4+ T cells. Overexpression of PTB in resting CD4+ T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4+ T cells. Virus culture experiments showed that overexpression of PTB in resting CD4+ T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications.

  5. HIV-1 Eradication: Early Trials (and Tribulations).

    Science.gov (United States)

    Spivak, Adam M; Planelles, Vicente

    2016-01-01

    Antiretroviral therapy (ART) has rendered HIV-1 infection a manageable illness for those with access to treatment. However, ART does not lead to viral eradication owing to the persistence of replication-competent, unexpressed proviruses in long-lived cellular reservoirs. The potential for long-term drug toxicities and the lack of access to ART for most people living with HIV-1 infection have fueled scientific interest in understanding the nature of this latent reservoir. Exploration of HIV-1 persistence at the cellular and molecular level in resting memory CD4(+) T cells, the predominant viral reservoir in patients on ART, has uncovered potential strategies to reverse latency. We review recent advances in pharmacologically based 'shock and kill' HIV-1 eradication strategies, including comparative analysis of early clinical trials. PMID:26691297

  6. TopoisomeraseIIβ in HIV-1 transactivation.

    Science.gov (United States)

    Chekuri, Anil; Bhaskar, C; Bollimpelli, V Satish; Kondapi, Anand K

    2016-03-01

    TopoisomeraseIIβ, an isoform of type II topoisomerase, was found to be functional in various viral infections. Its plausible role in HIV life cycle was also suggested earlier, but not clearly established. In the present study, we have investigated the role of TopoIIβ in HIV-1 infection by its gain and loss of function. Overexpression of TopoIIβ lead to an increase in viral replication, resulting in enhanced virion production. HIV-1 replication was impaired when TopoIIβ was down regulated by siRNA and inhibited by ICRF-193 and merbarone. The role of TopoIIβ in HIV-1 transcription was shown through its interaction with Tat and recruitement to long terminal repeat (LTR) region by co-immunoprecipitation and ChIP assays. Involvement of TopoIIβ in transactivation of HIV-1 LTR was confirmed by luciferase assay in reporter cell line, TZM bl and also by transfection of reporter exogenously. It was also observed that LTR transactivation commensurated with the expression of TopoIIβ in the presence of Tat. In addition, a decreased viral gene expression on treatment with merbarone exemplifies the importance of catalytic activity of TopoIIβ in viral replication. These observations indicate that TopoIIβ is involved in the cascade of coactivator complexes that are recruited to LTR for regulation of HIV-1 transcription. PMID:26876283

  7. Complement-Opsonized HIV-1 Overcomes Restriction in Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Wilfried Posch

    2015-06-01

    Full Text Available DCs express intrinsic cellular defense mechanisms to specifically inhibit HIV-1 replication. Thus, DCs are productively infected only at very low levels with HIV-1, and this non-permissiveness of DCs is suggested to go along with viral evasion. We now illustrate that complement-opsonized HIV-1 (HIV-C efficiently bypasses SAMHD1 restriction and productively infects DCs including BDCA-1 DCs. Efficient DC infection by HIV-C was also observed using single-cycle HIV-C, and correlated with a remarkable elevated SAMHD1 T592 phosphorylation but not SAMHD1 degradation. If SAMHD1 phosphorylation was blocked using a CDK2-inhibitor HIV-C-induced DC infection was also significantly abrogated. Additionally, we found a higher maturation and co-stimulatory potential, aberrant type I interferon expression and signaling as well as a stronger induction of cellular immune responses in HIV-C-treated DCs. Collectively, our data highlight a novel protective mechanism mediated by complement opsonization of HIV to effectively promote DC immune functions, which might be in the future exploited to tackle HIV infection.

  8. HIV-1 evades innate immune recognition through specific cofactor recruitment

    OpenAIRE

    Jane Rasaiyaah; Choon Ping Tan; Fletcher, Adam J.; Price, Amanda J.; Caroline Blondeau; Laura Hilditch; Jacques, David A.; Selwood, David L.; James, Leo C.; Mahdad Noursadeghi; Towers, Greg J.

    2013-01-01

    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 re...

  9. Cyclophilin inhibitors block arterivirus replication by interfering with viral RNA synthesis.

    Science.gov (United States)

    de Wilde, Adriaan H; Li, Yanhua; van der Meer, Yvonne; Vuagniaux, Grégoire; Lysek, Robert; Fang, Ying; Snijder, Eric J; van Hemert, Martijn J

    2013-02-01

    Virus replication strongly depends on cellular factors, in particular, on host proteins. Here we report that the replication of the arteriviruses equine arteritis virus (EAV) and porcine reproductive and respiratory syndrome virus (PRRSV) is strongly affected by low-micromolar concentrations of cyclosporine A (CsA), an inhibitor of members of the cyclophilin (Cyp) family. In infected cells, the expression of a green fluorescent protein (GFP) reporter gene inserted into the PRRSV genome was inhibited with a half-maximal inhibitory concentration (IC(50)) of 5.2 μM, whereas the GFP expression of an EAV-GFP reporter virus was inhibited with an IC(50) of 0.95 μM. Debio-064, a CsA analog that lacks its undesirable immunosuppressive properties, inhibited EAV replication with an IC(50) that was 3-fold lower than that of CsA, whereas PRRSV-GFP replication was inhibited with an IC(50) similar to that of CsA. The addition of 4 μM CsA after infection prevented viral RNA and protein synthesis in EAV-infected cells, and CsA treatment resulted in a 2.5- to 4-log-unit reduction of PRRSV or EAV infectious progeny. A complete block of EAV RNA synthesis was also observed in an in vitro assay using isolated viral replication structures. The small interfering RNA-mediated knockdown of Cyp family members revealed that EAV replication strongly depends on the expression of CypA but not CypB. Furthermore, upon fractionation of intracellular membranes in density gradients, CypA was found to cosediment with membranous EAV replication structures, which could be prevented by CsA treatment. This suggests that CypA is an essential component of the viral RNA-synthesizing machinery. PMID:23152531

  10. Revisiting HIV-1 uncoating

    OpenAIRE

    Arhel Nathalie

    2010-01-01

    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 wit...

  11. Hydroxylated tropolones inhibit hepatitis B virus replication by blocking viral ribonuclease H activity.

    Science.gov (United States)

    Lu, Gaofeng; Lomonosova, Elena; Cheng, Xiaohong; Moran, Eileen A; Meyers, Marvin J; Le Grice, Stuart F J; Thomas, Craig J; Jiang, Jian-kang; Meck, Christine; Hirsch, Danielle R; D'Erasmo, Michael P; Suyabatmaz, Duygu M; Murelli, Ryan P; Tavis, John E

    2015-02-01

    Hepatitis B virus (HBV) remains a major human pathogen despite the development of both antiviral drugs and a vaccine, in part because the current therapies do not suppress HBV replication far enough to eradicate the virus. Here, we screened 51 troponoid compounds for their ability to suppress HBV RNaseH activity and HBV replication based on the activities of α-hydroxytropolones against HIV RNaseH, with the goal of determining whether the tropolone pharmacophore may be a promising scaffold for anti-HBV drug development. Thirteen compounds inhibited HBV RNaseH, with the best 50% inhibitory concentration (IC50) being 2.3 μM. Similar inhibition patterns were observed against HBV genotype D and C RNaseHs, implying limited genotype specificity. Six of 10 compounds tested against HBV replication in culture suppressed replication via blocking of viral RNaseH activity, with the best 50% effective concentration (EC50) being 0.34 μM. Eighteen compounds inhibited recombinant human RNaseH1, and moderate cytotoxicity was observed for all compounds (50% cytotoxic concentration [CC50]=25 to 79 μM). Therapeutic indexes ranged from 3.8 to 94. Efficient inhibition required an intact α-hydroxytropolone moiety plus one or more short appendages on the tropolone ring, but a wide variety of constituents were permissible. These data indicate that troponoids and specifically α-hydroxytropolones are promising lead candidates for development as anti-HBV drugs, providing that toxicity can be minimized. Potential anti-RNaseH drugs are envisioned to be employed in combination with the existing nucleos(t)ide analogs to suppress HBV replication far enough to block genomic maintenance, with the goal of eradicating infection. PMID:25451058

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

    Directory of Open Access Journals (Sweden)

    Nicholas F Parrish

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

  13. The anti-HIV activity of ADS-J1 targets the HIV-1 gp120

    International Nuclear Information System (INIS)

    Recent data suggest that heparin sulfates may bind to a CD4 induced epitope in the HIV-1 gp120 that constitutes the coreceptor binding site. We have studied the mechanism of action of ADS-J1, a non-peptidic compound selected by docking analysis to interact with gp41 and to interfere with the formation of N-36/C-34 complexes in sandwich ELISA experiments. We show that ADS-J1 blocked the binding of wild-type HIV-1 NL4-3 strain to MT-4 cells but not virus-cell binding of a polyanion-resistant virus. However, ADS-J1 blocked the replication of polyanion-resistant, T-20- and C34-resistant HIV-1, suggesting a second mechanism of action. Development of resistance to ADS-J1 on the polyanion-resistant HIV-1 led to mutations in gp120 coreceptor binding site and not in gp41. Time of addition experiments confirmed that ADS-J1, but not polyanions such as dextran sulfate or AR177, worked at a step that mimics the activity of an HIV coreceptor antagonist but prior to gp41-dependent fusion. We conclude that ADS-J1 may bind to the HIV coreceptor binding site as its mechanism of anti-HIV activity

  14. Baculovirus resistance in codling moth (Cydia pomonella L.) caused by early block of virus replication.

    Science.gov (United States)

    Asser-Kaiser, Sabine; Radtke, Pit; El-Salamouny, Said; Winstanley, Doreen; Jehle, Johannes A

    2011-02-20

    An up to 10,000-fold resistance against the biocontrol agent Cydia pomonella granulovirus (CpGV) was observed in field populations of codling moth, C. pomonella, in Europe. Following different experimental approaches, a modified peritrophic membrane, a modified midgut receptor, or a change of the innate immune response could be excluded as possible resistance mechanisms. When CpGV replication was traced by quantitative PCR in different tissues of susceptible and resistant insects after oral and intra-hemocoelic infection, no virus replication could be detected in any of the tissues of resistant insects, suggesting a systemic block prior to viral DNA replication. This conclusion was corroborated by fluorescence microscopy using a modified CpGV (bacCpGV(hsp-eGFP)) carrying enhanced green fluorescent gene (eGFP), which showed that infection in resistant insects did not spread. In conclusion, the different lines of evidence indicate that CpGV can enter but not replicate in the cells of resistant codling moth larvae. PMID:21190707

  15. Iron chelators ICL670 and 311 inhibit HIV-1 transcription

    International Nuclear Information System (INIS)

    HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics

  16. Alterations in HIV-1 LTR promoter activity during AIDS progression

    International Nuclear Information System (INIS)

    HIV-1 variants evolving in AIDS patients frequently show increased replicative capacity compared to those present during early asymptomatic infection. It is known that late stage HIV-1 variants often show an expanded coreceptor tropism and altered Nef function. In the present study we investigated whether enhanced HIV-1 LTR promoter activity might also evolve during disease progression. Our results demonstrate increased LTR promoter activity after AIDS progression in 3 of 12 HIV-1-infected individuals studied. Further analysis revealed that multiple alterations in the U3 core-enhancer and in the transactivation-response (TAR) region seem to be responsible for the enhanced functional activity. Our findings show that in a subset of HIV-1-infected individuals enhanced LTR transcription contributes to the increased replicative potential of late stage virus isolates and might accelerate disease progression

  17. Caspase-3-mediated cleavage of p65/RelA results in a carboxy-terminal fragment that inhibits IκBα and enhances HIV-1 replication in human T lymphocytes

    Directory of Open Access Journals (Sweden)

    Alcamí José

    2008-12-01

    transactivation activity of wild-type p65/RelA, as well as an improvement of HIV-1 replication in PBLs. Moreover, ΔNH2p65 was increased in the nuclei of PMA-, PHA-, and TNFα-activated T cells, proving this phenomenon was related to cell activation. These data suggest the existence of a novel mechanism for maintaining NF-κB activity in human T cells through the binding of the carboxy-terminal fragment of p65/RelA to IκBα in order to protect wild-type p65/RelA from IκBα inhibition.

  18. Minimal Contribution of APOBEC3-Induced G-to-A Hypermutation to HIV-1 Recombination and Genetic Variation.

    Science.gov (United States)

    Delviks-Frankenberry, Krista A; Nikolaitchik, Olga A; Burdick, Ryan C; Gorelick, Robert J; Keele, Brandon F; Hu, Wei-Shau; Pathak, Vinay K

    2016-05-01

    Although the predominant effect of host restriction APOBEC3 proteins on HIV-1 infection is to block viral replication, they might inadvertently increase retroviral genetic variation by inducing G-to-A hypermutation. Numerous studies have disagreed on the contribution of hypermutation to viral genetic diversity and evolution. Confounding factors contributing to the debate include the extent of lethal (stop codon) and sublethal hypermutation induced by different APOBEC3 proteins, the inability to distinguish between G-to-A mutations induced by APOBEC3 proteins and error-prone viral replication, the potential impact of hypermutation on the frequency of retroviral recombination, and the extent to which viral recombination occurs in vivo, which can reassort mutations in hypermutated genomes. Here, we determined the effects of hypermutation on the HIV-1 recombination rate and its contribution to genetic variation through recombination to generate progeny genomes containing portions of hypermutated genomes without lethal mutations. We found that hypermutation did not significantly affect the rate of recombination, and recombination between hypermutated and wild-type genomes only increased the viral mutation rate by 3.9 × 10-5 mutations/bp/replication cycle in heterozygous virions, which is similar to the HIV-1 mutation rate. Since copackaging of hypermutated and wild-type genomes occurs very rarely in vivo, recombination between hypermutated and wild-type genomes does not significantly contribute to the genetic variation of replicating HIV-1. We also analyzed previously reported hypermutated sequences from infected patients and determined that the frequency of sublethal mutagenesis for A3G and A3F is negligible (4 × 10-21 and1 × 10-11, respectively) and its contribution to viral mutations is far below mutations generated during error-prone reverse transcription. Taken together, we conclude that the contribution of APOBEC3-induced hypermutation to HIV-1 genetic

  19. Aggressive HIV-1?

    OpenAIRE

    van der Hoek Lia; de Ronde Anthony; Berkhout Ben

    2005-01-01

    Abstract New York City health officials announced on February 11, 2005 that a patient rapidly developed full-blown AIDS shortly after being diagnosed with a rare, drug-resistant strain of HIV-1. The New York City Department of Health issued an alert to all hospitals and doctors and a press conference was held to announce the emergence of an aggressive HIV-1 strain that may be difficult to treat and that appears to trigger rapid progression to AIDS. Is the panic justified?

  20. MxB binds to the HIV-1 core and prevents the uncoating process of HIV-1

    OpenAIRE

    Fricke, Thomas; White, Tommy E; Schulte, Bianca; de Souza Aranha Vieira, Daniel A.; Dharan, Adarsh; Campbell, Edward M; Brandariz-Nuñez, Alberto; Diaz-Griffero, Felipe

    2014-01-01

    Background The IFN-α-inducible restriction factor MxB blocks HIV-1 infection after reverse transcription but prior to integration. Genetic evidence suggested that capsid is the viral determinant for restriction by MxB. This work explores the ability of MxB to bind to the HIV-1 core, and the role of capsid-binding in restriction. Results We showed that MxB binds to the HIV-1 core and that this interaction leads to inhibition of the uncoating process of HIV-1. These results identify MxB as an e...

  1. Enhanced clearance of HIV-1-infected cells by broadly neutralizing antibodies against HIV-1 in vivo.

    Science.gov (United States)

    Lu, Ching-Lan; Murakowski, Dariusz K; Bournazos, Stylianos; Schoofs, Till; Sarkar, Debolina; Halper-Stromberg, Ariel; Horwitz, Joshua A; Nogueira, Lilian; Golijanin, Jovana; Gazumyan, Anna; Ravetch, Jeffrey V; Caskey, Marina; Chakraborty, Arup K; Nussenzweig, Michel C

    2016-05-20

    Antiretroviral drugs and antibodies limit HIV-1 infection by interfering with the viral life cycle. In addition, antibodies also have the potential to guide host immune effector cells to kill HIV-1-infected cells. Examination of the kinetics of HIV-1 suppression in infected individuals by passively administered 3BNC117, a broadly neutralizing antibody, suggested that the effects of the antibody are not limited to free viral clearance and blocking new infection but also include acceleration of infected cell clearance. Consistent with these observations, we find that broadly neutralizing antibodies can target CD4(+) T cells infected with patient viruses and can decrease their in vivo half-lives by a mechanism that requires Fcγ receptor engagement in a humanized mouse model. The results indicate that passive immunotherapy can accelerate elimination of HIV-1-infected cells. PMID:27199430

  2. The hunt for HIV-1 integrase inhibitors.

    Science.gov (United States)

    Lataillade, Max; Kozal, Michael J

    2006-07-01

    Currently, there are three distinct mechanistic classes of antiretrovirals: inhibitors of the HIV- 1 reverse transcriptase and protease enzymes and inhibitors of HIV entry, including receptor and coreceptor binding and cell fusion. A new drug class that inhibits the HIV-1 integrase enzyme (IN) is in development and may soon be available in the clinic. IN is an attractive drug target because it is essential for a stable and productive HIV-1 infection and there is no mammalian homologue of IN. Inhibitors of integrase enzyme (INI) block the integration of viral double-stranded DNA into the host cell's chromosomal DNA. HIV-1 integration has many potential steps that can be inhibited and several new compounds that target specific integration steps have been identified by drug developers. Recently, two INIs, GS-9137 and MK-0518, demonstrated promising early clinical trial results and have been advanced into later stage trials. In this review, we describe how IN facilitates HIV-1 integration, the needed enzyme cofactors, and the resultant byproducts created during integration. Furthermore, we review the different INIs under development, their mechanism of actions, site of IN inhibition, potency, resistance patterns, and discuss the early clinical trial results. PMID:16839248

  3. Down-regulation of HIV-1 Infection by Inhibition of the MAPK Signaling Pathway

    Institute of Scientific and Technical Information of China (English)

    Jian Gong; Xi-hui Shen; Chao Chen; Hui Qiu; Rong-ge Yang

    2011-01-01

    The human immunodeficiency virus type 1(HIV-1)can interact with and exploit the host cellular machinery to replicate and propagate itself.Numerous studies have shown that the Mitogen-activated protein kinase(MAPK)signal pathway can positively regulate the replication of HIV-1,but exactly how each MAPK pathway affects HIV-1 infection and replication is not understood.In this study,we used the Extracellular signal-regulated kinase(ERK)pathway inhibitor,PD98059,the Jun N-terminal kinase(JNK)pathway inhibitor,SP600125,and the p38 pathway inhibitor,SB203580,to investigate the roles of these pathways in HIV-1replication.We found that application of PD98059 results in a strong VSV-G pseudotyped HIV-1NL4-3 luciferase reporter virus and HIV-1NL4-3 virus inhibition activity.In addition,SB203580 and SP600125 also elicited marked VSV-G pseudotyped HIV-1NL4-3 luciferase reporter virus inhibition activity but no HIV-1NL4-3 virus inhibition activity.We also found that SB203580 and SP600125 can enhance the HIV-1 inhibition activity of PD98059when cells were treated with all three MAPK pathway inhibitors in combination.Finally,we show that HIV-1virus inhibition activity of the MAPK pathway inhibitors was the result of the negative regulation of HIV-1 LTR promoter activity.

  4. Replication of engine block cylinder bridge microstructure and mechanical properties with lab scale 319 Al alloy billet castings

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, A., E-mail: a2lombar@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); D' Elia, F.; Ravindran, C. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard Street East, Toronto, Ontario M5B2K3 (Canada); MacKay, R. [Nemak of Canada Corporation, 4600 G.N. Booth Drive, Windsor, Ontario N9C4G8 (Canada)

    2014-01-15

    In recent years, aluminum alloy gasoline engine blocks have in large part successfully replaced nodular cast iron engine blocks, resulting in improved vehicle fuel efficiency. However, because of the inadequate wear resistance properties of hypoeutectic Al–Si alloys, gray iron cylinder liners are required. These liners cause the development of large tensile residual stress along the cylinder bores and necessitate the maximization of mechanical properties in this region to prevent premature engine failure. The aim of this study was to replicate the engine cylinder bridge microstructure and mechanical properties following TSR treatment (which removes the sand binder to enable easy casting retrieval) using lab scale billet castings of the same alloy composition with varying cooling rates. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy, while mechanical properties were assessed using tensile testing. The results suggest that the microstructure at the top and middle of the engine block cylinder bridge was successfully replicated by the billet castings. However, the microstructure at the bottom of the cylinder was not completely replicated due to variations in secondary phase morphology and distribution. The successful replication of engine block microstructure will enable the future optimization of heat treatment parameters. - Highlights: • A method to replicate engine block microstructure was developed. • Billet castings will allow cost effective optimization of heat treatment process. • The replication of microstructure in the cylinder region was mostly successful. • Porosity was more clustered in the billet castings compared to the engine block. • Mechanical properties were lower in billet castings due to porosity and inclusions.

  5. Replication of engine block cylinder bridge microstructure and mechanical properties with lab scale 319 Al alloy billet castings

    International Nuclear Information System (INIS)

    In recent years, aluminum alloy gasoline engine blocks have in large part successfully replaced nodular cast iron engine blocks, resulting in improved vehicle fuel efficiency. However, because of the inadequate wear resistance properties of hypoeutectic Al–Si alloys, gray iron cylinder liners are required. These liners cause the development of large tensile residual stress along the cylinder bores and necessitate the maximization of mechanical properties in this region to prevent premature engine failure. The aim of this study was to replicate the engine cylinder bridge microstructure and mechanical properties following TSR treatment (which removes the sand binder to enable easy casting retrieval) using lab scale billet castings of the same alloy composition with varying cooling rates. Comparisons in microstructure between the engine block and the billet castings were carried out using optical and scanning electron microscopy, while mechanical properties were assessed using tensile testing. The results suggest that the microstructure at the top and middle of the engine block cylinder bridge was successfully replicated by the billet castings. However, the microstructure at the bottom of the cylinder was not completely replicated due to variations in secondary phase morphology and distribution. The successful replication of engine block microstructure will enable the future optimization of heat treatment parameters. - Highlights: • A method to replicate engine block microstructure was developed. • Billet castings will allow cost effective optimization of heat treatment process. • The replication of microstructure in the cylinder region was mostly successful. • Porosity was more clustered in the billet castings compared to the engine block. • Mechanical properties were lower in billet castings due to porosity and inclusions

  6. Compensatory Substitutions in the HIV-1 Capsid Reduce the Fitness Cost Associated with Resistance to a Capsid-Targeting Small-Molecule Inhibitor

    Science.gov (United States)

    Shi, Jiong; Zhou, Jing; Halambage, Upul D.; Shah, Vaibhav B.; Burse, Mallori J.; Wu, Hua; Blair, Wade S.; Butler, Scott L.

    2014-01-01

    ABSTRACT The HIV-1 capsid plays multiple roles in infection and is an emerging therapeutic target. The small-molecule HIV-1 inhibitor PF-3450074 (PF74) blocks HIV-1 at an early postentry stage by binding the viral capsid and interfering with its function. Selection for resistance resulted in accumulation of five amino acid changes in the viral CA protein, which collectively reduced binding of the compound to HIV-1 particles. In the present study, we dissected the individual and combinatorial contributions of each of the five substitutions Q67H, K70R, H87P, T107N, and L111I to PF74 resistance, PF74 binding, and HIV-1 infectivity. Q67H, K70R, and T107N each conferred low-level resistance to PF74 and collectively conferred strong resistance. The substitutions K70R and L111I impaired HIV-1 infectivity, which was partially restored by the other substitutions at positions 67 and 107. PF74 binding to HIV-1 particles was reduced by the Q67H, K70R, and T107N substitutions, consistent with the location of these positions in the inhibitor-binding pocket. Replication of the 5Mut virus was markedly impaired in cultured macrophages, reminiscent of the previously reported N74D CA mutant. 5Mut substitutions also reduced the binding of the host protein CPSF6 to assembled CA complexes in vitro and permitted infection of cells expressing the inhibitory protein CPSF6-358. Our results demonstrate that strong resistance to PF74 requires accumulation of multiple substitutions in CA to inhibit PF74 binding and compensate for fitness impairments associated with some of the sequence changes. IMPORTANCE The HIV-1 capsid is an emerging drug target, and several small-molecule compounds have been reported to inhibit HIV-1 infection by targeting the capsid. Here we show that resistance to the capsid-targeting inhibitor PF74 requires multiple amino acid substitutions in the binding pocket of the CA protein. Three changes in CA were necessary to inhibit binding of PF74 while maintaining viral

  7. The CsA washout assay to detect HIV-1 uncoating in infected cells

    OpenAIRE

    Hulme, Amy E.; Hope, Thomas J.

    2014-01-01

    Uncoating is an early step of HIV-1 replication in which the viral capsid disassembles by p24 capsid (p24CA) protein dissociating from the viral complex. Although uncoating is required for HIV-1 replication, many questions remain about the mechanism of this process as well as its impact on other steps in viral replication. Here we describe a recently developed assay to study the process of uncoating in HIV-1 infected cells. The CsA washout assay is a cell based assay that utilizes the HIV-1 r...

  8. Dual mechanisms of translation initiation of the full-length HIV-1 mRNA contribute to gag synthesis.

    Science.gov (United States)

    Monette, Anne; Valiente-Echeverría, Fernando; Rivero, Matias; Cohen, Éric A; Lopez-Lastra, Marcelo; Mouland, Andrew J

    2013-01-01

    The precursor group-specific antigen (pr55(Gag)) is central to HIV-1 assembly. Its expression alone is sufficient to assemble into virus-like particles. It also selects the genomic RNA for encapsidation and is involved in several important virus-host interactions for viral assembly and restriction, making its synthesis essential for aspects of viral replication. Here, we show that the initiation of translation of the HIV-1 genomic RNA is mediated through both a cap-dependent and an internal ribosome entry site (IRES)-mediated mechanisms. In support of this notion, pr55(Gag) synthesis was maintained at 70% when cap-dependent translation initiation was blocked by the expression of eIF4G- and PABP targeting viral proteases in two in vitro systems and in HIV-1-expressing cells directly infected with poliovirus. While our data reveal that IRES-dependent translation of the viral genomic RNA ensures pr55(Gag) expression, the synthesis of other HIV-1 proteins, including that of pr160(Gag/Pol), Vpr and Tat is suppressed early during progressive poliovirus infection. The data presented herein implies that the unspliced HIV-1 genomic RNA utilizes both cap-dependent and IRES-dependent translation initiation to supply pr55(Gag) for virus assembly and production. PMID:23861855

  9. Extreme genetic fragility of the HIV-1 capsid.

    Science.gov (United States)

    Rihn, Suzannah J; Wilson, Sam J; Loman, Nick J; Alim, Mudathir; Bakker, Saskia E; Bhella, David; Gifford, Robert J; Rixon, Frazer J; Bieniasz, Paul D

    2013-01-01

    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

  10. 结构蛋白Gag及其相关基因(蛋白)在HIV-1晚期复制的作用及其抑制剂%The role of structural protein Gag and related gene (protein) in late stages of the HIV-1 replication cycle and the inhibitors

    Institute of Scientific and Technical Information of China (English)

    姜岩; 刘新泳

    2010-01-01

    人免疫缺陷病毒1型(human immunodeficiency virus type 1,HIV-1)复制的晚期阶段是整个复制周期中的关键环节.该阶段HIV-1经装配、出芽释放和成熟过程产生能感染新靶细胞的成熟病毒颗粒.结构蛋白Gag及其相关基因(蛋白)在此阶段发挥着重要作用,它通过协同自身不同区域,有利于蛋白质-蛋白质、蛋白质-RNA和蛋白质-脂质相互作用,从而促进成熟感染病毒颗粒的产生.针对此阶段设计的药物,可有效地阻断HIV-1成熟,从而抑制病毒感染.本文综述了结构蛋白Gag及其相关基因(蛋白)在HIV-1晚期复制的作用及其抑制剂的研究进展.

  11. Defining the roles for Vpr in HIV-1-associated neuropathogenesis.

    Science.gov (United States)

    James, Tony; Nonnemacher, Michael R; Wigdahl, Brian; Krebs, Fred C

    2016-08-01

    It is increasingly evident that the human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) has a unique role in neuropathogenesis. Its ability to induce G2/M arrest coupled with its capacity to increase viral gene transcription gives it a unique role in sustaining viral replication and aiding in the establishment and maintenance of a systemic infection. The requirement of Vpr for HIV-1 infection and replication in cells of monocytic origin (a key lineage of cells involved in HIV-1 neuroinvasion) suggests an important role in establishing and sustaining infection in the central nervous system (CNS). Contributions of Vpr to neuropathogenesis can be expanded further through (i) naturally occurring HIV-1 sequence variation that results in functionally divergent Vpr variants; (ii) the dual activities of Vpr as a intracellular protein delivered and expressed during HIV-1 infection and as an extracellular protein that can act on neighboring, uninfected cells; (iii) cell type-dependent consequences of Vpr expression and exposure, including cell cycle arrest, metabolic dysregulation, and cytotoxicity; and (iv) the effects of Vpr on exosome-based intercellular communication in the CNS. Revealing that the effects of this pleiotropic viral protein is an essential part of a greater understanding of HIV-1-associated pathogenesis and potential approaches to treating and preventing disease caused by HIV-1 infection. PMID:27056720

  12. HIV-1 infected monozygotic twins: a tale of two outcomes

    OpenAIRE

    Pérez-Losada Marcos; Orsega Susan; Metcalf Julia A; Hirschfeld Steven; Imamichi Hiromi; Tazi Loubna; Posada David; Lane H Clifford; Crandall Keith A

    2011-01-01

    Abstract Background Replicate experiments are often difficult to find in evolutionary biology, as this field is inherently an historical science. However, viruses, bacteria and phages provide opportunities to study evolution in both natural and experimental contexts, due to their accelerated rates of evolution and short generation times. Here we investigate HIV-1 evolution by using a natural model represented by monozygotic twins infected synchronically at birth with an HIV-1 population from ...

  13. Curcumin inhibits HIV-1 by promoting Tat protein degradation

    OpenAIRE

    Amjad Ali; Banerjea, Akhil C

    2016-01-01

    HIV-1 Tat is an intrinsically unfolded protein playing a pivotal role in viral replication by associating with TAR region of viral LTR. Unfolded proteins are degraded by 20S proteasome in an ubiquitin independent manner. Curcumin is known to activate 20S proteasome and promotes the degradation of intrinsically unfolded p53 tumor suppressor protein. Since HIV-1 Tat protein is largerly unfolded, we hypothesized that Tat may also be targeted through this pathway. Curcumin treated Tat transfected...

  14. Study on the Isolation and Replication of HIV-1 Clade B' from HIV Infected Long-term Survivors in China%我国 HIV-1 B'亚型感染长期存活者病毒分离及体外复制的研究

    Institute of Scientific and Technical Information of China (English)

    袁霖; 马丽英; 徐维四; 孙坚萍; 黄江虹; 赵全壁; 彭虹; 邵一鸣

    2008-01-01

    目的 从 HIV-1 B' 亚型感染的长期存活者分离 HIV-1 病毒,观察 HIV-1 病毒分离与 CD4 淋巴细胞水平和病毒载量的相关性.方法 采用外周血单核细胞共培养法,从感染者外周血分离 HIV-1 毒株,测定其复制动力学,并比较 HIV 分离率与 CD4 细胞计数和病毒载量的关系.结果 从 190 例 HIV 感染者中分离到 101 株 HIV-1 病毒,平均病毒分离率为 53%;载量为<103、103~104、104~105 和>105 拷贝/ml 时,病毒分离率分别为 3.7%、36%、68% 和 73%;CD4 细胞计数为<200、200~500 和≥500 个/μl 时,病毒分离率分别为 66%、59% 和 28%.结论 HIV 病毒培养阳性率与 CD4 细胞计数呈负相关,与病毒载量呈正相关;HIV 体外复制力与病毒载量呈正相关关系.

  15. 海洋硫酸多糖911抗AIDs作用机制的初步探讨%STUDY ON THE MECHANISM OF INHIBITORY ACTION OF 911 ON REPLICATION OF HIV-1 IN VITRO

    Institute of Scientific and Technical Information of China (English)

    辛现良; 耿美玉; 管华诗; 李泽琳

    2000-01-01

    研究了抗AIDs药物海洋硫酸多糖"911"对病毒逆转录酶及HIV-1与细胞吸附的影响,结果表明"911"可明显抑制病毒逆转录酶活性,对HIV-1无明显直接灭活作用,但可明显干扰HIV-1与细胞的吸附,半数有效浓度(IC50)为36.51mg·L-1.提示911的抗AIDs作用与抑制逆转录酶活性和干扰病毒与细胞的吸附有关.

  16. Efficient HIV-1 inhibition by a 16 nt-long RNA aptamer designed by combining in vitro selection and in silico optimisation strategies

    Science.gov (United States)

    Sánchez-Luque, Francisco J.; Stich, Michael; Manrubia, Susanna; Briones, Carlos; Berzal-Herranz, Alfredo

    2014-09-01

    The human immunodeficiency virus type-1 (HIV-1) genome contains multiple, highly conserved structural RNA domains that play key roles in essential viral processes. Interference with the function of these RNA domains either by disrupting their structures or by blocking their interaction with viral or cellular factors may seriously compromise HIV-1 viability. RNA aptamers are amongst the most promising synthetic molecules able to interact with structural domains of viral genomes. However, aptamer shortening up to their minimal active domain is usually necessary for scaling up production, what requires very time-consuming, trial-and-error approaches. Here we report on the in vitro selection of 64 nt-long specific aptamers against the complete 5'-untranslated region of HIV-1 genome, which inhibit more than 75% of HIV-1 production in a human cell line. The analysis of the selected sequences and structures allowed for the identification of a highly conserved 16 nt-long stem-loop motif containing a common 8 nt-long apical loop. Based on this result, an in silico designed 16 nt-long RNA aptamer, termed RNApt16, was synthesized, with sequence 5'-CCCCGGCAAGGAGGGG-3'. The HIV-1 inhibition efficiency of such an aptamer was close to 85%, thus constituting the shortest RNA molecule so far described that efficiently interferes with HIV-1 replication.

  17. The anti-HIV-1 effect of scutellarin

    International Nuclear Information System (INIS)

    Scutellarin was purified from the plant Erigeron breviscapus (Vant.) Hand.-Mazz. The activity against 3 strains of human immunodeficiency virus (HIV) was determined in vitro in this study. These were laboratory-derived virus (HIV-1IIIB), drug-resistant virus (HIV-174V), and low-passage clinical isolated virus (HIV-1KM018). From syncytia inhibition study, the EC50 of scutellarin against HIV-1IIIB direct infection in C8166 cells was 26 μM with a therapeutic index of 36. When the mode of infection changed from acute infection to cell-to-cell infection, this compound became even more potent and the EC50 reduced to 15 μM. This suggested that cell fusion might be affected by this compound. By comparing the inhibitory effects on p24 antigen, scutellarin was also found to be active against HIV-174V (EC50 253 μM) and HIV-1KM018 (EC50 136 μM) infection with significant difference in potency. The mechanism of its action was also explored in this study. At a concentration of 433 μM, scutellarin inhibited 48% of the cell free recombinant HIV-1 RT activity. It also caused 82% inhibition of HIV-1 particle attachment and 45% inhibition of fusion at the concentrations of 54 μM. In summary, scutellarin was found to inhibit several strains of HIV-1 replication with different potencies. It appeared to inhibit HIV-1 RT activity, HIV-1 particle attachment and cell fusion. These are essential activities for viral transmission and replication

  18. Evaluation of the Aptima(®) HIV-1 Quant Dx assay for HIV-1 RNA viral load detection and quantitation in plasma of HIV-1-infected individuals: A comparison with Abbott RealTime HIV-1 assay.

