scholarly journals Evidence of CD8+ T-Cell-Mediated Selective Pressure on Human Immunodeficiency Virus Type 1 nef in HLA-B*57+ Elite Suppressors

2008 ◽  
Vol 83 (1) ◽  
pp. 88-97 ◽  
Author(s):  
Justin R. Bailey ◽  
Timothy P. Brennan ◽  
Karen A. O'Connell ◽  
Robert F. Siliciano ◽  
Joel N. Blankson
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Selective Pressure ◽  
Plasma Virus ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Elite Suppressors ◽  
Hiv 1

ABSTRACT Elite suppressors (ES) are human immunodeficiency virus type 1 (HIV-1)-infected patients who maintain viral loads of <50 copies/ml without treatment. The observation that the HLA-B*57 allele is overrepresented in these patients implies that HIV-1-specific CD8+ T cells play a key role in suppressing viral replication. We have previously shown that while CD8+ T-cell escape mutations are rarely seen in proviral Gag sequences in resting CD4+ T cells from peripheral blood, they are present in every clone amplified from the low levels of free virus in the plasma of HLA-B*57+ ES. In this study, we compared the pattern of mutations in Nef sequences amplified from peripheral blood CD4+ T cells and from plasma virus. We show that Nef mutations are present in plasma virus but are rare in the cellular sequences and provide evidence that these plasma Nef variants represent novel escape mutants. The results provide further evidence of CD8+ T-cell-mediated selective pressure on plasma virus in ES and suggest that there must be ongoing HIV-1 replication in spite of the very low viral loads seen for these patients.

scholarly journals Preservation of FoxP3+ Regulatory T Cells in the Peripheral Blood of Human Immunodeficiency Virus Type 1-Infected Elite Suppressors Correlates with Low CD4+ T-Cell Activation

2008 ◽  
Vol 82 (17) ◽  
pp. 8307-8315 ◽  
Author(s):  
Amanda J. Chase ◽  
Hung-Chih Yang ◽  
Hao Zhang ◽  
Joel N. Blankson ◽  
Robert F. Siliciano
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Human Immunodeficiency Virus Type ◽  
Peripheral Blood ◽  
Immunodeficiency Virus ◽  
Elite Suppressors ◽  
Hiv 1

ABSTRACT Elite suppressors (ES) are untreated human immunodeficiency virus type 1 (HIV-1)-infected individuals who maintain normal CD4+ T-cell counts and control viremia to levels that are below the limit of detection of current assays. The mechanisms involved in long-term control of viremia have not been fully elucidated. CD4+ CD25+ regulatory T cells (Tregs) downmodulate chronic inflammation by suppressing the activation and proliferation of effector lymphocytes. We found that while Tregs were functional in ES and patients on highly active antiretroviral therapy (HAART), ES maintained high levels of Tregs in peripheral blood mononuclear cells whereas patients on HAART had evidence of Treg depletion. We also demonstrated that Tregs can serve as reservoirs for HIV-1 in vivo. These data suggest that both direct infection by HIV-1 and tissue redistribution are possible explanations for declining FoxP3+ Tregs in progressive HIV-1 infection. Furthermore, the maintenance of Tregs may be one mechanism associated with the nonprogressive nature of HIV-1 infection in ES.

scholarly journals Interleukin 7 Increases Human Immunodeficiency Virus Type 1 LAI-Mediated Fas-Induced T-Cell Death

