Journal articles: 'HIV-1 infectivity'

1

Fox, Philip C., Andy Wolff, Chih-Ko Yeh, Jane C. Atkinson, and Bruce J. Baum. "Saliva inhibits HIV-1 infectivity." Journal of the American Dental Association 116, no. 6 (May 1988): 635–37. http://dx.doi.org/10.14219/jada.archive.1988.0002.

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Maeda, Yosuke, Keisuke Yusa, and Shinji Harada. "Enhanced infectivity of HIV-1 by X4 HIV-1 coinfection." Biochemical and Biophysical Research Communications 308, no. 4 (September 2003): 906–13. http://dx.doi.org/10.1016/s0006-291x(03)01498-0.

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Hood, Joshua L., Andrew P. Jallouk, Nancy Campbell, Lee Ratner, and Samuel A. Wickline. "Cytolytic nanoparticles attenuate HIV-1 infectivity." Antiviral Therapy 18, no. 1 (2012): 95–103. http://dx.doi.org/10.3851/imp2346.

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Jones, Jennifer, William Whitford, Frederic Wagner, and Olaf Kutsch. "Optimization of HIV-1 infectivity assays." BioTechniques 43, no. 5 (November 2007): 589–94. http://dx.doi.org/10.2144/000112624.

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HAMMAR, LENA, IVAN HIRSCH, ALCYONE MACHADO, JEAN MAREUIL, JEAN BAILLON, and JEAN-CLAUDE CHERMANN. "Lectin Effects on HIV-1 Infectivity." Annals of the New York Academy of Sciences 724, no. 1 Slow Infectio (May 1994): 166–69. http://dx.doi.org/10.1111/j.1749-6632.1994.tb38907.x.

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Zhang, Jianyong, and Chen Liang. "BST-2 Diminishes HIV-1 Infectivity." Journal of Virology 84, no. 23 (September 22, 2010): 12336–43. http://dx.doi.org/10.1128/jvi.01228-10.

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ABSTRACT Bone marrow stromal cell antigen 2 (BST-2, also known as tetherin/CD317/HM1.24) inhibits the release of human immunodeficiency virus type 1 (HIV-1) and other enveloped viruses by tethering virus particles to the cell surface. In this study, we provide evidence not only that the yield of cell-free HIV-1 particles is significantly reduced by BST-2 but also that the infectivity of these progeny virions is severely impaired. The lowered virion infectivity is due to the accumulation of pr55 Gag precursor and the p40Gag intermediates as well as to the loss of a mature core in the majority of HIV-1 particles. These data suggest that, in addition to impeding the release of HIV-1 particles from host cells, BST-2 may also interfere with the activation of viral protease and, as a result, impairs viral Gag processing as well as maturation of HIV-1 particles.

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Konopka, K., B. R. Davis, C. E. Larsen, and N. Düzgünes. "Cardiolipin liposomes specifically inhibit HIV-1 infectivity." Antiviral Research 15 (April 1991): 68. http://dx.doi.org/10.1016/0166-3542(91)90131-a.

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Rapatski, Brandy L., Frederick Suppe, and James A. Yorke. "Reconciling Different Infectivity Estimates for HIV-1." JAIDS Journal of Acquired Immune Deficiency Syndromes 43, no. 3 (November 2006): 253–56. http://dx.doi.org/10.1097/01.qai.0000243095.19405.5c.

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Müller, Barbara, Maria Anders, Hisashi Akiyama, Sonja Welsch, Bärbel Glass, Krisztina Nikovics, Francois Clavel, Hanna-Mari Tervo, Oliver T. Keppler, and Hans-Georg Kräusslich. "HIV-1 Gag Processing Intermediates Trans-dominantly Interfere with HIV-1 Infectivity." Journal of Biological Chemistry 284, no. 43 (August 7, 2009): 29692–703. http://dx.doi.org/10.1074/jbc.m109.027144.

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Crombie, René, Roy L. Silverstein, Clarinda MacLow, S. Frieda A. Pearce, Ralph L. Nachman, and Jeffrey Laurence. "Identification of a CD36-related Thrombospondin 1–binding Domain in HIV-1 Envelope Glycoprotein gp120: Relationship to HIV-1–specific Inhibitory Factors in Human Saliva." Journal of Experimental Medicine 187, no. 1 (January 5, 1998): 25–35. http://dx.doi.org/10.1084/jem.187.1.25.

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Human and non–human primate salivas retard the infectivity of HIV-1 in vitro and in vivo. Because thrombospondin 1 (TSP1), a high molecular weight trimeric glycoprotein, is concentrated in saliva and can inhibit the infectivity of diverse pathogens in vitro, we sought to determine the role of TSP1 in suppression of HIV infectivity. Sequence analysis revealed a TSP1 recognition motif, previously defined for the CD36 gene family of cell adhesion receptors, in conserved regions flanking the disulfide-linked cysteine residues of the V3 loop of HIV envelope glycoprotein gp120, important for HIV binding to its high affinity cellular receptor CD4. Using solid-phase in vitro binding assays, we demonstrate direct binding of radiolabeled TSP1 to immobilized recombinant gp120. Based on peptide blocking experiments, the TSP1–gp120 interaction involves CSVTCG sequences in the type 1 properdin-like repeats of TSP1, the known binding site for CD36. TSP1 and fusion proteins derived from CD36-related TSP1-binding domains were able to compete with radiolabeled soluble CD4 binding to immobilized gp120. In parallel, purified TSP1 inhibited HIV-1 infection of peripheral blood mononuclear cells and transformed T and promonocytic cell lines. Levels of TSP1 required for both viral aggregation and direct blockade of HIV-1 infection were physiologic, and affinity depletion of salivary TSP1 abrogated >70% of the inhibitory effect of whole saliva on HIV infectivity. Characterization of TSP1–gp120 binding specificity suggests a mechanism for direct blockade of HIV infectivity that might be exploited to retard HIV transmission that occurs via mucosal routes.

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Balakrishnan, Kannan, Ananda Jaguva Vasudevan, Krishnaveni Mohareer, Tom Luedde, Carsten Münk, and Sharmistha Banerjee. "Encapsidation of Staufen-2 Enhances Infectivity of HIV-1." Viruses 13, no. 12 (December 8, 2021): 2459. http://dx.doi.org/10.3390/v13122459.

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Staufen, the RNA-binding family of proteins, affects various steps in the Human Immuno-Deficiency Virus (HIV-1) replication cycle. While our previous study established Staufen-2–HIV-1 Rev interaction and its role in augmenting nucleocytoplasmic export of RRE-containing viral RNA, viral incorporation of Staufen-2 and its effect on viral propagation were unknown. Here, we report that Staufen-2 interacts with HIV-1 Gag and is incorporated into virions and that encapsidated Staufen-2 boosted viral infectivity. Further, Staufen-2 gets co-packaged into virions, possibly by interacting with host factors Staufen-1 or antiviral protein APOBEC3G, which resulted in different outcomes on the infectivity of Staufen-2-encapsidated virions. These observations suggest that encapsidated host factors influence viral population dynamics and infectivity. With the explicit identification of the incorporation of Staufen proteins into HIV-1 and other retroviruses, such as Simian Immunodeficiency Virus (SIV), we propose that packaging of RNA binding proteins, such as Staufen, in budding virions of retroviruses is probably a general phenomenon that can drive or impact the viral population dynamics, infectivity, and evolution.