    Science.gov (United States)

    Amendola, Alessandra; Pisciotta, Maria; Aleo, Loredana; Ferraioli, Valeria; Angeletti, Claudio; Capobianchi, Maria Rosaria

    2016-09-01

    The Hologic Aptima(®) HIV-1 Quant Dx assay (Aptima HIV) is a real-time transcription-mediated amplification method CE-approved for use in diagnosis and monitoring of HIV-1 infection. The analytical performance of this new assay was compared to the FDA-approved Abbott RealTime HIV-1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV-1 International Standard, and the QCMD HIV-1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV-1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV-1 Subtypes. With clinical samples, inter-assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 (P R(2)  > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV-1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV-1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV-1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535-1544, 2016. © 2016 Wiley Periodicals, Inc. PMID:26864171

  19. 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.

  20. 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

    2013-11-21

    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. PMID:24196705

  1. Revisiting HIV-1 uncoating

    Directory of Open Access Journals (Sweden)

    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.

  2. Revisiting HIV-1 uncoating.

    Science.gov (United States)

    Arhel, Nathalie

    2010-01-01

    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. PMID:21083892

  3. Negative Feedback Regulation of HIV-1 by Gene Editing Strategy.

    Science.gov (United States)

    Kaminski, Rafal; Chen, Yilan; Salkind, Julian; Bella, Ramona; Young, Won-Bin; Ferrante, Pasquale; Karn, Jonathan; Malcolm, Thomas; Hu, Wenhui; Khalili, Kamel

    2016-01-01

    The CRISPR/Cas9 gene editing method is comprised of the guide RNA (gRNA) to target a specific DNA sequence for cleavage and the Cas9 endonuclease for introducing breaks in the double-stranded DNA identified by the gRNA. Co-expression of both a multiplex of HIV-1-specific gRNAs and Cas9 in cells results in the modification and/or excision of the segment of viral DNA, leading to replication-defective virus. In this study, we have personalized the activity of CRISPR/Cas9 by placing the gene encoding Cas9 under the control of a minimal promoter of HIV-1 that is activated by the HIV-1 Tat protein. We demonstrate that functional activation of CRISPR/Cas9 by Tat during the course of viral infection excises the designated segment of the integrated viral DNA and consequently suppresses viral expression. This strategy was also used in a latently infected CD4+ T-cell model after treatment with a variety of HIV-1 stimulating agents including PMA and TSA. Controlled expression of Cas9 by Tat offers a new strategy for safe implementation of the Cas9 technology for ablation of HIV-1 at a very early stage of HIV-1 replication during the course of the acute phase of infection and the reactivation of silent proviral DNA in latently infected cells. PMID:27528385

  4. Negative Feedback Regulation of HIV-1 by Gene Editing Strategy

    Science.gov (United States)

    Kaminski, Rafal; Chen, Yilan; Salkind, Julian; Bella, Ramona; Young, Won-bin; Ferrante, Pasquale; Karn, Jonathan; Malcolm, Thomas; Hu, Wenhui; Khalili, Kamel

    2016-01-01

    The CRISPR/Cas9 gene editing method is comprised of the guide RNA (gRNA) to target a specific DNA sequence for cleavage and the Cas9 endonuclease for introducing breaks in the double-stranded DNA identified by the gRNA. Co-expression of both a multiplex of HIV-1-specific gRNAs and Cas9 in cells results in the modification and/or excision of the segment of viral DNA, leading to replication-defective virus. In this study, we have personalized the activity of CRISPR/Cas9 by placing the gene encoding Cas9 under the control of a minimal promoter of HIV-1 that is activated by the HIV-1 Tat protein. We demonstrate that functional activation of CRISPR/Cas9 by Tat during the course of viral infection excises the designated segment of the integrated viral DNA and consequently suppresses viral expression. This strategy was also used in a latently infected CD4+ T-cell model after treatment with a variety of HIV-1 stimulating agents including PMA and TSA. Controlled expression of Cas9 by Tat offers a new strategy for safe implementation of the Cas9 technology for ablation of HIV-1 at a very early stage of HIV-1 replication during the course of the acute phase of infection and the reactivation of silent proviral DNA in latently infected cells. PMID:27528385

  5. A Truncated Nef Peptide from SIVcpz Inhibits the Production of HIV-1 Infectious Progeny.

    Science.gov (United States)

    Sabino Cunha, Marcela; Lima Sampaio, Thatiane; Peterlin, B Matija; Jesus da Costa, Luciana

    2016-01-01

    Nef proteins from all primate Lentiviruses, including the simian immunodeficiency virus of chimpanzees (SIVcpz), increase viral progeny infectivity. However, the function of Nef involved with the increase in viral infectivity is still not completely understood. Nonetheless, until now, studies investigating the functions of Nef from SIVcpz have been conducted in the context of the HIV-1 proviruses. In an attempt to investigate the role played by Nef during the replication cycle of an SIVcpz, a Nef-defective derivative was obtained from the SIVcpzWTGab2 clone by introducing a frame shift mutation at a unique restriction site within the nef sequence. This nef-deleted clone expresses an N-terminal 74-amino acid truncated peptide of Nef and was named SIVcpz-tNef. We found that the SIVcpz-tNef does not behave as a classic nef-deleted HIV-1 or simian immunodeficiency virus of macaques SIVmac. Markedly, SIVcpz-tNef progeny from both Hek-293T and Molt producer cells were completely non-infectious. Moreover, the loss in infectivity of SIVcpz-tNef correlated with the inhibition of Gag and GagPol processing. A marked accumulation of Gag and very low levels of reverse transcriptase were detected in viral lysates. Furthermore, these observations were reproduced once the tNef peptide was expressed in trans both in SIVcpzΔNef and HIV-1WT expressing cells, demonstrating that the truncated peptide is a dominant negative for viral processing and infectivity for both SIVcpz and HIV-1. We demonstrated that the truncated Nef peptide binds to GagPol outside the protease region and by doing so probably blocks processing of both GagPol and Gag precursors at a very early stage. This study demonstrates for the first time that naturally-occurring Nef peptides can potently block lentiviral processing and infectivity. PMID:27399760

  6. A Truncated Nef Peptide from SIVcpz Inhibits the Production of HIV-1 Infectious Progeny

    Directory of Open Access Journals (Sweden)

    Marcela Sabino Cunha

    2016-07-01

    Full Text Available Nef proteins from all primate Lentiviruses, including the simian immunodeficiency virus of chimpanzees (SIVcpz, increase viral progeny infectivity. However, the function of Nef involved with the increase in viral infectivity is still not completely understood. Nonetheless, until now, studies investigating the functions of Nef from SIVcpz have been conducted in the context of the HIV-1 proviruses. In an attempt to investigate the role played by Nef during the replication cycle of an SIVcpz, a Nef-defective derivative was obtained from the SIVcpzWTGab2 clone by introducing a frame shift mutation at a unique restriction site within the nef sequence. This nef-deleted clone expresses an N-terminal 74-amino acid truncated peptide of Nef and was named SIVcpz-tNef. We found that the SIVcpz-tNef does not behave as a classic nef-deleted HIV-1 or simian immunodeficiency virus of macaques SIVmac. Markedly, SIVcpz-tNef progeny from both Hek-293T and Molt producer cells were completely non-infectious. Moreover, the loss in infectivity of SIVcpz-tNef correlated with the inhibition of Gag and GagPol processing. A marked accumulation of Gag and very low levels of reverse transcriptase were detected in viral lysates. Furthermore, these observations were reproduced once the tNef peptide was expressed in trans both in SIVcpzΔNef and HIV-1WT expressing cells, demonstrating that the truncated peptide is a dominant negative for viral processing and infectivity for both SIVcpz and HIV-1. We demonstrated that the truncated Nef peptide binds to GagPol outside the protease region and by doing so probably blocks processing of both GagPol and Gag precursors at a very early stage. This study demonstrates for the first time that naturally-occurring Nef peptides can potently block lentiviral processing and infectivity.

  7. In vivo functions of CPSF6 for HIV-1 as revealed by HIV-1 capsid evolution in HLA-B27-positive subjects.

    Directory of Open Access Journals (Sweden)

    Matthew S Henning

    2014-01-01

    Full Text Available The host protein CPSF6 possesses a domain that can interact with the HIV-1 capsid (CA protein. CPSF6 has been implicated in regulating HIV-1 nuclear entry. However, its functional significance for HIV-1 replication has yet to be firmly established. Here we provide evidence for two divergent functions of CPSF6 for HIV-1 replication in vivo. We demonstrate that endogenous CPSF6 exerts an inhibitory effect on naturally occurring HIV-1 variants in individuals carrying the HLA-B27 allele. Conversely, we find a strong selective pressure in these individuals to preserve CPSF6 binding, while escaping from the restrictive activity by CPSF6. This active maintenance of CPSF6 binding during HIV-1 CA evolution in vivo contrasts with the in vitro viral evolution, which can reduce CPSF6 binding to evade from CPSF6-mediated restriction. Thus, these observations argue for a beneficial role of CPSF6 for HIV-1 in vivo. CPSF6-mediated restriction renders HIV-1 less dependent or independent from TNPO3, RanBP2 and Nup153, host factors implicated in HIV-1 nuclear entry. However, viral evolution that maintains CPSF6 binding in HLA-B27+ subjects invariably restores the ability to utilize these host factors, which may be the major selective pressure for CPSF6 binding in vivo. Our study uncovers two opposing CA-dependent functions of CPSF6 in HIV-1 replication in vivo; however, the benefit for binding CPSF6 appears to outweigh the cost, providing support for a vital function of CPSF6 during HIV-1 replication in vivo.

  8. Highly Conserved Structural Properties of the C-terminal Tail of HIV-1 gp41 Protein Despite Substantial Sequence Variation among Diverse Clades: IMPLICATIONS FOR FUNCTIONS IN VIRAL REPLICATION*

    OpenAIRE

    Steckbeck, Jonathan D.; Craigo, Jodi K.; Barnes, Christopher O.; Ronald C Montelaro

    2011-01-01

    Although the HIV-1 Env gp120 and gp41 ectodomain have been extensively characterized in terms of structure and function, similar characterizations of the C-terminal tail (CTT) of HIV gp41 remain relatively limited and contradictory. The current study was designed to examine in detail CTT sequence conservation relative to gp120 and the gp41 ectodomain and to examine the conservation of predicted physicochemical and structural properties across a number of divergent HIV clades and groups. Resul...

  9. Role of IL-7 in immune activation during HIV-1 infection

    OpenAIRE

    Sammicheli, Stefano

    2011-01-01

    Viral replication, lymphopenia and microbial translocation at the mucosal surfaces lead to a chronic state of immune activation during HIV-1 infection. Chronic immune activation is believed to impact on the functionality of cell types that are not the main target for virus replication, including CD8+T cells, B cells and NK cells. In this thesis two main aspects of the pathogenesis of HIV-1 infection were studied: 1) how viral replication and disease progression affect the homeo...

  10. Contribution of MxB Oligomerization to HIV-1 Capsid Binding and Restriction

    OpenAIRE

    Buffone, Cindy; Schulte, Bianca; OPP, Silvana; Diaz-Griffero, Felipe

    2015-01-01

    The alpha interferon (IFN-α)-inducible restriction factor myxovirus B (MxB) blocks HIV-1 infection after reverse transcription but prior to integration. MxB binds to the HIV-1 core, which is composed of capsid protein, and this interaction leads to inhibition of the uncoating process of HIV-1. Previous studies suggested that HIV-1 restriction by MxB requires binding to capsid. This work tests the hypothesis that MxB oligomerization is important for the ability of MxB to bind to the HIV-1 core...

  11. Block to influenza virus replication in cells preirradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Ultraviolet (uv) irradiation of CEF cells immediately before infection with influenza A (fowl plague) virus inhibited virus growth; no inhibition of the growth of a parainfluenza virus (Newcastle disease virus) could be detected in irradiated cells. The kinetics of inhibition after various doses of uv irradiation were multihit, with an extrapolation number of two. When irradiated cells were allowed to photoreactivate by exposure to visible light for 16 hr their capacity to support influenza virus replication was largely restored; this process was sensitive to caffeine, suggesting that it required DNA repair. In CEF cells exposed to 360 ergs/mm2 of uv radiation the rate of synthesis of host cellular RNA was reduced by more than 90%, and that of host cellular protein by 40 to 50%, as judged by incorporation of precursor molecules into an acid-insoluble form. When such irradiated cells were infected with influenza virus all the genome RNA segments were transcribed, but the overall concentration of virus-specific poly(A)-containing cRNA was reduced about 50-fold. Within this population of cRNA molecules, the RNAs coding for late proteins (HA, NA, and M) were reduced in amount relative to the other segments. The rates of synthesis of the M and HA proteins were specifically reduced in uv-irradiated cells, but the rates of synthesis of the P, NP, and NS proteins were only slightly reduced compared to normal cells. Immunofluorescent studies showed that, in uv-irradiated cells, NP migrated into the nucleus early after infection and later migrated out into the cytoplasm, as in normal cells. In contrast to normal cells, no specific immunofluorescence associated with M protein could be observed in uv-irradiated cells. It is concluded that uv-induced damage to host cellular DNA alters the pattern of RNA transcription in CEF cells infected with influenza virus, and that this results in a block to late protein synthesis which stops virus production

  12. Persistence of HIV-1 structural proteins and glycoproteins in lymph nodes of patients under highly active antiretroviral therapy

    OpenAIRE

    Popovic, Mikulas; Tenner-Racz, Klara; Pelser, Colleen; Stellbrink, Hans-Jurgen; van Lunzen, Jan; Lewis, George; Kalyanaraman, Vaniambadi S.; Gallo, Robert C.; Racz, Paul

    2005-01-01

    Here we report a long-term persistence of HIV-1 structural proteins and glycoproteins in germinal centers (GCs) of lymph nodes (LNs) in the absence of detectable virus replication in patients under highly active antiretroviral therapy (HAART). The persistence of viral structural proteins and glycoproteins in GCs was accompanied by specific antibody responses to HIV-1. Seven patients during the chronic phase of HIV-1 infection were analyzed for the presence of the capsid protein (HIV-1p24), ma...

  13. Safety and immunogenicity of recombinant poxvirus HIV-1 vaccines in young adults on highly active antiretroviral therapy

    OpenAIRE

    Greenough, Thomas C.; Cunningham, Coleen K; Muresan, Petronella; McManus, Margaret; Persaud, Deborah; Fenton, Terry; Barker, Piers; Gaur, Aditya; Panicali, Dennis; Sullivan, John L.; Luzuriaga, Katherine

    2008-01-01

    A trial to evaluate the safety and immunogenicity of recombinant modified vaccinia Ankara (MVA) and fowlpox (FP) vectors expressing multiple HIV-1 proteins was conducted in twenty HIV-1 infected youth with suppressed viral replication on HAART. The MVA and FP-based multigene HIV-1 vaccines were safe and well tolerated. Increased frequencies of HIV-1 specific CD4+ proliferative responses and cytokine secreting cells were detected following immunization. Increased frequencies and breadth of HIV...

  14. The brain-specific factor FEZ1 is a determinant of neuronal susceptibility to HIV-1 infection.

    LENUS (Irish Health Repository)

    Haedicke, Juliane

    2009-08-18

    Neurons are one of the few cell types in the human body that do not support HIV type-1 (HIV-1) replication. Although the lack of key receptors is a major obstacle to infection, studies suggest that additional functions inhibit virus replication to explain the exquisite resistance of neurons to HIV-1. However, specific neuronal factors that may explain this resistance remain to be discovered. In a screen for antiviral factors using a fibroblast line chemically mutagenized and selected for resistance to retroviral infection, we recently identified induction of rat FEZ1 (fasciculation and elongation protein zeta-1), a brain-specific protein, as the cause of this resistance. When exogenously expressed in nonneuronal cell lines rat FEZ1 blocked nuclear entry of retroviral DNA. Here, we demonstrate that among human brain cells, neurons naturally express high levels of FEZ1 compared to astrocytes or microglia cells and are correspondingly less susceptible to infection with pseudotyped HIV-1 that bypasses receptor-mediated viral entry. Demonstrating that endogenous FEZ1 was functionally important in the resistance of neurons to HIV-1 infection, siRNA-mediated knockdown of endogenous FEZ1 increased the infectivity of neurons while sensitive brain cell types like microglia became more resistant upon FEZ1 overexpression. In addition, FEZ1 expression was not induced in response to IFN treatment. As such, in contrast to other widely expressed, IFN-inducible antiviral factors, FEZ1 appears to represent a unique neuron-specific determinant of cellular susceptibility to infection in a cell type that is naturally resistant to HIV-1.

  15. An anti-HIV-1 gp120 antibody expressed as an endocytotic transmembrane protein mediates internalization of HIV-1

    International Nuclear Information System (INIS)

    In this study, we used HIV-1 as a model to demonstrate a novel approach for receptor-independent cell entry of virus. The heavy chain of an anti-HIV-1 gp120 antibody was engineered with endocytotic and transmembrane motifs from either the cation-independent mannose 6-phospate receptor or the low-density lipoprotein receptor. Flow cytometry and immunofluorescence studies showed that the chimeric antibodies were expressed on the cell surface and can undergo rapid internalization. Furthermore, one of the chimeric antibodies was able to bind and internalize HIV-1. Using a luciferase reporter HIV-1, we further showed that internalized viruses could undergo replication. Therefore, we have demonstrated a proof-of-principle of a novel method that can be used to internalize virus into cells, without prior knowledge of the cellular receptor for the virus. We propose that this approach would be particularly useful for studying viruses whose cellular receptor(s) is not known

  16. HIV-1 evades innate immune recognition through specific co-factor recruitment

    OpenAIRE

    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.

    2013-01-01

    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 (PRRs). We hypothesized 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 (CA) and host factors that putatively regulate these ...

  17. Discovery of a small-molecule antiviral targeting the HIV-1 matrix protein

    OpenAIRE

    Zentner, Isaac; Sierra, Luz-Jeannette; Maciunas, Lina; Vinnik, Andrei; Fedichev, Peter; Mankowski, Marie K.; Ptak, Roger G.; Martín-García, Julio; Cocklin, Simon

    2012-01-01

    Due to the emergence of drug-resistant strains and the cumulative toxicities associated with current therapies, demand remains for new inhibitors of HIV-1 replication. The HIV-1 matrix (MA) protein is an essential viral component with established roles in the assembly of the virus. Using virtual and surface plasmon resonance (SPR)-based screening, we describe the identification of the first small molecule to bind to the HIV-1 MA protein and to possess broad range anti-HIV properties.

  18. Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways.

    Directory of Open Access Journals (Sweden)

    Stephanie M Rainey

    2016-04-01

    Full Text Available The intracellular endosymbiotic bacterium Wolbachia can protect insects against viral infection, and is being introduced into mosquito populations in the wild to block the transmission of arboviruses that infect humans and are a major public health concern. To investigate the mechanisms underlying this antiviral protection, we have developed a new model system combining Wolbachia-infected Drosophila melanogaster cell culture with the model mosquito-borne Semliki Forest virus (SFV; Togaviridae, Alphavirus. Wolbachia provides strong antiviral protection rapidly after infection, suggesting that an early stage post-infection is being blocked. Wolbachia does appear to have major effects on events distinct from entry, assembly or exit as it inhibits the replication of an SFV replicon transfected into the cells. Furthermore, it causes a far greater reduction in the expression of proteins from the 3´ open reading frame than the 5´ non-structural protein open reading frame, indicating that it is blocking the replication of viral RNA. Further to this separation of the replicase proteins and viral RNA in transreplication assays shows that uncoupling of viral RNA and replicase proteins does not overcome Wolbachia's antiviral activity. This further suggests that replicative processes are disrupted, such as translation or replication, by Wolbachia infection. This may occur by Wolbachia mounting an active antiviral response, but the virus did not cause any transcriptional response by the bacterium, suggesting that this is not the case. Host microRNAs (miRNAs have been implicated in protection, but again we found that host cell miRNA expression was unaffected by the bacterium and neither do our findings suggest any involvement of the antiviral siRNA pathway. We conclude that Wolbachia may directly interfere with early events in virus replication such as translation of incoming viral RNA or RNA transcription, and this likely involves an intrinsic (as opposed

  19. Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways.

    Science.gov (United States)

    Rainey, Stephanie M; Martinez, Julien; McFarlane, Melanie; Juneja, Punita; Sarkies, Peter; Lulla, Aleksei; Schnettler, Esther; Varjak, Margus; Merits, Andres; Miska, Eric A; Jiggins, Francis M; Kohl, Alain

    2016-04-01

    The intracellular endosymbiotic bacterium Wolbachia can protect insects against viral infection, and is being introduced into mosquito populations in the wild to block the transmission of arboviruses that infect humans and are a major public health concern. To investigate the mechanisms underlying this antiviral protection, we have developed a new model system combining Wolbachia-infected Drosophila melanogaster cell culture with the model mosquito-borne Semliki Forest virus (SFV; Togaviridae, Alphavirus). Wolbachia provides strong antiviral protection rapidly after infection, suggesting that an early stage post-infection is being blocked. Wolbachia does appear to have major effects on events distinct from entry, assembly or exit as it inhibits the replication of an SFV replicon transfected into the cells. Furthermore, it causes a far greater reduction in the expression of proteins from the 3´ open reading frame than the 5´ non-structural protein open reading frame, indicating that it is blocking the replication of viral RNA. Further to this separation of the replicase proteins and viral RNA in transreplication assays shows that uncoupling of viral RNA and replicase proteins does not overcome Wolbachia's antiviral activity. This further suggests that replicative processes are disrupted, such as translation or replication, by Wolbachia infection. This may occur by Wolbachia mounting an active antiviral response, but the virus did not cause any transcriptional response by the bacterium, suggesting that this is not the case. Host microRNAs (miRNAs) have been implicated in protection, but again we found that host cell miRNA expression was unaffected by the bacterium and neither do our findings suggest any involvement of the antiviral siRNA pathway. We conclude that Wolbachia may directly interfere with early events in virus replication such as translation of incoming viral RNA or RNA transcription, and this likely involves an intrinsic (as opposed to an induced

  20. The SOCS-Box of HIV-1 Vif Interacts with ElonginBC by Induced-Folding to Recruit Its Cul5-Containing Ubiquitin Ligase Complex

    OpenAIRE

    Bergeron, Julien R. C.; Huthoff, Hendrik; Veselkov, Dennis A.; Beavil, Rebecca L.; Simpson, Peter J; Matthews, Stephen J.; Malim, Michael H.; Sanderson, Mark R.

    2010-01-01

    Author Summary HIV-1 is the etiologic agent of AIDS. Current therapies are based on cocktails of anti-viral drugs that inhibit viral enzymes essential for virus replication, but this strategy has several shortcomings, including the development of drug-resistant virus strains. Consequently, pharmacologic strategies that interfere with additional aspects of HIV-1 replication have the potential to enhance HIV-1 treatments. The HIV-1 Vif protein is a promising target for the development of new an...

  1. Selective translational repression of HIV-1 RNA by Sam68DeltaC occurs by altering PABP1 binding to unspliced viral RNA

    Directory of Open Access Journals (Sweden)

    Soros Vanessa

    2008-10-01

    Full Text Available Abstract HIV-1 structural proteins are translated from incompletely spliced 9 kb and 4 kb mRNAs, which are transported to the cytoplasm by Crm1. It has been assumed that once in the cytoplasm, translation of incompletely spliced HIV-1 mRNAs occurs in the same manner as host mRNAs. Previous analyses have demonstrated that Sam68 and a mutant thereof, Sam68ΔC, have dramatic effects on HIV gene expression, strongly enhancing and inhibiting viral structural protein synthesis, respectively. While investigating the inhibition of incompletely spliced HIV-1 mRNAs by Sam68ΔC, we determined that the effect was independent of the perinuclear bundling of the viral RNA. Inhibition was dependent upon the nuclear export pathway used, as translation of viral RNA exported via the Tap/CTE export pathway was not blocked by Sam68ΔC. We demonstrate that inhibition of HIV expression by Sam68ΔC is correlated with a loss of PABP1 binding with no attendant change in polyadenosine tail length of the affected RNAs. The capacity of Sam68ΔC to selectively inhibit translation of HIV-1 RNAs exported by Crm1 suggests that it is able to recognize unique characteristics of these viral RNPs, a property that could lead to new therapeutic approaches to controlling HIV-1 replication.

  2. Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial

    OpenAIRE

    Jairam R Lingappa; Lambdin, Barrot; Bukusi, Elizabeth Ann; Ngure, Kenneth; Kavuma, Linda; Inambao, Mubiana; Kanweka, William; Allen, Susan; Kiarie, James N.; Were, Edwin; Manongi, Rachel; Coetzee, David; de Bruyn, Guy; Delany-Moretlwe, Sinead; MAGARET, Amalia

    2008-01-01

    Background: Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 preval...

  3. Structure of HIV-1 protease determined by neutron crystallography

    International Nuclear Information System (INIS)

    HIV-1 protease is an aspartic protease, and plays an essential role in replication of HIV. To develop HIV-1 protease inhibitors through structure-based drug design, it is necessary to understand the catalytic mechanism and inhibitor recognition of HIV-1 protease. We have determined the crystal structure of HIV-1 protease in complex with KNI-272 to 1.9 A resolution by neutron crystallography in combination with 1.4 A resolution X-ray diffraction data. The results show that the carbonyl group of hydroxymethylcarbonyl (HMC) in KNI-272 forms a hydrogen bonding interaction with protonated Asp 25 and the hydrogen atom from the hydroxyl group of HMC forms a hydrogen bonding interaction with the deprotonated Asp125. This is the first neutron report for HIV-1/inhibitor complex and shows directly the locations of key hydrogen atoms in catalysis and in the binding of a transition-state analog. The results confirm key aspect of the presumed catalytic mechanism of HIV-1 protease and will aid in the further development of protease inhibitors. (author)

  4. Cyclophilin Inhibitors Block Arterivirus Replication by Interfering with Viral RNA Synthesis

    OpenAIRE

    de Wilde, A. H.; Li, Y; van der Meer, Y.; Vuagniaux, G; Lysek, R.; Fang, Y; Snijder, E J; van Hemert, M. J.

    2013-01-01

    Virus replication strongly depends on cellular factors, in particular, on host proteins. Here we report that the replication of the arteriviruses equine arteritis virus (EAV) and porcine reproductive and respiratory syndrome virus (PRRSV) is strongly affected by low-micromolar concentrations of cyclosporine A (CsA), an inhibitor of members of the cyclophilin (Cyp) family. In infected cells, the expression of a green fluorescent protein (GFP) reporter gene inserted into the PRRSV genome was in...

  5. CD8+-Cell Antiviral Factor Activity Is Not Restricted to Human Immunodeficiency Virus (HIV)-Specific T Cells and Can Block HIV Replication after Initiation of Reverse Transcription

    OpenAIRE

    Le Borgne, Sylvie; Février, Michèle; Callebaut, Christian; Lee, Steven P.; Rivière, Yves

    2000-01-01

    CD8+ lymphocytes from human immunodeficiency virus (HIV)-infected patients can suppress in vitro HIV replication in CD4+ T cells by a noncytolytic mechanism involving secreted CD8+-cell antiviral factor(s) (CAF). Using an HIV Nef-specific cytotoxic-T-lymphocyte (CTL) line and autologous CD4+ T cells infected with a nef-deleted HIV-1 virus, we demonstrated that, after a priming antigenic stimulation, this suppression does not require the presence of the specific antigen during the effector pha...

  6. Drug Repurposing Approach Identifies Inhibitors of the Prototypic Viral Transcription Factor IE2 that Block Human Cytomegalovirus Replication.

    Science.gov (United States)

    Mercorelli, Beatrice; Luganini, Anna; Nannetti, Giulio; Tabarrini, Oriana; Palù, Giorgio; Gribaudo, Giorgio; Loregian, Arianna

    2016-03-17

    New targets for antiviral strategies are needed against human cytomegalovirus (HCMV), a major human pathogen. A cell-based screen aimed at finding inhibitors of the viral transcription factor Immediate-Early 2 (IE2) was performed in HCMV-infected cells expressing EGFP under the control of an IE2-inducible viral promoter. Screening of a library of bioactive small molecules led to the identification of several compounds able to inhibit EGFP expression and also HCMV replication with potency in the low-micromolar range. Follow-up studies with four selected hits indicated that they all block viral DNA synthesis as well as viral Early and Late gene expression. Furthermore, mechanistic studies confirmed that the compounds specifically act via inhibition of IE2 transactivating activity, thus blocking viral Early gene expression and the progression of virus replication. These results provide proof of concept for identifying small molecules that modulate the activity of a microbial transcription factor to control pathogen replication. PMID:26877023

  7. A new functional role of HIV-1 integrase during uncoating of the viral core.

    Science.gov (United States)

    Briones, Marisa S; Chow, Samson A

    2010-12-01

    An early and critical event of the human immunodeficiency virus type 1 (HIV-1) life cycle is uncoating of the viral core. Uncoating involves the disassembly of HIV-1 capsid (CA). The underlying mechanisms governing uncoating are poorly defined, and the role of viral and host factors in uncoating is not well understood. Cyclophilin A and TRIM5α are two cellular factors that interact with CA in exerting their effects on HIV-1 replication. Here, we review the current understanding of uncoating and the new functional role of HIV-1 IN during uncoating. PMID:20721640

  8. Recombinant rabies virus as potential live-viral vaccines for HIV-1

    OpenAIRE

    Schnell, Matthias J.; Foley, Heather D.; Siler, Catherine A.; McGettigan, James P.; Dietzschold, Bernhard; Pomerantz, Roger J.

    2000-01-01

    Recombinant, replication-competent rabies virus (RV) vaccine strain-based vectors were developed expressing HIV type I (HIV-1) envelope glycoprotein (gp160) from both a laboratory-adapted (CXCR4-tropic) and a primary (dual-tropic) HIV-1 isolate. An additional transcription stop/start unit within the RV genome was used to express HIV-1 gp160 in addition to the other RV proteins. The HIV-1 gp160 protein was stably and functionally expressed, as indicated by fusion of human T cell lines after in...

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

    International Nuclear Information System (INIS)

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

  10. Contribution of PDZD8 to Stabilization of the Human Immunodeficiency Virus (HIV-1) Capsid

    OpenAIRE

    Guth, Charles Alexander

    2013-01-01

    Following human immunodeficiency virus (HIV-1) entry into the host cell, the viral capsid gradually disassembles in a process called uncoating. A proper rate of uncoating is important for reverse transcription of the HIV-1 genome. Host restriction factors such as TRIM5alpha; and TRIMCyp bind retroviral capsids and cause premature disassembly, leading to blocks in reverse transcription. Other host factors, such as cyclophilin A, stabilize the HIV-1 capsid and are required for efficient infe...

  11. Effects of human SAMHD1 polymorphisms on HIV-1 susceptibility

    International Nuclear Information System (INIS)

    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

  12. 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.

  13. Gene Expression Analysis of a Panel of Cell Lines That Differentially Restrict HIV-1 CA Mutants Infection in a Cyclophilin A-Dependent Manner

    Science.gov (United States)

    Shah, Vaibhav B.; Aiken, Christopher

    2014-01-01

    HIV-1 replication is dependent on binding of the viral capsid to the host protein cyclophilin A (CypA). Interference with cyclophilin A binding, either by mutations in the HIV-1 capsid protein (CA) or by the drug cyclosporine A (CsA), inhibits HIV-1 replication in cell culture. Resistance to CsA is conferred by A92E or G94D substitutions in CA. The mutant viruses are also dependent on CsA for their replication. Interestingly, infection of some cell lines by these mutants is enhanced by CsA, while infection of others is not affected by the drug. The cells are thus termed nonpermissive and permissive, respectively, for infection by CsA-dependent mutants. The mechanistic basis for the cell type dependence is not well understood, but has been hypothesized to result from a dominant-acting host factor that blocks HIV-1 infection by a mechanism that requires CypA binding to the viral capsid. In an effort to identify a CypA-dependent host restriction factor, we adopted a strategy involving comparative gene expression analysis in three permissive and three non-permissive cell types. We ranked the genes based on their relative overexpression in non-permissive cell types compared to the permissive cell types. Based on specific selection criteria, 26 candidate genes were selected and targeted using siRNA in nonpermissive (HeLa) cells. Depletion of none of the selected candidate genes led to the reversal of CsA-dependent phenotype of the A92E mutant. Our data suggest that none of the 26 genes tested is responsible for the dependence of the A92E mutant on CsA. Our study provides gene expression data that may be useful for future efforts to identify the putative CypA-dependent HIV-1 restriction factor and in studies of other cell-specific phenotypes. PMID:24663101

  14. Immunologic Strategies for HIV-1 Remission and Eradication

    OpenAIRE

    Barouch, Dan H.; Deeks, Steven G.

    2014-01-01

    Antiretroviral therapy (ART) is able to suppress HIV-1 replication indefinitely in individuals who have access to these medications, are able to tolerate these drugs, and are motivated to take them daily for life. However, ART is not curative. HIV-1 persists indefinitely during ART as quiescent integrated DNA within memory CD4+ T cells and perhaps other long-lived cellular reservoirs. In this review, we discuss the role of the immune system on the establishment and maintenance of this “latent...

  15. 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.

  16. Bacteriophage resistance of a Delta thyA mutant of Lactococcus lactis blocked in DNA replication

    DEFF Research Database (Denmark)

    Pedersen, M.B.; Jensen, Peter Ruhdal; Janzen, T.;

    2002-01-01

    , such as milk, there was no detectable d'ITP pool in the cells. Hence, DNA replication was abolished, and acidification by MBP71 was completely unaffected by the presence of nine different phages tested at a multiplicity of infection (MOI) of 0.1. Nonreplicating MBP71 must be inoculated at a higher...

