Exosomes from Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Cells License Quiescent CD4+ T Lymphocytes To Replicate HIV-1 through a Nef- and ADAM17-Dependent Mechanism

We have established long-term cultures of several cell lines stably and uniformly expressing human immunodeficiency virus type 1 (HIV-1) in order to (a) identify naturally processed HIV-1 peptides recognized by cytotoxic T lymphocytes (CTL) from HIV-1-seropositive individuals and (b) consider the hypothesis that naturally occurring epitope densities on HIV-infected cells may limit their lysis by CTL. Each of two A2-restricted CD8+ CTL specific for HIV-1 gag or reverse transcriptase (RT) recognized a single naturally processed HIV-1 peptide in trifluoroacetic acid (TFA) extracts of infected cells: gag 77-85 (SLYNTVATL) or RT 476-484 (ILKEPVHGV). Both processed peptides match the synthetic peptides that are optimally active in cytotoxicity assays and have the consensus motif described for A2-associated peptides. Their abundances were approximately 400 and approximately 12 molecules per infected Jurkat-A2 cell, respectively. Other synthetic HIV-1 peptides active at subnanomolar concentrations were not present in infected cells. Except for the antigen processing mutant line T2, HIV-infected HLA-A2+ cell lines were specifically lysed by both A2-restricted CTL, although infected Jurkat-A2 cells were lysed more poorly by RT-specific CTL than by gag-specific CTL, suggesting that low cell surface density of a natural peptide may limit the effectiveness of some HIV-specific CTL despite their vigorous activity against synthetic peptide-treated target cells.

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Comparative clonal analysis of human immunodeficiency virus type 1 (HIV-1)-specific CD4+ and CD8+ cytolytic T lymphocytes isolated from seronegative humans immunized with candidate HIV-1 vaccines.

Journal of Experimental Medicine ◽

10.1084/jem.176.6.1531 ◽

1992 ◽

Vol 176 (6) ◽

pp. 1531-1542 ◽

Cited By ~ 64

Author(s):

S A Hammond ◽

R C Bollinger ◽

P E Stanhope ◽

T C Quinn ◽

D Schwartz ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

T Lymphocytes ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Cytolytic T Lymphocytes ◽

Immunodeficiency Virus ◽

Infected Cells ◽

Hiv 1

The lysis of infected host cells by virus-specific cytolytic T lymphocytes (CTL) is an important factor in host resistance to viral infection. An optimal vaccine against human immunodeficiency virus type 1 (HIV-1) would elicit virus-specific CTL as well as neutralizing antibodies. The induction by a vaccine of HIV-1-specific CD8+ CTL in humans has not been previously reported. In this study, CTL responses were evaluated in HIV-1-seronegative human volunteers participating in a phase I acquired immune deficiency syndrome (AIDS) vaccine trial involving a novel vaccine regimen. Volunteers received an initial immunization with a live recombinant vaccinia virus vector carrying the HIV-1 env gene and a subsequent boost with purified env protein. An exceptionally strong env-specific CTL response was detected in one of two vaccine recipients, while modest but significant env-specific CTL activity was present in the second vaccinee. Cloning of the responding CTL gave both CD4+ and CD8+ env-specific CTL clones, permitting a detailed comparison of critical functional properties of these two types of CTL. In particular, the potential antiviral effects of these CTL were evaluated in an in vitro system involving HIV-1 infection of cultures of normal autologous CD4+ lymphoblasts. At extremely low effector-to-target ratios, vaccine-induced CD8+ CTL clones lysed productively infected cells present within these cultures. When tested for lytic activity against target cells expressing the HIV-1 env gene, CD8+ CTL were 3-10-fold more active on a per cell basis than CD4+ CTL. However, when tested against autologous CD4+ lymphoblasts acutely infected with HIV-1, CD4+ clones lysed a much higher fraction of the target cell population than did CD8+ CTL. CD4+ CTL were shown to recognize not only the infected cells within these acutely infected cultures but also noninfected CD4+ T cells that had passively taken up gp120 shed from infected cells and/or free virions. These results were confirmed in studies in which CD4+ lymphoblasts were exposed to recombinant gp120 and used as targets for gp120-specific CD4+ and CD8+ CTL clones. gp120-pulsed, noninfected targets were lysed in an antigen-specific fashion by CD4+ but not CD8+ CTL clones. Taken together, these observations demonstrate that in an in vitro HIV-1 infection, sufficient amounts of gp120 antigen are produced and shed by infected cells to enable uptake by cells that are not yet infected, resulting in the lysis of these noninfected cells by gp120-specific, CD4+ CTL.(ABSTRACT TRUNCATED AT 400 WORDS)

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Induction of Autophagy to Achieve a Human Immunodeficiency Virus Type 1 Cure

Cells ◽

10.3390/cells10071798 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1798

Author(s):

Grant R. Campbell ◽

Stephen A. Spector

Keyword(s):

Human Immunodeficiency Virus ◽

Antiretroviral Therapy ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Functional Cure ◽

Immunodeficiency Virus ◽

Latently Infected ◽

Infected Cells ◽

Hiv 1

Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.