2005 ◽  
Vol 79 (5) ◽  
pp. 3195-3199 ◽  
Author(s):  
Jean-Daniel Lelièvre ◽  
Frédéric Petit ◽  
Damien Arnoult ◽  
Jean-Claude Ameisen ◽  
Jérôme Estaquier
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Hiv Infection ◽  
Cell Infection ◽  
Interleukin 7 ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Fas-mediated T-cell death is known to occur during human immunodeficiency virus (HIV) infection. In this study, we found that HIV type 1 LAI (HIV-1LAI) primes CD8+ T cells from healthy donors for apoptosis, which occurs after Fas ligation. This effect is counteracted by a broad caspase inhibitor (zVAD-fmk). Fas-mediated cell death does not depend on CD8+ T-cell infection, because it occurred in the presence of reverse transcriptase inhibitors. However, purified CD8+ T cells are sensitive to Fas only in the presence of soluble CD4. Finally, we found that interleukin 7 (IL-7) increases Fas-mediated CD4+ and CD8+ T-cell death induced by HIV-1LAI. Since high levels of IL-7 are a marker of poor prognosis during HIV infection, our data suggest that enhancement of Fas-mediated T-cell death by HIV-1LAI and IL-7 is one of the mechanisms involved in progression to AIDS.

scholarly journals Requirement for an Intact T-Cell Actin and Tubulin Cytoskeleton for Efficient Assembly and Spread of Human Immunodeficiency Virus Type 1

2007 ◽  
Vol 81 (11) ◽  
pp. 5547-5560 ◽  
Author(s):  
Clare Jolly ◽  
Ivonne Mitar ◽  
Quentin J. Sattentau
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Plasma Membrane ◽  
T Cell ◽  
Immunodeficiency Virus ◽  
Fixed Cell ◽  
Cell Spread ◽  
Hiv 1 ◽  
Cell Cell

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T cells leads to the production of new virions that assemble at the plasma membrane. Gag and Env accumulate in the context of lipid rafts at the inner and outer leaflets of the plasma membrane, respectively, forming polarized domains from which HIV-1 buds. HIV-1 budding can result in either release of cell-free virions or direct cell-cell spread via a virological synapse (VS). The recruitment of Gag and Env to these plasma membrane caps in T cells is poorly understood but may require elements of the T-cell secretory apparatus coordinated by the cytoskeleton. Using fixed-cell immunofluorescence labeling and confocal microscopy, we observed a high percentage of HIV-1-infected T cells with polarized Env and Gag in capped, lipid raft-like assembly domains. Treatment of infected T cells with inhibitors of actin or tubulin remodeling disrupted Gag and Env compartmentalization within the polarized raft-like domains. Depolymerization of the actin cytoskeleton reduced Gag release and viral infectivity, and actin and tubulin inhibitors reduced Env incorporation into virions. Live- and fixed-cell confocal imaging and assay of de novo DNA synthesis by real-time PCR allowed quantification of HIV-1 cell-cell transfer. Inhibition of actin and tubulin remodeling in infected cells interfered with cell-cell spread across a VS and reduced new viral DNA synthesis. Based on these data, we propose that HIV-1 requires both actin and tubulin components of the T-cell cytoskeleton to direct its assembly and budding and to elaborate a functional VS.

scholarly journals Activation of the CD95 (APO-1/Fas) system in T cells from human immunodeficiency virus type-1-infected children

Blood ◽  
1996 ◽  
Vol 88 (5) ◽  
pp. 1741-1746 ◽  
Author(s):  
CB Baumler ◽  
T Bohler ◽  
I Herr ◽  
A Benner ◽  
PH Krammer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Depletion ◽  
T Cell Depletion ◽  
Immunodeficiency Virus ◽  
Hiv 1

Abstract Increased apoptosis of CD4+ T cells is considered to be involved in CD4+ T-cell depletion in human immunodeficiency virus type-1 (HIV-1)- infected individuals progressing toward acquired immunodeficiency syndrome (AIDS). We have recently shown that CD95 (APO-1/Fas) expression is strongly increased in T cells of HIV-1-infected children. In this report we provide further evidence for a deregulated CD95 system in AIDS. CD95 expression in HIV-1+ children is not restricted to previously activated CD45RO+ T cells but is also increased on freshly isolated naive CD45RA+ T cells. In addition, specific CD95-mediated apoptosis is enhanced in both CD4+ and CD8+ T cells. Furthermore, levels of CD95 ligand mRNA are profoundly increased. Specific T-cell receptor/CD3-triggered apoptosis in HIV-1+ children is more enhanced in CD8+ than in CD4+ T cells. Accelerated activation induced cell death of T cells could partially be inhibited by blocking anti-CD95 antibody fragments. These data suggest an involvement of the CD95 receptor/ligand system in T-cell depletion and apoptosis in AIDS and may open new avenues of rational intervention strategies.