  17. Recombinant rabies virus as potential live-viral vaccines for HIV-1.

    Science.gov (United States)

    Schnell, M J; Foley, H D; Siler, C A; McGettigan, J P; Dietzschold, B; Pomerantz, R J

    2000-03-28

    Recombinant, replication-competent rabies virus (RV) vaccine strain-based vectors were developed expressing HIV type I (HIV-1) envelope glycoprotein (gp160) from both a laboratory-adapted (CXCR4-tropic) and a primary (dual-tropic) HIV-1 isolate. An additional transcription stop/start unit within the RV genome was used to express HIV-1 gp160 in addition to the other RV proteins. The HIV-1 gp160 protein was stably and functionally expressed, as indicated by fusion of human T cell lines after infection with the recombinant RVs. Inoculation of mice with the recombinant RVs expressing HIV-1 gp160 induced a strong humoral response directed against the HIV-1 envelope protein after a single boost with recombinant HIV-1 gp120 protein. Moreover, high neutralization titers up to 1:800 against HIV-1 could be detected in the mouse sera. These data indicate that a live recombinant RV, a rhabdovirus, expressing HIV-1 gp160 may serve as an effective vector for an HIV-1 vaccine. PMID:10706640

  18. Nuclear trafficking of the HIV-1 pre-integration complex depends on the ADAM10 intracellular domain

    International Nuclear Information System (INIS)

    Previously, we showed that ADAM10 is necessary for HIV-1 replication in primary human macrophages and immortalized cell lines. Silencing ADAM10 expression interrupted the HIV-1 life cycle prior to nuclear translocation of viral cDNA. Furthermore, our data indicated that HIV-1 replication depends on the expression of ADAM15 and γ-secretase, which proteolytically processes ADAM10. Silencing ADAM15 or γ-secretase expression inhibits HIV-1 replication between reverse transcription and nuclear entry. Here, we show that ADAM10 expression also supports replication in CD4+ T lymphocytes. The intracellular domain (ICD) of ADAM10 associates with the HIV-1 pre-integration complex (PIC) in the cytoplasm and immunoprecipitates and co-localizes with HIV-1 integrase, a key component of PIC. Taken together, our data support a model whereby ADAM15/γ-secretase processing of ADAM10 releases the ICD, which then incorporates into HIV-1 PIC to facilitate nuclear trafficking. Thus, these studies suggest ADAM10 as a novel therapeutic target for inhibiting HIV-1 prior to nuclear entry. - Highlights: • Nuclear trafficking of the HIV-1 pre-integration complex depends on ADAM10. • ADAM10 associates with HIV-1 integrase in the pre-integration complex. • HIV-1 replication depends on the expression of ADAM15 and γ-secretase. • Silencing ADAM15 or γ-secretase expression inhibits nuclear import of viral cDNA. • ADAM10 is important for HIV-1 replication in human macrophages and CD4+ T lymphocytes

  19. Nuclear trafficking of the HIV-1 pre-integration complex depends on the ADAM10 intracellular domain

    Energy Technology Data Exchange (ETDEWEB)

    Endsley, Mark A., E-mail: maendsle@utmb.edu [Department Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 (United States); Somasunderam, Anoma D., E-mail: asomasun@utmb.edu [Department Internal Medicine, Division of Infectious Diseases, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555 (United States); Li, Guangyu, E-mail: LIG001@mail.etsu.edu [Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614 (United States); Oezguen, Numan, E-mail: numan.oezguen@bcm.edu [Department of Pathology and Immunology, Microbiome Center, Texas Children' s Hospital, Houston, TX 77030 (United States); Thiviyanathan, Varatharasa, E-mail: Varatharasa.Thiviyanathan@uth.tmc.edu [Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX 77030 (United States); Murray, James L., E-mail: jmurray100@yahoo.com [GeneTAG Technology, Inc., 3155 Northwoods Place, Norcross, GA 30071 (United States); Rubin, Donald H., E-mail: don.h.rubin@vanderbilt.edu [Research Medicine, VA Tennessee Valley Healthcare System, 1310 24th Ave. South, Nashville, TN 37212 (United States); Departments of Medicine, Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Ave South, Nashville, TN 37232 (United States); Hodge, Thomas W., E-mail: twhodge3@gmail.com [Pre-clinical and Antiviral Research, Tamir Biotechnology, Inc., 12625 High Bluff Dr., Suite 113, San Diego, CA 92130 (United States); and others

    2014-04-15

    Previously, we showed that ADAM10 is necessary for HIV-1 replication in primary human macrophages and immortalized cell lines. Silencing ADAM10 expression interrupted the HIV-1 life cycle prior to nuclear translocation of viral cDNA. Furthermore, our data indicated that HIV-1 replication depends on the expression of ADAM15 and γ-secretase, which proteolytically processes ADAM10. Silencing ADAM15 or γ-secretase expression inhibits HIV-1 replication between reverse transcription and nuclear entry. Here, we show that ADAM10 expression also supports replication in CD4{sup +} T lymphocytes. The intracellular domain (ICD) of ADAM10 associates with the HIV-1 pre-integration complex (PIC) in the cytoplasm and immunoprecipitates and co-localizes with HIV-1 integrase, a key component of PIC. Taken together, our data support a model whereby ADAM15/γ-secretase processing of ADAM10 releases the ICD, which then incorporates into HIV-1 PIC to facilitate nuclear trafficking. Thus, these studies suggest ADAM10 as a novel therapeutic target for inhibiting HIV-1 prior to nuclear entry. - Highlights: • Nuclear trafficking of the HIV-1 pre-integration complex depends on ADAM10. • ADAM10 associates with HIV-1 integrase in the pre-integration complex. • HIV-1 replication depends on the expression of ADAM15 and γ-secretase. • Silencing ADAM15 or γ-secretase expression inhibits nuclear import of viral cDNA. • ADAM10 is important for HIV-1 replication in human macrophages and CD4{sup +} T lymphocytes.

  20. A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R+L74I enzyme and a replication competent virus

    Directory of Open Access Journals (Sweden)

    Crumpacker Clyde S

    2011-01-01

    Full Text Available Abstract Background The major hurdle in the treatment of Human Immunodeficiency virus type 1 (HIV-1 includes the development of drug resistance-associated mutations in the target regions of the virus. Since reverse transcriptase (RT is essential for HIV-1 replication, several nucleoside analogues have been developed to target RT of the virus. Clinical studies have shown that mutations at RT codon 65 and 74 which are located in β3-β4 linkage group of finger sub-domain of RT are selected during treatment with several RT inhibitors, including didanosine, deoxycytidine, abacavir and tenofovir. Interestingly, the co-selection of K65R and L74V is rare in clinical settings. We have previously shown that K65R and L74V are incompatible and a R→K reversion occurs at codon 65 during replication of the virus. Analysis of the HIV resistance database has revealed that similar to K65R+L74V, the double mutant K65R+L74I is also rare. We sought to compare the impact of L→V versus L→I change at codon 74 in the background of K65R mutation, on the replication of doubly mutant viruses. Methods Proviral clones containing K65R, L74V, L74I, K65R+L74V and K65R+L74I RT mutations were created in pNL4-3 backbone and viruses were produced in 293T cells. Replication efficiencies of all the viruses were compared in peripheral blood mononuclear (PBM cells in the absence of selection pressure. Replication capacity (RC of mutant viruses in relation to wild type was calculated on the basis of antigen p24 production and RT activity, and paired analysis by student t-test was performed among RCs of doubly mutant viruses. Reversion at RT codons 65 and 74 was monitored during replication in PBM cells. In vitro processivity of mutant RTs was measured to analyze the impact of amino acid changes at RT codon 74. Results Replication kinetics plot showed that all of the mutant viruses were attenuated as compared to wild type (WT virus. Although attenuated in comparison to WT virus

  1. Tat RNA silencing suppressor activity contributes to perturbation of lymphocyte miRNA by HIV-1

    Directory of Open Access Journals (Sweden)

    Yu Lianbo

    2011-05-01

    Full Text Available Abstract Background MicroRNA (miRNA-mediated RNA silencing is integral to virtually every cellular process including cell cycle progression and response to virus infection. The interplay between RNA silencing and HIV-1 is multifaceted, and accumulating evidence posits a strike-counterstrike interface that alters the cellular environment to favor virus replication. For instance, miRNA-mediated RNA silencing of HIV-1 translation is antagonized by HIV-1 Tat RNA silencing suppressor activity. The activity of HIV-1 accessory proteins Vpr/Vif delays cell cycle progression, which is a process prominently modulated by miRNA. The expression profile of cellular miRNA is altered by HIV-1 infection in both cultured cells and clinical samples. The open question stands of what, if any, is the contribution of Tat RNA silencing suppressor activity or Vpr/Vif activity to the perturbation of cellular miRNA by HIV-1. Results Herein, we compared the perturbation of miRNA expression profiles of lymphocytes infected with HIV-1NL4-3 or derivative strains that are deficient in Tat RNA silencing suppressor activity (Tat K51A substitution or ablated of the vpr/vif open reading frames. Microarrays recapitulated the perturbation of the cellular miRNA profile by HIV-1 infection. The miRNA expression trends overlapped ~50% with published microarray results on clinical samples from HIV-1 infected patients. Moreover, the number of miRNA perturbed by HIV-1 was largely similar despite ablation of Tat RSS activity and Vpr/Vif; however, the Tat RSS mutation lessened HIV-1 downregulation of twenty-two miRNAs. Conclusions Our study identified miRNA expression changes attributable to Tat RSS activity in HIV-1NL4-3. The results accomplish a necessary step in the process to understand the interface of HIV-1 with host RNA silencing activity. The overlap in miRNA expression trends observed between HIV-1 infected CEMx174 lymphocytes and primary cells supports the utility of cultured

  2. Cyclophilin A regulates HIV-1 infectivity, as demonstrated by gene targeting in human T cells

    OpenAIRE

    Braaten, Douglas; Luban, Jeremy

    2001-01-01

    The human immunodeficiency virus type 1 (HIV-1) Gag polyprotein binds most members of the cyclophilin family of peptidyl-prolyl isomerases. Of 15 known human cyclophilins, cyclophilin A (CypA) has been the focus of investigation because it was detected in HIV-1 virions. To determine whether CypA promotes HIV-1 replication, we deleted the gene encoding CypA (PPIA) in human CD4+ T cells by homologous recombination. HIV-1 replication in PPIA–/– cells was decreased and not inhibited further by cy...

  3. Fucoidans as Potential Inhibitors of HIV-1

    Directory of Open Access Journals (Sweden)

    Vladimir S. Prassolov

    2013-08-01

    Full Text Available The antiviral activity of different structure fucoidans (α-l-fucans and galactofucans was studied using two model viral systems based on a lentiviral vectors and a replication competent Moloney murine leukemia virus (Mo-MuLV. It was found that investigated fucoidans have no cytotoxic effects on Jurkat and SC-1cell at the concentration range of 0.001–100 µg/mL. Fucoidans with different efficiency suppressed transduction of Jurkat cell line by pseudo-HIV-1 particles carrying the envelope protein of HIV-1 and infection of SC-1 cells by Mo-MuLV. According to our data, all natural fucoidans can be considered as potential anti-HIV agents regardless of their carbohydrate backbone and degree of sulfating, since their activity is shown at low concentrations (0.001–0.05 µg/mL. High molecular weight fucoidans isolated from Saccharina cichorioides (1.3-α-l-fucan, and S. japonica (galactofucan were the most effective inhibitors.

  4. Rational development of radiopharmaceuticals for HIV-1

    International Nuclear Information System (INIS)

    The global battle against HIV-1 would benefit from a sensitive and specific radiopharmaceutical to localize HIV-infected cells. Ideally, this probe would be able to identify latently infected host cells containing replication competent HIV sequences. Clinical and research applications would include assessment of reservoirs, informing clinical management by facilitating assessment of burden of infection in different compartments, monitoring disease progression and monitoring response to therapy. A “rational” development approach could facilitate efficient identification of an appropriate targeted radiopharmaceutical. Rational development starts with understanding characteristics of the disease that can be effectively targeted and then engineering radiopharmaceuticals to hone in on an appropriate target, which in the case of HIV-1 (HIV) might be an HIV-specific product on or in the host cell, a differentially expressed gene product, an integrated DNA sequence specific enzymatic activity, part of the inflammatory response, or a combination of these. This is different from the current approach that starts with a radiopharmaceutical for a target associated with a disease, mostly from autopsy studies, without a strong rationale for the potential to impact patient care. At present, no targeted therapies are available for HIV latency, although a number of approaches are under study. Here we discuss requirements for a radiopharmaceutical useful in strategies targeting persistently infected cells. The radiopharmaceutical for HIV should be developed based on HIV biology, studied in an animal model and then in humans, and ultimately used in clinical and research settings

  5. Caging the Beast: TRIM5α Binding to the HIV-1 Core

    OpenAIRE

    Felipe Diaz-Griffero

    2011-01-01

    The potent HIV-1 inhibitor TRIM5α blocks HIV-1 infection by accelerating the uncoating of HIV-1. TRIM5α is known to form higher-order self-association complexes that contribute to the avidity of TRIM5α for the HIV-1 capsid, and are essential to inhibit infection; these higher-order self-association complexes are dependent upon an intact B-box 2 domain. Even though the ability to form higher-order self-association complexes resembles the clathrin triskelion that forms a protein array, or cage,...

  6. Characterization of HIV-1 Resistance to Tenofovir Alafenamide In Vitro.

    Science.gov (United States)

    Margot, Nicolas A; Johnson, Audun; Miller, Michael D; Callebaut, Christian

    2015-10-01

    Tenofovir alafenamide (TAF) is an investigational prodrug of the HIV-1 nucleotide reverse transcriptase (RT) inhibitor (NtRTI) tenofovir (TFV), with improved potency and drug delivery properties over the current prodrug, tenofovir disoproxil fumarate (TDF). TAF is currently in phase 3 clinical studies for the treatment of HIV-1 infection, in combination with other antiretroviral agents. Phase 1 and 2 studies have shown that TAF was associated with increased peripheral blood mononuclear cell (PBMC) drug loading and increased suppression of HIV-1 replication compared to treatment with TDF. In this study, selection of in vitro resistance to both TAF and the parent compound, TFV, led to the emergence of HIV-1 with the K65R amino acid substitution in RT with 6.5-fold-reduced susceptibility to TAF. Although TAF is more potent than TFV in vitro, the antiviral susceptibilities to TAF and TFV of a large panel of nucleoside/nucleotide RT inhibitor (NRTI)-resistant mutants were highly correlated (R(2) = 0.97), indicating that the two compounds have virtually the same resistance profile when assessed as fold change from the wild type. TAF showed full antiviral activity in PBMCs against primary HIV-1 isolates with protease inhibitor, nonnucleoside RT inhibitor (NNRTI), or integrase strand transfer inhibitor resistance but reduced activity against isolates with extensive NRTI resistance amino acid substitutions. However, the increased cell loading of TFV with TAF versus TDF observed in vivo suggests that TAF may retain activity against TDF-resistant mutant viruses. PMID:26149983

  7. A novel peptide that inhibits HIV-1 entry

    Institute of Scientific and Technical Information of China (English)

    YU Yong; HUANG Xiaoxing; WANG Qiong; YANG Yaling; TIAN Po; ZHANG Wentao

    2004-01-01

    @@ The global epidemic of HIV infection, the cause of AIDS, has created an urgent need for novel classes of antiretroviral agent. Besides reverse transcriptase and protease, the viral entry process provides new anti-HIV-1 targets. A new generation of antiviral drugs intended to block HIV entry into host cells is now under develop- ment[1]. These compounds are generally referred to as fusion or entry inhibitor. Several HIV-1 entry inhibitors that target CD4-gp120 interactions, co-receptor function, and gp41-mediated membrane fusion are in different stages of clinical development[2].

  8. Differential expression and interaction of host factors augment HIV-1 gene expression in neonatal mononuclear cells

    International Nuclear Information System (INIS)

    We have previously shown a higher level of HIV-1 replication and gene expression in neonatal (cord) blood mononuclear cells (CBMC) compared with adult blood cells (PBMC), which could be due to differential expression of host factors. We performed the gene expression profile of CBMC and PBMC and found that 8013 genes were expressed at higher levels in CBMC than PBMC and 8028 genes in PBMC than CBMC, including 1181 and 1414 genes upregulated after HIV-1 infection in CBMC and PBMC, respectively. Several transcription factors (NF-κB, E2F, HAT-1, TFIIE, Cdk9, Cyclin T1), signal transducers (STAT3, STAT5A) and cytokines (IL-1β, IL-6, IL-10) were upregulated in CBMC than PBMC, which are known to influence HIV-1 replication. In addition, a repressor of HIV-1 transcription, YY1, was down regulated in CBMC than PBMC and several matrix metalloproteinase (MMP-7, -12, -14) were significantly upregulated in HIV-1 infected CBMC than PBMC. Furthermore, we show that CBMC nuclear extracts interacted with a higher extent to HIV-1 LTR cis-acting sequences, including NF-κB, NFAT, AP1 and NF-IL6 compared with PBMC nuclear extracts and retroviral based short hairpin RNA (shRNA) for STAT3 and IL-6 down regulated their own and HIV-1 gene expression, signifying that these factors influenced differential HIV-1 gene expression in CBMC than PBMC.

  9. miRNA Profiles of Monocyte-Lineage Cells Are Consistent with Complicated Roles in HIV-1 Restriction

    OpenAIRE

    Clements, Janice E.; Sisk, Jeanne M.; Witwer, Kenneth W.

    2012-01-01

    Long-lived HIV-1 reservoirs include tissue macrophages. Monocyte-derived macrophages are more susceptible to infection and more permissive to HIV-1 replication than monocytes for reasons that may include the effects of different populations of miRNAs in these two cell classes. Specifically, miRs-28-3p, -150, -223, -198, and -382 exert direct or indirect negative effects on HIV-1 and are reportedly downmodulated during monocyte-to-macrophage differentiation. Here, new experimental results are ...

  10. HIV-1 Integrase Inhibitor Resistance and Its Clinical Implications

    OpenAIRE

    Blanco, Jose-Luis; Varghese, Vici; Rhee, Soo-Yon; Gatell, Jose M.; Shafer, Robert W.

    2011-01-01

    With the approval in 2007 of the first integrase inhibitor (INI), raltegravir, clinicians became better able to suppress virus replication in patients infected with human immunodeficiency virus type 1 (HIV-1) who were harboring many of the most highly drug-resistant viruses. Raltegravir also provided clinicians with additional options for first-line therapy and for the simplification of regimens in patients with stable virological suppression. Two additional INIs in advanced clinical developm...

  11. TRIM5 and the Regulation of HIV-1 Infectivity

    OpenAIRE

    Jeremy Luban

    2012-01-01

    The past ten years have seen an explosion of information concerning host restriction factors that inhibit the replication of HIV-1 and other retroviruses. Among these factors is TRIM5, an innate immune signaling molecule that recognizes the capsid lattice as soon as the retrovirion core is released into the cytoplasm of otherwise susceptible target cells. Recognition of the capsid lattice has several consequences that include multimerization of TRIM5 into a complementary lattice, premature un...

  12. Extreme genetic fragility of the HIV-1 capsid

    OpenAIRE

    Rihn, S.J.; Wilson, S. J.; Loman, N. J.; Alim, M.; Bakker, S.E.; Bhella, D.; Gifford, R.J.; Rixon, F J; Bieniasz, P D

    2013-01-01

    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pres...

  13. High-Throughput Humanized Mouse Models for Evaluation of HIV-1 Therapeutics and Pathogenesis.

    Science.gov (United States)

    Thomas, Tynisha; Seay, Kieran; Zheng, Jian Hua; Zhang, Cong; Ochsenbauer, Christina; Kappes, John C; Goldstein, Harris

    2016-01-01

    Mice cannot be used as a model to evaluate HIV-1 therapeutics because they do not become infected by HIV-1 due to structural differences between several human and mouse proteins required for HIV-1 replication. This has limited their use for in vivo assessment of anti-HIV-1 therapeutics and the mechanism by which cofactors, such as illicit drug use accelerate HIV-1 replication and disease course in substance abusers. Here, we describe the development and application of two in vivo humanized mouse models that are highly sensitive and useful models for the in vivo evaluation of candidate anti-HIV therapeutics. The first model, hu-spl-PBMC-NSG mice, uses NOD-SCID IL2rγ(-/-) (NSG) mice intrasplenically injected with human peripheral blood mononuclear cells (PBMC) which develop productive splenic HIV-1 infection after intrasplenic inoculation with a replication-competent HIV-1 expressing Renilla reniformis luciferase (HIV-LucR) and enables investigators to use bioluminescence to visualize and quantitate the temporal effects of therapeutics on HIV-1 infection. The second model, hCD4/R5/cT1 mice, consists of transgenic mice carrying human CD4, CCR5 and cyclin T1 genes, which enables murine CD4-expressing cells to support HIV-1 entry, Tat-mediated LTR transcription and consequently develop productive infection. The hCD4/R5/cT1 mice develop disseminated infection of tissues including the spleen, small intestine, lymph nodes and lungs after intravenous injection with HIV-1-LucR. Because these mice can be infected with HIV-LucR expressing transmitted/founder and clade A/E and C Envs, these mouse models can also be used to evaluate the in vivo efficacy of broadly neutralizing antibodies and antibodies induced by candidate HIV-1 vaccines. Furthermore, because hCD4/R5/cT1 mice can be infected by vaginal inoculation with replication-competent HIV-1 expressing NanoLuc (HIV-nLucR)-, this mouse model can be used to evaluate the mechanisms by which substance abuse and other factors

  14. Cellular resistance to HIV-1 infection in target cells coincides with a rapid induction of X-DING-CD4 mRNA: indication of the unique host innate response to virus regulated through function of the X-DING-CD4 gene.

    Science.gov (United States)

    Shilpi, Rasheda Y; Sachdeva, Rakhee; Simm, Malgorzata

    2012-08-01

    Clinical reports indicate that some infected individuals control HIV-1 replication through undefined mechanisms. Our group reported that a human protein named X-DING-CD4 holds a potent antiviral activity, blocking transcription of HIV-1 LTR through the inhibition of NF-κB/DNA binding. Based on observations that transformed HIV-1 resistant CD4(+) T cells produce higher levels of soluble X-DING-CD4 protein upon their exposure to virus, we hypothesized that resistance to HIV-1 in these cells may be regulated through function of the X-DING-CD4 gene. Real-time PCR evaluations of X-DING-CD4 mRNA expression confirmed our hypothesis; HIV-1 exposure caused rapid up-regulation of X-DING-CD4 mRNA in resistant, but not susceptible, cells; and the burst of X-DING-CD4 mRNA expression correlated with restriction of HIV-1 transcription. Subsequently, we examined the activity of the X-DING-CD4 gene in monocytes and macrophages from (n = 13) HIV-negative donors. The assessment of HIV-1 gag mRNA showed that the majority of cells were permissive to virus replication; however, macrophages from four donors were refractory to HIV-1 infection. In response to virus, these cells up-regulated X-DING-CD4 gene expression by 2- to 1000-fold. These data provide evidence that the X-DING-CD4 gene contributes to early cellular protection from HIV infection in some individuals and this protection depends solely on the unique genetic regulation of the host. PMID:22042911

  15. 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.

  16. A noncovalent class of papain-like protease/deubiquitinase inhibitors blocks SARS virus replication

    Energy Technology Data Exchange (ETDEWEB)

    Ratia, Kiira; Pegan, Scott; Takayama, Jun; Sleeman, Katrina; Coughlin, Melissa; Baliji, Surendranath; Chaudhuri, Rima; Fu, Wentao; Prabhakar, Bellur S.; Johnson, Michael E.; Baker, Susan C.; Ghosh, Arun K.; Mesecar, Andrew D. (Loyola); (Purdue); (UIC)

    2008-10-27

    We report the discovery and optimization of a potent inhibitor against the papain-like protease (PLpro) from the coronavirus that causes severe acute respiratory syndrome (SARS-CoV). This unique protease is not only responsible for processing the viral polyprotein into its functional units but is also capable of cleaving ubiquitin and ISG15 conjugates and plays a significant role in helping SARS-CoV evade the human immune system. We screened a structurally diverse library of 50,080 compounds for inhibitors of PLpro and discovered a noncovalent lead inhibitor with an IC{sub 50} value of 20 {mu}M, which was improved to 600 nM via synthetic optimization. The resulting compound, GRL0617, inhibited SARS-CoV viral replication in Vero E6 cells with an EC{sub 50} of 15 {mu}M and had no associated cytotoxicity. The X-ray structure of PLpro in complex with GRL0617 indicates that the compound has a unique mode of inhibition whereby it binds within the S4-S3 subsites of the enzyme and induces a loop closure that shuts down catalysis at the active site. These findings provide proof-of-principle that PLpro is a viable target for development of antivirals directed against SARS-CoV, and that potent noncovalent cysteine protease inhibitors can be developed with specificity directed toward pathogenic deubiquitinating enzymes without inhibiting host DUBs.

  17. 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......, e.g. western blot. Antibodies to HIV-1 are not detectable until 2-3 months after infection, but antigens may be detectable during the last weeks of this initial period, though they disappear with the appearance of the antibodies. In the later stages of HIV infection, HIV antigen is again detectable...... 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...

  18. PIP2: choreographer of actin-adaptor proteins in the HIV-1 dance

    Science.gov (United States)

    Rocha-Perugini, Vera; Gordon-Alonso, Mónica; Sánchez-Madrid, Francisco

    2014-01-01

    The actin cytoskeleton plays a key role during the replication cycle of human immunodeficiency virus-1 (HIV-1). HIV-1 infection is affected by cellular proteins that influence the clustering of viral receptors or the subcortical actin cytoskeleton. Several of these actin-adaptor proteins are controlled by the second messenger phosphatidylinositol 4,5-biphosphate (PIP2), an important regulator of actin organization. PIP2 production is induced by HIV-1 attachment and facilitates viral infection. However, the importance of PIP2 in regulating cytoskeletal proteins and thus HIV-1 infection has been overlooked. This review examines recent reports describing the roles played by actin-adaptor proteins during HIV-1 infection of CD4+ T cells, highlighting the influence of the signaling lipid PIP2 in this process. PMID:24768560

  19. 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

  20. In vitro nuclear interactome of the HIV-1 Tat protein

    Directory of Open Access Journals (Sweden)

    Gautier Virginie W

    2009-05-01

    Full Text Available Abstract 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

  1. RING Domain Mutations Uncouple TRIM5α Restriction of HIV-1 from Inhibition of Reverse Transcription and Acceleration of Uncoating

    OpenAIRE

    Roa, Amanda; Hayashi, Fumiaki; Yang, Yang; Lienlaf, Maritza; Zhou, Jing; Shi, Jiong; Watanabe, Satoru; Kigawa, Takanori; Yokoyama, Shigeyuki; Aiken, Christopher; Diaz-Griffero, Felipe

    2012-01-01

    Rhesus TRIM5α (TRIM5αrh) is a cytosolic protein that potently restricts HIV-1 at an early postentry stage, prior to reverse transcription. The ability of TRIM5αrh to block HIV-1 infection has been correlated with a decrease of pelletable HIV-1 capsid during infection. To genetically dissect the ability of TRIM5α to block reverse transcription, we studied a set of TRIM5αrh RING domain mutants that potently restrict HIV-1 but allow the occurrence of reverse transcription. These TRIM5αrh RING va...

  2. Cytoplasmic HIV-1 RNA is mainly transported by diffusion in the presence or absence of Gag protein

    DEFF Research Database (Denmark)

    Chen, Jianbo; Grunwald, David; Sardo, Luca;

    2014-01-01

    Full-length HIV-1 RNA plays a central role in viral replication by serving as the mRNA for essential viral proteins and as the genome packaged into infectious virions. Proper RNA trafficking is required for the functions of RNA and its encoded proteins; however, the mechanism by which HIV-1 RNA...

  3. Impact of the Ku complex on HIV-1 expression and latency.

    Directory of Open Access Journals (Sweden)

    Gwenola Manic

    Full Text Available Ku, a cellular complex required for human cell survival and involved in double strand break DNA repair and multiple other cellular processes, may modulate retroviral multiplication, although the precise mechanism through which it acts is still controversial. Recently, Ku was identified as a possible anti-human immunodeficiency virus type 1 (HIV-1 target in human cells, in two global approaches. Here we investigated the role of Ku on the HIV-1 replication cycle by analyzing the expression level of a panel of non-replicative lentiviral vectors expressing the green fluorescent protein in human colorectal carcinoma HCT 116 cells, stably or transiently depleted of Ku. We found that in this cellular model the depletion of Ku did not affect the efficiency of (pre-integrative steps but decreased the early HIV-1 expression by acting at the transcriptional level. This negative effect was specific of the HIV-1 promoter, required the obligatory step of viral DNA integration and was reversed by transient depletion of p53. We also provided evidence on a direct binding of Ku to HIV-1 LTR in transduced cells. Ku not only promotes the early transcription from the HIV-1 promoter, but also limits the constitution of viral latency. Moreover, in the presence of a normal level of Ku, HIV-1 expression was gradually lost over time, likely due to the counter-selection of HIV-1-expressing cells. On the contrary, the reactivation of transgene expression from HIV-1 by means of trichostatin A- or tumor necrosis factor α-administration was enhanced under condition of Ku haplodepletion, suggesting a phenomenon of provirus latency. These observations plead in favor of the hypothesis that Ku has an impact on HIV-1 expression and latency at early- and mid-time after integration.

  4. Clinical significance of HIV-1 coreceptor usage

    Directory of Open Access Journals (Sweden)

    Lusso Paolo

    2010-01-01

    Full Text Available Abstract The identification of phenotypically distinct HIV-1 variants with different prevalence during the progression of the disease has been one of the earliest discoveries in HIV-1 biology, but its relevance to AIDS pathogenesis remains only partially understood. The physiological basis for the phenotypic variability of HIV-1 was elucidated with the discovery of distinct coreceptors employed by the virus to infect susceptible cells. The role of the viral phenotype in the variable clinical course and treatment outcome of HIV-1 infection has been extensively investigated over the past two decades. In this review, we summarize the major findings on the clinical significance of the HIV-1 coreceptor usage.

  5. The X awakens: multifactorial ramifications of sex-specific differences in HIV-1 infection.

    Science.gov (United States)

    Hagen, Sven; Altfeld, Marcus

    2016-01-01

    Sex-specific differences have been described for a variety of infectious and autoimmune diseases. In HIV-1 infection women present with significantly lower viral loads during early infection, but during chronic infection women progress faster to AIDS for the same amount of viral replication. Recent studies have shown that sex differences during HIV-1 infection might also include the size of the latent viral reservoir, which represents a major obstacle towards a cure for HIV-1. Here we review different immunological and virological aspects that can be influenced by sex hormones and sex-specific genetic factors and their contribution to viral replication, as well as the creation and maintenance of the HIV-1 reservoir. PMID:27482439

  6. Design and synthesis of á,á-trehalose derivatives bearing guanidino groups as inhibitors for the Tat Protein-TAR RNA interaction of HIV-1

    Institute of Scientific and Technical Information of China (English)

    Wang Min; Xu Zhidong; Tu Pengfei; Xiao Sulong; Yu Xiaolin; Yang Ming

    2004-01-01

    Replication of human immunodeficiency virus type 1 (HIV-1) requires specific interactions of Tat protein with the transactivation responsive region (TAR) RNA. Disruption of Tat-TAR RNA interaction could inhibit HIV-1 replication. Here four target compounds were designed and synthesized to bind to TAR RNA for blocking the interaction of Tat-TAR RNA. The core molecule 6,6′-diamino-6,6′ -dideoxy-á,á-trehalose was obtained from selective bromination of a,a-trehalose at C-6,6′, followed by acetylation, azide displacement, deacetylation and reduction.Coupling of the core molecule with the protected amino acid, then deprotection and guanidinylation generated 6,6′-bis(L-arginylamino)-6,6′-dideoxy-á,á-trehalose,6,6′-bisguanidino-6,6′-dideoxy-á ,á-trehalose, 6,6′-bis [((a)-guanidinobutyryl)amino]-6,6′-dideoxy-á,á-trehalose and 6,6′-bis(guanidinoacetylamino)-6,6′-dideoxy-á,á-trehalose, respectively.Their abilities to inhibit Tat-TAR RNA interaction were determined by a Tat-dependent HIV-1LTR-driven CAT assays.

  7. Identification and characterization of HIV-1 latent viral reservoirs in peripheral blood.

    Science.gov (United States)

    Chargin, Amanda; Yin, Fangfang; Song, Min; Subramaniam, Srividyabhuvaneswari; Knutson, Grace; Patterson, Bruce K

    2015-01-01

    Plasma viral load and CD4 counts are effective for clinical monitoring, but they do not give a full representation of HIV-1 quasispecies in cellular reservoirs, the major repository of replication-competent HIV-1 in infected individuals. We sought to develop a diagnostic system that might stimulate the replication-competent HIV-1 reservoirs for enhanced clinical monitoring, including selection of antiretroviral regimens. Whole-blood samples from 45 HIV-infected individuals were collected into 1 ViraStim HIV-1 activation tube and 1 EDTA tube. Samples were tested for viral load and cell type-specific HIV-1 replication. Further, 7 matched activated/nonactivated samples were sequenced using the Trugene HIV-1 genotyping kit. The percentage of patients with replication-competent virus in peripheral blood mononuclear cells (PBMCs) varied, depending on the baseline plasma viral load in the EDTA tubes. Six out of 24 patients with a starting plasma viral load of 20 and 1,000 all showed increases in viral replication of >5-fold. These increases came from cellular reservoirs in blood as determined by simultaneous ultrasensitive subpopulation staining/hybridization in situ (SUSHI). When resistance genotypes in plasma from activation tubes were compared to those from EDTA tubes for 7 patients, all patients showed additional mutations in the activation tube, while 3 patients demonstrated additional genotypic resistance determinants. We show that HIV-1 viral replication can be stimulated directly from infected whole blood. The sequencing results showed that 3 of 7 cases demonstrated additional drug resistance following stimulation. PMID:25339403

  8. Inhibition of human immunodeficiency virus type 1 (HIV-1) nuclear import via Vpr-Importin α interactions as a novel HIV-1 therapy

    International Nuclear Information System (INIS)

    The development of multidrug-resistant viruses compromises the efficacy of anti-human immunodeficiency virus (HIV) therapy and limits treatment options. Therefore, new targets that can be used to develop novel antiviral agents need to be identified. One such target is the interaction between Vpr, one of the accessory gene products of HIV-1 and Importin α, which is crucial, not only for the nuclear import of Vpr, but also for HIV-1 replication in macrophages. We have identified a potential parent compound, hematoxylin, which suppresses Vpr-Importin α interaction, thereby inhibiting HIV-1 replication in a Vpr-dependent manner. Analysis by real-time PCR demonstrated that hematoxylin specifically inhibited nuclear import step of pre-integration complex. Thus, hematoxylin is a new anti-HIV-1 inhibitor that targets the nuclear import of HIV-1 via the Vpr-Importin α interaction, suggesting that a specific inhibitor of the interaction between viral protein and the cellular factor may provide a new strategy for HIV-1 therapy.

  9. Compensatory Substitutions in the HIV-1 Capsid Reduce the Fitness Cost Associated with Resistance to a Capsid-Targeting Small-Molecule Inhibitor

    OpenAIRE

    Shi, Jiong; Zhou, Jing; Halambage, Upul D.; Shah, Vaibhav B.; Burse, Mallori J.; Wu, Hua; Blair, Wade S.; Butler, Scott L.; Aiken, Christopher

    2014-01-01

    The HIV-1 capsid plays multiple roles in infection and is an emerging therapeutic target. The small-molecule HIV-1 inhibitor PF-3450074 (PF74) blocks HIV-1 at an early postentry stage by binding the viral capsid and interfering with its function. Selection for resistance resulted in accumulation of five amino acid changes in the viral CA protein, which collectively reduced binding of the compound to HIV-1 particles. In the present study, we dissected the individual and combinatorial contribut...

  10. Potent nonnucleoside reverse transcriptase inhibitors target HIV-1 Gag-Pol.

    Directory of Open Access Journals (Sweden)

    Anna Figueiredo

    2006-11-01

    Full Text Available Nonnucleoside reverse transcriptase inhibitors (NNRTIs target HIV-1 reverse transcriptase (RT by binding to a pocket in RT that is close to, but distinct, from the DNA polymerase active site and prevent the synthesis of viral cDNA. NNRTIs, in particular, those that are potent inhibitors of RT polymerase activity, can also act as chemical enhancers of the enzyme's inter-subunit interactions. However, the consequences of this chemical enhancement effect on HIV-1 replication are not understood. Here, we show that the potent NNRTIs efavirenz, TMC120, and TMC125, but not nevirapine or delavirdine, inhibit the late stages of HIV-1 replication. These potent NNRTIs enhanced the intracellular processing of Gag and Gag-Pol polyproteins, and this was associated with a decrease in viral particle production from HIV-1-transfected cells. The increased polyprotein processing is consistent with premature activation of the HIV-1 protease by NNRTI-enhanced Gag-Pol multimerization through the embedded RT sequence. These findings support the view that Gag-Pol multimerization is an important step in viral assembly and demonstrate that regulation of Gag-Pol/Gag-Pol interactions is a novel target for small molecule inhibitors of HIV-1 production. Furthermore, these drugs can serve as useful probes to further understand processes involved in HIV-1 particle assembly and maturation.

