An HIV-induced mechanism for T cell quiescence and proviral latency

Abstract HIV persists in infected individuals despite effective antiretroviral therapy due to the rapid establishment of a latent HIV reservoir, mainly composed of quiescent memory CD4+ T cells1–3. The mechanisms governing the formation of the latent reservoir remain poorly understood. It is commonly assumed that entry of HIV into latency is a rare and random event associated with sporadic infection of effector T-cells transitioning to a memory phenotype4–8. Using human primary CD4+ T cell models, we show instead, that HIV infection itself triggers a strong transcriptomic remodeling that results in activation of a quiescence program, including downregulation of cellular proliferation and metabolic pathways. This transcriptional program is initiated by KLF2, a key regulator of quiescence, along with activation of the p53 pathway and downregulation of MYC. Loss and gain of function studies confirmed that KLF2 and p53 signaling are responsible for the downregulation of MYC and proliferation pathways, and consequently, proviral transcriptional silencing. Thus, HIV infection per se, enhances the formation of the latent reservoir in T-cells, ensuring viral persistence in infected individuals. These findings identify a new and unexpected mechanism for the formation of the latent HIV reservoir, and broaden the repertoire of strategies through which viruses can control the host cell to their advantage.

Download Full-text

FOXO1 promotes HIV Latency by suppressing ER stress in T cells

10.1101/2020.04.23.058123 ◽

2020 ◽

Author(s):

Albert Vallejo-Gracia ◽

Irene P. Chen ◽

Rosalba Perrone ◽

Emilie Besnard ◽

Daniela Boehm ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Hiv Infection ◽

Er Stress ◽

Viral Reservoir ◽

Activated T Cells ◽

Calcium Dependent ◽

Cell Quiescence ◽

Latently Infected ◽

Latent Hiv

AbstractQuiescence is a hallmark of CD4+ T cells latently infected with HIV-1. While reversing this quiescence is an effective approach to reactivate latent HIV from T cells in culture, it can cause deleterious cytokine dysregulation in patients. Here we report that FOXO1, a key regulator of T-cell quiescence, promotes latency and suppresses productive HIV infection. In resting T cells, FOXO1 inhibition induces ER stress and activates two associated transcription factors: activating transcription factor 4 (ATF4) and nuclear factor of activated T cells (NFAT). Both factors associate with HIV chromatin and are necessary for HIV reactivation. Indeed, inhibition of PKR-like endoplasmic reticulum kinase (PERK), a known link between ER stress and ATF4, and calcineurin, a calcium-dependent regulator of NFAT, synergistically suppress HIV reactivation induced by FOXO1 inhibition. Thus, our studies uncover a novel link between FOXO1, ER stress, and HIV infection that could be therapeutically exploited to selectively reverse T-cell quiescence and reduce the size of the latent viral reservoir.

Download Full-text

IL-15 regulates susceptibility of CD4+ T cells to HIV infection

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1806695115 ◽

2018 ◽

Vol 115 (41) ◽

pp. E9659-E9667 ◽

Cited By ~ 19

Author(s):

Lara Manganaro ◽

Patrick Hong ◽

Matthew M. Hernandez ◽

Dionne Argyle ◽

Lubbertus C. F. Mulder ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Hiv Infection ◽

Memory Cell ◽

Viral Reservoir ◽

Cell Infection ◽

Hiv Reservoir ◽

Sam Domain ◽

Reservoir Stimulation ◽

Immune Profiling

HIV integrates into the host genome to create a persistent viral reservoir. Stimulation of CD4+ memory T lymphocytes with common γc-chain cytokines renders these cells more susceptible to HIV infection, making them a key component of the reservoir itself. IL-15 is up-regulated during primary HIV infection, a time when the HIV reservoir established. Therefore, we investigated the molecular and cellular impact of IL-15 on CD4+ T-cell infection. We found that IL-15 stimulation induces SAM domain and HD domain-containing protein 1 (SAMHD1) phosphorylation due to cell cycle entry, relieving an early block to infection. Perturbation of the pathways downstream of IL-15 receptor (IL-15R) indicated that SAMHD1 phosphorylation after IL-15 stimulation is JAK dependent. Treating CD4+ T cells with Ruxolitinib, an inhibitor of JAK1 and JAK2, effectively blocked IL-15–induced SAMHD1 phosphorylation and protected CD4+ T cells from HIV infection. Using high-resolution single-cell immune profiling using mass cytometry by TOF (CyTOF), we found that IL-15 stimulation altered the composition of CD4+ T-cell memory populations by increasing proliferation of memory CD4+ T cells, including CD4+ T memory stem cells (TSCM). IL-15–stimulated CD4+ TSCM, harboring phosphorylated SAMHD1, were preferentially infected. We propose that IL-15 plays a pivotal role in creating a self-renewing, persistent HIV reservoir by facilitating infection of CD4+ T cells with stem cell-like properties. Time-limited interventions with JAK1 inhibitors, such as Ruxolitinib, should prevent the inactivation of the endogenous restriction factor SAMHD1 and protect this long-lived CD4+ T-memory cell population from HIV infection.