scholarly journals Human Immunodeficiency Virus Type 1 Derived from Cocultures of Immature Dendritic Cells with Autologous T Cells Carries T-Cell-Specific Molecules on Its Surface and Is Highly Infectious

1999 ◽  
Vol 73 (4) ◽  
pp. 3449-3454 ◽  
Author(s):  
Ines Frank ◽  
Laco Kacani ◽  
Heribert Stoiber ◽  
Hella Stössel ◽  
Martin Spruth ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cell Surface ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT During the budding process, human immunodeficiency virus type 1 (HIV-1) acquires cell surface molecules; thus, the viral surface of HIV-1 reflects the antigenic pattern of the host cell. To determine the source of HIV-1 released from cocultures of dendritic cells (DC) with T cells, immature DC (imDC), mature DC (mDC), T cells, and their cocultures were infected with different HIV-1 isolates. The macrophage-tropic HIV-1 isolate Ba-L allowed viral replication in both imDC and mDC, whereas the T-cell-line-tropic primary isolate PI21 replicated in mDC only. By a virus capture assay, HIV-1 was shown to carry a T-cell- or DC-specific cell surface pattern after production by T cells or DC, respectively. Upon cocultivation of HIV-1-pulsed DC with T cells, HIV-1 exclusively displayed a typical T-cell pattern. Additionally, functional analysis revealed that HIV-1 released from imDC–T-cell cocultures was more infectious than HIV-1 derived from mDC–T-cell cocultures and from cultures of DC, T cells, or peripheral blood mononuclear cells alone. Therefore, we conclude that the interaction of HIV-1-pulsed imDC with T cells in vivo might generate highly infectious virus which primarily originates from T cells.

scholarly journals Control of Viremia and Prevention of Simian-Human Immunodeficiency Virus-Induced Disease in Rhesus Macaques Immunized with Recombinant Vaccinia Viruses plus Inactivated Simian Immunodeficiency Virus and Human Immunodeficiency Virus Type 1 Particles

2003 ◽  
Vol 77 (2) ◽  
pp. 1163-1174 ◽  
Author(s):  
Ronald L. Willey ◽  
Russ Byrum ◽  
Michael Piatak ◽  
Young B. Kim ◽  
Michael W. Cho ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Recombinant Vaccinia ◽  
Immunodeficiency Virus ◽  
Vaccinia Viruses ◽  
Hiv 1

ABSTRACT An effective vaccine against the human immunodeficiency virus type 1 (HIV-1) will very likely have to elicit both cellular and humoral immune responses to control HIV-1 strains of diverse geographic and genetic origins. We have utilized a pathogenic chimeric simian-human immunodeficiency virus (SHIV) rhesus macaque animal model system to evaluate the protective efficacy of a vaccine regimen that uses recombinant vaccinia viruses expressing simian immunodeficiency virus (SIV) and HIV-1 structural proteins in combination with intact inactivated SIV and HIV-1 particles. Following virus challenge, control animals experienced a rapid and complete loss of CD4+ T cells, sustained high viral loads, and developed clinical disease by 17 to 21 weeks. Although all of the vaccinated monkeys became infected, they displayed reduced postpeak viremia, had no significant loss of CD4+ T cells, and have remained healthy for more than 15 months postinfection. CD8+ T-cell and neutralizing antibody responses in vaccinated animals following challenge were demonstrable. Despite the control of disease, virus was readily isolated from the circulating peripheral blood mononuclear cells of all vaccinees at 22 weeks postchallenge, indicating that immunologic control was incomplete. Virus recovered from the animal with the lowest postchallenge viremia generated high virus loads and an irreversible loss of CD4+ T-cell loss following its inoculation into a naïve animal. These results indicate that despite the protection from SHIV-induced disease, the vaccinated animals still harbored replication-competent and pathogenic virus.