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Wei, Bangdong L., Paul W. Denton, Eduardo O'Neill, Tianci Luo, John L. Foster, and J. Victor Garcia. "Inhibition of Lysosome and Proteasome Function Enhances Human Immunodeficiency Virus Type 1 Infection." Journal of Virology 79, no. 9 (May 1, 2005): 5705–12. http://dx.doi.org/10.1128/jvi.79.9.5705-5712.2005.

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ABSTRACT We previously reported that inhibition of endosomal/lysosomal function can dramatically enhance human immunodeficiency virus type 1 (HIV-1) infectivity, suggesting that under these conditions productive HIV-1 infection can occur via the endocytic pathway. Here we further examined this effect with bafilomycin A1 (BFLA-1) and show that this enhancement of infectivity extends to all HIV-1 isolates tested regardless of coreceptor usage. However, isolate-specific differences were observed in the magnitude of the effect. This was particularly evident in the case of the weakly infectious HIV-1SF2, for which we observed the greatest enhancement. Using reciprocal chimeric viruses, we were able to determine that both the disproportionate increase in the infectivity of HIV-1SF2 in response to BFLA-1 and its weak infectivity in the absence of BFLA-1 mapped to its envelope gene. Further, we found HIV-1SF2 to have lower fusion activity and to be 12-fold more sensitive to the fusion inhibitor T-20 than HIV-1NL4-3. Proteasomal inhibitors also enhance HIV-1 infectivity, and we report that the combination of a lysosomal and a proteasomal inhibitor greatly enhanced infectivity of all isolates tested. Again, HIV-1SF2 was unique in exhibiting a synergistic 400-fold increase in infectivity. We also determined that inhibition of proteasomal function increased the infectivity of HIV-1 pseudotyped with vesicular stomatitis virus G protein. The evidence presented here highlights the important role of the lysosomes/proteasomes in the destruction of infectious HIV-1SF2 and could have implications for the development of novel antiviral agents that might take advantage of these innate defenses.

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Khan, Mahfuz, Lingling Jin, Ming Bo Huang, Lesa Miles, Vincent C. Bond, and Michael D. Powell. "Chimeric Human Immunodeficiency Virus Type 1 (HIV-1) Virions Containing HIV-2 or Simian Immunodeficiency Virus Nef Are Resistant to Cyclosporine Treatment." Journal of Virology 78, no. 4 (February 15, 2004): 1843–50. http://dx.doi.org/10.1128/jvi.78.4.1843-1850.2004.

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ABSTRACT The viral protein Nef and the cellular factor cyclophilin A are both required for full infectivity of human immunodeficiency virus type 1 (HIV-1) virions. In contrast, HIV-2 and simian immunodeficiency virus (SIV) do not incorporate cyclophilin A into virions or need it for full infectivity. Since Nef and cyclophilin A appear to act in similar ways on postentry events, we determined whether chimeric HIV-1 virions that contained either HIV-2 or SIV Nef would have a direct effect on cyclophilin A dependence. Our results show that chimeric HIV-1 virions containing either HIV-2 or SIV Nef are resistant to treatment by cyclosporine and enhance the infectivity of virions with mutations in the cyclophilin A binding loop of Gag. Amino acids at the C terminus of HIV-2 and SIV are necessary for inducing cyclosporine resistance. However, transferring these amino acids to the C terminus of HIV-1 Nef is insufficient to induce cyclosporine resistance in HIV-1. These results suggest that HIV-2 and SIV Nef are able to compensate for the need for cyclophilin A for full infectivity and that amino acids present at the C termini of these proteins are important for this function.

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14

Nara, P. L., and P. J. Fischinger. "Quantitative infectivity assay for HIV-1 and -2." Nature 332, no. 6163 (March 1988): 469–70. http://dx.doi.org/10.1038/332469a0.

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15

Luban, Jeremy. "TRIM5 and the Regulation of HIV-1 Infectivity." Molecular Biology International 2012 (May 30, 2012): 1–6. http://dx.doi.org/10.1155/2012/426840.

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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.

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Richardson, Barbra A., and James P. Hughes. "Modeling Breastmilk Infectivity in HIV-1 Infected Mothers." Biometrics 59, no. 1 (March 2003): 179–85. http://dx.doi.org/10.1111/1541-0420.00021.

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Konopka, K., B. R. Davis, C. E. Larsen, and N. Düzgüneş. "Anionic Liposomes Inhibit Human Immunodeficiency Virus Type 1 (HIV-1) Infectivity in CD4+ A3.01 and H9 Cells." Antiviral Chemistry and Chemotherapy 4, no. 3 (June 1993): 179–87. http://dx.doi.org/10.1177/095632029300400308.

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Immunodeficiency viruses undergo fusion with liposomes containing anionic phospholipids (Larsen etal., 1990). We have investigated the effect of liposomes composed of cardiolipin, phosphatidylserine or phosphatidylinositol, on the infectivity of three strains of HIV-1 in A3.01 and H9 cells, measured by p24 (gag) production in the medium. The infectivity of HIV-1 in A3.01 or H9 cells was inhibited by the presence of cardiolipin liposomes during a 2 h infection period, with IC50's of 23.0, 4.8, and 5.0 μM phospholipid, respectively, for the different strains. Liposomes composed of phosphatidylserine or phosphatidylinositol were ineffective under similar conditions. However, prolonged pre-incubation of the virus with these liposomes also inhibited infectivity. Inhibition of virus binding to cells could not account for the inhibition of infectivity. We propose that the fusion products of HIV-1 and anionic liposomes are impaired in their ability to fuse with the plasma membrane.

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Bristow, Cynthia L., Danielle R. Mercatante, and Ryszard Kole. "HIV-1 preferentially binds receptors copatched with cell-surface elastase." Blood 102, no. 13 (December 15, 2003): 4479–86. http://dx.doi.org/10.1182/blood-2003-05-1635.

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Abstract Human leukocyte elastase (HLE) interacts with HIV-1 glycoprotein (gp)41, suggesting a nonenzymatic receptor function for HLE in the context of HIV-1. HLE is found localized to the cell surface, but not granules in HIV permissive clones, and to granules, but not the cell surface of HIV nonpermissive clones. Inducing cell-surface HLE expression on HLE null, HIV nonpermissive clones permits HIV infectivity. HIV binding and infectivity diminish in proportion to HLE RNA subtraction. HIV binding and infectivity show dose dependence for the natural HLE ligand α1 proteinase inhibitor (α1antitrypsin, α1PI). Chemokines prevent, whereas α1PI promotes, copatching of HLE with the canonical HIV receptors. Recent demonstration that decreased viral RNA is significantly correlated with decreased circulating α1PI in HIV seropositive individuals is consistent with a model in which HLE and α1PI can serve as HIV coreceptor and cofactor, respectively, and potentially participate in the pathophysiology of HIV disease progression. (Blood. 2003;102:4479-4486)

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Sadler, Holly A., Mark D. Stenglein, Reuben S. Harris, and Louis M. Mansky. "APOBEC3G Contributes to HIV-1 Variation through Sublethal Mutagenesis." Journal of Virology 84, no. 14 (May 12, 2010): 7396–404. http://dx.doi.org/10.1128/jvi.00056-10.