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The Late-Domain-Containing Protein p6 Is the Predominant Phosphoprotein of Human Immunodeficiency Virus Type 1 Particles

Journal of Virology ◽

10.1128/jvi.76.3.1015-1024.2002 ◽

2002 ◽

Vol 76 (3) ◽

pp. 1015-1024 ◽

Cited By ~ 36

Author(s):

Barbara Müller ◽

Tilo Patschinsky ◽

Hans-Georg Kräusslich

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Metabolic Labeling ◽

Immunodeficiency Virus ◽

Infected Cells ◽

A Minor ◽

Hiv 1

ABSTRACT The Gag-derived protein p6 of human immunodeficiency virus type 1 (HIV-1) plays a crucial role in the release of virions from the membranes of infected cells. It is presumed that p6 and functionally related proteins from other viruses act as adapters, recruiting cellular factors to the budding site. This interaction is mediated by so-called late domains within the viral proteins. Previous studies had suggested that virus release from the plasma membrane shares elements with the cellular endocytosis machinery. Since protein phosphorylation is known to be a regulatory mechanism in these processes, we have investigated the phosphorylation of HIV-1 structural proteins. Here we show that p6 is the major phosphoprotein of HIV-1 particles. After metabolic labeling of infected cells with [ortho- 32P]phosphate, we found that phosphorylated p6 from infected cells and from virus particles consisted of several forms, suggesting differential phosphorylation at multiple sites. Apparently, phosphorylation occurred shortly before or after the release of p6 from Gag and involved only a minor fraction of the total virion-associated p6 molecules. Phosphoamino acid analysis indicated phosphorylation at Ser and Thr, as well as a trace of Tyr phosphorylation, supporting the conclusion that multiple phosphorylation events do occur. In vitro experiments using purified virus revealed that endogenous or exogenously added p6 was efficiently phosphorylated by virion-associated cellular kinase(s). Inhibition experiments suggested that a cyclin-dependent kinase or a related kinase, most likely ERK2, was involved in p6 phosphorylation by virion-associated enzymes.

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Human immunodeficiency virus type 1-infected individuals make autoantibodies that bind to CD43 on normal thymic lymphocytes.

Journal of Experimental Medicine ◽

10.1084/jem.172.4.1151 ◽

1990 ◽

Vol 172 (4) ◽

pp. 1151-1158 ◽

Cited By ~ 40

Author(s):

B Ardman ◽

M A Sikorski ◽

M Settles ◽

D E Staunton

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

T Lymphocytes ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Lupus Erythematosus ◽

Viral Infections ◽

Immunodeficiency Virus ◽

Hiv 1

Sera from human immunodeficiency virus type 1 (HIV-1)-infected and -noninfected individuals were screened for antibodies that could bind to native T cell differentiation antigens. Antibodies that could immunoprecipitate CD43 (sialophorin, leukosialin) from a T cell lymphoma line were detected in sera from 27% of patients, and antibodies that could bind specifically to transfected cells expressing CD43 were detected in 47% of patients. The anti-CD43 antibodies were related to HIV-1 infection in that no patients with other chronic viral infections or systemic lupus erythematosus contained such antibodies in their sera. The anti-CD43 autoantibodies bound to a partially sialylated form of CD43 expressed by normal human thymocytes, but not by normal, circulating T lymphocytes. However, the determinant(s) recognized by the anti-CD43 autoantibodies was present on a large proportion of circulating T lymphocytes, but masked from antibody recognition by sialic acid residues. These results demonstrate that HIV-1 infection is specifically associated with the production of autoantibodies that bind to a native T cell surface antigen.

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Inhibition of Human Immunodeficiency Virus Type 1 Transcription by Chemical Cyclin-Dependent Kinase Inhibitors

Journal of Virology ◽

10.1128/jvi.75.16.7266-7279.2001 ◽

2001 ◽

Vol 75 (16) ◽

pp. 7266-7279 ◽

Cited By ~ 97

Author(s):

Dai Wang ◽

Cynthia de la Fuente ◽

Longwen Deng ◽

Lai Wang ◽

Irene Zilberman ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Mononuclear Cells ◽