  11. A delayed HIV-1 model with virus waning term.

    Science.gov (United States)

    Li, Bing; Chen, Yuming; Lu, Xuejuan; Liu, Shengqiang

    2016-02-01

    In this paper, we propose and analyze a delayed HIV-1 model with CTL immune response and virus waning. The two discrete delays stand for the time for infected cells to produce viruses after viral entry and for the time for CD8+ T cell immune response to emerge to control viral replication. We obtain the positiveness and boundedness of solutions and find the basic reproduction number R0. If R0 1, then the system is uniformly persistent and the viral concentration maintains at some constant level. The global dynamics when R0 > 1 is complicated. We establish the local stability of the infected steady state and show that Hopf bifurcation can occur. Both analytical and numerical results indicate that if, in the initial infection stage, the effect of delays on HIV-1 infection is ignored, then the risk of HIV-1 infection (if persists) will be underestimated. Moreover, the viral load differs from that without virus waning. These results highlight the important role of delays and virus waning on HIV-1 infection. PMID:26776264

  12. 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.

  13. Mode of antiviral action of silver nanoparticles against HIV-1

    Directory of Open Access Journals (Sweden)

    Rodriguez-Padilla Cristina

    2010-01-01

    Full Text Available Abstract Background Silver nanoparticles have proven to exert antiviral activity against HIV-1 at non-cytotoxic concentrations, but the mechanism underlying their HIV-inhibitory activity has not been not fully elucidated. In this study, silver nanoparticles are evaluated to elucidate their mode of antiviral action against HIV-1 using a panel of different in vitro assays. Results Our data suggest that silver nanoparticles exert anti-HIV activity at an early stage of viral replication, most likely as a virucidal agent or as an inhibitor of viral entry. Silver nanoparticles bind to gp120 in a manner that prevents CD4-dependent virion binding, fusion, and infectivity, acting as an effective virucidal agent against cell-free virus (laboratory strains, clinical isolates, T and M tropic strains, and resistant strains and cell-associated virus. Besides, silver nanoparticles inhibit post-entry stages of the HIV-1 life cycle. Conclusions These properties make them a broad-spectrum agent not prone to inducing resistance that could be used preventively against a wide variety of circulating HIV-1 strains.

  14. Complementary assays reveal a relationship between HIV-1 uncoating and reverse transcription

    OpenAIRE

    Hulme, Amy E.; Perez, Omar; Hope, Thomas J.

    2011-01-01

    During the early stages of HIV-1 replication the conical capsid composed of p24CA protein dissociates from the rest of the cytoplasmic viral complex by a process called uncoating. Although proper uncoating is known to be required for HIV-1 infection, many questions remain about the timing and factors involved in the process. Here we have used two complementary assays to study the process of uncoating in HIV-1–infected cells, specifically looking at the timing of uncoating and its relationship...

  15. HRP-2 determines HIV-1 integration site selection in LEDGF/p75 depleted cells

    Directory of Open Access Journals (Sweden)

    Schrijvers Rik

    2012-10-01

    Full Text Available Abstract Background Lens epithelium–derived growth factor (LEDGF/p75 is a cellular co-factor of HIV-1 integrase (IN that tethers the viral pre-integration complex to the host cell chromatin and determines the genome wide integration site distribution pattern of HIV-1. Recently, we demonstrated that HIV-1 replication was reduced in LEDGF/p75 knockout (KO cells. LEDGF/p75 KO significantly altered the integration site preference of HIV-1, but the pattern remained distinct from a computationally generated matched random control set (MRC, suggesting the presence of an alternative tethering factor. We previously identified Hepatoma-derived growth factor related protein 2 (HRP-2 as a factor mediating LEDGF/p75-independent HIV-1 replication. However, the role of HRP-2 in HIV-1 integration site selection was not addressed. Findings We studied the HIV-1 integration site distribution in the presence and absence of LEDGF/p75 and/or HRP-2, and in LEDGF/p75-depleted cells that overexpress HRP-2. We show that HRP-2 functions as a co-factor of HIV-1 IN in LEDGF/p75-depleted cells. Endogenous HRP-2 only weakly supported HIV-1 replication in LEDGF/p75 depleted cells. However, HRP-2 overexpression rescued HIV-1 replication and restored integration in RefSeq genes to wild-type levels. Additional HRP-2 KD in LEDGF/p75-depleted cells reduces integration frequency in transcription units and shifts the integration distribution towards random. Conclusions We demonstrate that HRP-2 overexpression can compensate for the absence of LEDGF/p75 and indicate that the residual bias in integration targeting observed in the absence of LEDGF/p75 can be ascribed to HRP-2. Knockdown of HRP-2 upon LEDGF/p75 depletion results in a more random HIV-1 integration pattern. These data therefore reinforce the understanding that LEDGF/p75 is the dominant HIV-1 IN co-factor.

  16. Substituted indoles as HIV-1 non-nucleoside reverse transcriptase inhibitors: a patent evaluation (WO2015044928).

    Science.gov (United States)

    Li, Xiao; Gao, Ping; Zhan, Peng; Liu, Xinyong

    2016-05-01

    The invention described in this patent (WO2015044928) is related to compounds based on the substituted indole scaffold, their synthetic process and application to inhibit HIV-1 replication as non-nucleoside reverse transcriptase inhibitors (NNRTIs). Some of the newly claimed compounds presented improved potency against wild-type (WT) HIV-1 strain in comparison to previously disclosed indole-based NNRTIs and were also shown to be effective against common resistant HIV-1 strains. In light of their novel structural characteristics, simple synthetic route and improved anti-HIV activity, these compounds deserve further study as promising NNRTIs. PMID:26742549

  17. RNA interactions in the 5' region of the HIV-1 genome

    DEFF Research Database (Denmark)

    Damgaard, Christian Kroun; Andersen, Ebbe Sloth; Knudsen, Bjarne;

    2004-01-01

    The untranslated leader of the dimeric HIV-1 RNA genome is folded into a complex structure that plays multiple and essential roles in the viral replication cycle. Here, we have investigated secondary and tertiary structural elements within the 5' 744 nucleotides of the HIV-1 genome using a...... combination of bioinformatics, enzymatic probing, native gel electrophoresis, and UV-crosslinking experiments. We used a recently developed RNA folding algorithm (Pfold) to predict the common secondary structure of an alignment of 20 divergent HIV-1 sequences. Combining this analysis with biochemical data, we...

  18. VSV-G pseudotyping rescues HIV-1 CA mutations that impair core assembly or stability

    OpenAIRE

    Chaloin Laurent; Bernard Eric; Gay Bernard; Solignat Maxime; Brun Sonia; Fenard David; Devaux Christian; Chazal Nathalie; Briant Laurence

    2008-01-01

    Abstract Background The machinery of early HIV-1 replication still remains to be elucidated. Recently the viral core was reported to persist in the infected cell cytoplasm as an assembled particle, giving rise to the reverse transcription complex responsible for the synthesis of proviral DNA and its transport to the nucleus. Numerous studies have demonstrated that reverse transcription of the HIV-1 genome into proviral DNA is tightly dependent upon proper assembly of the capsid (CA) protein i...

  19. HIV-1 integrase inhibitors are substrates for the multidrug transporter MDR1-P-glycoprotein

    OpenAIRE

    Cara Andrea; Andreotti Mauro; Galluzzo Clementina; Verdoliva Antonio; Costi Roberta; Molinari Agnese; Dupuis Maria; Cianfriglia Maurizio; Di Santo Roberto; Palmisano Lucia

    2007-01-01

    Abstract Background The discovery of diketoacid-containing derivatives as inhibitors of HIV-1 Integrase (IN) (IN inhibitors, IINs) has played a major role in validating this enzyme as an important target for antiretroviral therapy. Since the in vivo efficacy depends on access of these drugs to intracellular sites where HIV-1 replicates, we determined whether the IINs are recognized by the multidrug transporter MDR1-P-glycoprotein (P-gp) thereby reducing their intracellular accumulation. To ad...

  20. APOBEC3H polymorphisms and susceptibility to HIV-1 infection in an Indian population.

    Science.gov (United States)

    Naruse, Taeko K; Sakurai, Daisuke; Ohtani, Hitoshi; Sharma, Gaurav; Sharma, Surendra K; Vajpayee, Madhu; Mehra, Narinder K; Kaur, Gurvinder; Kimura, Akinori

    2016-03-01

    Human APOBEC3H (A3H) is a member of APOBEC cytidine deaminase family intensively constraining the HIV-1 replication. A3H is known to be polymorphic with different protein stability and anti-HIV-1 activity in vitro. We recently reported that A3H haplotypes composed of two functional polymorphisms, rs139292 (N15del) and rs139297 (G105R), were associated with the susceptibility to HIV-1 infection in Japanese. To confirm the association of A3H and HIV-1 infection in another ethnic group, a total of 241 HIV-1-infected Indian individuals and ethnic-matched 286 healthy controls were analyzed for the A3H polymorphisms. The frequency of 15del allele was high in the HIV-1-infected subjects as compared with the controls (0.477 vs 0.402, odds ratio (OR)=1.36, P=0.014). Haplotype analysis showed that the frequencies of 15del-105R was high (0.475 vs 0.400, OR=1.36, permutation P=0.037) in the HIV-1-infected subjects, confirming the association of A3H polymorphisms with the susceptibility to HIV-1 infection. PMID:26559750

  1. Experimethod of studying latent HIV-1 in vitro%体外研究HIV-1潜伏库实验方法进展

    Institute of Scientific and Technical Information of China (English)

    焦艳梅; 吴昊

    2009-01-01

    Although HIV-1 can replicate continuously in untreated patients, they can also be hidden in the intra-cellular to evade the host immune clearance, that is latent virus. As the latent virus is a challenge to antiviral treatment, it has been aroused great concern. In this article, the experimental method for studying latent HIV-1 is reviewed.%HIV-1在未治疗的艾滋病患者体内,虽可以持续复制,但也可潜伏在细胞内以逃避宿主的免疫清除,这一现象即病毒潜伏.由于病毒潜伏对抗病毒治疗带来了挑战,也引起人们的高度关注.此文对体外研究HIV-1潜伏库的实验方法 进展进行综述.

  2. Inhibition of HIV-1 entry by the tricyclic coumarin GUT-70 through the modification of membrane fluidity

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Kouki; Hattori, Shinichiro; Kariya, Ryusho [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Komizu, Yuji [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082 (Japan); Kudo, Eriko; Goto, Hiroki; Taura, Manabu [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Ueoka, Ryuichi [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Nishi-ku, Kumamoto 860-0082 (Japan); Kimura, Shinya [Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501 (Japan); Okada, Seiji, E-mail: okadas@kumamoto-u.ac.jp [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan)

    2015-02-13

    Membrane fusion between host cells and HIV-1 is the initial step in HIV-1 infection, and plasma membrane fluidity strongly influences infectivity. In the present study, we demonstrated that GUT-70, a natural product derived from Calophyllum brasiliense, stabilized plasma membrane fluidity, inhibited HIV-1 entry, and down-regulated the expression of CD4, CCR5, and CXCR4. Since GUT-70 also had an inhibitory effect on viral replication through the inhibition of NF-κB, it is expected to be used as a dual functional and viral mutation resistant reagent. Thus, these unique properties of GUT-70 enable the development of novel therapeutic agents against HIV-1 infection.

  3. Inhibition of HIV-1 entry by the tricyclic coumarin GUT-70 through the modification of membrane fluidity

    International Nuclear Information System (INIS)

    Membrane fusion between host cells and HIV-1 is the initial step in HIV-1 infection, and plasma membrane fluidity strongly influences infectivity. In the present study, we demonstrated that GUT-70, a natural product derived from Calophyllum brasiliense, stabilized plasma membrane fluidity, inhibited HIV-1 entry, and down-regulated the expression of CD4, CCR5, and CXCR4. Since GUT-70 also had an inhibitory effect on viral replication through the inhibition of NF-κB, it is expected to be used as a dual functional and viral mutation resistant reagent. Thus, these unique properties of GUT-70 enable the development of novel therapeutic agents against HIV-1 infection

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

    Directory of Open Access Journals (Sweden)

    Beda Brichacek

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

  5. The use of HIV-1 integration site analysis information in clinical studies aiming at HIV cure.

    Science.gov (United States)

    Kiselinova, Maja; De Spiegelaere, Ward; Vandekerckhove, Linos

    2016-01-01

    The mechanisms for the establishment and the persistence of the latent HIV-1 reservoir remain to be completely defined. HIV-1 infection is characterised by the integration of the reverse transcribed proviral DNA into the host's genome. This integrated proviral DNA can remain replication silent, but a small part of it is fully competent to restart viral replication when treatment is interrupted. Hence, this replication-competent provirus is the cause of viral rebound and is called the viral reservoir. The exact site of proviral integration within the host's cellular chromosome may affect the transcriptional activity of HIV. Thanks to recent technological advances, HIV-1 integration site analysis has been used to assess HIV-1 reservoirs in HIV-infected individuals. Analysis of HIV-1 integration sites in infected individuals undergoing suppressive ART led to identification of expanded clonal cell populations, indicating that clonal proliferation of the proviral reservoir may contribute to the long-term persistence of viral reservoirs. Here we describe the findings of several clinical studies, where a comprehensive HIV-1 integration site analysis was performed. PMID:27482458

  6. HIV-1 reverse transcriptase mutations that confer decreased in vitro susceptibility to anti-RT DNA aptamer RT1t49 confer cross resistance to other anti-RT aptamers but not to standard RT inhibitors

    Directory of Open Access Journals (Sweden)

    Joshi Pheroze

    2005-10-01

    Full Text Available Abstract RNA and DNA aptamers specific for HIV-1 reverse transcriptase (RT can inhibit reverse transcription in vitro. RNA aptamers have been shown to potently block HIV-1 replication in culture. We previously reported mutants of HIV-1 RT with substitutions N255D or N265D that display resistance to the DNA aptamer RT1t49. Variant viruses bearing these mutations singly or in combination were compromised for replication. In order to address the wider applicability of such aptamers, HIV-1 RT variants containing the N255D, N265D or both (Dbl were tested for the extent of their cross-resistance to other DNA/RNA aptamers as well as to other RT inhibitors. Both N265D and Dbl RTs were resistant to most aptamers tested. N255D mutant displayed mild resistance to two of the DNA aptamers, little change in sensitivity to three and hypersensitivity to one. Although all mutants displayed wild type-like ribonuclease H activity, their activity was compromised under conditions that prevent re-binding. This suggests that the processivity defect caused by these mutations can also affect RNase H function thus contributing further to the replication defect in mutant viruses. These results indicate that mutants conferring resistance to anti-RT aptamers significantly affect many HIV-1 RT enzymatic activities, which could contribute to preventing the development of resistance in vivo. If such mutations were to arise in vivo, our results suggest that variant viruses should remain susceptible to many existing anti-RT inhibitors. This result was tempered by the observation that NRTI-resistance mutations such as K65R can confer resistance to some anti-RT aptamers.

  7. miRNA在HIV-1感染中的生物学功能%Biological function of microRNA in HIV-1 infection: summary of recent progress

    Institute of Scientific and Technical Information of China (English)

    吴还梅; 孟哲峰; 张晓燕

    2013-01-01

    MicroRNA (miRNA) is one of the multifunctional small RNAs that have been extensively investigated in recent years. MiRNA-mediated RNA interference regulates cell proliferation, differentiation, development and plays a critical role in many infectious diseases such as acquired immunodeficiency syndrome (AIDS). MiRNA inhibits HIV-1 replication by targeting the genome RNA or interacting with protein-coding mRNA but it also facilitates HIV-1 infection and AIDS progress by promoting T cell proliferation that is mediated by activating innate immune system and producing cytokines. Meanwhile, miRNA can also affect HIV-1 replication by interacting with viral accessory proteins and host cellular factors. Some miRNAs are involved in HIV-1 latency. Furthermore, miRNA expression profile could be fluctuated with HIV-1 infection which can be used as a diagnostic indicator in the near future.

  8. HIV-1 infected monozygotic twins: a tale of two outcomes

    Directory of Open Access Journals (Sweden)

    Pérez-Losada Marcos

    2011-03-01

    Full Text Available Abstract Background Replicate experiments are often difficult to find in evolutionary biology, as this field is inherently an historical science. However, viruses, bacteria and phages provide opportunities to study evolution in both natural and experimental contexts, due to their accelerated rates of evolution and short generation times. Here we investigate HIV-1 evolution by using a natural model represented by monozygotic twins infected synchronically at birth with an HIV-1 population from a shared blood transfusion source. We explore the evolutionary processes and population dynamics that shape viral diversity of HIV in these monozygotic twins. Results Despite the identical host genetic backdrop of monozygotic twins and the identical source and timing of the HIV-1 inoculation, the resulting HIV populations differed in genetic diversity, growth rate, recombination rate, and selection pressure between the two infected twins. Conclusions Our study shows that the outcome of evolution is strikingly different between these two "replicates" of viral evolution. Given the identical starting points at infection, our results support the impact of random epigenetic selection in early infection dynamics. Our data also emphasize the need for a better understanding of the impact of host-virus interactions in viral evolution.

  9. Molecular cloning and anti-HIV-1 activities of APOBEC3s from northern pig-tailed macaques (Macaca leonina)

    Science.gov (United States)

    ZHANG, Xiao-Liang; SONG, Jia-Hao; PANG, Wei; ZHENG, Yong-Tang

    2016-01-01

    Northern pig-tailed macaques (NPMs, Macaca leonina) are susceptible to HIV-1 infection largely due to the loss of HIV-1-restricting factor TRIM5α. However, great impediments still exist in the persistent replication of HIV-1 in vivo, suggesting some viral restriction factors are reserved in this host. The APOBEC3 proteins have demonstrated a capacity to restrict HIV-1 replication, but their inhibitory effects in NPMs remain elusive. In this study, we cloned the NPM A3A-A3H genes, and determined by BLAST searching that their coding sequences (CDSs) showed 99% identity to the corresponding counterparts from rhesus and southern pig-tailed macaques. We further analyzed the anti-HIV-1 activities of the A3A-A3H genes, and found that A3G and A3F had the greatest anti-HIV-1 activity compared with that of other members. The results of this study indicate that A3G and A3F might play critical roles in limiting HIV-1 replication in NPMs in vivo. Furthermore, this research provides valuable information for the optimization of monkey models of HIV-1 infection. PMID:27469256

  10. Molecular cloning and anti-HIV-1 activities of APOBEC3s from northern pig-tailed macaques (Macaca leonina).

    Science.gov (United States)

    Zhang, Xiao-Liang; Song, Jia-Hao; Pang, Wei; Zheng, Yong-Tang

    2016-07-18

    Northern pig-tailed macaques (NPMs, Macaca leonina) are susceptible to HIV-1 infection largely due to the loss of HIV-1-restricting factor TRIM5α. However, great impediments still exist in the persistent replication of HIV-1 in vivo, suggesting some viral restriction factors are reserved in this host. The APOBEC3 proteins have demonstrated a capacity to restrict HIV-1 replication, but their inhibitory effects in NPMs remain elusive. In this study, we cloned the NPM A3A-A3H genes, and determined by BLAST searching that their coding sequences (CDSs) showed 99% identity to the corresponding counterparts from rhesus and southern pig-tailed macaques. We further analyzed the anti-HIV-1 activities of the A3A-A3H genes, and found that A3G and A3F had the greatest anti-HIV-1 activity compared with that of other members. The results of this study indicate that A3G and A3F might play critical roles in limiting HIV-1 replication in NPMs in vivo. Furthermore, this research provides valuable information for the optimization of monkey models of HIV-1 infection. PMID:27469256

  11. Interleukin-7 facilitates HIV-1 transmission to cervico-vaginal tissue ex vivo.

    Directory of Open Access Journals (Sweden)

    Andrea Introini

    2013-02-01

    Full Text Available The majority of HIV-1 infections in women occur through vaginal intercourse, in which virus-containing semen is deposited on the cervico-vaginal mucosa. Semen is more than a mere carrier of HIV-1, since it contains many biological factors, in particular cytokines, that may affect HIV-1 transmission. The concentration of interleukin (IL-7, one of the most prominent cytokines in semen of healthy individuals, is further increased in semen of HIV-1-infected men. Here, we investigated the potential role of IL-7 in HIV-1 vaginal transmission in an ex vivo system of human cervico-vaginal tissue. We simulated an in vivo situation by depositing HIV-1 on cervico-vaginal tissue in combination with IL-7 at concentrations comparable with those measured in semen of HIV-1-infected individuals. We found that IL-7 significantly enhanced virus replication in ex vivo infected cervico-vaginal tissue. Similarly, we observed an enhancement of HIV-1 replication in lymphoid tissue explants. Analysis of T cells isolated from infected tissues showed that IL-7 reduced CD4⁺ T cell depletion preventing apoptosis, as shown by the decrease in the number of cells expressing the apoptotic marker APO2.7 and the increase in the expression of the anti-apoptotic protein B-cell lymphoma (Bcl-2. Also, IL-7 increased the fraction of cycling CD4⁺ T cells, as evidenced by staining for the nuclear factor Ki-67. High levels of seminal IL-7 in vivo may be relevant to the survival of the founder pool of HIV-1-infected cells in the cervico-vaginal mucosa at the initial stage of infection, promoting local expansion and dissemination of HIV infection.

  12. Protein methylation is required to maintain optimal HIV-1 infectivity

    Directory of Open Access Journals (Sweden)

    Piller Sabine C

    2006-12-01

    Full Text Available Abstract Background: Protein methylation is recognized as a major protein modification pathway regulating diverse cellular events such as protein trafficking, transcription, and signal transduction. More recently, protein arginine methyltransferase activity has been shown to regulate HIV-1 transcription via Tat. In this study, adenosine periodate (AdOx was used to globally inhibit protein methyltransferase activity so that the effect of protein methylation on HIV-1 infectivity could be assessed. Results: Two cell culture models were used: HIV-1-infected CEM T-cells and HEK293T cells transfected with a proviral DNA plasmid. In both models, AdOx treatment of cells increased the levels of virion in culture supernatant. However, these viruses had increased levels of unprocessed or partially processed Gag-Pol, significantly increased diameter, and displayed reduced infectivity in a MAGI X4 assay. AdOx reduced infectivity equally in both dividing and non-dividing cells. However, infectivity was further reduced if Vpr was deleted suggesting virion proteins, other than Vpr, were affected by protein methylation. Endogenous reverse transcription was not inhibited in AdOx-treated HIV-1, and infectivity could be restored by pseudotyping HIV with VSV-G envelope protein. These experiments suggest that AdOx affects an early event between receptor binding and uncoating, but not reverse transcription. Conclusion: Overall, we have shown for the first time that protein methylation contributes towards maximal virus infectivity. Furthermore, our results also indicate that protein methylation regulates HIV-1 infectivity in a complex manner most likely involving the methylation of multiple viral or cellular proteins and/or multiple steps of replication.

  13. Varying modulation of HIV-1 LTR activity by Baf complexes.

    Science.gov (United States)

    Van Duyne, Rachel; Guendel, Irene; Narayanan, Aarthi; Gregg, Edward; Shafagati, Nazly; Tyagi, Mudit; Easley, Rebecca; Klase, Zachary; Nekhai, Sergei; Kehn-Hall, Kylene; Kashanchi, Fatah

    2011-08-19

    The human immunodeficiency virus type 1 (HIV-1) long terminal repeat is present on both ends of the integrated viral genome and contains regulatory elements needed for transcriptional initiation and elongation. Post-integration, a highly ordered chromatin structure consisting of at least five nucleosomes, is found at the 5' long terminal repeat, the location and modification state of which control the state of active viral replication as well as silencing of the latent HIV-1 provirus. In this context, the chromatin remodeling field rapidly emerges as having a critical role in the control of viral gene expression. In the current study, we focused on unique Baf subunits that are common to the most highly recognized of chromatin remodeling proteins, the SWI/SNF (switching-defective-sucrose non-fermenting) complexes. We find that at least two Baf proteins, Baf53 and Baf170, are highly regulated in HIV-1-infected cells. Previously, studies have shown that the depletion of Baf53 in uninfected cells leads to the expansion of chromosomal territories and the decompaction of the chromatin. Baf53, in the presence of HIV-1 infection, co-elutes off of a chromatographic column as a different-sized complex when compared to uninfected cells and appears to be predominantly phosphorylated. The innate function of Baf53-containing complexes appears to be transcriptionally suppressive, in that knocking down Baf53 increases viral gene expression from cells both transiently and chronically infected with HIV-1. Additionally, cdk9/cyclin T in the presence of Tat is able to phosphorylate Baf53 in vitro, implying that this posttranslationally modified form relieves the suppressive effect and allows for viral transcription to proceed. PMID:21699904

  14. Effect of HIV-1-related protein expression on cardiac and skeletal muscles from transgenic rats

    Directory of Open Access Journals (Sweden)

    Guidot David M

    2008-04-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 infection and the consequent acquired immunodeficiency syndrome (AIDS has protean manifestations, including muscle wasting and cardiomyopathy, which contribute to its high morbidity. The pathogenesis of these myopathies remains partially understood, and may include nutritional deficiencies, biochemical abnormalities, inflammation, and other mechanisms due to viral infection and replication. Growing evidence has suggested that HIV-1-related proteins expressed by the host in response to viral infection, including Tat and gp120, may also be involved in the pathophysiology of AIDS, particularly in cells or tissues that are not directly infected with HIV-1. To explore the potentially independent effects of HIV-1-related proteins on heart and skeletal muscles, we used a transgenic rat model that expresses several HIV-1-related proteins (e.g., Tat, gp120, and Nef. Outcome measures included basic heart and skeletal muscle morphology, glutathione metabolism and oxidative stress, and gene expressions of atrogin-1, muscle ring finger protein-1 (MuRF-1 and Transforming Growth Factor-β1 (TGFβ1, three factors associated with muscle catabolism. Results Consistent with HIV-1 associated myopathies in humans, HIV-1 transgenic rats had increased relative heart masses, decreased relative masses of soleus, plantaris and gastrocnemius muscles, and decreased total and myosin heavy chain type-specific plantaris muscle fiber areas. In both tissues, the levels of cystine (Cyss, the oxidized form of the anti-oxidant cysteine (Cys, and Cyss:Cys ratios were significantly elevated, and cardiac tissue from HIV-1 transgenic rats had altered glutathione metabolism, all reflective of significant oxidative stress. In HIV-1 transgenic rat hearts, MuRF-1 gene expression was increased. Further, HIV-1-related protein expression also increased atrogin-1 (~14- and ~3-fold and TGFβ1 (~5-fold and ~3-fold in heart and

  15. Copy number variation of KIR genes influences HIV-1 control

    DEFF Research Database (Denmark)

    Pelak, Kimberly; Need, Anna C; Fellay, Jacques;

    2011-01-01

    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...... individuals with multiple copies of KIR3DL1, in the presence of KIR3DS1 and the appropriate ligands, inhibit HIV-1 replication more robustly, and associated with a significant expansion in the frequency of KIR3DS1+, but not KIR3DL1+, NK cells in their peripheral blood. Our results suggest that the relative...

  16. Cytoplasmic Dynein Promotes HIV-1 Uncoating

    OpenAIRE

    Paulina Pawlica; Lionel Berthoux

    2014-01-01

    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 d...

  17. HIV-1 associated dementia: symptoms and causes

    OpenAIRE

    Khalili Kamel; Amini Shohreh; Ghafouri Mohammad; Sawaya Bassel E

    2006-01-01

    Abstract Despite the use of highly active antiretroviral therapy (HAART), neuronal cell death remains a problem that is frequently found in the brains of HIV-1-infected patients. HAART has successfully prevented many of the former end-stage complications of AIDS, however, with increased survival times, the prevalence of minor HIV-1 associated cognitive impairment appears to be rising among AIDS patients. Further, HIV-1 associated dementia (HAD) is still prevalent in treated patients as well a...

  18. NOVEL DELIVERY SYSTEM ENHANCES EFFICACY OF ANTIRETROVIRAL THERAPY IN ANIMAL MODEL FOR HIV-1 ENCEPHALITIS (HIVE)

    OpenAIRE

    Spitzenberger, Timothy J.; Heilman, David; Diekmann, Casey; Batrakova, Elena; Kabanov, Alexander; Gendelman, Howard E.; Elmquist, William F.; Persidsky, Yuri

    2006-01-01

    Most potent anti-retroviral drugs (e.g., HIV-1 protease inhibitors) poorly penetrate the blood-brain barrier. Brain distribution can be limited by the efflux transporter, P-glycoprotein (P-gp). The ability of a novel drug delivery system (block co-polymer P85) that inhibits P-gp, to increase the efficacy of anti-retroviral drugs in brain was examined using a severe combined immunodeficiency (SCID) mouse model of HIV-1 encephalitis (HIVE). SCID mice inoculated with HIV-1 infected human monocyt...

  19. Cyclophilin B enhances HIV-1 infection.

    Science.gov (United States)

    DeBoer, Jason; Madson, Christian J; Belshan, Michael

    2016-02-01

    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. PMID:26774171

  20. DVC1 (C1orf124) is a DNA damage-targeting p97 adaptor that promotes ubiquitin-dependent responses to replication blocks.

    Science.gov (United States)

    Mosbech, Anna; Gibbs-Seymour, Ian; Kagias, Konstantinos; Thorslund, Tina; Beli, Petra; Povlsen, Lou; Nielsen, Sofie Vincents; Smedegaard, Stine; Sedgwick, Garry; Lukas, Claudia; Hartmann-Petersen, Rasmus; Lukas, Jiri; Choudhary, Chunaram; Pocock, Roger; Bekker-Jensen, Simon; Mailand, Niels

    2012-11-01

    Ubiquitin-mediated processes orchestrate critical DNA-damage signaling and repair pathways. We identify human DVC1 (C1orf124; Spartan) as a cell cycle-regulated anaphase-promoting complex (APC) substrate that accumulates at stalled replication forks. DVC1 recruitment to sites of replication stress requires its ubiquitin-binding UBZ domain and PCNA-binding PIP box motif but is independent of RAD18-mediated PCNA monoubiquitylation. Via a conserved SHP box, DVC1 recruits the ubiquitin-selective chaperone p97 to blocked replication forks, which may facilitate p97-dependent removal of translesion synthesis (TLS) DNA polymerase η (Pol η) from monoubiquitylated PCNA. DVC1 knockdown enhances UV light-induced mutagenesis, and depletion of human DVC1 or the Caenorhabditis elegans ortholog DVC-1 causes hypersensitivity to replication stress-inducing agents. Our findings establish DVC1 as a DNA damage-targeting p97 adaptor that protects cells from deleterious consequences of replication blocks and suggest an important role of p97 in ubiquitin-dependent regulation of TLS. PMID:23042605

  1. Structure and function of HIV-1 reverse transcriptase: molecular mechanisms of polymerization and inhibition

    OpenAIRE

    Sarafianos, Stefan G.; Marchand, Bruno; Das, Kalyan; Himmel, Daniel; Parniak, Michael A.; Hughes, Stephen H.; Arnold, Eddy

    2008-01-01

    The rapid replication of HIV-1 and the errors made during viral replication, cause the virus to evolve rapidly in patients, making the problems of vaccine development and drug therapy particularly challenging. In the absence of an effective vaccine, drugs are the only useful treatment. Anti-HIV drugs work; so far drug therapy has saved more than three million years of life. Unfortunately, HIV-1 develops resistance to all of the available drugs. Although a number of useful anti-HIV drugs have ...

  2. Dendritic Cells from HIV Controllers Have Low Susceptibility to HIV-1 Infection In Vitro but High Capacity to Capture HIV-1 Particles.

    Science.gov (United States)

    Hamimi, Chiraz; David, Annie; Versmisse, Pierre; Weiss, Laurence; Bruel, Timothée; Zucman, David; Appay, Victor; Moris, Arnaud; Ungeheuer, Marie-Noëlle; Lascoux-Combe, Caroline; Barré-Sinoussi, Françoise; Muller-Trutwin, Michaela; Boufassa, Faroudy; Lambotte, Olivier; Pancino, Gianfranco; Sáez-Cirión, Asier

    2016-01-01

    HIV controllers (HICs), rare HIV-1 infected individuals able to control viral replication without antiretroviral therapy, are characterized by an efficient polyfunctional and cytolytic HIV-specific CD8+ T cell response. The mechanisms underlying the induction and maintenance of such response in many HICs despite controlled viremia are not clear. Dendritic cells play a crucial role in the generation and reactivation of T cell responses but scarce information is available on those cells in HICs. We found that monocyte derived dendritic cells (MDDCs) from HICs are less permissive to HIV-1 infection than cells from healthy donors. In contrast MDDCs from HICs are particularly efficient at capturing HIV-1 particles when compared to cells from healthy donors or HIV-1 patients with suppressed viral load on antiretroviral treatment. MDDCs from HICs expressed on their surface high levels of syndecan-3, DC-SIGN and MMR, which could cooperate to facilitate HIV-1 capture. The combination of low susceptibility to HIV-1 infection but enhanced capacity to capture particles might allow MDDCs from HICs to preserve their function from the deleterious effect of infection while facilitating induction of HIV-specific CD8+ T cells by cross-presentation in a context of low viremia. PMID:27505169

  3. Drug 9AA reactivates p21/Waf1 and Inhibits HIV-1 progeny formation

    Directory of Open Access Journals (Sweden)

    Dubrovsky Larisa

    2008-03-01

    Full Text Available Abstract It has been demonstrated that the p53 pathway plays an important role in HIV-1 infection. Previous work from our lab has established a model demonstrating how p53 could become inactivated in HIV-1 infected cells through binding to Tat. Subsequently, p53 was inactivated and lost its ability to transactivate its downstream target gene p21/waf1. P21/waf1 is a well-known cdk inhibitor (CKI that can lead to cell cycle arrest upon DNA damage. Most recently, the p21/waf1 function was further investigated as a molecular barrier for HIV-1 infection of stem cells. Therefore, we reason that the restoration of the p53 and p21/waf1 pathways could be a possible theraputical arsenal for combating HIV-1 infection. In this current study, we show that a small chemical molecule, 9-aminoacridine (9AA at low concentrations, could efficiently reactivate p53 pathway and thereby restoring the p21/waf1 function. Further, we show that the 9AA could significantly inhibit virus replication in activated PBMCs, likely through a mechanism of inhibiting the viral replication machinery. A mechanism study reveals that the phosphorylated p53ser15 may be dissociated from binding to HIV-1 Tat protein, thereby activating the p21/waf1 gene. Finally, we also show that the 9AA-activated p21/waf1 is recruited to HIV-1 preintegration complex, through a mechanism yet to be elucidated.

  4. Functional characteristics of the natural polymorphisms of HIV-1 gp41 in HIV-1 isolates from enfuvirtide-naïve Korean patients.