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ABSTRACT The mammalian APOBEC3 proteins are an important component of the cellular innate immune response to retroviral infection. APOBEC3G can extinguish HIV-1 infectivity by its incorporation into virus particles and subsequent cytosine deaminase activity that attacks the nascent viral cDNA during reverse transcription, causing lethal mutagenesis. It has been suggested, but not formally shown, that APOBEC3G can also induce sublethal mutagenesis, which would maintain virus infectivity and contribute to HIV-1 variation. To test this, we developed a novel model system utilizing an HIV-1 vector and a panel of APOBEC3G-expressing cells. We observed proviruses with single APOBEC3G-mediated mutations (in the presence or absence of Vif), occurring at distinct hot spots and which could be rescued and shown to have infectivity. These data indicate that APOBEC3G-dependent restriction of HIV-1 can result in viable viral progeny that harbor sublethal levels of G-to-A mutations. Such mutations have the potential to contribute significantly to HIV-1 evolution, pathogenesis, immune escape, and drug resistance.

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Sokolskaja, Elena, Silvia Olivari, Madeleine Zufferey, Caterina Strambio-De-Castillia, Massimo Pizzato, and Jeremy Luban. "Cyclosporine Blocks Incorporation of HIV-1 Envelope Glycoprotein into Virions." Journal of Virology 84, no. 9 (February 24, 2010): 4851–55. http://dx.doi.org/10.1128/jvi.01699-09.

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ABSTRACT Cyclosporine (CsA) decreases HIV-1 infectivity by blocking HIV-1 capsid (CA) interaction with target cell cyclophilin A (CypA). Yet, HIV-1 virions produced in the presence of CsA also exhibit decreased infectivity that was previously shown to be independent of the well-characterized HIV-1 CA-CypA interaction. Here, we demonstrate that CsA decreases gp120 and gp41 incorporation into HIV-1 virions and that the fusion of these virions with susceptible target cells is impaired. This effect was not observed with HIV-1 virions pseudotyped with the vesicular stomatitis virus glycoprotein or with the amphotropic envelope protein of murine leukemia virus. It was independent of calcineurin signaling, the endoplasmic reticulum luminal protein cyclophilin B, and the long cytoplasmic tail of gp41. Thus, cyclosporine blocks HIV-1 infectivity via two independent mechanisms, the first involving HIV-1 CA in target cells and the second involving HIV-1 Env in producer cells.

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Pizzato, Massimo, Elena Popova, and Heinrich G. Göttlinger. "Nef Can Enhance the Infectivity of Receptor-Pseudotyped Human Immunodeficiency Virus Type 1 Particles." Journal of Virology 82, no. 21 (August 20, 2008): 10811–19. http://dx.doi.org/10.1128/jvi.01150-08.

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ABSTRACT Nef is an accessory protein of human immunodeficiency virus type 1 (HIV-1) that enhances the infectivity of progeny virions when expressed in virus-producing cells. The requirement for Nef for optimal infectivity is, at least in part, determined by the envelope (Env) glycoprotein, because it can be eliminated by pseudotyping HIV-1 particles with pH-dependent Env proteins. To investigate the role of Env in the function of Nef, we have examined the effect of Nef on the infectivity of Env-deficient HIV-1 particles pseudotyped with viral receptors for cells expressing cognate Env proteins. We found that Nef significantly enhances the infectivity of CD4-chemokine receptor pseudotypes for cells expressing HIV-1 Env. Nef also increased the infectivity of HIV-1 particles pseudotyped with Tva, the receptor for subgroup A Rous sarcoma virus (RSV-A), even though Nef had no effect if the pH-dependent Env protein of RSV-A was used for pseudotyping. However, Nef does not always enhance viral infectivity if the normal orientation of the Env-receptor interaction is reversed, because the entry of Env-deficient HIV-1 into cells expressing the vesicular stomatitis virus G protein was unaffected by Nef. Together, our results demonstrate that the presence of a viral Env protein during virus production is not required for the ability of Nef to increase viral infectivity. Furthermore, since the infectivity of Tva pseudotypes was blocked by inhibitors of endosomal acidification, we conclude that low-pH-dependent entry does not always bypass the requirement for Nef.

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Palmer, Carol J., G. Fred Bonilla, Yu-Li Tsai, Moon H. Lee, Brenda J. Javier, and Edward B. Siwak. "Analysis of sewage effluent for human immunodeficiency virus (HIV) using infectivity assay and reverse transcriptase polymerase chain reaction." Canadian Journal of Microbiology 41, no. 9 (September 1, 1995): 809–15. http://dx.doi.org/10.1139/m95-111.

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Environmental survival of human immunodeficiency virus type 1 (HIV-1) is an important public health concern. Survival of HIV in waste water is of particular interest to those who work at treatment facilities and to the general public who have contact with rivers or ocean water receiving treated sewage effluent. Other researchers have reported that HIV can be detected in waste water. Their studies, however, detected homologous nucleic acid sequences but did not attempt to determine infectivity. The current study tested primary and secondary effluent from a major metropolitan sewage agency for the presence of HIV-1 using reverse transcriptase polymerase chain reaction (RT-PCR), HIV-1 p24 antigen enzyme-linked immunosorbent assay, and infectivity testing. For RT-PCR, primers SK38/SK39 and M667/AA55 were used to identify HIV-1 RNA sequences from concentrated and extracted sewage samples. Infectivity assays employed donor peripheral blood mononuclear cells (PBMCs) stimulated with phytohemagglutinin. Coxsackievirus B4, echovirus 7, and poliovirus 1, enteroviruses normally present in sewage, were tested for replication in PBMCs. Poliovirus 1 was found to infect the PBMCs. To eliminate other enteroviruses that may also infect the PBMCs and interfere with HIV-1 testing, concentrated sewage was treated with human immunoglobulin (free of HIV antibodies) and poliovirus antisera before infectivity assays were performed. All treated sewage samples tested negative for HIV-1 by all methods used. HIV-1 seeded into sewage, however, remained infectious in the assay, indicating that the sewage water sample did not interfere with HIV infectivity nor was it toxic to the PBMCs.Key words: HIV, sewage, RT-PCR, infectivity.

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Misra, Anisha, Emile Gleeson, Weiming Wang, Chaobaihui Ye, Paul Zhou, and Jason T. Kimata. "Glycosyl-Phosphatidylinositol-Anchored Anti-HIV Env Single-Chain Variable Fragments Interfere with HIV-1 Env Processing and Viral Infectivity." Journal of Virology 92, no. 7 (January 10, 2018): e02080-17. http://dx.doi.org/10.1128/jvi.02080-17.