scholarly journals Induction of Potent CD8+ T-Cell Responses by Novel Biodegradable Nanoparticles Carrying Human Immunodeficiency Virus Type 1 gp120

2007 ◽  
Vol 81 (18) ◽  
pp. 10009-10016 ◽  
Author(s):  
Xin Wang ◽  
Tomofumi Uto ◽  
Takami Akagi ◽  
Mitsuru Akashi ◽  
Masanori Baba
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Memory T Cells ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The mainstream of recent anti-AIDS vaccines is a prime/boost approach with multiple doses of the target DNA of human immunodeficiency virus type 1 (HIV-1) and recombinant viral vectors. In this study, we have attempted to construct an efficient protein-based vaccine using biodegradable poly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs), which are capable of inducing potent cellular immunity. A significant expansion of CD8+ T cells specific to the major histocompatibility complex class I-restricted gp120 epitope was observed in mice intranasally immunized once with gp120-carrying NPs but not with gp120 alone or gp120 together with the B-subunit of cholera toxin. Both the gp120-encapsulating and -immobilizing forms of NPs could induce antigen-specific spleen CD8+ T cells having a functional profile of cytotoxic T lymphocytes. Long-lived memory CD8+ T cells could also be elicited. Although a substantial decay in the effector memory T cells was observed over time in the immunized mice, the central memory T cells remained relatively constant from day 30 to day 238 after immunization. Furthermore, the memory CD8+ T cells rapidly expanded with boosting with the same immunogen. In addition, γ-PGA NPs were found to be a much stronger inducer of antigen-specific CD8+ T-cell responses than nonbiodegradable polystyrene NPs. Thus, γ-PGA NPs carrying various HIV-1 antigens may have great potential as a novel priming and/or boosting tool in current vaccination regimens for the induction of cellular immune responses.

scholarly journals Production of a Dendritic Cell-Based Vaccine Containing Inactivated Autologous Virus for Therapy of Patients with Chronic Human Immunodeficiency Virus Type 1 Infection

2008 ◽  
Vol 16 (2) ◽  
pp. 233-240 ◽  
Author(s):  
Theresa L. Whiteside ◽  
Paolo Piazza ◽  
Amanda Reiter ◽  
Joanna Stanson ◽  
Nancy C. Connolly ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
Human Immunodeficiency Virus Type ◽  
Endogenous Virus ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT In preparation for a pilot clinical trial in patients with chronic human immunodeficiency virus type 1 (HIV-1) infection, a novel dendritic cell (DC)-based vaccine is being manufactured. The trial will test the hypothesis that isolated endogenous virus presented by DCs serves as a potent immunogen for activation of CD8+ and CD4+ T cells specific for a broad range of autologous HIV-1 antigens. Production of the vaccine under good manufacture practice conditions involves (i) autologous virus isolation; (ii) superinfection of CD4+ T cells with the virus; (iii) inactivation of the virus in CD4+ T cells, T-cell apoptosis, and coincubation of T cells with autologous DCs; and (iv) product testing and release. Endogenous virus was isolated from peripheral blood-derived CD4+ T cells of three HIV-1-positive subjects by coincubation with autologous OKT-3-stimulated CD4+ T cells. CD4+ T-cell supernatants were tested for p24 levels by enzyme-linked immunosorbent assay (>25 ng/ml) and for the 50% tissue culture infective doses (TCID50; which ranged from 4,642 to 46,416/ml on day 19 of culture). Autologous CD4+ T cells that were separated on immunobeads (>95% purity) and superinfected with virus-expressed p24 (28 to 54%) had TCID50 of >400/ml on days 5 to 10. Virus inactivation with psoralen (20 μg/ml) and UVB irradiation (312 nm) reduced the TCID50 of the supernatants from 199,986 to 11/ml (>99%). 7-Amino-actinomycin D-positive, annexin V-positive CD4+ T cells were fed to autologous DCs generated by using the Elutra cell separation system and the Aastrom system. Flow analysis showed that DC loading was complete in 24 h. On the basis of these translational results and experience with the generation of DCs from HIV-1-infected patients in a previous clinical trial, the Investigational New Drug application for clinical vaccination was submitted and approved by the FDA (application no. BB-IND-13137).