    Science.gov (United States)

    Shin, YoungHyun; Yoon, Cheol-Hee; Yang, Hyo-Jin; Lim, Hoyong; Choi, Byeong-Sun; Kim, Sung Soon; Kang, Chun

    2016-06-01

    HIV-1 gp41 plays a key role in viral entry. The insertion of Thr at position 4 and Met/Val/Phe substitutions at position 7 are frequently observed in the fusion peptide (FP) motif of gp41 without major enfuvirtide resistance associated with mutation in heptad repeats 1/2 (HR1/2) of HIV-1 isolates from Korean patients. Here, the influence of these mutations on their biological function was evaluated by employing HIV-1 variants with mutant FPs as shown previously and with recombinant HIV-1 using the env genes of 20 HIV-1 isolates from Korean patients. In an infectivity assay, all FP mutants showed lower infectivity than the wild-type NL4-3. In particular, the substitutions at position 7 led to much greater reductions in infectivity than the insertions at position 4. Nevertheless, the replication kinetics of most mutants were similar to those of the wild type, except that the FP mutants with an Ile insertion at position 4 and a Phe substitution at position 7 showed reduced replication. Moreover, most point mutants showed lower IC50 values for enfuvirtide than the wild type, whereas the L7M substitution resulted in a slightly increased IC50 value. The infectivity using the HIV-1 env recombinant viruses decreased in 14 cases but increased slightly in six cases compared with the wild type. Most recombinants were more susceptible to enfuvirtide than the wild type, except for three recombinants that showed slight resistance. Our findings may help to explain the potential mechanisms corresponding to the natural polymorphism of gp41 and to predict the efficiency of enfuvirtide in treatment of HIV-1-infected patients in Korea. PMID:26997611

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

    Science.gov (United States)

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

    2015-11-01

    Blocking the binding of the envelope HIV-1 protein to immune cells is a popular concept for development of anti-HIV therapeutics. R5 HIV-1 binds CCR5, X4 HIV-1 binds CXCR4, and dual-tropic HIV-1 can bind either coreceptor for cellular entry. R5 viruses are associated with early infection and over time can evolve to X4 viruses that are associated with immune failure. Dual-tropic HIV-1 is less studied; however, it represents functional antigenic intermediates during the transition of R5 to X4 viruses. Viral tropism is linked partly to the HIV-1 envelope V3 domain, where the amino acid sequence helps dictate the receptor a particular virus will target; however, using V3 sequence information to identify dual-tropic HIV-1 isolates has remained difficult. Our goal in this study was to elucidate features of dual-tropic HIV-1 isolates that assist in the biological understanding of dual-tropism and develop an approach for their detection. Over 1559 HIV-1 subtype B sequences with known tropisms were analyzed. Each sequence was represented by 73 structural, biochemical and regional features. These features were provided to an evolved neural network classifier and evaluated using balanced and unbalanced data sets. The study resolved R5X4 viruses from R5 with an accuracy of 81.8% and from X4 with an accuracy of 78.8%. The approach also identified a set of V3 features (hydrophobicity, structural and polarity) that are associated with tropism transitions. The ability to distinguish R5X4 isolates will improve computational tropism decisions for R5 vs. X4 and assist in HIV-1 research and drug development efforts. PMID:26419858

  6. Humans with chimpanzee-like major histocompatibility complex-specificities control HIV-1 infection

    DEFF Research Database (Denmark)

    Hoof, Ilka; Kesmir, Can; Lund, Ole;

    2008-01-01

    the progression rate to AIDS. Chimpanzees control HIV-1 viral replication and develop a chronic infection without progressing to AIDS. A similar course of disease is observed in human long-term non-progressors. Objective: To investigate if long-term non-progressors and chimpanzees have functional......Background: Major histocompatibility complex (MHC) class I molecules allow immune surveillance by presenting a snapshot of the intracellular state of a cell to circulating cytotoxic T lymphocytes. The MHC class I alleles of an HIV-1 infected individual strongly influence the level of viremia and...... similarities in their MHC class I repertoire. Methods: We compared the specificity of groups of human MHC molecules associated with different levels of viremia in HIV-1 infected individuals with those of chimpanzee. Results and conclusion: We demonstrate that human MHC with control of HIV-1 viral load share...

  7. 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.

  8. Lack of association between intact/deletion polymorphisms of the APOBEC3B gene and HIV-1 risk.

    Directory of Open Access Journals (Sweden)

    Mayumi Imahashi

    Full Text Available OBJECTIVE: The human APOBEC3 family of proteins potently restricts HIV-1 replication APOBEC3B, one of the family genes, is frequently deleted in human populations. Two previous studies reached inconsistent conclusions regarding the effects of APOBEC3B loss on HIV-1 acquisition and pathogenesis. Therefore, it was necessary to verify the effects of APOBEC3B on HIV-1 infection in vivo. METHODS: Intact (I and deletion (D polymorphisms of APOBEC3B were analyzed using PCR. The syphilis, HBV and HCV infection rates, as well as CD4(+ T cell counts and viral loads were compared among three APOBEC3B genotype groups (I/I, D/I, and D/D. HIV-1 replication kinetics was assayed in vitro using primary cells derived from PBMCs. RESULTS: A total of 248 HIV-1-infected Japanese men who have sex with men (MSM patients and 207 uninfected Japanese MSM were enrolled in this study. The genotype analysis revealed no significant differences between the APOBEC3B genotype ratios of the infected and the uninfected cohorts (p = 0.66. In addition, HIV-1 disease progression parameters were not associated with the APOBEC3B genotype. Furthermore, the PBMCs from D/D and I/I subjects exhibited comparable HIV-1 susceptibility. CONCLUSION: Our analysis of a population-based matched cohort suggests that the antiviral mechanism of APOBEC3B plays only a negligible role in eliminating HIV-1 in vivo.

  9. The Presence and Anti-HIV-1 Function of Tenascin C in Breast Milk and Genital Fluids.

    Directory of Open Access Journals (Sweden)

    Robin G Mansour

    Full Text Available Tenascin-C (TNC is a newly identified innate HIV-1-neutralizing protein present in breast milk, yet its presence and potential HIV-inhibitory function in other mucosal fluids is unknown. In this study, we identified TNC as a component of semen and cervical fluid of HIV-1-infected and uninfected individuals, although it is present at a significantly lower concentration and frequency compared to that of colostrum and mature breast milk, potentially due to genital fluid protease degradation. However, TNC was able to neutralize HIV-1 after exposure to low pH, suggesting that TNC could be active at low pH in the vaginal compartment. As mucosal fluids are complex and contain a number of proteins known to interact with the HIV-1 envelope, we further studied the relationship between the concentration of TNC and neutralizing activity in breast milk. The amount of TNC correlated only weakly with the overall innate HIV-1-neutralizing activity of breast milk of uninfected women and negatively correlated with neutralizing activity in milk of HIV-1 infected women, indicating that the amount of TNC in mucosal fluids is not adequate to impede HIV-1 transmission. Moreover, the presence of polyclonal IgG from milk of HIV-1 infected women, but not other HIV-1 envelope-binding milk proteins or monoclonal antibodies, blocked the neutralizing activity of TNC. Finally, as exogenous administration of TNC would be necessary for it to mediate measurable HIV-1 neutralizing activity in mucosal compartments, we established that recombinantly produced TNC has neutralizing activity against transmitted/founder HIV-1 strains that mimic that of purified TNC. Thus, we conclude that endogenous TNC concentration in mucosal fluids is likely inadequate to block HIV-1 transmission to uninfected individuals.

  10. The Presence and Anti-HIV-1 Function of Tenascin C in Breast Milk and Genital Fluids

    Science.gov (United States)

    Jaeger, Frederick; McGuire, Erin; Fouda, Genevieve; Amos, Joshua; Barbas, Kimberly; Ohashi, Tomoo; Alam, S. Munir; Erickson, Harold; Permar, Sallie R.

    2016-01-01

    Tenascin-C (TNC) is a newly identified innate HIV-1-neutralizing protein present in breast milk, yet its presence and potential HIV-inhibitory function in other mucosal fluids is unknown. In this study, we identified TNC as a component of semen and cervical fluid of HIV-1-infected and uninfected individuals, although it is present at a significantly lower concentration and frequency compared to that of colostrum and mature breast milk, potentially due to genital fluid protease degradation. However, TNC was able to neutralize HIV-1 after exposure to low pH, suggesting that TNC could be active at low pH in the vaginal compartment. As mucosal fluids are complex and contain a number of proteins known to interact with the HIV-1 envelope, we further studied the relationship between the concentration of TNC and neutralizing activity in breast milk. The amount of TNC correlated only weakly with the overall innate HIV-1-neutralizing activity of breast milk of uninfected women and negatively correlated with neutralizing activity in milk of HIV-1 infected women, indicating that the amount of TNC in mucosal fluids is not adequate to impede HIV-1 transmission. Moreover, the presence of polyclonal IgG from milk of HIV-1 infected women, but not other HIV-1 envelope-binding milk proteins or monoclonal antibodies, blocked the neutralizing activity of TNC. Finally, as exogenous administration of TNC would be necessary for it to mediate measurable HIV-1 neutralizing activity in mucosal compartments, we established that recombinantly produced TNC has neutralizing activity against transmitted/founder HIV-1 strains that mimic that of purified TNC. Thus, we conclude that endogenous TNC concentration in mucosal fluids is likely inadequate to block HIV-1 transmission to uninfected individuals. PMID:27182834

  11. In vitro anti-HIV-1 activity of salicylidene acylhydrazide compounds.

    Science.gov (United States)

    Forthal, Donald N; Phan, Tran B; Slepenkin, Anatoly V; Landucci, Gary; Chu, Hencelyn; Elofsson, Mikael; Peterson, Ellena

    2012-10-01

    Salicylidene acylhydrazide compounds have been shown to inhibit bacterial pathogens, including Chlamydia and Neisseria gonorrhoeae. If such compounds could also target HIV-1, their potential use as topical microbicides to prevent sexually transmitted infections would be considerable. In this study, the in vitro anti-HIV-1 activity, cytotoxicity and mechanism of action of several salicylidene acylhydrazides were determined. Inhibitory activity was assessed using TZM-bl cells and primary peripheral blood mononuclear cells (PBMCs) as targets for HIV-1 infection. Antiviral activity was measured against cell-free and cell-associated virus and in vaginal fluid and semen simulants. Since the antibacterial activity of salicylidene acylhydrazides is reversible by Fe(2+), the ability of Fe(2+) and other cations to reverse the anti-HIV-1 activity of the compounds was determined. Real-time PCR was also employed to determine the stage affected in the HIV-1 replication cycle. Four compounds with 50% inhibitory concentrations against HIV-1 of 1-7 μM were identified. In vitro toxicity varied but was generally limited. Activity was similar against three R5 clade B primary isolates and whether the target for virus replication was TZM-bl cells or PBMCs. Compounds inhibited cell-free and cell-associated virus and were active in vaginal fluid and semen simulants. Fe(2+), but not other cations, reversed the anti-HIV-1 effect. Finally, the inhibitory effect of the compounds occurred at a post-integration step. In conclusion, salicylidene acylhydrazides were identified with in vitro anti-HIV-1 activity in the micromolar range. The activity of these compounds against other sexually transmitted pathogens makes them potential candidates to formulate for use as a broad-spectrum topical genital microbicide. PMID:22819150

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

    Science.gov (United States)

    Tay, Matthew Zirui; Liu, Pinghuang; Williams, LaTonya D; McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T; Dennison, S Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S Munir; Moody, M Anthony; Hope, Thomas J; Haynes, Barton F; Tomaras, Georgia D

    2016-08-01

    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

  13. Host genetic effects on HIV-1 replication in macrophages

    OpenAIRE

    Bol, S. M.

    2011-01-01

    Sebastiaan Bol ging op zoek naar humane eiwitten die hiv-vermenigvuldiging ondersteunen of remmen, met name in macrofagen. Deze cellen leven lang, gaan niet dood als gevolg van hiv-infectie en zijn - doordat ze zich veelal in weefsels bevinden - lastig bereikbaar voor hiv-remmers. Hierdoor vormen hiv-geïnfecteerde macrofagen één van de belangrijke barrières voor het genezen van mensen met hiv. Bol infecteerde macrofagen van honderden gezonde donoren met hiv en zocht naar verbanden tussen de m...

  14. Host genetic effects on HIV-1 replication in macrophages

    NARCIS (Netherlands)

    S.M. Bol

    2011-01-01

    Sebastiaan Bol ging op zoek naar humane eiwitten die hiv-vermenigvuldiging ondersteunen of remmen, met name in macrofagen. Deze cellen leven lang, gaan niet dood als gevolg van hiv-infectie en zijn - doordat ze zich veelal in weefsels bevinden - lastig bereikbaar voor hiv-remmers. Hierdoor vormen hi

  15. Dynamics of the human and viral m(6)A RNA methylomes during HIV-1 infection of T cells.

    Science.gov (United States)

    Lichinchi, Gianluigi; Gao, Shang; Saletore, Yogesh; Gonzalez, Gwendolyn Michelle; Bansal, Vikas; Wang, Yinsheng; Mason, Christopher E; Rana, Tariq M

    2016-01-01

    N(6)-methyladenosine (m(6)A) is the most prevalent internal modification of eukaryotic mRNA. Very little is known of the function of m(6)A in the immune system or its role in host-pathogen interactions. Here, we investigate the topology, dynamics and bidirectional influences of the viral-host RNA methylomes during HIV-1 infection of human CD4 T cells. We show that viral infection triggers a massive increase in m(6)A in both host and viral mRNAs. In HIV-1 mRNA, we identified 14 methylation peaks in coding and noncoding regions, splicing junctions and splicing regulatory sequences. We also identified a set of 56 human gene transcripts that were uniquely methylated in HIV-1-infected T cells and were enriched for functions in viral gene expression. The functional relevance of m(6)A for viral replication was demonstrated by silencing of the m(6)A writer or the eraser enzymes, which decreased or increased HIV-1 replication, respectively. Furthermore, methylation of two conserved adenosines in the stem loop II region of HIV-1 Rev response element (RRE) RNA enhanced binding of HIV-1 Rev protein to the RRE in vivo and influenced nuclear export of RNA. Our results identify a new mechanism for the control of HIV-1 replication and its interaction with the host immune system. PMID:27572442

  16. Inhibition of HIV-1 endocytosis allows lipid mixing at the plasma membrane, but not complete fusion

    Directory of Open Access Journals (Sweden)

    de la Vega Michelle

    2011-12-01

    Full Text Available Abstract Background We recently provided evidence that HIV-1 enters HeLa-derived TZM-bl and lymphoid CEMss cells by fusing with endosomes, whereas its fusion with the plasma membrane does not proceed beyond the lipid mixing step. The mechanism of restriction of HIV-1 fusion at the cell surface and/or the factors that aid the virus entry from endosomes remain unclear. Results We examined HIV-1 fusion with a panel of target cells lines and with primary CD4+ T cells. Kinetic measurements of fusion combined with time-resolved imaging of single viruses further reinforced the notion that HIV-1 enters the cells via endocytosis and fusion with endosomes. Furthermore, we attempted to deliberately redirect virus fusion to the plasma membrane, using two experimental strategies. First, the fusion reaction was synchronized by pre-incubating the viruses with cells at reduced temperature to allow CD4 and coreceptors engagement, but not the virus uptake or fusion. Subsequent shift to a physiological temperature triggered accelerated virus uptake followed by entry from endosomes, but did not permit fusion at the cell surface. Second, blocking HIV-1 endocytosis by a small-molecule dynamin inhibitor, dynasore, resulted in transfer of viral lipids to the plasma membrane without any detectable release of the viral content into the cytosol. We also found that a higher concentration of dynasore is required to block the HIV-endosome fusion compared to virus internalization. Conclusions Our results further support the notion that HIV-1 enters disparate cell types through fusion with endosomes. The block of HIV-1 fusion with the plasma membrane at a post-lipid mixing stage shows that this membrane is not conducive to fusion pore formation and/or enlargement. The ability of dynasore to interfere with the virus-endosome fusion suggests that dynamin could be involved in two distinct steps of HIV-1 entry - endocytosis and fusion within intracellular compartments.

  17. TRIM5 and the Regulation of HIV-1 Infectivity.

    Science.gov (United States)

    Luban, Jeremy

    2012-01-01

    The past ten years have seen an explosion of information concerning host restriction factors that inhibit the replication of HIV-1 and other retroviruses. Among these factors is TRIM5, an innate immune signaling molecule that recognizes the capsid lattice as soon as the retrovirion core is released into the cytoplasm of otherwise susceptible target cells. Recognition of the capsid lattice has several consequences that include multimerization of TRIM5 into a complementary lattice, premature uncoating of the virion core, and activation of TRIM5 E3 ubiquitin ligase activity. Unattached, K63-linked ubiquitin chains are generated that activate the TAK1 kinase complex and downstream inflammatory mediators. Polymorphisms in the capsid recognition domain of TRIM5 explain the observed species-specific differences among orthologues and the relatively weak anti-HIV-1 activity of human TRIM5. Better understanding of the complex interaction between TRIM5 and the retrovirus capsid lattice may someday lead to exploitation of this interaction for the development of potent HIV-1 inhibitors. PMID:22701176

  18. TRIM5 and the Regulation of HIV-1 Infectivity

    Directory of Open Access Journals (Sweden)

    Jeremy Luban

    2012-01-01

    Full Text Available The past ten years have seen an explosion of information concerning host restriction factors that inhibit the replication of HIV-1 and other retroviruses. Among these factors is TRIM5, an innate immune signaling molecule that recognizes the capsid lattice as soon as the retrovirion core is released into the cytoplasm of otherwise susceptible target cells. Recognition of the capsid lattice has several consequences that include multimerization of TRIM5 into a complementary lattice, premature uncoating of the virion core, and activation of TRIM5 E3 ubiquitin ligase activity. Unattached, K63-linked ubiquitin chains are generated that activate the TAK1 kinase complex and downstream inflammatory mediators. Polymorphisms in the capsid recognition domain of TRIM5 explain the observed species-specific differences among orthologues and the relatively weak anti-HIV-1 activity of human TRIM5. Better understanding of the complex interaction between TRIM5 and the retrovirus capsid lattice may someday lead to exploitation of this interaction for the development of potent HIV-1 inhibitors.

  19. Caging the Beast: TRIM5α Binding to the HIV-1 Core

    Directory of Open Access Journals (Sweden)

    Felipe Diaz-Griffero

    2011-04-01

    Full Text Available The potent HIV-1 inhibitor TRIM5α blocks HIV-1 infection by accelerating the uncoating of HIV-1. TRIM5α is known to form higher-order self-association complexes that contribute to the avidity of TRIM5α for the HIV-1 capsid, and are essential to inhibit infection; these higher-order self-association complexes are dependent upon an intact B-box 2 domain. Even though the ability to form higher-order self-association complexes resembles the clathrin triskelion that forms a protein array, or cage, around the endocytic vesicle, evidence for the ability of TRIM5α to assemble a similar type of structure surrounding the HIV-1 core has been lacking. Recent work by Ganser-Pornillos, Chandrasekaran and colleagues has now demonstrated the ability of the restriction factor TRIM5α to “cage” or “net” the HIV-1 core by forming an hexagonal array on the surface of the viral capsid [1]. This hexagonal array is strikingly similar in design to the array formed by the clathrin triskelion on the surface of the clathrin-coated endocytic vesicle. This remarkable finding represents an important advance on our understanding of the restriction factor TRIM5α, and suggests that TRIM5α cages the HIV-1 core in order to terminate infection. The present note discusses the implications of this discovery.

  20. Caging the beast: TRIM5α binding to the HIV-1 core.

    Science.gov (United States)

    Diaz-Griffero, Felipe

    2011-05-01

    The potent HIV-1 inhibitor TRIM5α blocks HIV-1 infection by accelerating the uncoating of HIV-1. TRIM5α is known to form higher-order self-association complexes that contribute to the avidity of TRIM5α for the HIV-1 capsid, and are essential to inhibit infection; these higher-order self-association complexes are dependent upon an intact B-box 2 domain. Even though the ability to form higher-order self-association complexes resembles the clathrin triskelion that forms a protein array, or cage, around the endocytic vesicle, evidence for the ability of TRIM5α to assemble a similar type of structure surrounding the HIV-1 core has been lacking. Recent work by Ganser-Pornillos, Chandrasekaran and colleagues has now demonstrated the ability of the restriction factor TRIM5α to "cage" or "net" the HIV-1 core by forming an hexagonal array on the surface of the viral capsid. This hexagonal array is strikingly similar in design to the array formed by the clathrin triskelion on the surface of the clathrin-coated endocytic vesicle. This remarkable finding represents an important advance on our understanding of the restriction factor TRIM5α, and suggests that TRIM5α cages the HIV-1 core in order to terminate infection. The present note discusses the implications of this discovery. PMID:21994740

  1. Copy number variation of KIR genes influences HIV-1 control.

    Directory of Open Access Journals (Sweden)

    Kimberly Pelak

    2011-11-01

    Full Text Available 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 KIR3DS1 count associates with a lower viral set point if its putative ligand is present (p = 0.00028, as does an increase in KIR3DL1 count in the presence of KIR3DS1 and appropriate ligands for both receptors (p = 0.0015. We further provide functional data that demonstrate that NK cells from individuals with multiple copies of KIR3DL1, in the presence of KIR3DS1 and the appropriate ligands, inhibit HIV-1 replication more robustly, and associated with a significant expansion in the frequency of KIR3DS1+, but not KIR3DL1+, NK cells in their peripheral blood. Our results suggest that the relative 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.

  2. Gene Expression Analysis of a Panel of Cell Lines That Differentially Restrict HIV-1 CA Mutants Infection in a Cyclophilin A-Dependent Manner

    OpenAIRE

    Shah, Vaibhav B.; Aiken, Christopher

    2014-01-01

    HIV-1 replication is dependent on binding of the viral capsid to the host protein cyclophilin A (CypA). Interference with cyclophilin A binding, either by mutations in the HIV-1 capsid protein (CA) or by the drug cyclosporine A (CsA), inhibits HIV-1 replication in cell culture. Resistance to CsA is conferred by A92E or G94D substitutions in CA. The mutant viruses are also dependent on CsA for their replication. Interestingly, infection of some cell lines by these mutants is enhanced by CsA, w...

  3. Establishment of human colorectal tissue model in HIV-1 mucosal infection%人结直肠活组织HIV-1黏膜感染模型的建立

    Institute of Scientific and Technical Information of China (English)

    杨瑜; 刘爱平; 孟庆来; 徐建青; 张晓燕

    2011-01-01

    Objective To establish human colorectal tissue model in HIV-1 mucosal infection and by using pseudotyped virus to simulate the biological process of HIV-1 mucosal infection from HIV-1 entrying into mucosa to local infection establishment. Methods Tumor adjacent normal colorectal tissues were obtained with informed consent.After excised the muscularis externa,the mucosa and submucosa were dissected into the same blocks and cultured in 12-well cell culture plates.The cultured tissue structure and morphology were observed from day 0 to day 13 by staining with the hematoxylin eosin (HE),and the tissue activity was detected by 3(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.The established tissues explants were infected by a single cycle replicated pseudotyped virus and propagated for 6-7 days,then subjected to the detection of p24 production within supernatant to verify the applicability of the model for the studying of HIV-1 mucosal infection.The applicability of the established explants for safety and reactivity evaluation of mucosa topical drugs was conducted by the using of first generation antiseptic Nonoxynol-9(N-9) as an example. Results HE staining showed the structure of colorectal tissue was remained well until 5th day and still evident until 13th day.The tissue activity of cultured mucosa was above 80% at day 4,and still remained over 50% at day 7 as detected by MTT assay.After infected by pseudo virus,the increased level of p24 was detected from supernatant collected on 1st,4th,8th day,which indicated a local infection was created.In addition,the dose changing of N-9 was reflected sensitively by the activity of this model. Conclusion Ex vivo human colorectal tissue model mimic HIV-1 mucosal infection was established that can be used to replicate the bioprocess of human HIV-1 mucosal infection.%目的 建立与HIV-1黏膜感染相关的结直肠活组织体外培养模型,利用假病毒模拟HIV-1进入黏膜

  4. Cytoplasmic dynein promotes HIV-1 uncoating.

    Science.gov (United States)

    Pawlica, Paulina; Berthoux, Lionel

    2014-11-01

    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. PMID:25375884

  5. 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.

  6. In vitro uncoating of HIV-1 cores.

    Science.gov (United States)

    Shah, Vaibhav B; Aiken, Christopher

    2011-01-01

    The genome of the retroviruses is encased in a capsid surrounded by a lipid envelope. For lentiviruses, such as HIV-1, the conical capsid shell is composed of CA protein arranged as a lattice of hexagon. The capsid is closed by 7 pentamers at the broad end and 5 at the narrow end of the cone(1, 2). Encased in this capsid shell is the viral ribonucleoprotein complex, and together they comprise the core. Following fusion of the viral membrane with the target cell membrane, the HIV-1 is released into the cytoplasm. The capsid then disassembles releasing free CA in the soluble form(3) in a process referred to as uncoating. The intracellular location and timing of HIV-1 uncoating are poorly understood. Single amino-acid substitutions in CA that alter the stability of the capsid also impair the ability of HIV-1 to infect cells(4). This indicates that the stability of the capsid is critical for HIV-1 infection. HIV-1 uncoating has been difficult to study due to lack of availability of sensitive and reliable assays for this process. Here we describe a quantitative method for studying uncoating in vitro using cores isolated from infectious HIV-1 particles. The approach involves isolation of cores by sedimentation of concentrated virions through a layer of detergent and into a linear sucrose gradient, in the cold. To quantify uncoating, the isolated cores are incubated at 37°C for various timed intervals and subsequently pelleted by ultracentrifugation. The extent of uncoating is analyzed by quantifying the fraction of CA in the supernatant. This approach has been employed to analyze effects of viral mutations on HIV-1 capsid stability(4, 5, 6). It should also be useful for studying the role of cellular factors in HIV-1 uncoating. PMID:22105356

  7. In vitro Uncoating of HIV-1 Cores

    Science.gov (United States)

    Shah, Vaibhav B.; Aiken, Christopher

    2011-01-01

    The genome of the retroviruses is encased in a capsid surrounded by a lipid envelope. For lentiviruses, such as HIV-1, the conical capsid shell is composed of CA protein arranged as a lattice of hexagon. The capsid is closed by 7 pentamers at the broad end and 5 at the narrow end of the cone1, 2. Encased in this capsid shell is the viral ribonucleoprotein complex, and together they comprise the core. Following fusion of the viral membrane with the target cell membrane, the HIV-1 is released into the cytoplasm. The capsid then disassembles releasing free CA in the soluble form3 in a process referred to as uncoating. The intracellular location and timing of HIV-1 uncoating are poorly understood. Single amino-acid substitutions in CA that alter the stability of the capsid also impair the ability of HIV-1 to infect cells4. This indicates that the stability of the capsid is critical for HIV-1 infection. HIV-1 uncoating has been difficult to study due to lack of availability of sensitive and reliable assays for this process. Here we describe a quantitative method for studying uncoating in vitro using cores isolated from infectious HIV-1 particles. The approach involves isolation of cores by sedimentation of concentrated virions through a layer of detergent and into a linear sucrose gradient, in the cold. To quantify uncoating, the isolated cores are incubated at 37°C for various timed intervals and subsequently pelleted by ultracentrifugation. The extent of uncoating is analyzed by quantifying the fraction of CA in the supernatant. This approach has been employed to analyze effects of viral mutations on HIV-1 capsid stability4, 5, 6. It should also be useful for studying the role of cellular factors in HIV-1 uncoating. PMID:22105356

  8. Drugs That Fight HIV-1

    Science.gov (United States)

    ... program of the National Institutes of Health Nucleoside Reverse Transcriptase Inhibitors (NRTIs) NRTIs block reverse transcriptase, an enzyme HIV- ... these products are on last page.) Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) NNRTIs bind to and alter reverse transcriptase, ...

  9. Crystal structures of HIV-1 nonnucleoside reverse transcriptase inhibitors: N-benzyl-4-methyl-benzimidazoles

    Science.gov (United States)

    Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

    2009-07-01

    HIV-1 nonnucleoside reverse transcriptase inhibitors are potentially specific and effective drugs in AIDS therapy. The presence of two aromatic systems with an angled orientation in the molecule of the inhibitor is crucial for interactions with HIV-1 RT. The inhibitor drives like a wedge into the cluster of aromatic residues of RT HIV-1 and restrains the enzyme in a conformation that blocks the chemical step of nucleotide incorporation. Structural studies provide useful information for designing new, more active inhibitors. The crystal structures of four NNRTIs are presented here. The investigated compounds are derivatives of N-benzyl-4-methyl-benzimidazole with various aliphatic and aromatic substituents at carbon 2 positions and a 2,6-dihalogeno-substituted N-benzyl moiety. Structural data reported here show that the conformation of the investigated compounds is relatively rigid. Such feature is important for the nonnucleoside inhibitor binding to HIV-1 reverse transcriptase.

  10. HIV-1 RNA quantification in CRF02_AG HIV-1 infection: too easy to make mistakes.

    Science.gov (United States)

    Tatarelli, Paola; Taramasso, Lucia; Di Biagio, Antonio; Sticchi, Laura; Nigro, Nicola; Barresi, Renata; Viscoli, Claudio; Bruzzone, Bianca

    2016-04-01

    The number of patients newly infected by HIV-1 non-B subtypes and circulating recombinant forms (CRFs) is increasing worldwide, including in the western countries. We report on a primary HIV-1 infection in a Caucasian patient. A routine quantitative assay (Nuclisens EasyQ HIV-1 2.0, BioMérieux SA) showed 6,700 HIV-1 RNA copies/ml. A combined antiretroviral therapy (cART) consistent with low baseline HIV-1 RNA was started. Few days later, the analysis performed with REGA HIV-1 Subtyping Tool - Version 3.0 attributed the HIV-1 sequence to the CRF02_AG recombinant form. Therefore, a second real-time PCR assay was performed, using the Versant HIV-1 RNA 1.0 Assay (kPCR) (Siemens HealthCare Diagnostics) which revealed a HIV-1 RNA of 230,000 copies/ml. Consequently, the ongoing cART was potentiated. This case suggests that the wide genetic variability of HIV-1 subtypes may affect the capability of the commonly used assays to detect and accurately quantify HIV-1 RNA in non-B subtypes and CRFs. In presence of CRFs different commercial HIV-1 RNA tests should be performed to find the most reliable for viral load quantification at the diagnosis, because it influences the choice of cART, and during the follow-up. Indeed, international guidelines for HIV-1 infection management suggest to monitor patient' HIV-RNA with the same assay over the course of treatment. As different commercial tests can be performed in the same laboratory with considerable difficulty, the laboratory should select an assay that is suitable not only for the more prevalent strain, but also for less frequent ones that, nevertheless, can occur. Then, knowing and investigating the spread of non-B strains has essential clinical and laboratory implications. PMID:27196556

  11. CIB1 and CIB2 are HIV-1 helper factors involved in viral entry

    Science.gov (United States)

    Godinho-Santos, Ana; Hance, Allan J.; Gonçalves, João; Mammano, Fabrizio

    2016-01-01

    HIV-1 relies on the host-cell machinery to accomplish its replication cycle, and characterization of these helper factors contributes to a better understanding of HIV-host interactions and can identify potential novel antiviral targets. Here we explored the contribution of CIB2, previously identified by RNAi screening as a potential helper factor, and its homolog, CIB1. Knockdown of either CIB1 or CIB2 strongly impaired viral replication in Jurkat cells and in primary CD4+ T-lymphocytes, identifying these proteins as non-redundant helper factors. Knockdown of CIB1 and CIB2 impaired envelope-mediated viral entry for both for X4- and R5-tropic HIV-1, and both cell-free and cell-associated entry pathways were affected. In contrast, the level of CIB1 and CIB2 expression did not influence cell viability, cell proliferation, receptor-independent viral binding to the cell surface, or later steps in the viral replication cycle. CIB1 and CIB2 knockdown was found to reduce the expression of surface molecules implicated in HIV-1 infection, including CXCR4, CCR5 and integrin α4β7, suggesting at least one mechanism through which these proteins promote viral infection. Thus, this study identifies CIB1 and CIB2 as host helper factors for HIV-1 replication that are required for optimal receptor-mediated viral entry. PMID:27489023

  12. New Insights into HIV-1 Persistence in Sanctuary Sites During Antiretroviral Therapy.

    Science.gov (United States)

    Poveda, Eva; Tabernilla, Andrés

    2016-01-01

    Current combinations of antiretroviral drugs for the treatment of HIV infection can successfully achieve and maintain long-term suppression of HIV-1 replication in plasma. Still, none of these therapies is capable of eradicating the virus from the long-lived cellular reservoir that represents the major barrier to HIV cure. PMID:27028272

  13. HIV-1 Viral RNA Dynamics at the Plasma Membrane May Provide Insight into Viral Assembly | Poster

    Science.gov (United States)

    Many aspects of how infectious viruses assemble in cells have yet to be completely deciphered. However, as reported in a recent Journal of Virology paper, researchers may be one step closer to understanding how HIV-1, the virus that causes AIDS, assembles and replicates.

  14. CIB1 and CIB2 are HIV-1 helper factors involved in viral entry.

    Science.gov (United States)

    Godinho-Santos, Ana; Hance, Allan J; Gonçalves, João; Mammano, Fabrizio

    2016-01-01

    HIV-1 relies on the host-cell machinery to accomplish its replication cycle, and characterization of these helper factors contributes to a better understanding of HIV-host interactions and can identify potential novel antiviral targets. Here we explored the contribution of CIB2, previously identified by RNAi screening as a potential helper factor, and its homolog, CIB1. Knockdown of either CIB1 or CIB2 strongly impaired viral replication in Jurkat cells and in primary CD4+ T-lymphocytes, identifying these proteins as non-redundant helper factors. Knockdown of CIB1 and CIB2 impaired envelope-mediated viral entry for both for X4- and R5-tropic HIV-1, and both cell-free and cell-associated entry pathways were affected. In contrast, the level of CIB1 and CIB2 expression did not influence cell viability, cell proliferation, receptor-independent viral binding to the cell surface, or later steps in the viral replication cycle. CIB1 and CIB2 knockdown was found to reduce the expression of surface molecules implicated in HIV-1 infection, including CXCR4, CCR5 and integrin α4β7, suggesting at least one mechanism through which these proteins promote viral infection. Thus, this study identifies CIB1 and CIB2 as host helper factors for HIV-1 replication that are required for optimal receptor-mediated viral entry. PMID:27489023

  15. Impact of HLA class I restricted T cells on HIV-1 disease progression

    NARCIS (Netherlands)

    Schellens, I.M.M.

    2009-01-01

    This thesis focuses on the impact of HLA class I restricted T cells on HIV-1 disease progression. It is generally accepted that cytotoxic T lymphocytes (CTL) play an important role in controlling HIV replication. In line with this, it has been well established that HLA class I alleles influence the

  16. HIV-1 Viral RNA Dynamics at the Plasma Membrane May Provide Insight into Viral Assembly | Poster

    Science.gov (United States)

    Many aspects of how infectious viruses assemble in cells have yet to be completely deciphered. However, as reported in a recent Journal of Virology paper, researchers may be one step closer to understanding how HIV-1, the virus that causes AIDS, assembles and replicates.

  17. Toll-Interacting Protein Suppresses HIV-1 Long-Terminal-Repeat-Driven Gene Expression and Silences the Post-Integrational Transcription of Viral Proviral DNA.

    Directory of Open Access Journals (Sweden)

    Fu-Chun Yang

    Full Text Available Toll-interacting protein (Tollip is a host adaptor protein for negatively regulating Toll-like receptor 2-, 4-, and IL-1R (interleukin-1 receptor-mediated signaling. We found that Tollip expression could be induced in MDDCs (monocyte-derived dendritic cells by HIV-1 particles and recombinant gp120 glycoprotein. Hence, we investigated the role of Tollip in modulating HIV-1 infection. We found that Tollip expression suppressed NF-κB-dependent HIV-1 long terminal repeat (LTR-driven transcription and thus inhibited HIV-1 infection. Our protein truncation experiments proved that the intact C-terminus of Tollip was required for inhibition of both NF-κB activity and HIV-1 LTR-driven gene expression. Intriguingly, Tollip silenced the post-integrational transcription of HIV-1 proviral DNA, indicating the potential role of Tollip in maintaining viral persistence. Our results reveal the novel role of host factor Tollip in modulating HIV-1 infection, and may suggest the hijacking of Tollip as the negative regulator of the TLR pathway and even the downstream signaling, by HIV-1 for maintaining persistent infection. Further elucidation of the mechanisms by which HIV-1 induces Tollip expression and identification of the role of Tollip in modulating HIV-1 latency will facilitate the understanding of host regulation in viral replication and benefit the exploration of novel strategies for combating HIV-1 infection.