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ABSTRACTIn previous studies, we demonstrated that single-chain variable fragments (scFvs) from anti-human immunodeficiency virus (HIV) Env monoclonal antibodies act as entry inhibitors when tethered to the surface of target cells by a glycosyl-phosphatidylinositol (GPI) anchor. Interestingly, even if a virus escapes inhibition at entry, its replication is ultimately controlled. We hypothesized that in addition to functioning as entry inhibitors, anti-HIV GPI-scFvs may also interact with Env in an infected cell, thereby interfering with the infectivity of newly produced virions. Here, we show that expression of the anti-HIV Env GPI-scFvs in virus-producing cells reduced the release of HIV from cells 5- to 22-fold, and infectivity of the virions that were released was inhibited by 74% to 99%. Additionally, anti-HIV Env GPI-scFv X5 inhibited virion production and infectivity after latency reactivation and blocked transmitter/founder virus production and infectivity in primary CD4+T cells. In contrast, simian immunodeficiency virus (SIV) production and infectivity were not affected by the anti-HIV Env GPI-scFvs. Loss of infectivity of HIV was associated with a reduction in the amount of virion-associated Env gp120. Interestingly, an analysis of Env expression in cell lysates demonstrated that the anti-Env GPI-scFvs interfered with processing of Env gp160 precursors in cells. These data indicate that GPI-scFvs can inhibit Env processing and function, thereby restricting production and infectivity of newly synthesized HIV. Anti-Env GPI-scFvs therefore appear to be unique anti-HIV molecules as they derive their potent inhibitory activity by interfering with both early (receptor binding/entry) and late (Env processing and incorporation into virions) stages of the HIV life cycle.IMPORTANCEThe restoration of immune function and persistence of CD4+T cells in HIV-1-infected individuals without antiretroviral therapy requires a way to increase resistance of CD4+T cells to infection by both R5- and X4-tropic HIV-1. Previously, we reported that anchoring anti-HIV-1 single-chain variable fragments (scFvs) via glycosyl-phosphatidylinositol (GPI) to the surface of permissive cells conferred a high level of resistance to HIV-1 variants at the level of entry. Here, we report that anti-HIV GPI-scFvs also derive their potent antiviral activity in part by blocking HIV production and Env processing, which consequently inhibits viral infectivity even in primary infection models. Thus, we conclude that GPI-anchored anti-HIV scFvs derive their potent blocking activity of HIV replication by interfering with successive stages of the viral life cycle. They may be effectively used in genetic intervention of HIV-1 infection.

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Hughes, James P., Jared M. Baeten, Jairam R. Lingappa, Amalia S. Magaret, Anna Wald, Guy de Bruyn, James Kiarie, et al. "Determinants of Per-Coital-Act HIV-1 Infectivity Among African HIV-1–Serodiscordant Couples." Journal of Infectious Diseases 205, no. 3 (January 12, 2012): 358–65. http://dx.doi.org/10.1093/infdis/jir747.

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Dungan, J. S. "Determinants of Per-Coital-Act HIV-1 Infectivity Among African HIV-1–Serodiscordant Couples." Yearbook of Obstetrics, Gynecology and Women's Health 2012 (January 2012): 304–5. http://dx.doi.org/10.1016/j.yobg.2012.06.180.

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Perugi, Fabien, Delphine Muriaux, Bertha Cecilia Ramirez, Sabah Chabani, Etienne Decroly, Jean-Luc Darlix, Vincent Blot, and Claudine Pique. "Human Discs Large Is a New Negative Regulator of Human Immunodeficiency Virus-1 Infectivity." Molecular Biology of the Cell 20, no. 1 (January 2009): 498–508. http://dx.doi.org/10.1091/mbc.e08-02-0189.

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Human immunodeficiency virus (HIV)-1 replication is positively or negatively regulated through multiple interactions with host cell proteins. We report here that human Discs Large (Dlg1), a scaffold protein recruited beneath the plasma membrane and involved in the assembly of multiprotein complexes, restricts HIV-1 infectivity. The endogenous Dlg1 and HIV-1 Gag polyprotein spontaneously interact in HIV-1-chronically infected T cells. Depleting endogenous Dlg1 in either adherent cells or T cells does not affect Gag maturation, production, or release, but it enhances the infectivity of progeny viruses five- to sixfold. Conversely, overexpression of Dlg1 reduces virus infectivity by ∼80%. Higher virus infectivity upon Dlg1 depletion correlates with increased Env content in cells and virions, whereas the amount of virus-associated Gag or genomic RNA remains identical. Dlg1 knockdown is also associated with the redistribution and colocalization of Gag and Env toward CD63 and CD82 positive vesicle-like structures, including structures that seem to still be connected to the plasma membrane. This study identifies both a new negative regulator that targets the very late steps of the HIV-1 life cycle, and an assembly pathway that optimizes HIV-1 infectivity.

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Yang, Xiaoyu, and Dana Gabuzda. "Regulation of Human Immunodeficiency Virus Type 1 Infectivity by the ERK Mitogen-Activated Protein Kinase Signaling Pathway." Journal of Virology 73, no. 4 (April 1, 1999): 3460–66. http://dx.doi.org/10.1128/jvi.73.4.3460-3466.1999.

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ABSTRACT ERK1 and ERK2 mitogen-activated protein kinases (MAPK) play a critical role in regulation of cell proliferation and differentiation in response to mitogens and other extracellular stimuli. Mitogens and cytokines that activate MAPK in T cells have been shown to activate human immunodeficiency virus type 1 (HIV-1) replication. Little is known about the signal transduction pathways that activate HIV-1 replication in T cells upon activation by extracellular stimulation. Here, we report that activation of MAPK through the Ras/Raf/MEK signaling pathway enhances the infectivity of HIV-1 virions. Virus infectivity was enhanced by treatment of cells with MAPK stimulators, such as serum and phorbol myristate acetate, as well as by coexpression of constitutively activated Ras, Raf, or MEK (MAPK kinase) in the absence of extracellular stimulation. Treatment of cells with PD 098059, a specific inhibitor of MAPK activation, or with a MAPK antisense oligonucleotide reduced the infectivity of HIV-1 virions without significantly affecting virus production or the levels of virion-associated Gag and Env proteins. MAPK has been shown to regulate HIV-1 infectivity by phosphorylating Vif (X. Yang and D. Gabuzda, J. Biol. Chem. 273:29879–29887, 1998). However, MAPK activation enhanced virus infectivity in some cells lines that do not require Vif function. The HIV-1 Rev, Tat, p17Gag, and Nef proteins were directly phosphorylated by MAPK in vitro, suggesting that other HIV-1 proteins are potential substrates for MAPK phosphorylation. These results suggest that activation of the ERK MAPK pathway plays a role in HIV-1 replication by enhancing the infectivity of HIV-1 virions through Vif-dependent as well as Vif-independent mechanisms. MAPK activation in producer cells may contribute to the activation of HIV-1 replication when T cells are activated by mitogens and other extracellular stimuli.