Virion Release ◽

Immunodeficiency Virus ◽

Infected Cells ◽

P21 Waf1 ◽

Hiv 1

ABSTRACT Cyclin-dependent kinases (cdk's) have recently been suggested to regulate human immunodeficiency virus type 1 (HIV-1) transcription. Previously, we have shown that expression of one cdk inhibitor, p21/Waf1, is abrogated in HIV-1 latently infected cells. Based on this result, we investigated the transcription of HIV-1 in the presence of chemical drugs that specifically inhibited cdk activity and functionally mimicked p21/Waf1 activity. HIV-1 production in virally integrated lymphocytic and monocytic cell lines, such as ACH2, 8E5, and U1, as well as activated peripheral blood mononuclear cells infected with syncytium-inducing (SI) or non-syncytium-inducing (NSI) HIV-1 strains, were all inhibited by Roscovitine, a purine derivative that reversibly competes for the ATP binding site present in cdk's. The decrease in viral progeny in the HIV-1-infected cells was correlated with a decrease in the transcription of HIV-1 RNAs in cells treated with Roscovitine and not with the non-cdk general cell cycle inhibitors, such as hydroxyurea (G1/S blocker) or nocodazole (M-phase blocker). Cyclin A- and E-associated histone H1 kinases, as well as cdk 7 and 9 activities, were all inhibited in the presence of Roscovitine. The 50% inhibitory concentration of Roscovitine on cdk's 9 and 7 was determined to be ∼0.6 μM. Roscovitine could selectively sensitize HIV-1-infected cells to apoptosis at concentrations that did not impede the growth and proliferation of uninfected cells. Apoptosis induced by Roscovitine was found in both latent and activated infected cells, as evident by Annexin V staining and the cleavage of the PARP protein by caspase-3. More importantly, contrary to many apoptosis-inducing agents, where the apoptosis of HIV-1-infected cells accompanies production and release of infectious HIV-1 viral particles, Roscovitine treatment selectively killed HIV-1-infected cells without virion release. Collectively, our data suggest that cdk's are required for efficient HIV-1 transcription and, therefore, we propose specific cdk inhibitors as potential antiviral agents in the treatment of AIDS.

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Cell-Free versus Cell-to-Cell Infection by Human Immunodeficiency Virus Type 1 and Human T-Lymphotropic Virus Type 1: Exploring the Link among Viral Source, Viral Trafficking, and Viral Replication

Journal of Virology ◽

10.1128/jvi.00407-16 ◽

2016 ◽

Vol 90 (17) ◽

pp. 7607-7617 ◽

Cited By ~ 24

Author(s):

Hélène Dutartre ◽

Mathieu Clavière ◽

Chloé Journo ◽

Renaud Mahieux

Keyword(s):

Human Immunodeficiency Virus ◽

T Lymphocytes ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Viral Escape ◽

Productive Infection ◽

T Lymphotropic Virus ◽

Immunodeficiency Virus ◽

Hiv 1

Human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type 1 (HTLV-1) are complex retroviruses mainly infecting CD4+T lymphocytes. In addition, antigen-presenting cells such as dendritic cells (DCs) are targetedin vivoby both viruses, although to a lesser extent. Interaction of HIV-1 with DCs plays a key role in viral dissemination from the mucosa to CD4+T lymphocytes present in lymphoid organs. While similar mechanisms may occur for HTLV-1 as well, most HTLV-1 data were obtained from T-cell studies, and little is known regarding the trafficking of this virus in DCs. We first compared the efficiency of cell-free versus cell-associated viral sources of both retroviruses at infecting DCs. We showed that both HIV-1 and HTLV-1 cell-free particles are poorly efficient at productively infecting DCs, except when DC-SIGN has been engaged. Furthermore, while SAMHD-1 accounts for restriction of cell-free HIV-1 infection, it is not involved in HTLV-1 restriction. In addition, cell-free viruses lead mainly to a nonproductive DC infection, leading totrans-infection of T-cells, a process important for HIV-1 spread but not for that of HTLV-1. Finally, we show that T-DC cell-to-cell transfer implies viral trafficking in vesicles that may both increase productive infection of DCs (“cis-infection”) and allow viral escape from immune surveillance. Altogether, these observations allowed us to draw a model of HTLV-1 and HIV-1 trafficking in DCs.

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Ubiquitination of the Human Immunodeficiency Virus Type 1 Env Glycoprotein

Journal of Virology ◽

10.1128/jvi.74.11.5373-5376.2000 ◽

2000 ◽

Vol 74 (11) ◽

pp. 5373-5376 ◽

Cited By ~ 13

Author(s):

Andreas Bültmann ◽

Josef Eberle ◽

Jürgen Haas

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Ubiquitin Proteasome System ◽

Immunodeficiency Virus ◽

Ubiquitin Proteasome ◽

Infected Cells ◽

Hiv 1 ◽

Env Glycoprotein

ABSTRACT Expression of the human immunodeficiency virus type 1 (HIV-1) Env glycoprotein is stringently regulated in infected cells. The majority of the glycoprotein does not reach the cell surface but rather is retained in the endoplasmic reticulum or a cis-Golgi compartment and subsequently degraded. We here report that Env of various HIV-1 isolates is ubiquitinated at the extracellular domain of gp41 and that Env expression could be increased by lactacystin, a specific proteasome inhibitor, suggesting that the ubiquitin/proteasome system is involved in control of expression and degradation.

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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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