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

    Directory of Open Access Journals (Sweden)

    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. Mechanism of Inhibition to HIV-1 by Mycoplasma Fermentans

    Institute of Scientific and Technical Information of China (English)

    尚红; 姜拥军; 王琪; 王亚男; 张子宁

    2003-01-01

    To explore the mechanism of the inhibition of HIV-1 by Mycoplasma fermerttans, culture supernatants and thallodic proteins from M.fermerttans PG18 were prepared and the protein components of the supernatants were purified withhigh performance liquid chromatography (HPLC). The inhibitory activities to reverse transcriptase (RT) and the nuclease activities were detected; the influence of M.fermerttans on IL-10 secretion by both normal and H1V-1 infected human PBMC were determined, and the inhibitory effect of rhIL-10 on H1V-1 replication was detected with EI,ISA method. The results showed that the purified proteins with a molecular weight of 67-100 kDa or 10-25 kDa showed a 36% or 34% in hibitory ac-tivity to RT and partial nuclease activity. The thallodic protein could induce both normal and H1V-1 infected PBMC to secret IL-10 remarkably, and to the latter, this effect was more apparent. While rhIL-10 could inhibit replication of H1V-1 in PB-MC in vitro in a dose-dependant manner. It concludes that the inhibitory effect of the M.fermentans PG18 culture supernatants on RT and the promoting effect of PG18 thallodic protein on IL-10 secretion in PBMC explain the mechanisms of inhibition to HIV-1 by M.fermentans PG18.

  20. Intracellular overexpression of HIV-1 Nef impairs differentiation and maturation of monocytic precursors towards dendritic cells.

    Directory of Open Access Journals (Sweden)

    Yan Guo

    Full Text Available Nef functions as an immunosuppressive factor critical for HIV-1 replication, survival and development of AIDS following HIV-1 infection. What effects Nef exerts on differentiation and maturation of monocytes towards dendritic cells (DCs remains greatly controversial. In this study, we used THP-1 (human monocytic leukemia cell line as monocytic DC precursors to investigate how overexpression of HIV-1 Nef influences the processes of differentiation and maturation of dendritic cells. In striking contrast to negative controls, our results showed that morphological and phenotypical changes (CD11c, CD14, CD40, CD80, CD83, CD86, and HLA-DR occurred on recombinant THP-1 expressing HIV-1 Nef (short for Nef upon co-stimulation of GM-CSF/IL-4 or GM-CSF/IL-4/TNF-α/ionomycin. Moreover, CD4, CCR5, and CXCR4 were also down-regulated on Nef. It might be hypothesized that Nef prevents superinfection and signal transduction in HIV-1 infected monocytes. Collectively, our study demonstrates that long-lasting expression of Nef at high levels indeed retards differentiation and maturation of dendritic cells in terms of phenotype and morphology. We are hopeful that potentially, stable expression of intracellular Nef in vivo may function as a subtle mode to support long-lasting HIV-1 existence.

  1. Readily Accessible Multiplane Microscopy: 3D Tracking the HIV-1 Genome in Living Cells.

    Science.gov (United States)

    Itano, Michelle S; Bleck, Marina; Johnson, Daniel S; Simon, Sanford M

    2016-02-01

    Human immunodeficiency virus (HIV)-1 infection and the associated disease AIDS are a major cause of human death worldwide with no vaccine or cure available. The trafficking of HIV-1 RNAs from sites of synthesis in the nucleus, through the cytoplasm, to sites of assembly at the plasma membrane are critical steps in HIV-1 viral replication, but are not well characterized. Here we present a broadly accessible microscopy method that captures multiple focal planes simultaneously, which allows us to image the trafficking of HIV-1 genomic RNAs with high precision. This method utilizes a customization of a commercial multichannel emission splitter that enables high-resolution 3D imaging with single-macromolecule sensitivity. We show with high temporal and spatial resolution that HIV-1 genomic RNAs are most mobile in the cytosol, and undergo confined mobility at sites along the nuclear envelope and in the nucleus and nucleolus. These provide important insights regarding the mechanism by which the HIV-1 RNA genome is transported to the sites of assembly of nascent virions. PMID:26567131

  2. Anti-HIV-1 activity and structure-activity relationship of pyranocoumarin analogs%吡喃香豆素衍生物对HIV-1的抑制作用及其构效关系

    Institute of Scientific and Technical Information of China (English)

    董飚; 马涛; 章天; 周春梅; 刘刚; 王琳; 陶佩珍; 张兴权

    2011-01-01

    The purpose of this study is to find out anti-HIV-1 reverse transcriptase (RT)/protease (PR) activity and inhibition of virus replication in cell cultures of novel coumarin analogs and determine their structure-activity relationship. Coumarin derivatives have been demonstrated to inhibit the activity of HIV-1 RT/PR in cell free system. It also shows inhibition effects to HIV-1 replication in cell culture. Based on the Chinese traditional pharmacological characteristics and protein three dimension computer aided design, analogs of tetracyclic dipyranocoumarin were synthesized from natural leading compounds. We studied the relationship of antiviral effects and chemical structures via HIV-1 PR/RT enzyme models and cell culture model system. Seven compounds were designed and tested. Several compounds showed anti-HIV-1 activity in varying degrees, especially V0201 showed much higher anti-HIV-1 activity with 3.56 and 0.78 μmol·L-1 of IC50 against HIV-1 PR/RT and 0.036 μmol·L-1 against HIV-1 replication in PBMC cultures. V0201 with a novel structure may be a new leading compound. These new compounds are valuable for development of new anti-HIV drugs in the future.%研究香豆素衍生物对人类免疫缺陷病毒l型逆转录酶(HIV-1 RT)、蛋白酶(HIV-1 PR)和细胞内复制的抑制作用及其构效关系.不同香豆素衍生物具有抑制HIV-1 RT、HIV-1 PR活性,且在细胞内显示出抑制HIV-1复制的作用已见报道.本课题根据国内传统药学的特点,考察以天然产物为先导化合物、结合HIV-1蛋白酶三维结构计算机辅助药物设计、合成的四环双吡喃香豆素及其类似物.以HIV-1 RT及HIV-1 PR以及细胞内病毒复制为靶点,利用酶学模型和细胞培养模型进行药物筛选及其构效关系研究,设计合成的7个化合物的药效学实验结果显示.部分化合物显示了不同程度的抗HIV-1活性.其中V0201作用最强,它对HIV-1 PR和HIV-1 RT的IC50分别为3.56和0.78 μmol·L-1;

  3. Small animal model for HIV-1 Disease

    Institute of Scientific and Technical Information of China (English)

    Yoshio; Koyanagi

    2005-01-01

    Development of a viral infection model of the humanimmune systemusingsmall animalsis animportant goal in biomedi-cal research,especiallyinstudiesof HIV-1infection.Thisis particularlyimportant since susceptibilityto HIV-1islimit-edto humans.The C.B-17-scid/scid-mouselacks mature Tand Bcells dueto a defective rearrangement of the Tcell re-ceptor andimmunoglobulin genes.Twotypes of humanlymphoid chimeras have been establishedin scid-mice.The firstsuccess withthe human mouse chimera was achieved.Human fetal liv...

  4. Complementary assays reveal a relationship between HIV-1 uncoating and reverse transcription.

    Science.gov (United States)

    Hulme, Amy E; Perez, Omar; Hope, Thomas J

    2011-06-14

    During the early stages of HIV-1 replication the conical capsid composed of p24(CA) protein dissociates from the rest of the cytoplasmic viral complex by a process called uncoating. Although proper uncoating is known to be required for HIV-1 infection, many questions remain about the timing and factors involved in the process. Here we have used two complementary assays to study the process of uncoating in HIV-1-infected cells, specifically looking at the timing of uncoating and its relationship to reverse transcription. We developed a fluorescent microscopy-based uncoating assay that detects the association of p24(CA) with HIV-1 viral complexes in cells. We also used an owl monkey kidney (OMK) cell assay that is based on timed TRIM-CypA-mediated restriction of HIV-1 replication. Results from both assays indicate that uncoating is initiated within 1 h of viral fusion. In addition, treatment with the reverse transcriptase inhibitor nevirapine delayed uncoating in both assays. Analysis of reverse transcription products in OMK cells revealed that the generation of early reverse transcription products coincides with the timing of uncoating in these assays. Collectively, these results suggest that some aspect of reverse transcription has the ability to influence the kinetics of uncoating. PMID:21628558

  5. 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

  6. Molecular modeling, synthesis and biological evaluation of N-heteroaryl compounds as reverse transcriptase inhibitors against HIV-1.

    Science.gov (United States)

    Singh, Anuradha; Yadav, Dipti; Yadav, Madhu; Dhamanage, Ashwini; Kulkarni, Smita; Singh, Ramendra K

    2015-03-01

    Different N-heteroaryl compounds bearing pyrimidine and benzimidazole moieties have been designed in silico using Discovery studio 2.5 software, synthesized and evaluated for their inhibitory activity as reverse transcriptase inhibitors against HIV-1 replication using laboratory adapted strains HIV-1IIIB (X4, subtype B) and HIV-1Ada5 (R5, subtype B), and the primary isolates HIV-1UG070 (X4, subtype D) and HIV-1VB59 (R5, subtype C). Cell-based assay showed that compounds were active at 1.394 μm concentrations (Selectivity Index: 1.29-38.39). The studies on structure-activity relationship clearly suggested anti-HIV activity of pyrimidine and benzimidazole derivatives and these findings were consistent with the in vitro cell-based experimental data. The results of molecular modeling and docking confirmed that all compounds assumed a butterfly-like conformation and showed H-bond, 'π-π' and 'π-+' and hydrophobic interactions within flexible non-nucleoside inhibitor binding pocket of HIV-1 reverse transcriptase, similar to known non-nucleoside reverse transcriptase inhibitors, such as nevirapine. In view of the results obtained, it can be said that the chemical skeletons of N, N'-bis-(pyridin-2-yl)-succinamide (14 and 15) and 1, 4-bis-benzoimidazol-1-yl-butane-1, 4-dione (16 and 17) may be used for developing potent inhibitors of HIV-1 replication, with suitable structure/pharmacophore modifications. PMID:25055732

  7. Successful isolation of infectious and high titer human monocyte-derived HIV-1 from two subjects with discontinued therapy.

    Directory of Open Access Journals (Sweden)

    Tong Wang

    Full Text Available BACKGROUND: HIV-1 DNA in blood monocytes is considered a viral source of various HIV-1 infected tissue macrophages, which is also known as "Trojan horse" hypothesis. However, whether these DNA can produce virions has been an open question for years, due to the inability of isolating high titer and infectious HIV-1 directly from monocytes. RESULTS: In this study, we demonstrated successful isolation of two strains of M-HIV-1 (1690 M and 1175 M from two out of four study subjects, together with their in vivo controls, HIV-1 isolated from CD4+ T-cells (T-HIV-1, 1690 T and 1175 T. All M- and T- HIV-1 isolates were detected CCR5-tropic. Both M- HIV-1 exhibited higher levels of replication in monocyte-derived macrophages (MDM than the two T- HIV-1. Consistent with our previous reports on the subject 1175 with late infection, compartmentalized env C2-V3-C3 sequences were identified between 1175 M and 1175 T. In contrast, 1690 M and 1690 T, which were isolated from subject 1690 with relatively earlier infection, showed homogenous env C2-V3-C3 sequences. However, multiple reverse transcriptase (RT inhibitor resistance-associated variations were detected in the Gag-Pol region of 1690 M, but not of 1690 T. By further measuring HIV DNA intracellular copy numbers post-MDM infection, 1690 M was found to have significantly higher DNA synthesis efficiency than 1690 T in macrophages, indicating a higher RT activity, which was confirmed by AZT inhibitory assays. CONCLUSIONS: These results suggested that the M- and T- HIV-1 are compartmentalized in the two study subjects, respectively. Therefore, we demonstrated that under in vitro conditions, HIV-1 infected human monocytes can productively release live viruses while differentiating into macrophages.

  8. Diketo acid inhibitor mechanism and HIV-1 integrase: Implications for metal binding in the active site of phosphotransferase enzymes

    OpenAIRE

    Grobler, Jay A.; Stillmock, Kara; Hu, Binghua; Witmer, Marc; Felock, Peter; Espeseth, Amy S.; Wolfe, Abigail; Egbertson, Melissa; Bourgeois, Michele; Melamed, Jeffrey; Wai, John S.; Young, Steve; Vacca, Joseph; Hazuda, Daria J.

    2002-01-01

    The process of integrating the reverse-transcribed HIV-1 DNA into the host chromosomal DNA is catalyzed by the virally encoded enzyme integrase (IN). Integration requires two metal-dependent reactions, 3′ end processing and strand transfer. Compounds that contain a diketo acid moiety have been shown to selectively inhibit the strand transfer reaction of IN in vitro and in infected cells and are effective as inhibitors of HIV-1 replication. To characterize the molecular basis of inhibition, we...

  9. GCN5-dependent acetylation of HIV-1 integrase enhances viral integration

    Directory of Open Access Journals (Sweden)

    Albanese Alberto

    2010-03-01

    Full Text Available Abstract Background An essential event during the replication cycle of HIV-1 is the integration of the reverse transcribed viral DNA into the host cellular genome. Our former report revealed that HIV-1 integrase (IN, the enzyme that catalyzes the integration reaction, is positively regulated by acetylation mediated by the histone acetyltransferase (HAT p300. Results In this study we demonstrate that another cellular HAT, GCN5, acetylates IN leading to enhanced 3'-end processing and strand transfer activities. GCN5 participates in the integration step of HIV-1 replication cycle as demonstrated by the reduced infectivity, due to inefficient provirus formation, in GCN5 knockdown cells. Within the C-terminal domain of IN, four lysines (K258, K264, K266, and K273 are targeted by GCN5 acetylation, three of which (K264, K266, and K273 are also modified by p300. Replication analysis of HIV-1 clones carrying substitutions at the IN lysines acetylated by both GCN5 and p300, or exclusively by GCN5, demonstrated that these residues are required for efficient viral integration. In addition, a comparative analysis of the replication efficiencies of the IN triple- and quadruple-mutant viruses revealed that even though the lysines targeted by both GCN5 and p300 are required for efficient virus integration, the residue exclusively modified by GCN5 (K258 does not affect this process. Conclusions The results presented here further demonstrate the relevance of IN post-translational modification by acetylation, which results from the catalytic activities of multiple HATs during the viral replication cycle. Finally, this study contributes to clarifying the recent debate raised on the role of IN acetylated lysines during HIV-1 infection.

  10. Elimination of HIV-1 Genomes from Human T-lymphoid Cells by CRISPR/Cas9 Gene Editing

    Science.gov (United States)

    Kaminski, Rafal; Chen, Yilan; Fischer, Tracy; Tedaldi, Ellen; Napoli, Alessandro; Zhang, Yonggang; Karn, Jonathan; Hu, Wenhui; Khalili, Kamel

    2016-01-01

    We employed an RNA-guided CRISPR/Cas9 DNA editing system to precisely remove the entire HIV-1 genome spanning between 5′ and 3′ LTRs of integrated HIV-1 proviral DNA copies from latently infected human CD4+ T-cells. Comprehensive assessment of whole-genome sequencing of HIV-1 eradicated cells ruled out any off-target effects by our CRISPR/Cas9 technology that might compromise the integrity of the host genome and further showed no effect on several cell health indices including viability, cell cycle and apoptosis. Persistent co-expression of Cas9 and the specific targeting guide RNAs in HIV-1-eradicated T-cells protected them against new infection by HIV-1. Lentivirus-delivered CRISPR/Cas9 significantly diminished HIV-1 replication in infected primary CD4+ T-cell cultures and drastically reduced viral load in ex vivo culture of CD4+ T-cells obtained from HIV-1 infected patients. Thus, gene editing using CRISPR/Cas9 may provide a new therapeutic path for eliminating HIV-1 DNA from CD4+ T-cells and potentially serve as a novel and effective platform toward curing AIDS. PMID:26939770

  11. Cyclophilin A promotes HIV-1 reverse transcription but its effect on transduction correlates best with its effect on nuclear entry of viral cDNA

    OpenAIRE

    De Iaco, Alberto; Luban, Jeremy

    2014-01-01

    Background The human peptidyl-prolyl isomerase Cyclophilin A (CypA) binds HIV-1 capsid (CA) and influences early steps in the HIV-1 replication cycle. The mechanism by which CypA regulates HIV-1 transduction efficiency is unknown. Disruption of CypA binding to CA, either by genetic means or by the competitive inhibitor cyclosporine A (CsA), reduces the efficiency of HIV-1 transduction in some cells but not in others. Transduction of certain cell types increases significantly when CypA binding...

  12. Viral escape in the CNS with multidrug-resistant HIV-1

    Directory of Open Access Journals (Sweden)

    Charles Béguelin

    2014-11-01

    persisted. The neuro-psychological evaluation confirmed neurocognitive impairments in executive functions, attention, working and nonverbal memory, speed of information processing, visuospatial abilities and motor skills. Conclusions: HIV-1 infected patients with neurological complaints prompt further investigations of the CSF including measurement of HIV viral load and genotypic resistance testing since isolated replication of HIV with drug resistant variants can rarely occur despite viral suppression in plasma. Optimizing ART by using drugs with improved CNS penetration may achieve viral suppression in CSF with improvement of neurological symptoms.

  13. Identification of Capsid Mutations That Alter the Rate of HIV-1 Uncoating in Infected Cells

    OpenAIRE

    Hulme, Amy E.; Kelley, Z; Okocha, Eneniziaogochukwu A.; Hope, Thomas J.

    2014-01-01

    After viral fusion with the cell membrane, the conical capsid of HIV-1 disassembles by a process called uncoating. We recently utilized the cyclosporine (CsA) washout assay, in which TRIM-CypA-mediated restriction of viral replication is used to detect the state of the viral capsid, to study the kinetics of uncoating in HIV-1-infected cells. Here we have extended this analysis to examine the effects of p24 capsid protein (p24CA) mutations and cellular environment on the kinetics of uncoating ...

  14. Tumor Necrosis Factor-alpha Levels in HIV-1 Seropositive Injecting Drug Users

    OpenAIRE

    Ownby, Raymond L; Kumar, Adarsh M.; Fernandez, J. Benny; Moleon-Borodowsky, Irina; Gonzalez, Louis; Eisdorfer, Seth; Waldrop-Valverde, Drenna; Kumar, Mahendra

    2009-01-01

    TNF-α is a highly pleiotropic cytokine and plays an important role in regulating HIV-1 replication. It may compromise the integrity of the blood-brain-barrier and, thus, may contribute to the neurotoxicity of HIV-1-infection. Both intravenous drug abuse (IDU) and HIV infection can increase TNF-α activity, but little information is available on the effects of a combination of these factors on TNF-α. We investigated plasma TNF-α levels and mRNA in the peripheral monocytes of 166 men and women i...

  15. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    International Nuclear Information System (INIS)

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants

  16. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Roehrig, John T., E-mail: jtr1@cdc.gov [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Butrapet, Siritorn; Liss, Nathan M. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Bennett, Susan L. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  17. The cyclosporin A washout assay to detect HIV-1 uncoating in infected cells.

    Science.gov (United States)

    Hulme, Amy E; Hope, Thomas J

    2014-01-01

    Uncoating is an early step of HIV-1 replication in which the viral capsid disassembles by p24 capsid (p24(CA)) protein dissociating from the viral complex. Although uncoating is required for HIV-1 replication, many questions remain about the mechanism of this process as well as its impact on other steps in viral replication. Here we describe a recently developed assay to study the process of uncoating in HIV-1-infected cells. The CsA washout assay is a cell-based assay that utilizes the HIV-1 restriction factor TRIM-CypA to detect and inhibit infection of coated viral complexes. Owl monkey kidney (OMK) cells are infected with a GFP reporter virus and TRIM-CypA restriction is switched on at various times postinfection allowing the kinetics of uncoating to be monitored in infected cells. This assay also can be used to examine the effect of different viral or cellular factors on the process of uncoating. PMID:24158812

  18. The influence of Mycobacterium tuberculosis co-infection and other factors on HIV-1 replication in Guangxi, China%广西地区HIV合并结核感染及其他因素对HIV复制影响的研究

    Institute of Scientific and Technical Information of China (English)

    韩晓旭; 杨志军; 尚红; 安明晖; 徐俊杰; 成诗明; 周林; 赖钰基; 刘飞鹰; 张慧; 赵彬

    2011-01-01

    目的 分析合并结核( tuberculosis,TB)感染及其他因素对广西地区HIV感染者病毒复制的影响.方法 2010年4月至2010年9月间在广西招募到未接受抗病毒治疗、CD4+T细胞数<350个/μl的HIV/TB感染者61例,单纯HIV感染者34例.收集人口学、流行病学、临床信息,测定HIV病毒载量.结果 HIV/TB双重感染者与单纯HIV感染者血浆病毒载量差异无统计学意义[ (5.05±0.93) lg拷贝/ml vs (5.06±0.76) lg拷贝/ml,P=0.94].二元logistic回归分析显示,CRF01_AE亚型较其他亚型HIV感染者血浆病毒复制水平高,OR=8.07 (95%CI 1.07~61.20,P=0.04).年龄、感染途径、CD4+T细胞数,是否合并结核分枝杆菌(MTB)感染及TB临床类型对病毒复制水平的影响均不明显.结论 广西地区CD4+T细胞数较低的HIV感染者中,合并结核感染对病毒复制影响不明显;CRF01_AE亚型HIV-1病毒复制水平较高,在监测和治疗过程中需加强关注.%Objective To investigate the influence of Mycobacterium tuberculosis (MTB) co-infection and other factors on the HIV replication level in antiretroviral treatment na(i)ve patients.Methods Six hundred TB patients and 465 HIV infectors were recruited between April 2010 and September 2010.TB coinfections were diagnosed in HIV infected cases with chest X-ray,checking TB in sputum with anti-acid staining and culture of the sputum,histopatholo diagnosis and clinical diagnosis.HIV infections were screened in TB patients with the 3rd generation ELISA antibody test.Sixty-one antiretroviral treatment na(i)ve HIV/TB co-infectors and 34 HIV infectors with CD4 T cell count below 350 cells/μl were included in this study.Information about the demography,epidemiology and results of clinical diagnostic tests of HIV and TB was collected through pathography and questionnaires from all participants.HIV viral load were detected with COBAS AmpliPrep/COBAS TaqMan(R) System of Roche Company.Results The viral load of HIV/TB co-infectors was

  19. Blocking the PI3K/AKT pathway enhances mammalian reovirus replication by repressing IFN-stimulated genes

    Science.gov (United States)

    Tian, Jin; Zhang, Xiaozhan; Wu, Hongxia; Liu, Chunguo; Li, Zhijie; Hu, Xiaoliang; Su, Shuo; Wang, Lin-Fa; Qu, Liandong

    2015-01-01

    Many host cellular signaling pathways were activated and exploited by virus infection for more efficient replication. The PI3K/Akt pathway has recently attracted considerable interest due to its role in regulating virus replication. This study demonstrated for the first time that the mammalian reovirus strains Masked Palm Civet/China/2004 (MPC/04) and Bat/China/2003 (B/03) can induce transient activation of the PI3K/Akt pathway early in infection in vitro. When UV-treated, both viruses activated PI3K/Akt signaling, indicating that the virus/receptor interaction was sufficient to activate PI3K/Akt. Reovirus virions can use both clathrin- and caveolae-mediated endocytosis, but only chlorpromazine, a specific inhibitor of clathrin-mediated endocytosis, or siRNA targeting clathrin suppressed Akt phosphorylation. We also identified the upstream molecules of the PI3K pathway. Virus infection induced phosphorylation of focal adhesion kinase (FAK) but not Gab1, and blockage of FAK phosphorylation suppressed Akt phosphorylation. Blockage of PI3K/Akt activation increased virus RNA synthesis and viral yield. We also found that reovirus infection activated the IFN-stimulated response element (ISRE) in an interferon-independent manner and up-regulated IFN-stimulated genes (ISGs) via the PI3K/Akt/EMSY pathway. Suppression of PI3K/Akt activation impaired the induction of ISRE and down-regulated the expression of ISGs. Overexpression of ISG15 and Viperin inhibited virus replication, and knockdown of either enhanced virus replication. Collectively, these results demonstrate that PI3K/Akt activated by mammalian reovirus serves as a pathway for sensing and then inhibiting virus replication/infection. PMID:26388843

  20. Second site escape of a T20-dependent HIV-1 variant by a single amino acid change in the CD4 binding region of the envelope glycoprotein

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2006-11-01

    Full Text Available Abstract Background We previously described the selection of a T20-dependent human immunodeficiency virus type-1 (HIV-1 variant in a patient on T20 therapy. The fusion inhibitor T20 targets the viral envelope (Env protein by blocking a conformational switch that is critical for viral entry into the host cell. T20-dependent viral entry is the result of 2 mutations in Env (GIA-SKY, creating a protein that undergoes a premature conformational switch, and the presence of T20 prevents this premature switch and rescues viral entry. In the present study, we performed 6 independent evolution experiments with the T20-dependent HIV-1 variant in the absence of T20, with the aim to identify second site compensatory changes, which may provide new mechanistic insights into Env function and the T20-dependence mechanism. Results Escape variants with improved replication capacity appeared within 42 days in 5 evolution cultures. Strikingly, 3 cultures revealed the same single amino acid change in the CD4 binding region of Env (glycine at position 431 substituted for arginine: G431R. This mutation was sufficient to abolish the T20-dependence phenotype and restore viral replication in the absence of T20. The GIA-SKY-G431R escape variant produces an Env protein that exhibits reduced syncytia formation and reduced cell-cell fusion activity. The escape variant was more sensitive to an antibody acting on an early gp41 intermediate, suggesting that the G431R mutation helps preserve a pre-fusion Env conformation, similar to T20 action. The escape variant was also less sensitive to soluble CD4, suggesting a reduced CD4 receptor affinity. Conclusion The forced evolution experiments indicate that the premature conformational switch of the T20-dependent HIV-1 Env variant (GIA-SKY can be corrected by a second site mutation in Env (GIA-SKY-G431R that affects the interaction with the CD4 receptor.

  1. Intercellular adhesion molecule 1 promotes HIV-1 attachment but not fusion to target cells.

    Directory of Open Access Journals (Sweden)

    Naoyuki Kondo

    Full Text Available Incorporation of intercellular adhesion molecule 1 (ICAM-1 into HIV-1 particles is known to markedly enhance the virus binding and infection of cells expressing lymphocyte function-associated antigen-1 (LFA-1. At the same time, ICAM-1 has been reported to exert a less pronounced effect on HIV-1 fusion with lymphoid cells. Here we examined the role of ICAM-1/LFA-1 interactions in productive HIV-1 entry into lymphoid cells using a direct virus-cell fusion assay. ICAM-1 promoted HIV-1 attachment to cells in a temperature-dependent manner. It exerted a marginal effect on virus binding in the cold, but enhanced binding up to 4-fold at physiological temperature. ICAM-1-independent attachment in the cold was readily reversible upon subsequent incubation at elevated temperature, whereas ICAM-1-bearing particles were largely retained by cells. The better virus retention resulted in a proportional increase in HIV-1 internalization and fusion, suggesting that ICAM-1 did not specifically accelerate endocytosis or fusion steps. We also measured the rates of CD4 engagement, productive endocytosis and HIV-endosome fusion using specific fusion inhibitors. These rates were virtually independent of the presence of ICAM-1 in viral particles. Importantly, irrespective of the presence of ICAM-1, HIV-1 escaped from the low temperature block, which stopped virus endocytosis and fusion, much later than from a membrane-impermeant fusion inhibitor targeting surface-accessible particles. This result, along with the complete inhibition of HIV-1 fusion by a small molecule dynamin inhibitor, implies this virus enters lymphoid cells used in this study via endocytosis and that this pathway is not altered by the viral ICAM-1. Our data highlight the role of ICAM-1 in stabilizing the HIV-1 attachment to LFA-1 expressing cells, which leads to a proportional enhancement of the receptor-mediated uptake and fusion with endosomes.

  2. Short chain fatty acids potently induce latent HIV-1 in T-cells by activating P-TEFb and multiple histone modifications.

    Science.gov (United States)

    Das, Biswajit; Dobrowolski, Curtis; Shahir, Abdel-Malek; Feng, Zhimin; Yu, Xiaolan; Sha, Jinfeng; Bissada, Nabil F; Weinberg, Aaron; Karn, Jonathan; Ye, Fengchun

    2015-01-01

    HIV patients with severe periodontitis have high levels of residual virus in their saliva and plasma despite effective therapy (HAART). Multiple short chain fatty acids (SCFAs) from periodontal pathogens reactivate HIV-1 in both Jurkat and primary T-cell models of latency. SCFAs not only activate positive transcription elongation factor b (P-TEFb), which is an essential cellular cofactor for Tat, but can also reverse chromatin blocks by inducing histone modifications. SCFAs simultaneously increase histone acetylation by inhibiting class-1/2 histone deacetylases (HDACs) and decrease repressive histone tri-methylation at the proviral LTR by downregulating expression of the class-3 HDAC sirtuin-1 (SIRT1), and the histone methyltransferases enhancer of Zeste homolog 2 (EZH2) and suppressor of variegation 3-9 homolog 1 (SUV39H1). Our findings provide a mechanistic link between periodontal disease and enhanced HIV-1 replication, and suggest that treatment of periodontal disease, or blocking the activities of SCFAs, will have a therapeutic benefit for HIV patients. PMID:25463605

  3. The HIV-1 Integrase Mutant R263A/K264A Is 2-fold Defective for TRN-SR2 Binding and Viral Nuclear Import*

    Science.gov (United States)

    De Houwer, Stéphanie; Demeulemeester, Jonas; Thys, Wannes; Rocha, Susana; Dirix, Lieve; Gijsbers, Rik; Christ, Frauke; Debyser, Zeger

    2014-01-01

    Transportin-SR2 (Tnpo3, TRN-SR2), a human karyopherin encoded by the TNPO3 gene, has been identified as a cellular cofactor of HIV-1 replication, specifically interacting with HIV-1 integrase (IN). Whether this interaction mediates the nuclear import of HIV remains controversial. We previously characterized the TRN-SR2 binding interface in IN and introduced mutations at these positions to corroborate the biological relevance of the interaction. The pleiotropic nature of IN mutations complicated the interpretation. Indeed, all previously tested IN interaction mutants also affected RT. Here we report on a virus with a pair of IN mutations, INR263A/K264A, that significantly reduce interaction with TRN-SR2. The virus retains wild-type reverse transcription activity but displays a block in nuclear import and integration, as measured by quantitative PCR. The defect in integration of this mutant resulted in a smaller increase in the number of two-long terminal repeat circles than for virus specifically blocked at integration by raltegravir or catalytic site mutations (IND64N/D116N/E152Q). Finally, using an eGFP-IN-labeled HIV fluorescence-based import assay, the defect in nuclear import was corroborated. These data altogether underscore the importance of the HIV-IN TRN-SR2 protein-protein interaction for HIV nuclear import and validate the IN/TRN-SR2 interaction interface as a promising target for future antiviral therapy. PMID:25063804

  4. N6-methyladenosine of HIV-1 RNA regulates viral infection and HIV-1 Gag protein expression

    Science.gov (United States)

    Tirumuru, Nagaraja; Zhao, Boxuan Simen; Lu, Wuxun; Lu, Zhike; He, Chuan; Wu, Li

    2016-01-01

    The internal N6-methyladenosine (m6A) methylation of eukaryotic nuclear RNA controls post-transcriptional gene expression, which is regulated by methyltransferases (writers), demethylases (erasers), and m6A-binding proteins (readers) in cells. The YTH domain family proteins (YTHDF1–3) bind to m6A-modified cellular RNAs and affect RNA metabolism and processing. Here, we show that YTHDF1–3 proteins recognize m6A-modified HIV-1 RNA and inhibit HIV-1 infection in cell lines and primary CD4+ T-cells. We further mapped the YTHDF1–3 binding sites in HIV-1 RNA from infected cells. We found that the overexpression of YTHDF proteins in cells inhibited HIV-1 infection mainly by decreasing HIV-1 reverse transcription, while knockdown of YTHDF1–3 in cells had the opposite effects. Moreover, silencing the m6A writers decreased HIV-1 Gag protein expression in virus-producing cells, while silencing the m6A erasers increased Gag expression. Our findings suggest an important role of m6A modification of HIV-1 RNA in viral infection and HIV-1 protein synthesis. DOI: http://dx.doi.org/10.7554/eLife.15528.001 PMID:27371828

  5. 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. PMID:27049645

  6. Development of HIV-1 rectal-specific microbicides and colonic tissue evaluation.

    Science.gov (United States)

    Dezzutti, Charlene S; Russo, Julie; Wang, Lin; Abebe, Kaleab Z; Li, Jie; Friend, David R; McGowan, Ian M; Rohan, Lisa C

    2014-01-01

    The gastrointestinal tract is structurally and functionally different from the vagina. Thus, the paradigm of topical microbicide development and evaluation has evolved to include rectal microbicides (RMs). Our interest was to create unique RM formulations to safely and effectively deliver antiretroviral drugs to mucosal tissue. RMs were designed to include those that spread and coat all surfaces of the rectum and distal colon rapidly (liquid) and those that create a deformable, erodible barrier and remain localized at the administration site (gel). Tenofovir (TFV) (1%) was formulated as an aqueous thermoreversible fluid and a carbopol-based aqueous hydrogel. Lipid-based liquid and gel formulations were prepared for UC781 (0.1%) using isopropyl myristate and GTCC (Caprylic/Capric Triglycerides), respectively. Formulations were characterized for pH, viscosity, osmolality, and drug content. Pre-clinical testing incorporated ex vivo colonic tissue obtained through surgical resections and flexible sigmoidoscopy (flex sig). As this was the first time using tissue from both sources side-by-side, the ability to replicate HIV-1 was compared. Efficacy of the RM formulations was tested by applying the products with HIV-1 directly to polarized colonic tissue and following viral replication. Safety of the formulations was determined by MTT assay and histology. All products had a neutral pH and were isoosmolar. While HIV-1BaL and HIV-1JR-CSF alone and in the presence of semen had similar replication trends between surgically resected and flex sig tissues, the magnitude of viral replication was significantly better in flex sig tissues. Both TFV and UC781 formulations protected the colonic tissue, regardless of tissue source, from HIV-1 and retained tissue viability and architecture. Our in vitro and ex vivo results show successful formulation of unique RMs. Moreover, the results of flex sig and surgically resected tissues were comparable suggesting the incorporation of both in

  7. Development of HIV-1 rectal-specific microbicides and colonic tissue evaluation.

    Directory of Open Access Journals (Sweden)

    Charlene S Dezzutti

    Full Text Available The gastrointestinal tract is structurally and functionally different from the vagina. Thus, the paradigm of topical microbicide development and evaluation has evolved to include rectal microbicides (RMs. Our interest was to create unique RM formulations to safely and effectively deliver antiretroviral drugs to mucosal tissue. RMs were designed to include those that spread and coat all surfaces of the rectum and distal colon rapidly (liquid and those that create a deformable, erodible barrier and remain localized at the administration site (gel. Tenofovir (TFV (1% was formulated as an aqueous thermoreversible fluid and a carbopol-based aqueous hydrogel. Lipid-based liquid and gel formulations were prepared for UC781 (0.1% using isopropyl myristate and GTCC (Caprylic/Capric Triglycerides, respectively. Formulations were characterized for pH, viscosity, osmolality, and drug content. Pre-clinical testing incorporated ex vivo colonic tissue obtained through surgical resections and flexible sigmoidoscopy (flex sig. As this was the first time using tissue from both sources side-by-side, the ability to replicate HIV-1 was compared. Efficacy of the RM formulations was tested by applying the products with HIV-1 directly to polarized colonic tissue and following viral replication. Safety of the formulations was determined by MTT assay and histology. All products had a neutral pH and were isoosmolar. While HIV-1BaL and HIV-1JR-CSF alone and in the presence of semen had similar replication trends between surgically resected and flex sig tissues, the magnitude of viral replication was significantly better in flex sig tissues. Both TFV and UC781 formulations protected the colonic tissue, regardless of tissue source, from HIV-1 and retained tissue viability and architecture. Our in vitro and ex vivo results show successful formulation of unique RMs. Moreover, the results of flex sig and surgically resected tissues were comparable suggesting the incorporation

  8. Crystal structure of HIV-1 Tat complexed with human P-TEFb

    Energy Technology Data Exchange (ETDEWEB)

    Tahirov, Tahir H.; Babayeva, Nigar D.; Varzavand, Katayoun; Cooper, Jeffrey J.; Sedore, Stanley C.; Price, David H. (Nebraska-Med); (Iowa)

    2010-08-23

    Regulation of the expression of the human immunodeficiency virus (HIV) genome is accomplished in large part by controlling transcription elongation. The viral protein Tat hijacks the host cell's RNA polymerase II elongation control machinery through interaction with the positive transcription elongation factor, P-TEFb, and directs the factor to promote productive elongation of HIV mRNA. Here we describe the crystal structure of the Tat-P-TEFb complex containing HIV-1 Tat, human Cdk9 (also known as CDK9), and human cyclin T1 (also known as CCNT1). Tat adopts a structure complementary to the surface of P-TEFb and makes extensive contacts, mainly with the cyclin T1 subunit of P-TEFb, but also with the T-loop of the Cdk9 subunit. The structure provides a plausible explanation for the tolerance of Tat to sequence variations at certain sites. Importantly, Tat induces significant conformational changes in P-TEFb. This finding lays a foundation for the design of compounds that would specifically inhibit the Tat-P-TEFb complex and block HIV replication.