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Etsuko, Kumagai, and Wei Song. "Inhibitory effect of human saliva on HIV-1 infectivity." Japanese Journal of Clinical Immunology 24, no. 4 (2001): 152–59. http://dx.doi.org/10.2177/jsci.24.152.

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Hoque, Sheikh Ariful, Atsushi Tanaka, Salequl Islam, Gias Uddin Ahsan, Atsushi Jinno-Oue, and Hiroo Hoshino. "Suppression of HIV-1 Infectivity by Human Glioma Cells." AIDS Research and Human Retroviruses 32, no. 5 (May 2016): 480–88. http://dx.doi.org/10.1089/aid.2015.0077.

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Rose, Kristine M., Mariana Marin, Susan L. Kozak, and David Kabat. "The viral infectivity factor (Vif) of HIV-1 unveiled." Trends in Molecular Medicine 10, no. 6 (June 2004): 291–97. http://dx.doi.org/10.1016/j.molmed.2004.04.008.

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Lorin, V., M. Malbec, C. Eden, T. Bruel, F. Porrot, M. S. Seaman, O. Schwartz, and H. Mouquet. "Broadly neutralizing antibodies suppress post-transcytosis HIV-1 infectivity." Mucosal Immunology 10, no. 3 (December 14, 2016): 814–26. http://dx.doi.org/10.1038/mi.2016.106.

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Zhao, Fei, Fengwen Xu, Xiaoman Liu, Yamei Hu, Liang Wei, Zhangling Fan, Liming Wang, et al. "SERINC5 restricts influenza virus infectivity." PLOS Pathogens 18, no. 10 (October 12, 2022): e1010907. http://dx.doi.org/10.1371/journal.ppat.1010907.

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SERINC5 is a multi-span transmembrane protein that is incorporated into HIV-1 particles in producing cells and inhibits HIV-1 entry. Multiple retroviruses like HIV-1, equine infectious anemia virus and murine leukemia virus are subject to SERINC5 inhibition, while HIV-1 pseudotyped with envelope glycoproteins of vesicular stomatitis virus and Ebola virus are resistant to SERINC5. The antiviral spectrum and the underlying mechanisms of SERINC5 restriction are not completely understood. Here we show that SERINC5 inhibits influenza A virus infection by targeting virus-cell membrane fusion at an early step of infection. Further results show that different influenza hemagglutinin (HA) subtypes exhibit diverse sensitivities to SERINC5 restriction. Analysis of the amino acid sequences of influenza HA1 strains indicates that HA glycosylation sites correlate with the sensitivity of influenza HA to SERINC5, and the inhibitory effect of SERINC5 was lost when certain HA glycosylation sites were mutated. Our study not only expands the antiviral spectrum of SERINC5, but also reveals the role of viral envelope glycosylation in resisting SERINC5 restriction.

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Kiernan, Rosemary E., and Eric O. Freed. "Cleavage of the Murine Leukemia Virus Transmembrane Env Protein by Human Immunodeficiency Virus Type 1 Protease: Transdominant Inhibition by Matrix Mutations." Journal of Virology 72, no. 12 (December 1, 1998): 9621–27. http://dx.doi.org/10.1128/jvi.72.12.9621-9627.1998.

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ABSTRACT We have identified mutations in the human immunodeficiency virus type 1 (HIV-1) matrix protein (MA) which block infectivity of virions pseudotyped with murine leukemia virus (MuLV) envelope (Env) glycoproteins without affecting infectivity conferred by HIV-1 Env or vesicular stomatitis virus G glycoproteins. This inhibition is very potent and displays a strong transdominant effect; infectivity is reduced more than 100-fold when wild-type and mutant molecular clones are cotransfected at a 1:1 ratio. This phenomenon is observed with both ecotropic and amphotropic MuLV Env. The MA mutations do not affect the incorporation of MuLV Env into virions. We demonstrate that in HIV-1 virions pseudotyped with MuLV Env, the HIV-1 protease (PR) efficiently catalyzes the cleavage of the p15(E) transmembrane (TM) protein to p12(E). Immunoprecipitation analysis of pseudotyped virions reveals that the mutant MA blocks this HIV-1 PR-mediated cleavage of MuLV TM. Furthermore, the transdominant inhibition exerted by the mutant MA on wild-type infectivity correlates with the relative level of p15(E) cleavage. Consistent with the hypothesis that abrogation of infectivity imposed by the mutant MA is due to inhibition of p15(E) cleavage, mutant virions are significantly more infectious when pseudotyped with a truncated p12(E) form of MuLV Env. These results indicate that HIV-1 Gag sequences can influence the viral PR-mediated processing of the MuLV TM Env protein p15(E). These findings have implications for the development of HIV-1-based retroviral vectors pseudotyped with MuLV Env, since p15(E) cleavage is essential for activating membrane fusion and virus infectivity.

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Mwimanzi, Philip, Ian Tietjen, Scott C. Miller, Aniqa Shahid, Kyle Cobarrubias, Natalie N. Kinloch, Bemuluyigza Baraki, et al. "Novel Acylguanidine-Based Inhibitor of HIV-1." Journal of Virology 90, no. 20 (August 10, 2016): 9495–508. http://dx.doi.org/10.1128/jvi.01107-16.

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ABSTRACTThe emergence of transmissible HIV-1 strains with resistance to antiretroviral drugs highlights a continual need for new therapies. Here we describe a novel acylguanidine-containing compound, 1-(2-(azepan-1-yl)nicotinoyl)guanidine (or SM111), that inhibitsin vitroreplication of HIV-1, including strains resistant to licensed protease, reverse transcriptase, and integrase inhibitors, without major cellular toxicity. At inhibitory concentrations, intracellular p24Gagproduction was unaffected, but virion release (measured as extracellular p24Gag) was reduced and virion infectivity was substantially impaired, suggesting that SM111 acts at a late stage of viral replication. SM111-mediated inhibition of HIV-1 was partially overcome by a Vpu I17R mutation alone or a Vpu W22* truncation in combination with Env N136Y. These mutations enhanced virion infectivity and Env expression on the surface of infected cells in the absence and presence of SM111 but also impaired Vpu's ability to downregulate CD4 and BST2/tetherin. Taken together, our results support acylguanidines as a class of HIV-1 inhibitors with a distinct mechanism of action compared to that of licensed antiretrovirals. Further research on SM111 and similar compounds may help to elucidate knowledge gaps related to Vpu's role in promoting viral egress and infectivity.IMPORTANCENew inhibitors of HIV-1 replication may be useful as therapeutics to counteract drug resistance and as reagents to perform more detailed studies of viral pathogenesis. SM111 is a small molecule that blocks the replication of wild-type and drug-resistant HIV-1 strains by impairing viral release and substantially reducing virion infectivity, most likely through its ability to prevent Env expression at the infected cell surface. Partial resistance to SM111 is mediated by mutations in Vpu and/or Env, suggesting that the compound affects host/viral protein interactions that are important during viral egress. Further characterization of SM111 and similar compounds may allow more detailed pharmacological studies of HIV-1 egress and provide opportunities to develop new treatments for HIV-1.