scholarly journals Cytopathic Effects of Non-Syncytium-Inducing and Syncytium-Inducing Human Immunodeficiency Virus Type 1 Variants on Different CD4+-T-Cell Subsets Are Determined Only by Coreceptor Expression

2001 ◽  
Vol 75 (21) ◽  
pp. 10455-10459 ◽  
Author(s):  
David Kwa ◽  
Jose Vingerhoed ◽  
Brigitte Boeser-Nunnink ◽  
Silvia Broersen ◽  
Hanneke Schuitemaker
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Subset ◽  
T Cell Subsets ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT In peripheral blood mononuclear cells, syncytium-inducing (SI) human immunodeficiency virus type 1 (HIV-1) infected and depleted all CD4+ T cells, including naive T cells. Non-SI HIV-1 infected and depleted only the CCR5-expressing T-cell subset. This may explain the accelerated CD4 cell loss after SI conversion in vivo.

scholarly journals Displacement of SATB1-Bound Histone Deacetylase 1 Corepressor by the Human Immunodeficiency Virus Type 1 Transactivator Induces Expression of Interleukin-2 and Its Receptor in T Cells

2005 ◽  
Vol 25 (5) ◽  
pp. 1620-1633 ◽  
Author(s):  
P. Pavan Kumar ◽  
Prabhat Kumar Purbey ◽  
Dyavar S. Ravi ◽  
Debashis Mitra ◽  
Sanjeev Galande
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Histone Deacetylase ◽  
Interleukin 2 ◽  
Histone Deacetylase 1 ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT One hallmark of human immunodeficiency virus type 1 (HIV-1) infection is the dysregulation of cytokine gene expression in T cells. Transfection of T cells with human T-cell leukemia type 1 or 2 transactivator results in the induction of the T-cell-restricted cytokine interleukin-2 (IL-2) and its receptor (IL-2Rα). However, no T-cell-specific factor(s) has been directly linked with the regulation of IL-2 and IL-2Rα transcription by influencing the promoter activity. Thymocytes from SATB1 (special AT-rich sequence binding protein 1) knockout mice have been shown to ectopically express IL-2Rα, suggesting involvement of SATB1 in its negative regulation. Here we show that SATB1, a T-cell-specific global gene regulator, binds to the promoters of human IL-2 and IL-2Rα and recruits histone deacetylase 1 (HDAC1) in vivo. SATB1 also interacts with Tat in HIV-1-infected T cells. The functional interaction between HIV-1 Tat and SATB1 requires its PDZ-like domain, and the binding of the HDAC1 corepressor occurs through the same. Furthermore, Tat competitively displaces HDAC1 that is bound to SATB1, leading to increased acetylation of the promoters in vivo. Transduction with SATB1 interaction-deficient soluble Tat (Tat 40-72) and reporter assays using a transactivation-negative mutant (C22G) of Tat unequivocally demonstrated that the displacement of HDAC1 itself is sufficient for derepression of these promoters in vivo. These results suggest a novel mechanism by which HIV-1 Tat might overcome SATB1-mediated repression in T cells.

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