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

    Directory of Open Access Journals (Sweden)

    Li Yun-Yao

    2004-10-01

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

  10. Significant impact of non-B HIV-1 variants genetic diversity in Gabon on plasma HIV-1 RNA quantitation

    OpenAIRE

    Mouinga-Ondeme, A.; Mabika-Mabika, A.; Alalade, P.; Mongo, A. D.; Sica, J.; Liégeois, Florian; Rouet, F.

    2014-01-01

    Evaluations of HIV-1 RNA viral load assays are lacking in Central Africa. The main objective of our study was to assess the reliability of HIV-1 RNA results obtained with three different assays for samples collected in Gabon. A total of 137 plasma specimens were assessed for HIV-1 RNA using the Abbott RealTime HIV-1 (R) and Nuclisens HIV-1 EasyQ (R) version 2.0 assays. It included HIV-1 non-B samples (n = 113) representing six subtypes, 10 CRFs and 18 URFs from patients infected with HIV-1 an...

  11. Identification of a D-amino acid decapeptide HIV-1 entry inhibitor

    International Nuclear Information System (INIS)

    Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide DC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While DC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonal antibody and chemokine SDF-1α to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of DC13 implies additional mode(s) of action. These results suggest that DC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors

  12. In vitro replication capacity of HIV-2 variants from long-term aviremic individuals

    OpenAIRE

    Blaak, Hetty; Ende, Marchina; Boers, Patrick; Schuitemaker, H; Osterhaus, Albert

    2006-01-01

    textabstractTo establish whether efficient suppression of virus replication in HIV-2-infected individuals is associated with low replicative capacity of HIV-2, replication kinetics of HIV-2 variants from long-term aviremic individuals was analyzed and compared with that of the relatively slow-replicating HIV-1 variants from asymptomatics and long-term nonprogressors (AS/LTNP). On average, HIV-2 from aviremic individuals had lower replication rates than HIV-1 variants from AS/LTNP in cells of ...

  13. Multiple T-cell responses are associated with better control of acute HIV-1 infection: An observational study.

    Science.gov (United States)

    Sun, Jianping; Zhao, Yan; Peng, Yanchun; Han, Zhen; Liu, Guihai; Qin, Ling; Liu, Sai; Sun, Huanhuan; Wu, Hao; Dong, Tao; Zhang, Yonghong

    2016-07-01

    Cytotoxic T lymphocyte (CTL) responses play pivotal roles in controlling the replication of human immunodeficiency virus type 1 (HIV-1), but the correlation between CTL responses and the progression of HIV-1 infection are controversial on account of HIV immune escape mutations driven by CTL pressure were reported.The acute HIV-1-infected patients from Beijing were incorporated into our study to investigate the effects of CTL response on the progression of HIV-1 infection.A longitudinal study was performed on acute HIV-1-infected patients to clarify the kinetic of T-cell responses, the dynamic of escape mutations, as well as the correlation between effective T-cell response and the progression of HIV infection.Seven human leukocyte antigen-B51+ (HLA-B51+) individuals were screened from 105 acute HIV-1 infectors. The detailed kinetic of HLA-B51-restricted CTL responses was described through blood sampling time points including seroconversion, 3 and 6 months after HIV-1 infection in the 7 HLA-B51+ individuals, by using 16 known HLA-B51 restricted epitopes. Pol743-751 (LPPVVAKEI, LI9), Pol283-289 (TAFTIPSI, TI8), and Gag327-3459 (NANPDCKTI, NI9) were identified as 3 dominant epitopes, and ranked as starting with LI9, followed by TI8 and NI9 in the ability to induce T-cell responses. The dynamics of escape mutations in the 3 epitopes were also found with the same order as T-cell response, by using sequencing for viral clones on blood sampling at seroconversion, 3 and 6 months after HIV-1 infection.We use solid evidence to demonstrate the correlation between T-cell response and HIV-1 mutation, and postulate that multiple T-cell responses might benefit the control of HIV-1 infection, especially in acute infection phase. PMID:27472741

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

    International Nuclear Information System (INIS)

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

  15. Predicting Pregnancy in HIV-1-Discordant Couples

    OpenAIRE

    Guthrie, Brandon L.; Choi, Robert Y.; Bosire, Rose; Kiarie, James N.; Mackelprang, Romel D.; Gatuguta, Anne; John-Stewart, Grace C.; FARQUHAR, Carey

    2010-01-01

    This study examines the incidence and predictors of pregnancy in HIV-1-discordant couples from Nairobi, Kenya. Women from 454 discordant couples were followed for up to 2 years. One-year cumulative incidence of pregnancy was 9.7%. Pregnancy rates did not differ significantly between HIV-1-infected and uninfected women (HR = 1.46). The majority of pregnancies occurred among women < 30 years old reporting a desire for future children (1-year incidence 22.2%). Pregnancy rates may be high among d...

  16. Lipid domains in HIV-1 assembly

    OpenAIRE

    CyrilFavard

    2014-01-01

    In CD+ 4 T cells, HIV-1 buds from the host cell plasma membrane. The viral Gag polyprotein is mainly responsible for this process. However, the intimate interaction of Gag and lipids at the plasma membrane as well as its consequences, in terms of lipids lateral organization and virus assembly, is still under debate. In this review we propose to revisit the role of plasma membrane lipids in HIV-1 Gag targeting and assembly, at the light of lipid membranes biophysics and literature dealing with...

  17. Contribution of immunological and virological factors to extremely severe primary HIV-1 infection

    Science.gov (United States)

    Dalmau, Judith; Puertas, Maria Carmen; Azuara, Marta; Mariño, Ana; Frahm, Nicole; Mothe, Beatriz; Izquierdo-Useros, Nuria; Buzón, Maria José; Paredes, Roger; Matas, Lourdes; Allen, Todd M.; Brander, Christian; Rodrigo, Carlos; Clotet, Bonaventura; Martinez-Picado, Javier

    2009-01-01

    Background During acute HIV infection, high viral loads and the induction of host immune responses typically coincide with the onset of clinical symptoms. However, clinically severe presentations during acute HIV-1 infection, including AIDS-defining symptoms, are unusual. Methods Virus isolates were tested for clade, drug susceptibility, coreceptor usage, and growth rate for two cases of clinically severe sexual transmission. HLA genotype was determined, and HIV-1-specific CTL responses to an overlapping peptide set spanning the entire HIV clade A and clade B proteome were assayed. Results The virus isolated from the two unrelated cases of severe primary HIV-1 infection showed R5/X4 dual/mixed tropism, belonged to clade B and CRF02-AG, and were highly replicative in peripheral blood mononuclear cell culture. Impaired humoral responses were paralleled by a profound absence of HIV-1-specific CTL responses to the entire viral proteome in the two study cases. One case for which the virus source was available, showed a remarkable HLA similarity between the transmission pair as all 4 HLA-A and -B alleles were HLA supertype-matched between the subjects involved in the transmission case. Conclusions The data suggest that concurrence of viral and host factors contribute to the clinical severity of primary HIV-1 infection and that subjects infected with highly replicative dual tropic viruses are more prone to develop AIDS-defining symptoms during acute infection if they are unable to mount humoral and cellular HIV-1-specific immune responses. Concordant HLA supertypes might facilitate the preferential transmission of HLA-adapted viral variants, further accelerating disease progression. PMID:19093810

  18. Comparative analysis of measures of viral reservoirs in HIV-1 eradication studies.

    Directory of Open Access Journals (Sweden)

    Susanne Eriksson

    2013-02-01

    Full Text Available HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART. The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4(+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4(+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4(+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy

  19. Patterns of HIV-1 protein interaction identify perturbed host-cellular subsystems.

    Directory of Open Access Journals (Sweden)

    Jamie I MacPherson

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 exploits a diverse array of host cell functions in order to replicate. This is mediated through a network of virus-host interactions. A variety of recent studies have catalogued this information. In particular the HIV-1, Human Protein Interaction Database (HHPID has provided a unique depth of protein interaction detail. However, as a map of HIV-1 infection, the HHPID is problematic, as it contains curation error and redundancy; in addition, it is based on a heterogeneous set of experimental methods. Based on identifying shared patterns of HIV-host interaction, we have developed a novel methodology to delimit the core set of host-cellular functions and their associated perturbation from the HHPID. Initially, using biclustering, we identify 279 significant sets of host proteins that undergo the same types of interaction. The functional cohesiveness of these protein sets was validated using a human protein-protein interaction network, gene ontology annotation and sequence similarity. Next, using a distance measure, we group host protein sets and identify 37 distinct higher-level subsystems. We further demonstrate the biological significance of these subsystems by cross-referencing with global siRNA screens that have been used to detect host factors necessary for HIV-1 replication, and investigate the seemingly small intersect between these data sets. Our results highlight significant host-cell subsystems that are perturbed during the course of HIV-1 infection. Moreover, we characterise the patterns of interaction that contribute to these perturbations. Thus, our work disentangles the complex set of HIV-1-host protein interactions in the HHPID, reconciles these with siRNA screens and provides an accessible and interpretable map of infection.

  20. HIV-1 and HIV-2 exhibit divergent interactions with HLTF and UNG2 DNA repair proteins.

    Science.gov (United States)

    Hrecka, Kasia; Hao, Caili; Shun, Ming-Chieh; Kaur, Sarabpreet; Swanson, Selene K; Florens, Laurence; Washburn, Michael P; Skowronski, Jacek

    2016-07-01

    HIV replication in nondividing host cells occurs in the presence of high concentrations of noncanonical dUTP, apolipoprotein B mRNA-editing, enzyme-catalytic, polypeptide-like 3 (APOBEC3) cytidine deaminases, and SAMHD1 (a cell cycle-regulated dNTP triphosphohydrolase) dNTPase, which maintains low concentrations of canonical dNTPs in these cells. These conditions favor the introduction of marks of DNA damage into viral cDNA, and thereby prime it for processing by DNA repair enzymes. Accessory protein Vpr, found in all primate lentiviruses, and its HIV-2/simian immunodeficiency virus (SIV) SIVsm paralogue Vpx, hijack the CRL4(DCAF1) E3 ubiquitin ligase to alleviate some of these conditions, but the extent of their interactions with DNA repair proteins has not been thoroughly characterized. Here, we identify HLTF, a postreplication DNA repair helicase, as a common target of HIV-1/SIVcpz Vpr proteins. We show that HIV-1 Vpr reprograms CRL4(DCAF1) E3 to direct HLTF for proteasome-dependent degradation independent from previously reported Vpr interactions with base excision repair enzyme uracil DNA glycosylase (UNG2) and crossover junction endonuclease MUS81, which Vpr also directs for degradation via CRL4(DCAF1) E3. Thus, separate functions of HIV-1 Vpr usurp CRL4(DCAF1) E3 to remove key enzymes in three DNA repair pathways. In contrast, we find that HIV-2 Vpr is unable to efficiently program HLTF or UNG2 for degradation. Our findings reveal complex interactions between HIV-1 and the DNA repair machinery, suggesting that DNA repair plays important roles in the HIV-1 life cycle. The divergent interactions of HIV-1 and HIV-2 with DNA repair enzymes and SAMHD1 imply that these viruses use different strategies to guard their genomes and facilitate their replication in the host. PMID:27335459

  1. Large-scale functional purification of recombinant HIV-1 capsid.

    Directory of Open Access Journals (Sweden)

    Magdeleine Hung

    Full Text Available During human immunodeficiency virus type-1 (HIV-1 virion maturation, capsid proteins undergo a major rearrangement to form a conical core that protects the viral nucleoprotein complexes. Mutations in the capsid sequence that alter the stability of the capsid core are deleterious to viral infectivity and replication. Recently, capsid assembly has become an attractive target for the development of a new generation of anti-retroviral agents. Drug screening efforts and subsequent structural and mechanistic studies require gram quantities of active, homogeneous and pure protein. Conventional means of laboratory purification of Escherichia coli expressed recombinant capsid protein rely on column chromatography steps that are not amenable to large-scale production. Here we present a function-based purification of wild-type and quadruple mutant capsid proteins, which relies on the inherent propensity of capsid protein to polymerize and depolymerize. This method does not require the packing of sizable chromatography columns and can generate double-digit gram quantities of functionally and biochemically well-behaved proteins with greater than 98% purity. We have used the purified capsid protein to characterize two known assembly inhibitors in our in-house developed polymerization assay and to measure their binding affinities. Our capsid purification procedure provides a robust method for purifying large quantities of a key protein in the HIV-1 life cycle, facilitating identification of the next generation anti-HIV agents.

  2. The cell biology of HIV-1 and other retroviruses

    Directory of Open Access Journals (Sweden)

    Mouland Andrew J

    2006-11-01

    Full Text Available Abstract In recognition of the growing influence of cell biology in retrovirus research, we recently organized a Summer conference sponsored by the American Society for Cell Biology (ASCB on the Cell Biology of HIV-1 and other Retroviruses (July 20–23, 2006, Emory University, Atlanta, Georgia. The meeting brought together a number of leading investigators interested in the interplay between cell biology and retrovirology with an emphasis on presentation of new and unpublished data. The conference was arranged from early to late events in the virus replication cycle, with sessions on viral fusion, entry, and transmission; post-entry restrictions to retroviral infection; nuclear import and integration; gene expression/regulation of retroviral Gag and genomic RNA; and assembly/release. In this review, we will attempt to touch briefly on some of the highlights of the conference, and will emphasize themes and trends that emerged at the meeting. Meeting report The conference began with a keynote address from W. Sundquist on the biochemistry of HIV-1 budding. This presentation will be described in the section on Assembly and Release of Retroviruses.

  3. Novel 3′-Processing Integrase Activity Assay by Real-Time PCR for Screening and Identification of HIV-1 Integrase Inhibitors

    OpenAIRE

    Supachai Sakkhachornphop; Weeraya Thongkum; Chatchai Tayapiwatana

    2015-01-01

    The 3′-end processing (3′P) of each viral long terminal repeat (LTR) during human immunodeficiency virus type-1 (HIV-1) integration is a vital step in the HIV life cycle. Blocking the 3′P using 3′P inhibitor has recently become an attractive strategy for HIV-1 therapeutic intervention. Recently, we have developed a novel real-time PCR based assay for the detection of 3′P activity in vitro. The methodology usually involves biotinylated HIV-1 LTR, HIV-1 integrase (IN), and specific primers and ...

  4. Impact of the N348I Mutation in HIV-1 Reverse Transcriptase on Nonnucleoside Reverse Transcriptase Inhibitor Resistance in Non-Subtype B HIV-1

    OpenAIRE

    McCormick, A L; Parry, C M; Crombe, A.; Goodall, R. L.; Gupta, R K; Kaleebu, P.; Kityo, C.; Chirara, M.; Towers, G.J.; Pillay, D.

    2011-01-01

    We investigated the effect of N348I alone and with M184V on nonnucleoside reverse transcriptase inhibitor (NNRTI) drug susceptibility and replicative capacity in B and non-B HIV-1 isolates. N348I reduced the susceptibility to all NNRTI drugs across subtypes. The replication capacity of all viruses in a variety of cell lines was impaired by N348I. Interestingly, the N348I and M184V double mutation compensated for the reduced NNRTI drug susceptibility observed in the N348I single mutant and mar...

  5. Recent advances in RNAi-based strategies for therapy and prevention of HIV-1/AIDS.

    Science.gov (United States)

    Swamy, Manjunath N; Wu, Haoquan; Shankar, Premlata

    2016-08-01

    RNA interference (RNAi) provides a powerful tool to silence specific gene expression and has been widely used to suppress host factors such as CCR5 and/or viral genes involved in HIV-1 replication. Newer nuclease-based gene-editing technologies, such as zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN) and the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system, also provide powerful tools to ablate specific genes. Because of differences in co-receptor usage and the high mutability of the HIV-1 genome, a combination of host factors and viral genes needs to be suppressed for effective prevention and treatment of HIV-1 infection. Whereas the continued presence of small interfering/short hairpin RNA (si/shRNA) mediators is needed for RNAi to be effective, the continued expression of nucleases in the gene-editing systems is undesirable. Thus, RNAi provides the only practical way for expression of multiple silencers in infected and uninfected cells, which is needed for effective prevention/treatment of infection. There have been several advances in the RNAi field in terms of si/shRNA design, targeted delivery to HIV-1 susceptible cells, and testing for efficacy in preclinical humanized mouse models. Here, we comprehensively review the latest advances in RNAi technology towards prevention and treatment of HIV-1. PMID:27013255

  6. Zn(2+ inhibits coronavirus and arterivirus RNA polymerase activity in vitro and zinc ionophores block the replication of these viruses in cell culture.

    Directory of Open Access Journals (Sweden)

    Aartjan J W te Velthuis

    Full Text Available Increasing the intracellular Zn(2+ concentration with zinc-ionophores like pyrithione (PT can efficiently impair the replication of a variety of RNA viruses, including poliovirus and influenza virus. For some viruses this effect has been attributed to interference with viral polyprotein processing. In this study we demonstrate that the combination of Zn(2+ and PT at low concentrations (2 µM Zn(2+ and 2 µM PT inhibits the replication of SARS-coronavirus (SARS-CoV and equine arteritis virus (EAV in cell culture. The RNA synthesis of these two distantly related nidoviruses is catalyzed by an RNA-dependent RNA polymerase (RdRp, which is the core enzyme of their multiprotein replication and transcription complex (RTC. Using an activity assay for RTCs isolated from cells infected with SARS-CoV or EAV--thus eliminating the need for PT to transport Zn(2+ across the plasma membrane--we show that Zn(2+ efficiently inhibits the RNA-synthesizing activity of the RTCs of both viruses. Enzymatic studies using recombinant RdRps (SARS-CoV nsp12 and EAV nsp9 purified from E. coli subsequently revealed that Zn(2+ directly inhibited the in vitro activity of both nidovirus polymerases. More specifically, Zn(2+ was found to block the initiation step of EAV RNA synthesis, whereas in the case of the SARS-CoV RdRp elongation was inhibited and template binding reduced. By chelating Zn(2+ with MgEDTA, the inhibitory effect of the divalent cation could be reversed, which provides a novel experimental tool for in vitro studies of the molecular details of nidovirus replication and transcription.

  7. Editing of HIV-1 RNA by the double-stranded RNA deaminase ADAR1 stimulates viral infection

    Science.gov (United States)

    Doria, Margherita; Neri, Francesca; Gallo, Angela; Farace, Maria Giulia; Michienzi, Alessandro

    2009-01-01

    Adenosine deaminases that act on dsRNA (ADARs) are enzymes that target double-stranded regions of RNA converting adenosines into inosines (A-to-I editing) thus contributing to genome complexity and fine regulation of gene expression. It has been described that a member of the ADAR family, ADAR1, can target viruses and affect their replication process. Here we report evidence showing that ADAR1 stimulates human immuno deficiency virus type 1 (HIV-1) replication by using both editing-dependent and editing-independent mechanisms. We show that over-expression of ADAR1 in HIV-1 producer cells increases viral protein accumulation in an editing-independent manner. Moreover, HIV-1 virions generated in the presence of over-expressed ADAR1 but not an editing-inactive ADAR1 mutant are released more efficiently and display enhanced infectivity, as demonstrated by challenge assays performed with T cell lines and primary CD4+ T lymphocytes. Finally, we report that ADAR1 associates with HIV-1 RNAs and edits adenosines in the 5′ untranslated region (UTR) and the Rev and Tat coding sequence. Overall these results suggest that HIV-1 has evolved mechanisms to take advantage of specific RNA editing activity of the host cell and disclose a stimulatory function of ADAR1 in the spread of HIV-1. PMID:19651874

  8. Viral persistence, latent reservoir, and blips: a review on HIV-1 dynamics and modeling during HAART and related treatment implications

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Libin [Los Alamos National Laboratory; Perelson, Alan [Los Alamos National Laboratory

    2008-01-01

    HIV-1 eradication from infected individuals has not been achieved with the use of highly active antiretroviral therapy (HAART) for a prolonged period of time. The cellular reservoir for HIV-1 in resting memory CD4{sup +} T cells remains a major obstacle to viral elimination. The reservoir does not decay significantly over long periods of time as is able to release replication competent HIV-1 upon cell activation. Residual ongoing viral replication may likely occur in many patients because low levels of virus can be detected in plasma by sensitive assays and transient episodes of viremia, or HIV-1 blips, are often observed in patients even with successful viral suppression for many years. Here we review our current knowledge of the factors contributing to viral persistence, the latent reservoir, and blips, and mathematical models developed to explore them and their relationships. We show how mathematical modeling can help improve our understanding of HIV-1 dynamics in patients on HAART and the quantitative events underlying HIV-1 latency, reservoir stability, low-level viremic persistence, and emergence of intermittent viral blips. We also discuss treatment implications related to these studies.

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

    Science.gov (United States)

    Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M; Vives-Pi, Marta; Esté, José A; Ballana, Ester

    2016-08-01

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

  10. Microplate-based assay for identifying small molecules that bind a specific intersubunit interface within the assembled HIV-1 capsid.

    Science.gov (United States)

    Halambage, Upul D; Wong, Jason P; Melancon, Bruce J; Lindsley, Craig W; Aiken, Christopher

    2015-09-01

    Despite the availability of >30 effective drugs for managing HIV-1 infection, no current therapy is curative, and long-term management is challenging owing to the emergence and spread of drug-resistant mutants. Identification of drugs against novel HIV-1 targets would expand the current treatment options and help to control resistance. The highly conserved HIV-1 capsid protein represents an attractive target because of its multiple roles in replication of the virus. However, the low antiviral potencies of the reported HIV-1 capsid-targeting inhibitors render them unattractive for therapeutic development. To facilitate the identification of more-potent HIV-1 capsid inhibitors, we developed a scintillation proximity assay to screen for small molecules that target a biologically active and specific intersubunit interface in the HIV-1 capsid. The assay, which is based on competitive displacement of a known capsid-binding small-molecule inhibitor, exhibited a signal-to-noise ratio of >9 and a Z factor of >0.8. In a pilot screen of a chemical library containing 2,400 druglike compounds, we obtained a hit rate of 1.8%. This assay has properties that are suitable for screening large compound libraries to identify novel HIV-1 capsid ligands with antiviral activity. PMID:26077250

  11. A Study on Placental Factors in the First,Second and Third Trimester against HIV-1 in Vitro%早、中、晚孕期胎盘因子体外抗HIV-1的研究

    Institute of Scientific and Technical Information of China (English)

    李莉平; 康佳丽; 夏薇; 曾耀英

    2008-01-01

    Objective To systemically investigate the effects of PF in the first,second and third trimesters against HIV-1 infection in vitro,and to evaluate their possible roles in HIV-1 intrauterine infection.Methods Calcein-AM stained H9/HIV-1 ⅢB cells were treated with difierent concentrations of PF in the first,second and third trimesters respectively,which was then mixed with MT2 cells and put under fluorescent microscopy for detection of HIV-1-mediated syncytium formation.MT2 cells were treated with cell-free HIV-1 Ⅲ B,and then washed and cultured with different concentrations of PF in the first,second and third trimesters respectively.Furthcrly,the protecting effect of PFs against HIV-1-infected cells Was determined with MTT,viral replication Was evaluated by measurement of the levels of p24 antigen in culture supernatants with ELISA and the inhibition rate Was calculated.Results PFs did not suppress HIV-1-mediated syncytium formation,however,they significantly increased the viabilities of HIV-1-infected cells and the inhibition rates of p24 antigen levels.Moreover,their effects arrived at the highest in the first trimester,and decreased along with the progress of pregnancy.In addition,the anti-HIV-1 activities of PFs were dose-dependent.Conclusion PFs from placental cells can decrease HIV-1 infection in vitro,and may have an essential role in mducing HIV-1 vertical transmission via placenta.%目的:探讨早、中、晚孕期胎盘因子(PF)体外抗人免疫缺陷病毒-1(HTV-1)的作用及其在HIV-1垂直传播中可能的作用.方法:采用荧光染料Calcien-AM标记的H9/HIV-1 ⅢB分别与早、中、晚孕期不同稀释浓度的PF作用后,与MT2细胞混合培养,荧光显微镜下观察合胞体的形成;用游离的HIV-1 ⅢB感染MT2细胞,并分别与早、中、晚孕期不同稀释浓度的PF作用后,用MTT法检测HW-1感染细胞的存活率,用HIV-1 p24抗原试剂盒检测细胞培养上清中p24抗原含量的变化.结

  12. CD4+ T cell-mediated presentation of non-infectious HIV-1virion antigens to HIV-specific CD8+ T cells

    Institute of Scientific and Technical Information of China (English)

    XU Jian-qing; Franco Lori; Julianna Lisziewicz

    2006-01-01

    Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4+ T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals.Methods HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens.Results CD4+ T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8+ T cells. Cross presentation required the entry of HIV-1 to CD4+ T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4+mediated activation of HIV-specific CD8+ T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses.Conclusions One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4+ T cells cross presenting HIV-1 antigen to activate CD8+ T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1. Virions play a role in the immunopathogenesis of HIV-1 infection.

  13. Rhesus TRIM5α Disrupts the HIV-1 Capsid at the Inter­Hexamer Interfaces

    OpenAIRE

    Zhao, Gongpu; Ke, Danxia; Vu, Thomas; Ahn, Jinwoo; Shah, Vaibhav B.; Yang, Ruifeng; Aiken, Christopher; Charlton, Lisa M.; Gronenborn, Angela M.; Zhang, Peijun

    2011-01-01

    TRIM proteins play important roles in the innate immune defense against retroviral infection, including human immunodeficiency virus type-1 (HIV-1). Rhesus macaque TRIM5α (TRIM5αrh) targets the HIV-1 capsid and blocks infection at an early post-entry stage, prior to reverse transcription. Studies have shown that binding of TRIM5α to the assembled capsid is essential for restriction and requires the coiled-coil and B30.2/SPRY domains, but the molecular mechanism of restriction is not fully und...

  14. HIV-1 therapy with monoclonal antibody 3BNC117 elicits host immune responses against HIV-1

    OpenAIRE

    Schoofs, Till; Klein, Florian; Braunschweig, Malte; Kreider, Edward F.; Feldmann, Anna; Nogueira, Lilian; Oliveira, Thiago; Lorenzi, Julio C. C.; Parrish, Erica H.; Learn, Gerald H.; West, Anthony P.; Bjorkman, Pamela J.; Schlesinger, Sarah J.; Seaman, Michael S.; Czartoski, Julie

    2016-01-01

    3BNC117 is a broad and potent neutralizing antibody to HIV-1 that targets the CD4 binding site on the viral envelope spike. When administered passively, this antibody can prevent infection in animal models and suppress viremia in HIV-1–infected individuals. Here we report that HIV-1 immunotherapy with a single injection of 3BNC117 affects host antibody responses in viremic individuals. In comparison to untreated controls that showed little change in their neutralizing activity over a 6-month ...

  15. HIV-1 integrase inhibitor resistance and its clinical implications.

    Science.gov (United States)

    Blanco, Jose-Luis; Varghese, Vici; Rhee, Soo-Yon; Gatell, Jose M; Shafer, Robert W

    2011-05-01

    With the approval in 2007 of the first integrase inhibitor (INI), raltegravir, clinicians became better able to suppress virus replication in patients infected with human immunodeficiency virus type 1 (HIV-1) who were harboring many of the most highly drug-resistant viruses. Raltegravir also provided clinicians with additional options for first-line therapy and for the simplification of regimens in patients with stable virological suppression. Two additional INIs in advanced clinical development-elvitegravir and S/GSK1349572-may prove equally versatile. However, the INIs have a relatively low genetic barrier to resistance in that 1 or 2 mutations are capable of causing marked reductions in susceptibility to raltegravir and elvitegravir, the most well-studied INIs. This perspective reviews the genetic mechanisms of INI resistance and their implications for initial INI therapy, the treatment of antiretroviral-experienced patients, and regimen simplification. PMID:21459813

  16. HIV-1 Quasispecies Delineation by Tag Linkage Deep Sequencing

    Science.gov (United States)

    Wu, Nicholas C.; De La Cruz, Justin; Al-Mawsawi, Laith Q.; Olson, C. Anders; Qi, Hangfei; Luan, Harding H.; Nguyen, Nguyen; Du, Yushen; Le, Shuai; Wu, Ting-Ting; Li, Xinmin; Lewis, Martha J.; Yang, Otto O.; Sun, Ren

    2014-01-01

    Trade-offs between throughput, read length, and error rates in high-throughput sequencing limit certain applications such as monitoring viral quasispecies. Here, we describe a molecular-based tag linkage method that allows assemblage of short sequence reads into long DNA fragments. It enables haplotype phasing with high accuracy and sensitivity to interrogate individual viral sequences in a quasispecies. This approach is demonstrated to deduce ∼2000 unique 1.3 kb viral sequences from HIV-1 quasispecies in vivo and after passaging ex vivo with a detection limit of ∼0.005% to ∼0.001%. Reproducibility of the method is validated quantitatively and qualitatively by a technical replicate. This approach can improve monitoring of the genetic architecture and evolution dynamics in any quasispecies population. PMID:24842159

  17. HIV-1 Nef: Taking Control of Protein Trafficking.

    Science.gov (United States)

    Pereira, Estela A; daSilva, Luis L P

    2016-09-01

    The Nef protein of the human immunodeficiency virus is a crucial determinant of viral pathogenesis and disease progression. Nef is abundantly expressed early in infection and is thought to optimize the cellular environment for viral replication. Nef controls expression levels of various cell surface molecules that play important roles in immunity and virus life cycle, by directly interfering with the itinerary of these proteins within the endocytic and late secretory pathways. To exert these functions, Nef physically interacts with host proteins that regulate protein trafficking. In recent years, considerable progress was made in identifying host-cell-interacting partners for Nef, and the molecular machinery used by Nef to interfere with protein trafficking has started to be unraveled. Here, we briefly review the knowledge gained and discuss new findings regarding the mechanisms by which Nef modifies the intracellular trafficking pathways to prevent antigen presentation, facilitate viral particle release and enhance the infectivity of HIV-1 virions. PMID:27161574

  18. Development and identification of a novel anti-HIV-1 peptide derived by modification of the N-terminal domain of HIV-1 integrase

    Directory of Open Access Journals (Sweden)

    Marina eSala

    2016-06-01

    Full Text Available The viral enzyme integrase (IN is essential for the replication of human immunodeficiency virus type 1 (HIV-1 and represents an important target for the development of new antiretroviral drugs. In this study, we focused on the N-terminal domain (NTD, which is mainly involved into protein oligomerization process, for the development and synthesis of a library of overlapping peptide sequences, with specific length and specific offset covering the entire native protein sequence NTD IN 1-50. The most potent fragment, VVAKEIVAH (peptide 18, which includes a His residue instead of the natural Ser at position 39, inhibits the HIV-1 IN activity with an IC50 value of 4.5 M. Amino acid substitution analysis on this peptide revealed essential residues for activity and allowed us to identify two nonapeptides (peptides 24 and 25, that show a potency of inhibition similar to the one of peptide 18. Interestingly, peptide 18 does not interfere with the dynamic interplay between IN subunits, while peptides 24 and 25 modulated these interactions in different manners. In fact, peptide 24 inhibited the IN-IN dimerization, while peptide 25 promoted IN multimerization, with IC50 values of 32 and 4.8 µM, respectively. In addition, peptide 25 has shown to have selective anti-infective cell activity for HIV-1. These results confirmed peptide 25 as a hit for further development of new chemotherapeutic agents against HIV-1.

  19. Development and Identification of a Novel Anti-HIV-1 Peptide Derived by Modification of the N-Terminal Domain of HIV-1 Integrase

    Science.gov (United States)

    Sala, Marina; Spensiero, Antonia; Esposito, Francesca; Scala, Maria C.; Vernieri, Ermelinda; Bertamino, Alessia; Manfra, Michele; Carotenuto, Alfonso; Grieco, Paolo; Novellino, Ettore; Cadeddu, Marta; Tramontano, Enzo; Schols, Dominique; Campiglia, Pietro; Gomez-Monterrey, Isabel M.