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Selyutina, Anastasia, Lacy M. Simons, Karen A. Kirby, Angel Bulnes-Ramos, Pan Hu, Stefan G. Sarafianos, Judd F. Hultquist, and Felipe Diaz-Griffero. "TRIM5α Restriction of HIV-1-N74D Viruses in Lymphocytes Is Caused by a Loss of Cyclophilin A Protection." Viruses 14, no. 2 (February 10, 2022): 363. http://dx.doi.org/10.3390/v14020363.

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The core of HIV-1 viruses bearing the capsid change N74D (HIV-1-N74D) do not bind the human protein CPSF6. In primary human CD4+ T cells, HIV-1-N74D viruses exhibit an infectivity defect when compared to wild-type. We first investigated whether loss of CPSF6 binding accounts for the loss of infectivity. Depletion of CPSF6 in human CD4+ T cells did not affect the early stages of wild-type HIV-1 replication, suggesting that defective infectivity in the case of HIV-1-N74D viruses is not due to the loss of CPSF6 binding. Based on our previous result that cyclophilin A (Cyp A) protected HIV-1 from human tripartite motif-containing protein 5α (TRIM5αhu) restriction in CD4+ T cells, we found that depletion of TRIM5αhu in CD4+ T cells rescued the infectivity of HIV-1-N74D, suggesting that HIV-1-N74D cores interacted with TRIM5αhu. Accordingly, TRIM5αhu binding to HIV-1-N74D cores was increased compared with that of wild-type cores, and consistently, HIV-1-N74D cores lost their ability to bind Cyp A. In agreement with the notion that N74D capsids are defective in their ability to bind Cyp A, we found that HIV-1-N74D viruses were 20-fold less sensitive to TRIMCyp restriction when compared to wild-type viruses in OMK cells. Structural analysis revealed that N74D hexameric capsid protein in complex with PF74 is different from wild-type hexameric capsid protein in complex with PF74, which explains the defect of N74D capsids to interact with Cyp A. In conclusion, we showed that the decreased infectivity of HIV-1-N74D in CD4+ T cells is due to a loss of Cyp A protection from TRIM5αhu restriction activity.

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Nance, Christina L., Edward B. Siwak, Melinda D'Souza, Sonia Songa, Ashley M. McMullen, and William T. Shearer. "Inhibition of HIV-1 infectivity across subtypes by the green tea catechin, epigallocatechin gallate, without altered immune function (128.6)." Journal of Immunology 182, no. 1_Supplement (April 1, 2009): 128.6. http://dx.doi.org/10.4049/jimmunol.182.supp.128.6.

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Abstract Previously, we presented evidence that the green tea catechin, epigallocatechin gallate (EGCG), binds to the CD4 molecule at the gp120 attachment site on T cells. CD4+ T cells, B cells and macrophages were isolated from HIV-1 uninfected donors. HIV-1 infectivity by HIV-1 p24 ELISA on M-tropic (R5) subtypes B, C and G; T-tropic (X4) subtypes B and D; and dual tropic (R5/X4) subtype B. Immune function studies: cytotoxicity by ViCell, apoptosis by flow cytometry, immunoglobulin (Ig) production by ELISA and cytokine profiling by multiplex platform. Statistical significance by Student's t test. EGCG significantly inhibited HIV-1 infectivity on human immune cells in a dose-dependent manner (6-100μM) (p<0.01-0.001). At physiologic concentration of 6μM, EGCG significantly inhibited HIV-1 p24 antigen production across HIV-1 subtypes [B (p<0.001), C, D, and G (p<0.01)]. The specificity of the EGCG-induced inhibition was substantiated by the failure of EGCG derivatives lacking galloyl and/or pyrogallol side groups to alter HIV-1 p24 levels. EGCG-induced inhibition of HIV-1 infectivity was not due to cytotoxcity, cell growth inhibition, nor apoptosis. Neither Ig nor cytokine production were significantly altered. EGCG inhibits HIV-1 infectivity across a broad spectrum of HIV-1 subtypes without significant effects on immune function, thereby supporting EGCG as a candidate for HIV-1 therapy. (NIH AT003084)

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Nance, Christina L., Edward Siwak, Susan Westerfield, Van Willis, and William T. Shearer. "Binding of the green tea catechin, epigallocatechin gallate, to the CD4 receptor on human immune cells resulting in inhibition of HIV-1-gp120 binding and HIV-1 infectivity (47.18)." Journal of Immunology 178, no. 1_Supplement (April 1, 2007): S69. http://dx.doi.org/10.4049/jimmunol.178.supp.47.18.

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Abstract Binding of HIV-1 envelope glycoprotein, gp120, to the CD4 T cell receptor results in HV-1 infection. We previously presented evidence of high affinity binding of the green tea catechin, epigallocatechin gallate (EGCG) to the CD4 molecule. We now present evidence in parallel studies that EGCG inhibits the binding of gp120 on human CD4+ T cells and PBMC and prevents the HIV-1 infectivity of macrophages and PBMC. Binding studies utilized spectroscopy and flow cytometry. HIV-1 infectivity was assessed by HIV-1 p24 EIA. Studies indicated that EGCG binds to CD4 at the same binding pocket as gp120. EGCG markedly inhibited the binding of HIV-1-gp120 to CD4+T cells in a dose-dependent manner at physiologically relevant levels (32% at 0.2uM p<0.05, 42% at 2uM, 47% at 20uM p<0.01). EGCG significantly inhibited the HIV-1infectivity of human primary macrophages in a dose-dependent manner. There was 100% inhibition of p24 production by EGCG at 25–100uM (p<0.0001), 95% at 12uM, and 79% at 6uM (p<0.001). The response by human PBMC was similar. The control catechin did not alter gp120 binding nor inhibit HIV-1 infectivity. We conclude that EGCG is able to significantly reduce the attachment of HIV-1-gp120 to CD4, along with a decrease in the infectivity of HIV-1 to target cells. The competitive binding properties of EGCG for the CD4 binding sites by gp120 may translate to an HIV-1 preventative strategy. Supported by NIH grant R21AT003084.

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Akari, Hirofumi, Tsuneo Uchiyama, Tomoharu Fukumori, Shinya Iida, A. Hajime Koyama, and Akio Adachi. "Pseudotyping human immunodeficiency virus type 1 by vesicular stomatitis virus G protein does not reduce the cell-dependent requirement of Vif for optimal infectivity: functional difference between Vif and Nef." Journal of General Virology 80, no. 11 (November 1, 1999): 2945–49. http://dx.doi.org/10.1099/0022-1317-80-11-2945.

