Immune Selection In Vitro Reveals Human Immunodeficiency Virus Type 1 Nef Sequence Motifs Important for Its Immune Evasion Function In Vivo

The mechanisms by which cellular immunity maintains the asymptomatic state after human immunodeficiency virus type 1 (HIV-1) infection are poorly understood. CD4+ T lymphocytes play a complex role in regulating anti-HIV effector pathways, including activation of macrophages, which are themselves implicated in clinical latency and pathogenesis of symptomatic acquired immune deficiency syndrome. We have found that a newly identified T helper type 2 lymphokine, interleukin 13 (IL-13), inhibits HIV-1ADA and Ba-L replication in primary tissue culture-derived macrophages but not in peripheral blood lymphocytes. Viral production in cells was measured by viral protein (p24) and reverse transcriptase levels, while entry was assessed by proviral DNA analysis at timed intervals after infection. Inhibition by IL-13 was dose and time dependent and not mediated through altered viral entry, reverse transcription, or viral release. IL-13 is therefore a candidate cytokine for the suppression of HIV infection within monocytes and macrophages in vivo.

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Interaction of human immunodeficiency virus type 1 Vif with Gag and Gag–Pol precursors: co-encapsidation and interference with viral protease-mediated Gag processing

Journal of General Virology ◽

10.1099/0022-1317-82-11-2719 ◽

2001 ◽

Vol 82 (11) ◽

pp. 2719-2733 ◽

Cited By ~ 27

Author(s):

Martine Bardy ◽

Bernard Gay ◽

Stéphanie Pébernard ◽

Nathalie Chazal ◽

Marianne Courcoul ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Viral Protease ◽

Extracellular Virus ◽

Immunodeficiency Virus ◽

Pr Domain

Interactions of human immunodeficiency virus type 1 (HIV-1) Vif protein with various forms of Gag and Gag–Pol precursors expressed in insect cells were investigated in vivo and in vitro by co-encapsidation, co-precipitation and viral protease (PR)-mediated Gag processing assays. Addressing of Gag to the plasma membrane, its budding as extracellular virus-like particles (VLP) and the presence of the p6 domain were apparently not required for Vif encapsidation, as non-N-myristoylated Δp6-Gag and Vif proteins were co-encapsidated into intracellular VLP. Encapsidation of Vif occurred at significantly higher copy numbers in extracellular VLP formed from N-myristoylated, budding-competent Gag–Pol precursors harbouring an inactive PR domain or in chimaeric VLP composed of Gag and Gag–Pol precursors compared with the Vif content of Pr55Gag VLP. Vif encapsidation efficiency did not seem to correlate directly with VLP morphology, since these chimaeric VLP were comparable in size and shape to Pr55Gag VLP. Vif apparently inhibited PR-mediated Pr55Gag processing in vitro, with preferential protection of cleavage sites at the MA–CA and CA–NC junctions. Vif was resistant to PR action in vitro under conditions that allowed full Gag processing, and no direct interaction between Vif and PR was detected in vivo or in vitro. This suggested that inhibition by Vif of PR-mediated Gag processing resulted from interaction of Vif with the Gag substrate and not with the enzyme. Likewise, the higher efficiency of Vif encapsidation by Gag–Pol precursor compared with Pr55Gag was probably not mediated by direct binding of Vif to the Gag–Pol-embedded PR domain, but more likely resulted from a particular conformation of the Gag structural domains of the Gag–Pol precursor.

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Separation of Human Immunodeficiency Virus Type 1 Replication from nef-Mediated Pathogenesis in the Human Thymus

Journal of Virology ◽

10.1128/jvi.75.8.3916-3924.2001 ◽

2001 ◽

Vol 75 (8) ◽

pp. 3916-3924 ◽

Cited By ~ 21

Author(s):

Karen M. Duus ◽

Eric D. Miller ◽

Jonathan A. Smith ◽

Grigoriy I. Kovalev ◽

Lishan Su

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

In Vivo Model ◽

Immunodeficiency Virus ◽

Pathogenic Activity ◽

Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) is frequently attenuated after long-term culture in vitro. The attenuation process probably involves mutations of functions required for replication and pathogenicity in vivo. Analysis of attenuated HIV-1 for replication and pathogenicity in vivo will help to define these functions. In this study, we examined the pathogenicity of an attenuated HIV-1 isolate in a laboratory worker accidentally exposed to a laboratory-adapted HIV-1 isolate. Using heterochimeric SCID-hu Thy/Liv mice as an in vivo model, we previously defined HIV-1 env determinants (HXB/LW) that reverted to replicate in vivo (L. Su, H. Kaneshima, M. L. Bonyhadi, R. Lee, J. Auten, A. Wolf, B. Du, L. Rabin, B. H. Hahn, E. Terwilliger, and J. M. McCune, Virology 227:46–52, 1997). Here we further demonstrate that HIV-1 replication in vivo can be separated from its pathogenic activity, in that the HXB/LW virus replicated to high levels in SCID-hu Thy/Liv mice, with no significant thymocyte depletion. Restoration of the nef gene in the recombinant HXB/LW genome restored its pathogenic activity, with no significant effect on HIV-1 replication in the thymus. Our results suggest that in vitro-attenuated HIV-1 lacks determinants for pathogenicity as well as for replication in vivo. Our data indicate that (i) the replication defect can be recovered in vivo by mutations in the envgene, without an associated pathogenic phenotype, and (ii)nef can function in the HXB/LW clone as a pathogenic factor that does not enhance HIV-1 replication in the thymus. Furthermore, the HXB/LW virus may be used to study mechanisms of HIV-1nef-mediated pathogenesis in vivo.