    2016-01-01

    The viral enzyme integrase (IN) is essential for the replication of human immunodeficiency virus type 1 (HIV-1) and represents an important target for the development of new antiretroviral drugs. In this study, we focused on the N-terminal domain (NTD), which is mainly involved into protein oligomerization process, for the development and synthesis of a library of overlapping peptide sequences, with specific length and specific offset covering the entire native protein sequence NTD IN 1–50. The most potent fragment, VVAKEIVAH (peptide 18), which includes a His residue instead of the natural Ser at position 39, inhibits the HIV-1 IN activity with an IC50 value of 4.5 μM. Amino acid substitution analysis on this peptide revealed essential residues for activity and allowed us to identify two nonapeptides (peptides 24 and 25), that show a potency of inhibition similar to the one of peptide 18. Interestingly, peptide 18 does not interfere with the dynamic interplay between IN subunits, while peptides 24 and 25 modulated these interactions in different manners. In fact, peptide 24 inhibited the IN-IN dimerization, while peptide 25 promoted IN multimerization, with IC50 values of 32 and 4.8 μM, respectively. In addition, peptide 25 has shown to have selective anti-infective cell activity for HIV-1. These results confirmed peptide 25 as a hit for further development of new chemotherapeutic agents against HIV-1. PMID:27375570

  20. Pyrazolo[1,5-a]pyrimidine-based macrocycles as novel HIV-1 inhibitors: a patent evaluation of WO2015123182.

    Science.gov (United States)

    Sun, Lin; Gao, Ping; Zhan, Peng; Liu, Xinyong

    2016-09-01

    The emergence of drug resistance in Combination Antiretroviral Therapy (cART) confirms a continuing need to investigate novel HIV-1 inhibitors with unexplored mechanisms of action. Recently, a series of pyrazolopyrimidine-based macrocyclic compounds were reported as inhibitors of HIV-1 replication disclosed in the patent WO2015123182. Most of the disclosed compounds possessed in vitro antiviral potency in single-digit nanomolar range, which were determined by MT-2 cell assay. Then, the structural diversity, pharmacophore similarity of HIV-1 IN-LEDGF/p75 inhibitors, and implications for drug design were analyzed. In the end of this article, a glimpse of some macrocycles as potent antiviral agents (drug candidates) was provided. Some strategies and technologies enabling macrocycle design were also described. We expect that further development of these macrocyclic compounds will offer new anti-HIV-1 drug candidates. PMID:27398994

  1. Alterations in the nuclear proteome of HIV-1 infected T-cells

    International Nuclear Information System (INIS)

    Virus infection of a cell involves the appropriation of host factors and the innate defensive response of the cell. The identification of proteins critical for virus replication may lead to the development of novel, cell-based inhibitors. In this study we mapped the changes in T-cell nuclei during human immunodeficiency virus type 1 (HIV-1) at 20 hpi. Using a stringent data threshold, a total of 13 and 38 unique proteins were identified in infected and uninfected cells, respectively, across all biological replicates. An additional 15 proteins were found to be differentially regulated between infected and control nuclei. STRING analysis identified four clusters of protein–protein interactions in the data set related to nuclear architecture, RNA regulation, cell division, and cell homeostasis. Immunoblot analysis confirmed the differential expression of several proteins in both C8166-45 and Jurkat E6-1 T-cells. These data provide a map of the response in host cell nuclei upon HIV-1 infection. - Highlights: • We identify changes in the expression of nuclear proteins during HIV-1 infection. • 163 nuclear proteins were found differentially regulated during HIV-1 infection. • Bioinformatic analysis identified several nuclear pathways altered by HIV infection. • Candidate factors were validated in two independent cell lines

  2. Alterations in the nuclear proteome of HIV-1 infected T-cells

    Energy Technology Data Exchange (ETDEWEB)

    DeBoer, Jason [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Jagadish, Teena; Haverland, Nicole A. [Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 (United States); Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); Ciborowski, Pawel [Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198 (United States); The Nebraska Center for Virology, University of Nebraska, Lincoln 68583 (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178 (United States); The Nebraska Center for Virology, University of Nebraska, Lincoln 68583 (United States)

    2014-11-15

    Virus infection of a cell involves the appropriation of host factors and the innate defensive response of the cell. The identification of proteins critical for virus replication may lead to the development of novel, cell-based inhibitors. In this study we mapped the changes in T-cell nuclei during human immunodeficiency virus type 1 (HIV-1) at 20 hpi. Using a stringent data threshold, a total of 13 and 38 unique proteins were identified in infected and uninfected cells, respectively, across all biological replicates. An additional 15 proteins were found to be differentially regulated between infected and control nuclei. STRING analysis identified four clusters of protein–protein interactions in the data set related to nuclear architecture, RNA regulation, cell division, and cell homeostasis. Immunoblot analysis confirmed the differential expression of several proteins in both C8166-45 and Jurkat E6-1 T-cells. These data provide a map of the response in host cell nuclei upon HIV-1 infection. - Highlights: • We identify changes in the expression of nuclear proteins during HIV-1 infection. • 163 nuclear proteins were found differentially regulated during HIV-1 infection. • Bioinformatic analysis identified several nuclear pathways altered by HIV infection. • Candidate factors were validated in two independent cell lines.

  3. HIV-1 Nef: a multifaceted modulator of T cell receptor signaling

    Directory of Open Access Journals (Sweden)

    Abraham Libin

    2012-12-01

    Full Text Available Abstract Nef, an accessory protein of the Human Immunodeficiency Virus type 1 (HIV-1, is dispensable for viral replication in cell culture, but promotes virus replication and pathogenesis in the infected host. Acting as protein-interaction adaptor, HIV-1 Nef modulates numerous target cell activities including cell surface receptor expression, cytoskeletal remodeling, vesicular transport, and signal transduction. In infected T-lymphocytes, altering T-cell antigen receptor (TCR signaling has long been recognized as one key function of the viral protein. However, reported effects of Nef range from inhibition to activation of this cascade. Recent advances in the field begin to explain these seemingly contradictory observations and suggest that Nef alters intracellular trafficking of TCR proximal machinery to disrupt plasma membrane bound TCR signaling while at the same time, the viral protein induces localized signal transduction at the trans-Golgi network. This review summarizes these new findings on how HIV-1 Nef reprograms TCR signalling output from a broad response to selective activation of the RAS-Erk pathway. We also discuss the implications of these alterations in the context of HIV-1 infection and in light of current concepts of TCR signal transduction.

  4. Immunodeficient Parameters in the HIV-1 Transgenic Rat Model

    OpenAIRE

    Chang, Sulie L.; Frank Ocasio; Joseq A. Beltran

    2007-01-01

    Recently an HIV-1 transgenic (HIV-1Tg) rat model was created that carries a gag-pol-deleted HIV-1 genome under the control of the HIV-1 viral promoter. However, other viral proteins are expressed in most organs and tissues, and are found in the circulating blood. Since HIV-1 targets the immune system in humans, we examined two immunological parameters, leukocyte-endothelial adhesion (LEA) and inflammatory cytokine production, in 5 mo old HIV-1Tg rats to identify immune functions that may be i...

  5. The role of lysine 186 in HIV-1 integrase multimerization

    International Nuclear Information System (INIS)

    HIV-1 integrase (IN) catalyzes biochemical reactions required for viral cDNA insertion into host cell chromosomal DNA, an essential step in the HIV-1 replication cycle. In one of these reactions, the two ends of the linear viral cDNA are believed to be simultaneously ligated to chromosomal DNA by a tetrameric form of IN. The structure of the full-length IN tetramer is not known but a model consisting of the N-terminal domain and the catalytic core revealed basic residues 186 to 188 at the interface between the two IN dimers. We found that alteration of these residues, in particular changing IN lysine residue 186 to glutamate (K186Q), impairs IN oligomerization in the yeast two-hybrid system and decreases oligomeric forms of IN within virions. When expressed independently of other viral proteins in human cells, IN-K186Q did not concentrate in the nucleus as did wild-type IN. Co-expression of wild-type IN restored the multimerization defects of IN-K186Q, in both the two-hybrid system and in virions, and also rescued the nuclear targeting defects. Virions bearing IN-K186Q were not infectious in a single cycle of replication but when mixed virions containing two different IN mutants were produced, IN-K186Q was capable of complementing the catalytically inactive mutant IN-D116A. Our biochemical and functional data support the crystallographic model in which IN residue K186 lies at the interface between IN dimers and suggest that tetramerization is important, not only for concerted integration, but also for IN nuclear targeting

  6. HIV-1 Nef interaction influences the ATP-binding site of the Src-family kinase, Hck

    Directory of Open Access Journals (Sweden)

    Pene-Dumitrescu Teodora

    2012-03-01

    Full Text Available Abstract Background Nef is an HIV-1 accessory protein essential for viral replication and AIDS progression. Nef interacts with a multitude of host cell signaling partners, including members of the Src kinase family. Nef preferentially activates Hck, a Src-family kinase (SFK strongly expressed in macrophages and other HIV target cells, by binding to its regulatory SH3 domain. Recently, we identified a series of kinase inhibitors that preferentially inhibit Hck in the presence of Nef. These compounds also block Nef-dependent HIV replication, validating the Nef-SFK signaling pathway as an antiretroviral drug target. Our findings also suggested that by binding to the Hck SH3 domain, Nef indirectly affects the conformation of the kinase active site to favor inhibitor association. Results To test this hypothesis, we engineered a "gatekeeper" mutant of Hck with enhanced sensitivity to the pyrazolopyrimidine tyrosine kinase inhibitor, NaPP1. We also modified the RT loop of the Hck SH3 domain to enhance interaction of the kinase with Nef. This modification stabilized Nef:Hck interaction in solution-based kinase assays, as a way to mimic the more stable association that likely occurs at cellular membranes. Introduction of the modified RT loop rendered Hck remarkably more sensitive to activation by Nef, and led to a significant decrease in the Km for ATP as well as enhanced inhibitor potency. Conclusions These observations suggest that stable interaction with Nef may induce Src-family kinase active site conformations amenable to selective inhibitor targeting.

  7. Triterpene Derivatives that Inhibit Human Immunodeficiency Virus Type 1 Replication

    OpenAIRE

    Dorr, Casey R.; Yemets, Sergiy; Kolomitsyna, Oksana; Krasutsky, Pavel; Louis M. Mansky

    2011-01-01

    Triterpene derivatives were analyzed for anti-HIV-1 activity and for cellular toxicity. Betulinic aldehyde, betulinic nitrile, and morolic acid derivatives were identified to have anti-HIV-1 activity. These derivatives inhibit a late step in virus replication, likely virus maturation.

  8. Species-specific activity of HIV-1 Vpu and positive selection of tetherin transmembrane domain variants.

    Directory of Open Access Journals (Sweden)

    Matthew W McNatt

    2009-02-01

    Full Text Available Tetherin/BST-2/CD317 is a recently identified antiviral protein that blocks the release of nascent retrovirus, and other virus, particles from infected cells. An HIV-1 accessory protein, Vpu, acts as an antagonist of tetherin. Here, we show that positive selection is evident in primate tetherin sequences and that HIV-1 Vpu appears to have specifically adapted to antagonize variants of tetherin found in humans and chimpanzees. Tetherin variants found in rhesus macaques (rh, African green monkeys (agm and mice were able to inhibit HIV-1 particle release, but were resistant to antagonism by HIV-1 Vpu. Notably, reciprocal exchange of transmembrane domains between human and monkey tetherins conferred sensitivity and resistance to Vpu, identifying this protein domain as a critical determinant of Vpu function. Indeed, differences between hu-tetherin and rh-tetherin at several positions in the transmembrane domain affected sensitivity to antagonism by Vpu. Two alterations in the hu-tetherin transmembrane domain, that correspond to differences found in rh- and agm-tetherin proteins, were sufficient to render hu-tetherin completely resistant to HIV-1 Vpu. Interestingly, transmembrane and cytoplasmic domain sequences in primate tetherins exhibit variation at numerous codons that is likely the result of positive selection, and some of these changes coincide with determinants of HIV-1 Vpu sensitivity. Overall, these data indicate that tetherin could impose a barrier to viral zoonosis as a consequence of positive selection that has been driven by ancient viral antagonists, and that the HIV-1 Vpu protein has specialized to target the transmembrane domains found in human/chimpanzee tetherin proteins.

  9. Safety and immunogenicity of therapeutic DNA vaccination in individuals treated with antiretroviral therapy during acute/early HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Eric S Rosenberg

    Full Text Available BACKGROUND: An effective therapeutic vaccine that could augment immune control of HIV-1 replication may abrogate or delay the need for antiretroviral therapy. AIDS Clinical Trials Group (ACTG A5187 was a phase I/II, randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of an HIV-1 DNA vaccine (VRC-HVDNA 009-00-VP in subjects treated with antiretroviral therapy during acute/early HIV-1 infection. (clinicaltrials.gov NCT00125099 METHODS: Twenty healthy HIV-1 infected subjects who were treated with antiretroviral therapy during acute/early HIV-1 infection and had HIV-1 RNA<50 copies/mL were randomized to receive either vaccine or placebo. The objectives of this study were to evaluate the safety and immunogenicity of the vaccine. Following vaccination, subjects interrupted antiretroviral treatment, and set-point HIV-1 viral loads and CD4 T cell counts were determined 17-23 weeks after treatment discontinuation. RESULTS: Twenty subjects received all scheduled vaccinations and discontinued antiretroviral therapy at week 30. No subject met a primary safety endpoint. No evidence of differences in immunogenicity were detected in subjects receiving vaccine versus placebo. There were also no significant differences in set-point HIV-1 viral loads or CD4 T cell counts following treatment discontinuation. Median set-point HIV-1 viral loads after treatment discontinuation in vaccine and placebo recipients were 3.5 and 3.7 log(10 HIV-1 RNA copies/mL, respectively. CONCLUSIONS: The HIV-1 DNA vaccine (VRC-HIVDNA 009-00-VP was safe but poorly immunogenic in subjects treated with antiretroviral therapy during acute/early HIV-1 infection. Viral set-points were similar between vaccine and placebo recipients following treatment interruption. However, median viral load set-points in both groups were lower than in historical controls, suggesting a possible role for antiretroviral therapy in persons with acute or early HIV-1

  10. RING domain mutations uncouple TRIM5α restriction of HIV-1 from inhibition of reverse transcription and acceleration of uncoating.

    Science.gov (United States)

    Roa, Amanda; Hayashi, Fumiaki; Yang, Yang; Lienlaf, Maritza; Zhou, Jing; Shi, Jiong; Watanabe, Satoru; Kigawa, Takanori; Yokoyama, Shigeyuki; Aiken, Christopher; Diaz-Griffero, Felipe

    2012-02-01

    Rhesus TRIM5α (TRIM5α(rh)) is a cytosolic protein that potently restricts HIV-1 at an early postentry stage, prior to reverse transcription. The ability of TRIM5α(rh) to block HIV-1 infection has been correlated with a decrease of pelletable HIV-1 capsid during infection. To genetically dissect the ability of TRIM5α to block reverse transcription, we studied a set of TRIM5α(rh) RING domain mutants that potently restrict HIV-1 but allow the occurrence of reverse transcription. These TRIM5α(rh) RING variants blocked HIV-1 infection after reverse transcription but prior to integration, as suggested by the routing of nuclear viral DNA to circularization in the form of 2-long terminal repeat (2-LTR) circles. The folding of RING domain variants was similar to that of the wild type, as evaluated by nuclear magnetic resonance. RING domain changes that allowed the occurrence of reverse transcription were impaired in their ability to decrease the amount of pelletable capsid compared with wild-type TRIM5α. Similar effects of this particular group of mutations were observed with human TRIM5α inhibition of N-tropic murine leukemia virus (N-MLV). Interestingly, TRIM5α(rh) RING domain variants also prevented the degradation of TRIM5α(rh) that occurs following cell entry of HIV-1. These data correlated the block of reverse transcription with the ability of TRIM5α to accelerate uncoating. Collectively, these results suggest that TRIM5α(rh) blocks HIV-1 reverse transcription by inducing premature viral uncoating in target cells. PMID:22114335

  11. Tyrosine-sulfated V2 peptides inhibit HIV-1 infection via coreceptor mimicry.

    Science.gov (United States)

    Cimbro, Raffaello; Peterson, Francis C; Liu, Qingbo; Guzzo, Christina; Zhang, Peng; Miao, Huiyi; Van Ryk, Donald; Ambroggio, Xavier; Hurt, Darrell E; De Gioia, Luca; Volkman, Brian F; Dolan, Michael A; Lusso, Paolo

    2016-08-01

    Tyrosine sulfation is a post-translational modification that facilitates protein-protein interaction. Two sulfated tyrosines (Tys173 and Tys177) were recently identified within the second variable (V2) loop of the major HIV-1 envelope glycoprotein, gp120, and shown to contribute to stabilizing the intramolecular interaction between V2 and the third variable (V3) loop. Here, we report that tyrosine-sulfated peptides derived from V2 act as structural and functional mimics of the CCR5 N-terminus and potently block HIV-1 infection. Nuclear magnetic and surface plasmon resonance analyses indicate that a tyrosine-sulfated V2 peptide (pV2α-Tys) adopts a CCR5-like helical conformation and directly interacts with gp120 in a CD4-dependent fashion, competing with a CCR5 N-terminal peptide. Sulfated V2 mimics, but not their non-sulfated counterparts, inhibit HIV-1 entry and fusion by preventing coreceptor utilization, with the highly conserved C-terminal sulfotyrosine, Tys177, playing a dominant role. Unlike CCR5 N-terminal peptides, V2 mimics inhibit a broad range of HIV-1 strains irrespective of their coreceptor tropism, highlighting the overall structural conservation of the coreceptor-binding site in gp120. These results document the use of receptor mimicry by a retrovirus to occlude a key neutralization target site and provide leads for the design of therapeutic strategies against HIV-1. PMID:27389109

  12. Epigenetic modulations in activated cells early after HIV-1 infection and their possible functional consequences.

    Directory of Open Access Journals (Sweden)

    Juliana T Maricato

    Full Text Available Epigenetic modifications refer to a number of biological processes which alter the structure of chromatin and its transcriptional activity such as DNA methylation and histone post-translational processing. Studies have tried to elucidate how the viral genome and its products are affected by epigenetic modifications imposed by cell machinery and how it affects the ability of the virus to either, replicate and produce a viable progeny or be driven to latency. The purpose of this study was to evaluate epigenetic modifications in PBMCs and CD4+ cells after HIV-1 infection analyzing three approaches: (i global DNA- methylation; (ii qPCR array and (iii western blot. HIV-1 infection led to methylation increases in the cellular DNA regardless the activation status of PBMCs. The analysis of H3K9me3 and H3K27me3 suggested a trend towards transcriptional repression in activated cells after HIV-1 infection. Using a qPCR array, we detected genes related to epigenetic processes highly modulated in activated HIV-1 infected cells. SETDB2 and RSK2 transcripts showed highest up-regulation levels. SETDB2 signaling is related to transcriptional silencing while RSK2 is related to either silencing or activation of gene expression depending on the signaling pathway triggered down-stream. In addition, activated cells infected by HIV-1 showed lower CD69 expression and a decrease of IL-2, IFN-γ and metabolism-related factors transcripts indicating a possible functional consequence towards global transcriptional repression found in HIV-1 infected cells. Conversely, based on epigenetic markers studied here, non-stimulated cells infected by HIV-1, showed signs of global transcriptional activation. Our results suggest that HIV-1 infection exerts epigenetic modulations in activated cells that may lead these cells to transcriptional repression with important functional consequences. Moreover, non-stimulated cells seem to increase gene transcription after HIV-1 infection

  13. Discovery of novel inhibitors of HIV-1 reverse transcriptase through virtual screening of experimental and theoretical ensembles.

    Science.gov (United States)

    Ivetac, Anthony; Swift, Sara E; Boyer, Paul L; Diaz, Arturo; Naughton, John; Young, John A T; Hughes, Stephen H; McCammon, J Andrew

    2014-05-01

    Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are potent anti-HIV chemotherapeutics. Although there are FDA-approved NNRTIs, challenges such as the development of resistance have limited their utility. Here, we describe the identification of novel NNRTIs through a combination of computational and experimental approaches. Based on the known plasticity of the NNRTI binding pocket (NNIBP), we adopted an ensemble-based virtual screening strategy: coupling receptor conformations from 10 X-ray crystal structures with 120 snapshots from a total of 480 ns of molecular dynamics (MD) trajectories. A screening library of 2864 National Cancer Institute (NCI) compounds was built and docked against the ensembles in a hierarchical fashion. Sixteen diverse compounds were tested for their ability to block HIV infection in human tissue cultures using a luciferase-based reporter assay. Three promising compounds were further characterized, using a HIV-1 RT-based polymerase assay, to determine the specific mechanism of inhibition. We found that 2 of the three compounds inhibited the polymerase activity of RT (with potency similar to the positive control, the FDA-approved drug nevirapine). Through a computational approach, we were able to discover two compounds which inhibit HIV replication and block the activity of RT, thus offering the potential for optimization into mature inhibitors. PMID:24405985

  14. Intracellular interactions between APOBEC3G, RNA, and HIV-1 Gag: APOBEC3G multimerization is dependent on its association with RNA

    Directory of Open Access Journals (Sweden)

    Friew Yeshitila N

    2009-06-01

    Full Text Available Abstract Background Host restriction factor APOBEC3G (A3G blocks human immunodeficiency virus type 1 (HIV-1 replication by G-to-A hypermutation, and by inhibiting DNA synthesis and provirus formation. Previous reports have suggested that A3G is a dimer and its virion incorporation is mediated through interactions with viral or nonviral RNAs and/or HIV-1 Gag. We have now employed a bimolecular fluorescence complementation assay (BiFC to analyze the intracellular A3G-A3G, A3G-RNA, and A3G-Gag interactions in living cells by reconstitution of yellow fluorescent protein (YFP from its N- or C-terminal fragments. Results The results obtained with catalytic domain 1 and 2 (CD1 and CD2 mutants indicate that A3G-A3G and A3G-Gag multimerization is dependent on an intact CD1 domain, which is required for RNA binding. A mutant HIV-1 Gag that exhibits reduced RNA binding also failed to reconstitute BiFC with wild-type A3G, indicating a requirement for both HIV-1 Gag and A3G to bind to RNA for their multimerization. Addition of a non-specific RNA binding peptide (P22 to the N-terminus of a CD1 mutant of A3G restored BiFC and virion incorporation, but failed to inhibit viral replication, indicating that the mutations in CD1 resulted in additional defects that interfere with A3G's antiviral activity. Conclusion These studies establish a robust BiFC assay for analysis of intracellular interactions of A3G with other macromolecules. The results indicate that in vivo A3G is a monomer that forms multimers upon binding to RNA. In addition, we observed weak interactions between wild-type A3G molecules and RNA binding-defective mutants of A3G, which could explain previously described protein-protein interactions between purified A3G molecules.

  15. Novel HIV-1 Therapeutics through Targeting Altered Host Cell Pathways

    OpenAIRE

    Coley, William; Kehn-Hall, Kylene; Van Duyne, Rachel; KASHANCHI, FATAH

    2009-01-01

    The emergence of drug-resistant human immunodeficiency virus type I (HIV-1) strains presents a challenge for the design of new drugs. Anti-HIV compounds currently in use are the subject of advanced clinical trials using either HIV-1 reverse-transcriptase, viral protease, or integrase inhibitors. Recent studies show an increase in the number of HIV-1 variants resistant to anti-retroviral agents in newly infected individuals. Targeting host cell factors involved in the regulation of HIV-1 repli...

  16. Identifying and Characterizing a Functional HIV-1 Reverse Transcriptase-binding Site on Integrase*

    OpenAIRE

    Wilkinson, Thomas A.; Januszyk, Kurt; Phillips, Martin L.; Tekeste, Shewit S.; Zhang, Min; Miller, Jennifer T.; Stuart F. J. Le Grice; Clubb, Robert T.; Chow, Samson A

    2009-01-01

    Integrase (IN) from human immunodeficiency virus, type 1 (HIV-1) exerts pleiotropic effects in the viral replication cycle. Besides integration, IN mutations can impact nuclear import, viral maturation, and reverse transcription. IN and reverse transcriptase (RT) interact in vitro, and the IN C-terminal domain (CTD) is both necessary and sufficient for binding RT. We used nuclear magnetic resonance spectroscopy to identify a putative RT-binding surface on the IN CTD, a...

  17. HIV-1 Mutation and Recombination Rates Are Different in Macrophages and T-cells

    OpenAIRE

    Deborah Cromer; Schlub, Timothy E.; Smyth, Redmond P.; Grimm, Andrew J.; Abha Chopra; Simon Mallal; Davenport, Miles P.; Johnson Mak

    2016-01-01

    High rates of mutation and recombination help human immunodeficiency virus (HIV) to evade the immune system and develop resistance to antiretroviral therapy. Macrophages and T-cells are the natural target cells of HIV-1 infection. A consensus has not been reached as to whether HIV replication results in differential recombination between primary T-cells and macrophages. Here, we used HIV with silent mutation markers along with next generation sequencing to compare the mutation and the recombi...

  18. Coevolutionary Analysis Identifies Protein–Protein Interaction Sites between HIV-1 Reverse Transcriptase and Integrase

    OpenAIRE

    Arachchilage, Madara Hetti; Piontkivska, Helen

    2016-01-01

    The replication of human immunodeficiency virus-1 (HIV-1) requires reverse transcription of the viral RNA genome and integration of newly synthesized pro-viral DNA into the host genome. This is mediated by the viral proteins reverse transcriptase (RT) and integrase (IN). The formation and stabilization of the pre-integration complex (PIC), which is an essential step for reverse transcription, nuclear import, chromatin targeting, and subsequent integration, involves direct and indirect modes o...

  19. Construction of Nef-positive doxycycline-dependent HIV-1 variants using bicistronic expression elements.

    Science.gov (United States)

    van der Velden, Yme U; Kleibeuker, Wendy; Harwig, Alex; Klaver, Bep; Siteur-van Rijnstra, Esther; Frankin, Esmay; Berkhout, Ben; Das, Atze T

    2016-01-15

    Conditionally replicating HIV-1 variants that can be switched on and off at will are attractive tools for HIV research. We previously developed a genetically modified HIV-1 variant that replicates exclusively when doxycycline (dox) is administered. The nef gene in this HIV-rtTA variant was replaced with the gene encoding the dox-dependent rtTA transcriptional activator. Because loss of Nef expression compromises virus replication in primary cells and precludes studies on Nef function, we tested different approaches to restore Nef production in HIV-rtTA. Strategies that involved translation via an EMCV or synthetic internal ribosome entry site (IRES) failed because these elements were incompatible with efficient virus replication. Fusion protein approaches with the FMDV 2A peptide and human ubiquitin were successful and resulted in genetically-stable Nef-expressing HIV-rtTA strains that replicate more efficiently in primary T-cells and human immune system (HIS) mice than Nef-deficient variants, thus confirming the positive effect of Nef on in vivo virus replication. PMID:26615334

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

    NARCIS (Netherlands)

    T.L.G.M. van den Kerkhof

    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 bi

  1. HIV-1病毒储存库的特征及检测方法%The characteristics and the detection approach of HIV-1 latency

    Institute of Scientific and Technical Information of China (English)

    焦艳梅; 吴昊

    2009-01-01

    Although HIV-1 can replicate continuously in untreated patients, it can also be hidden in the intracellular to evade the host immune clearance, that is latent vires. As the latent virus is a challenge to antiviral treatment, it has been paid great attention. In this article, the establishment of the latent virus and detection in vivo are reviewed.%HIV-1在未治疗的艾滋病患者体内,虽可持续复制,但也可潜伏在细胞内以逃避宿主的免疫清除,这一现象即病毒潜伏.由于病毒潜伏对抗病毒治疗带来了挑战,也引起人们的高度关注.此文就病毒储存库的建立和体内潜伏感染细胞的检测等进行综述.

  2. Control of HIV-1 env RNA splicing and transport: investigating the role of hnRNP A1 in exon splicing silencer (ESS3a) function

    International Nuclear Information System (INIS)

    The control of HIV-1 viral RNA splicing and transport plays an important role in the successful replication of the virus. Previous studies have identified both an exon splicing enhancer (ESE) and a bipartite exon splicing silencer (ESS3a and ESS3b) within the terminal exon of HIV-1 that are involved in modulating both splicing and Rev-mediated export of viral RNA. To define the mechanism of ESS3a function, experiments were carried out to better define the cis and trans components required for ESS3a activity. Mutations throughout the 30-nt element resulted in partial loss of ESS function. Combining mutations was found to have an additive effect, suggesting the presence of multiple binding sites. Analysis of interacting factors identified hnRNP A1 as one component of the complex that modulates ESS3a activity. However, subsequent binding analyses determined that hnRNP A1 interacts with only one portion of ESS3a, suggesting the involvement of another host factor. Parallel analysis of the effect of the mutations on Rev-mediated export determined that there is not a direct correlation between the effect of the mutations on splicing and RNA transport. Consistent with this hypothesis, replacement of ESS3a with consensus hnRNP A1 binding sites was found to be insufficient to block Rev-mediated RNA export

  3. The kinase inhibitor SFV785 dislocates dengue virus envelope protein from the replication complex and blocks virus assembly.

    Directory of Open Access Journals (Sweden)

    Azlinda Anwar

    Full Text Available Dengue virus (DENV is the etiologic agent for dengue fever, for which there is no approved vaccine or specific anti-viral drug. As a remedy for this, we explored the use of compounds that interfere with the action of required host factors and describe here the characterization of a kinase inhibitor (SFV785, which has selective effects on NTRK1 and MAPKAPK5 kinase activity, and anti-viral activity on Hepatitis C, DENV and yellow fever viruses. SFV785 inhibited DENV propagation without inhibiting DENV RNA synthesis or translation. The compound did not cause any changes in the cellular distribution of non-structural 3, a protein critical for DENV RNA synthesis, but altered the distribution of the structural envelope protein from a reticulate network to enlarged discrete vesicles, which altered the co-localization with the DENV replication complex. Ultrastructural electron microscopy analyses of DENV-infected SFV785-treated cells showed the presence of viral particles that were distinctly different from viable enveloped virions within enlarged ER cisternae. These viral particles were devoid of the dense nucleocapsid. The secretion of the viral particles was not inhibited by SFV785, however a reduction in the amount of secreted infectious virions, DENV RNA and capsid were observed. Collectively, these observations suggest that SFV785 inhibited the recruitment and assembly of the nucleocapsid in specific ER compartments during the DENV assembly process and hence the production of infectious DENV. SFV785 and derivative compounds could be useful biochemical probes to explore the DENV lifecycle and could also represent a new class of anti-virals.

  4. Identification of mechanistically distinct inhibitors of HIV-1 reverse transcriptase through fragment screening.

    Science.gov (United States)

    La, Jennifer; Latham, Catherine F; Tinetti, Ricky N; Johnson, Adam; Tyssen, David; Huber, Kelly D; Sluis-Cremer, Nicolas; Simpson, Jamie S; Headey, Stephen J; Chalmers, David K; Tachedjian, Gilda

    2015-06-01

    Fragment-based screening methods can be used to discover novel active site or allosteric inhibitors for therapeutic intervention. Using saturation transfer difference (STD) NMR and in vitro activity assays, we have identified fragment-sized inhibitors of HIV-1 reverse transcriptase (RT) with distinct chemical scaffolds and mechanisms compared to nonnucleoside RT inhibitors (NNRTIs) and nucleoside/nucleotide RT inhibitors (NRTIs). Three compounds were found to inhibit RNA- and DNA-dependent DNA polymerase activity of HIV-1 RT in the micromolar range while retaining potency against RT variants carrying one of three major NNRTI resistance mutations: K103N, Y181C, or G190A. These compounds also inhibit Moloney murine leukemia virus RT but not the Klenow fragment of Escherichia coli DNA polymerase I. Steady-state kinetic analyses demonstrate that one of these fragments is a competitive inhibitor of HIV-1 RT with respect to deoxyribonucleoside triphosphate (dNTP) substrate, whereas a second compound is a competitive inhibitor of RT polymerase activity with respect to the DNA template/primer (T/P), and consequently also inhibits RNase H activity. The dNTP competing RT inhibitor retains activity against the NRTI-resistant mutants K65R and M184V, demonstrating a drug resistance profile distinct from the nucleotide competing RT inhibitors indolopyridone-1 (INDOPY-1) and 4-dimethylamino-6-vinylpyrimidine-1 (DAVP-1). In antiviral assays, the T/P competing compound inhibits HIV-1 replication at a step consistent with an RT inhibitor. Screening of additional structurally related compounds to the three fragments led to the discovery of molecules with improved potency against HIV-1 RT. These fragment inhibitors represent previously unidentified scaffolds for development of novel drugs for HIV-1 prevention or treatment. PMID:26038551

  5. LILRB2 interaction with HLA class I correlates with control of HIV-1 infection.

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    Arman A Bashirova

    2014-03-01

    Full Text Available Natural progression of HIV-1 infection depends on genetic variation in the human major histocompatibility complex (MHC class I locus, and the CD8+ T cell response is thought to be a primary mechanism of this effect. However, polymorphism within the MHC may also alter innate immune activity against human immunodeficiency virus type 1 (HIV-1 by changing interactions of human leukocyte antigen (HLA class I molecules with leukocyte immunoglobulin-like receptors (LILR, a group of immunoregulatory receptors mainly expressed on myelomonocytic cells including dendritic cells (DCs. We used previously characterized HLA allotype-specific binding capacities of LILRB1 and LILRB2 as well as data from a large cohort of HIV-1-infected individuals (N = 5126 to test whether LILR-HLA class I interactions influence viral load in HIV-1 infection. Our analyses in persons of European descent, the largest ethnic group examined, show that the effect of HLA-B alleles on HIV-1 control correlates with the binding strength between corresponding HLA-B allotypes and LILRB2 (p = 10(-2. Moreover, overall binding strength of LILRB2 to classical HLA class I allotypes, defined by the HLA-A/B/C genotypes in each patient, positively associates with viral replication in the absence of therapy in patients of both European (p = 10(-11-10(-9 and African (p = 10(-5-10(-3 descent. This effect appears to be driven by variations in LILRB2 binding affinities to HLA-B and is independent of individual class I allelic effects that are not related to the LILRB2 function. Correspondingly, in vitro experiments suggest that strong LILRB2-HLA binding negatively affects antigen-presenting properties of DCs. Thus, we propose an impact of LILRB2 on HIV-1 disease outcomes through altered regulation of DCs by LILRB2-HLA engagement.

  6. HIV-1 integrase inhibitors are substrates for the multidrug transporter MDR1-P-glycoprotein

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    Cara Andrea

    2007-03-01

    Full Text Available Abstract Background The discovery of diketoacid-containing derivatives as inhibitors of HIV-1 Integrase (IN (IN inhibitors, IINs has played a major role in validating this enzyme as an important target for antiretroviral therapy. Since the in vivo efficacy depends on access of these drugs to intracellular sites where HIV-1 replicates, we determined whether the IINs are recognized by the multidrug transporter MDR1-P-glycoprotein (P-gp thereby reducing their intracellular accumulation. To address the effect of IINs on drug transport, nine quinolonyl diketo acid (DKA derivatives active on the HIV-1 IN strand transfer (ST step and with EC50 ranging from 1.83 to >50 μm in cell-based assays were tested for their in vitro interaction with P-gp in the CEM-MDR cell system. IINs were investigated for the inhibition and induction of the P-gp function and expression as well as for multidrug resistance (MDR reversing ability. Results The HIV-1 IINs act as genuine P-gp substrates by inhibiting doxorubicin efflux and inducing P-gp functional conformation changes as evaluated by the modulation of UIC2 mAb epitope. Further, IINs chemosensitize MDR cells to vinblastine and induce P-gp expression in drug sensitive revertants of CEM-MDR cells. Conclusion To our knowledge, this is the first demonstration that HIV-1 IINs are P-gp substrates. This biological property may influence the absorption, distribution and elimination of these novels anti HIV-1 compounds.

  7. Microarray data on gene modulation by HIV-1 in immune cells: 2000-2006.

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    Giri, Malavika S; Nebozhyn, Michael; Showe, Louise; Montaner, Luis J

    2006-11-01

    Here, we review 34 HIV microarray studies in human immune cells over the period of 2000-March 2006 with emphasis on analytical approaches used and conceptual advances on HIV modulation of target cells (CD4 T cell, macrophage) and nontargets such as NK cell, B cell, and dendritic cell subsets. Results to date address advances on gene modulation associated with immune dysregulation, susceptibility to apoptosis, virus replication, and viral persistence following in vitro or in vivo infection/exposure to HIV-1 virus or HIV-1 accessory proteins. In addition to gene modulation associated with known functional correlates of HIV infection and replication (e.g., T cell apoptosis), microarray data have yielded novel, potential mechanisms of HIV-mediated pathogenesis such as modulation of cholesterol biosynthetic genes in CD4 T cells (relevant to virus replication and infectivity) and modulation of proteasomes and histone deacetylases in chronically infected cell lines (relevant to virus latency). Intrinsic challenges in summarizing gene modulation studies remain in development of sound approaches for comparing data obtained using different platforms and analytical tools, deriving unifying concepts to distil the large volumes of data collected, and the necessity to impose a focus for validation on a small fraction of genes. Notwithstanding these challenges, the field overall continues to demonstrate progress in expanding the pool of target genes validated to date in in vitro and in vivo datasets and understanding the functional correlates of gene modulation to HIV-1 pathogenesis in vivo. PMID:16940334

  8. NKT cells in HIV-1 infection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Natural killer T (NKT) cells are a unique T cell population that have important immunoregulatory functions and have been shown to be involved in host immunity against a range of microorganisms. It also emerges that they might play a role in HIV-1 infection, and therefore be selectively depleted during the early stages of infection. Recent studies are reviewed regarding the dynamics of NKT depletion during HIV-I infection and their recovery under highly active antiretrovirai treatment (HAART). Possible mechanisms for these changes are proposed based on the recent developments in HIV pathogenesis. Further discussions are focused on HIV's disruption of NKT activation by downregulating CDId expression on antigen presentation cells (APC). HIV-1 protein Nefis found to play the major role by interrupting the intraceilular trafficking of nascent and recycling CDId molecules.

  9. Intestinal microbiota and HIV-1 infection

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    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.