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The functions of Vif and Nef in human immunodeficiency virus type 1 (HIV-1) infection have some similarities: Vif- and Nef-dependent enhancement of HIV-1 replication is cell type-specific, and defective mutations in these genes result in restricted proviral DNA synthesis in infected cells. It has recently been shown that pseudotyping HIV-1 by the envelope glycoprotein of vesicular stomatitis virus (VSV-G) targets HIV-1 entry to an endocytic pathway and suppresses the requirement of Nef for virus infectivity. In this study, we examined whether VSV-G pseudotyping suppresses the requirement of Vif for HIV-1 infectivity. It was found that pseudotyping HIV-1 by VSV-G did not compensate for the Vif function. Together with the findings that Vif does not influence virus binding/entry and virion incorporation of Env, it is concluded that Vif enhances HIV-1 infectivity at the post-entry step(s) independently of the Env function by a different mechanism to that of Nef.

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Fu, Yajing, Sijia He, Abdul A. Waheed, Deemah Dabbagh, Zheng Zhou, Benjamin Trinité, Zhao Wang, et al. "PSGL-1 restricts HIV-1 infectivity by blocking virus particle attachment to target cells." Proceedings of the National Academy of Sciences 117, no. 17 (April 9, 2020): 9537–45. http://dx.doi.org/10.1073/pnas.1916054117.

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P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric, mucin-like, 120-kDa glycoprotein that binds to P-, E-, and L-selectins. PSGL-1 is expressed primarily on the surface of lymphoid and myeloid cells and is up-regulated during inflammation to mediate leukocyte tethering and rolling on the surface of endothelium for migration into inflamed tissues. Although it has been reported that PSGL-1 expression inhibits HIV-1 replication, the mechanism of PSGL-1–mediated anti-HIV activity remains to be elucidated. Here we report that PSGL-1 in virions blocks the infectivity of HIV-1 particles by preventing the binding of particles to target cells. This inhibitory activity is independent of the viral glycoprotein present on the virus particle; the binding of particles bearing the HIV-1 envelope glycoprotein or vesicular stomatitis virus G glycoprotein or even lacking a viral glycoprotein is impaired by PSGL-1. Mapping studies show that the extracellular N-terminal domain of PSGL-1 is necessary for its anti–HIV-1 activity, and that the PSGL-1 cytoplasmic tail contributes to inhibition. In addition, we demonstrate that the PSGL-1–related monomeric E-selectin–binding glycoprotein CD43 also effectively blocks HIV-1 infectivity. HIV-1 infection, or expression of either Vpu or Nef, down-regulates PSGL-1 from the cell surface; expression of Vpu appears to be primarily responsible for enabling the virus to partially escape PSGL-1–mediated restriction. Finally, we show that PSGL-1 inhibits the infectivity of other viruses, such as murine leukemia virus and influenza A virus. These findings demonstrate that PSGL-1 is a broad-spectrum antiviral host factor with a unique mechanism of action.

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Rapista, Aprille, Jian Ding, Bernadette Benito, Yung-Tai Lo, Matthew B. Neiditch, Wuyuan Lu, and Theresa L. Chang. "Human defensins 5 and 6 enhance HIV-1 infectivity through promoting HIV attachment." Retrovirology 8, no. 1 (2011): 45. http://dx.doi.org/10.1186/1742-4690-8-45.

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Lucas, Tiffany M., Terri D. Lyddon, Paula M. Cannon, and Marc C. Johnson. "Pseudotyping Incompatibility between HIV-1 and Gibbon Ape Leukemia Virus Env Is Modulated by Vpu." Journal of Virology 84, no. 6 (December 30, 2009): 2666–74. http://dx.doi.org/10.1128/jvi.01562-09.

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ABSTRACT The Env protein from gibbon ape leukemia virus (GaLV) has been shown to be incompatible with human immunodeficiency virus type 1 (HIV-1) in the production of infectious pseudotyped particles. This incompatibility has been mapped to the C-terminal cytoplasmic tail of GaLV Env. Surprisingly, we found that the HIV-1 accessory protein Vpu modulates this incompatibility. The infectivity of HIV-1 pseudotyped with murine leukemia virus (MLV) Env was not affected by Vpu. However, the infectivity of HIV-1 pseudotyped with an MLV Env with the cytoplasmic tail from GaLV Env (MLV/GaLV Env) was restricted 50- to 100-fold by Vpu. A Vpu mutant containing a scrambled membrane-spanning domain, VpuRD, was still able to restrict MLV/GaLV Env, but mutation of the serine residues at positions 52 and 56 completely alleviated the restriction. Loss of infectivity appeared to be caused by reduced MLV/GaLV Env incorporation into viral particles. The mechanism of this downmodulation appears to be distinct from Vpu-mediated CD4 downmodulation because Vpu-expressing cells that failed to produce infectious HIV-1 particles nonetheless continued to display robust surface MLV/GaLV Env expression. In addition, if MLV and HIV-1 were simultaneously introduced into the same cells, only the HIV-1 particle infectivity was restricted by Vpu. Collectively, these data suggest that Vpu modulates the cellular distribution of MLV/GaLV Env, preventing its recruitment to HIV-1 budding sites.

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Ribeiro, Ana Clara, Alexandra Maia e Silva, Mariana Santa-Marta, Ana Pombo, José Moniz-Pereira, Joao Goncalves, and Isabel Barahona. "Functional Analysis of Vif Protein Shows Less Restriction of Human Immunodeficiency Virus Type 2 by APOBEC3G." Journal of Virology 79, no. 2 (January 15, 2005): 823–33. http://dx.doi.org/10.1128/jvi.79.2.823-833.2005.

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ABSTRACT Viral infectivity factor (Vif) is one of the human immunodeficiency virus (HIV) accessory proteins and is conserved in the primate lentivirus group. This protein is essential for viral replication in vivo and for productive infection of nonpermissive cells, such as peripheral blood mononuclear cells (PBMC). Vif counteracts an antiretroviral cellular factor in nonpermissive cells named CEM15/APOBEC3G. Although HIV type 1 (HIV-1) Vif protein (Vif1) can be functionally replaced by HIV-2 Vif protein (Vif2), its identity is very small. Most of the functional studies have been carried out with Vif1. Characterization of functional domains of Vif2 may elucidate its function, as well as differences between HIV-1 and HIV-2 infectivity. Our aim was to identify the permissivity of different cell lines for HIV-2 vif-minus viruses. By mutagenesis specific conserved motifs of HIV-2 Vif protein were analyzed, as well as in conserved motifs between Vif1 and Vif2 proteins. Vif2 mutants were examined for their stability, expression, and cellular localization in order to characterize essential domains of Vif2 proteins. Viral replication in various target cells (PBMC and H9, A3.01, U38, and Jurkat cells) and infectivity in single cycle assays in the presence of APOBEC3G were also analyzed. Our results of viral replication show that only PBMC have a nonpermissive phenotype in the absence of Vif2. Moreover, the HIV-1 vif-minus nonpermissive cell line H9 does not show a similar phenotype for vif-negative HIV-2. We also report a limited effect of APOBEC3G in a single-cycle infectivity assay, where only conserved domains between HIV-1 and HIV-2 Vif proteins influence viral infectivity. Taken together, these results allow us to speculate that viral inhibition by APOBEC3G is not the sole and most important determinant of antiviral activity against HIV-2.