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Increased Neutralization Sensitivity and Reduced Replicative Capacity of Human Immunodeficiency Virus Type 1 after Short-Term In Vivo or In Vitro Passage through Chimpanzees

Journal of Virology ◽

10.1128/jvi.74.17.7699-7707.2000 ◽

2000 ◽

Vol 74 (17) ◽

pp. 7699-7707 ◽

Cited By ~ 12

Author(s):

Tim Beaumont ◽

Silvia Broersen ◽

Ad van Nuenen ◽

Han G. Huisman ◽

Ana-Maria de Roda Husman ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Short Term ◽

Neutralization Sensitivity ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Development of disease is extremely rare in chimpanzees when inoculated with either T-cell-line-adapted neutralization-sensitive or primary human immunodeficiency virus type 1 (HIV-1), at first excluding a role for HIV-1 neutralization sensitivity in the clinical course of infection. Interestingly, we observed that short-term in vivo and in vitro passage of primary HIV-1 isolates through chimpanzee peripheral blood mononuclear cells (PBMC) resulted in a neutralization-sensitive phenotype. Furthermore, an HIV-1 variant reisolated from a chimpanzee 10 years after experimental infection was still sensitive to neutralization by soluble CD4, the CD4 binding site recognizing antibody IgG1b12 and autologous chimpanzee serum samples, but had become relatively resistant to neutralization by polyclonal human sera and neutralizing monoclonal antibodies. The initial adaptation of HIV-1 to replicate in chimpanzee PBMC seemed to coincide with a selection for viruses with low replicative kinetics. Neither coreceptor usage nor the expression level of CD4, CCR5, or CXCR4 on chimpanzee PBMC compared to human cells could explain the phenotypic changes observed in these chimpanzee-passaged viruses. Our data suggest that the increased neutralization sensitivity of HIV-1 after replication in chimpanzee cells may in part contribute to the long-term asymptomatic HIV-1 infection in experimentally infected chimpanzees.

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How Many Human Immunodeficiency Virus Type 1-Infected Target Cells Can a Cytotoxic T-Lymphocyte Kill?

Journal of Virology ◽

10.1128/jvi.79.21.13579-13586.2005 ◽

2005 ◽

Vol 79 (21) ◽

pp. 13579-13586 ◽

Cited By ~ 32

Author(s):

W. David Wick ◽

Otto O. Yang ◽

Lawrence Corey ◽

Steven G. Self

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Target Cells ◽

Immunodeficiency Virus ◽

Infected Cells ◽

Hiv 1

ABSTRACT The antiviral role of CD8+ cytotoxic T lymphocytes (CTLs) in human immunodeficiency virus type 1 (HIV-1) infection is poorly understood. Specifically, the degree to which CTLs reduce viral replication by killing HIV-1-infected cells in vivo is not known. Here we employ mathematical models of the infection process and CTL action to estimate the rate that CTLs can kill HIV-1-infected cells from in vitro and in vivo data. Our estimates, which are surprisingly consistent considering the disparities between the two experimental systems, demonstrate that on average CTLs can kill from 0.7 to 3 infected target cells per day, with the variability in this figure due to epitope specificity or other factors. These results are compatible with the observed decline in viremia after primary infection being primarily a consequence of CTL activity and have interesting implications for vaccine design.

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TRIM5 genotypes in cynomolgus monkeys primarily influence inter-individual diversity in susceptibility to monkey-tropic human immunodeficiency virus type 1

Journal of General Virology ◽

10.1099/vir.0.050252-0 ◽

2013 ◽

Vol 94 (6) ◽

pp. 1318-1324 ◽

Cited By ~ 9

Author(s):

Akatsuki Saito ◽

Masako Nomaguchi ◽

Ken Kono ◽

Yasumasa Iwatani ◽

Masaru Yokoyama ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Cynomolgus Monkeys ◽

Gene Variation ◽

Immunodeficiency Virus ◽

Hiv 1

TRIM5α restricts human immunodeficiency virus type 1 (HIV-1) infection in cynomolgus monkey (CM) cells. We previously reported that a TRIMCyp allele expressing TRIM5–cyclophilin A fusion protein was frequently found in CMs. Here, we examined the influence of TRIM5 gene variation on the susceptibility of CMs to a monkey-tropic HIV-1 derivative (HIV-1mt) and found that TRIMCyp homozygotes were highly susceptible to HIV-1mt not only in vitro but also in vivo. These results provide important insights into the inter-individual differences in susceptibility of macaques to HIV-1mt.

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