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Fu, Yajing, Sijia He, Abdul Waheed, Deemah Dabbagh, Zheng Zhou, Benjamin Trinité, Zhao Wang, et al. "PSGL-1 Restricts HIV-1 Infectivity by Blocking Virus Particle Attachment to Target Cells." Proceedings 50, no. 1 (June 17, 2020): 77. http://dx.doi.org/10.3390/proceedings2020050077.

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P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric, mucin-like, 120-kDa glycoprotein that binds to P-, E-, and L-selectins. PSGL-1 is primarily expressed on the surface of lymphoid and myeloid cells and is up-regulated during inflammation to mediate leukocyte tethering and rolling on the surface of endothelium for migration into inflamed tissues. Although it has been reported that PSGL-1 expression inhibits human immunodeficiency virus type 1 (HIV-1) replication, the mechanism of PSGL-1-mediated anti-HIV activity remains to be elucidated. Here, we report that PSGL-1 in virions blocks the infectivity of HIV-1 particles by preventing the binding of particles to target cells. This inhibitory activity is independent of the viral glycoprotein present on the virus particle; the binding of particles bearing the HIV-1 envelope glycoprotein, vesicular stomatitis virus G glycoprotein, or lacking a viral glycoprotein, is impaired by PSGL-1. Mapping studies show that the extracellular, N-terminal domain of PSGL-1 is necessary for its anti-HIV-1 activity, and the PSGL-1 cytoplasmic tail contributes to its inhibition. In addition, we demonstrate that the PSGL-1-related monomeric E-selectin-binding glycoprotein CD43 also effectively blocks HIV-1 infectivity. HIV-1 infection, or the expression of either Vpu or Nef, downregulates PSGL-1 from the cell surface; the expression of Vpu appears to be primarily responsible for enabling the virus to partially escape PSGL-1-mediated restriction. Finally, we show that PSGL-1 inhibits the infectivity of other viruses such as murine leukemia virus and influenza A virus. These findings demonstrate that PSGL-1 is a broad-spectrum antiviral host factor with a novel mechanism of action.

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Nance, Christina, Melinda D'Souza, Sean McMaster, Ashley McMullen, Zak Rajut, Daisy Tran, Edward Siwak, and William Shearer. "Development of Epigallocatechin Gallate as an HIV-1 Microbicide Agent: Impact on Dendritic Cell Innate Immune Responses (46.12)." Journal of Immunology 184, no. 1_Supplement (April 1, 2010): 46.12. http://dx.doi.org/10.4049/jimmunol.184.supp.46.12.

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Abstract Langerhans cells (LC) and monocyte-derived dendritic cells (MDDC), the first line of defense against viral infection, initiate innate immune responses via toll-like receptors (TLR). Previously, we showed inhibition of HIV-1-gp120 binding to CD4 on T cells by the green tea catechin, epigallocatechin gallate (EGCG). We present evidence of EGCG inhibition of the mucosal route of HIV-1 without alteration of dendritic cell (DC) innate immune responses. Methods utilized were CD34+ hematopoietic stem cells and CD14+ cells differentiated to LC and MDDC, respectively, isolated from peripheral blood of HIV-1 seronegative donors, flow cytometry of HIV-1-gp120 binding and TLR profiling with RT-PCR, radioisotope assays for antigen (Ag) studies, MTT assay for cytotoxicity, p24 ELISA for HIV-1 infectivity studies and statistical significance by Student’s t test. EGCG significantly inhibited HIV-1 infectivity in LC in a dose-dependent manner; 100%(50uM;p<0.001), 67%(25uM;p<0.01), 45%(10uM;p<0.05). EGCG significantly inhibited HIV-1-gp120 binding to CD4 in a dose-dependent manner on LC by 95%(50uM;p<0.001), 70%(25uM;p<0.01) and 27%(10uM;p<0.05). Similar results on MDDC. Control catechin did not alter HIV-1-gp120 binding nor infectivity. Neither DC function, as measured by Ag uptake/presentation, nor viability was significantly altered by EGCG. The inhibitory effect on HIV-1-gp120 binding and infectivity of mucosal cells by EGCG may be beneficial in the development of an HIV-1 microbicide.

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Barklis, Eric, Ayna Alfadhli, Jennifer E. Kyle, Lisa M. Bramer, Kent J. Bloodsworth, Robin Lid Barklis, Hans C. Leier, et al. "Ceramide synthase 2 deletion decreases the infectivity of HIV-1." Journal of Biological Chemistry 296 (January 2021): 100340. http://dx.doi.org/10.1016/j.jbc.2021.100340.

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Goffinet, Christine. "Cellular Antiviral Factors that Target Particle Infectivity of HIV-1." Current HIV Research 14, no. 3 (March 4, 2016): 211–16. http://dx.doi.org/10.2174/1570162x14666151216145521.

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Alfadhli, Ayna, CeAnn Romanaggi, Robin Lid Barklis, Ilaria Merutka, Timothy A. Bates, Fikadu G. Tafesse, and Eric Barklis. "Capsid-specific nanobody effects on HIV-1 assembly and infectivity." Virology 562 (October 2021): 19–28. http://dx.doi.org/10.1016/j.virol.2021.07.001.

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Moody, H., P. Quaedflieg, L. Koole, M. van Genderen, H. Buck, L. Smit, S. Jurriaans, J. Geelen, and J. Goudsmit. "Inhibition of HIV-1 infectivity by phosphate-methylated DNA: retraction." Science 250, no. 4977 (October 5, 1990): 125–26. http://dx.doi.org/10.1126/science.2218505.

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Mamede, João I., Gianguido C. Cianci, Meegan R. Anderson, and Thomas J. Hope. "Early cytoplasmic uncoating is associated with infectivity of HIV-1." Proceedings of the National Academy of Sciences 114, no. 34 (August 7, 2017): E7169—E7178. http://dx.doi.org/10.1073/pnas.1706245114.

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After fusion, HIV delivers its conical capsid into the cytoplasm. To release the contained reverse-transcribing viral genome, the capsid must disassemble in a process termed uncoating. Defining the kinetics, dynamics, and cellular location of uncoating of virions leading to infection has been confounded by defective, noninfectious particles and the stochastic minefield blocking access to host DNA. We used live-cell fluorescent imaging of intravirion fluid phase markers to monitor HIV-1 uncoating at the individual particle level. We find that HIV-1 uncoating of particles leading to infection is a cytoplasmic process that occurs ∼30 min postfusion. Most, but not all, of the capsid protein is rapidly shed in tissue culture and primary target cells, independent of entry pathway. Extended time-lapse imaging with less than one virion per cell allows identification of infected cells by Gag-GFP expression and directly links individual particle behavior to infectivity, providing unprecedented insights into the biology of HIV infection.

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Jacque, Jean-Marc, and Mario Stevenson. "The inner-nuclear-envelope protein emerin regulates HIV-1 infectivity." Nature 441, no. 7093 (May 7, 2006): 641–45. http://dx.doi.org/10.1038/nature04682.

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Journal articles on the topic 'HIV-1 infectivity'

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