Download Full-text

Effects of Prostratin on T-Cell Activation and Human Immunodeficiency Virus Latency

Journal of Virology ◽

10.1128/jvi.76.16.8118-8123.2002 ◽

2002 ◽

Vol 76 (16) ◽

pp. 8118-8123 ◽

Cited By ~ 155

Author(s):

Yael D. Korin ◽

David G. Brooks ◽

Stephen Brown ◽

Andrew Korotzer ◽

Jerome A. Zack

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Hiv Infection ◽

Cell Activation ◽

Cellular Proliferation ◽

Latent Virus ◽

Immunodeficiency Virus ◽

Latently Infected ◽

Infected Cells ◽

Latent Hiv

ABSTRACT Human immunodeficiency virus (HIV) replication is linked to cellular gene transcription and requires target cell activation. The latent reservoir of HIV-1 in quiescent T cells is thought to be a major obstacle to clearance of infection by highly active antiretroviral therapy (HAART). Thus, identification of agents that can induce expression of latent virus may, in the presence of HAART, allow elimination of the infected cells by the immune response. We previously used the SCID-hu (Thy/Liv) mouse model to establish that activation-inducible HIV can be generated at high frequency during thymopoiesis. Latently infected mature thymocytes can be exported into the periphery, providing an efficient primary cell model to determine cellular activation signals that induce renewed expression of latent virus. Here we characterized the effects of prostratin, a non-tumor-promoting phorbol ester, on primary human peripheral blood lymphocytes (PBLs) and assessed its ability to reactivate latent HIV infection from thymocytes and PBLs in the SCID-hu (Thy/Liv) model. Prostratin stimulation alone did not induce proliferation of quiescent PBLs; however, it could provide a secondary signal in the context of T-cell receptor stimulation or a primary activation signal in the presence of CD28 stimulation to induce T-cell proliferation. While prostratin alone was not sufficient to allow de novo HIV infection, it efficiently reactivated HIV expression from latently infected cells generated in the SCID-hu mouse. Our data indicate that prostratin alone is able to specifically reactivate latent virus in the absence of cellular proliferation, making it an attractive candidate for further study as an adjunctive therapy for the elimination of the latent HIV reservoir.

Download Full-text

Impact of Biological Sex on Immune Activation and Frequency of the Latent HIV Reservoir During Suppressive Antiretroviral Therapy

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa298 ◽

2020 ◽

Vol 222 (11) ◽

pp. 1843-1852 ◽

Cited By ~ 3

Author(s):

Shane D Falcinelli ◽

Bonnie E Shook-Sa ◽

Morgan G Dewey ◽

Sumati Sridhar ◽

Jenna Read ◽

...

Keyword(s):

T Cells ◽

Antiretroviral Therapy ◽

Hiv Infection ◽

Immune Activation ◽

Cd4 T Cells ◽

Acute Infection ◽

Interferon Response ◽

Suppressive Therapy ◽

Hiv Reservoir ◽

Latent Hiv

Abstract Background Persistent HIV infection of long-lived resting CD4 T cells, despite antiretroviral therapy (ART), remains a barrier to HIV cure. Women have a more robust type 1 interferon response during HIV infection relative to men, contributing to lower initial plasma viremia. As lower viremia during acute infection is associated with reduced frequency of latent HIV infection, we hypothesized that women on ART would have a lower frequency of latent HIV compared to men. Methods ART-suppressed, HIV seropositive women (n = 22) were matched 1:1 to 22 of 39 ART-suppressed men. We also compared the 22 women to all 39 men, adjusting for age and race as covariates. We measured the frequency of latent HIV using the quantitative viral outgrowth assay, the intact proviral DNA assay, and total HIV gag DNA. We also performed activation/exhaustion immunophenotyping on peripheral blood mononuclear cells and quantified interferon-stimulated gene (ISG) expression in CD4 T cells. Results We did not observe evident sex differences in the frequency of persistent HIV in resting CD4 T cells. Immunophenotyping and CD4 T-cell ISG expression analysis revealed marginal differences across the sexes. Conclusions Differences in HIV reservoir frequency and immune activation appear to be small across sexes during long-term suppressive therapy.

Download Full-text

Establishment and Reversal of HIV-1 Latency in Naive and Central Memory CD4+T CellsIn Vitro

Journal of Virology ◽

10.1128/jvi.00553-16 ◽

2016 ◽

Vol 90 (18) ◽

pp. 8059-8073 ◽

Cited By ~ 20

Author(s):

Jennifer M. Zerbato ◽

Erik Serrao ◽

Gina Lenzi ◽

Baek Kim ◽

Zandrea Ambrose ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Central Memory ◽

T Cell Subsets ◽

Latent Reservoir ◽

Memory Cells ◽

Consistent Finding ◽

Latent Hiv ◽

Hiv 1 ◽

Reversing Agents

ABSTRACTThe latent HIV-1 reservoir primarily resides in resting CD4+T cells which are a heterogeneous population composed of both naive (TN) and memory cells. In HIV-1-infected individuals, viral DNA has been detected in both naive and memory CD4+T cell subsets although the frequency of HIV-1 DNA is typically higher in memory cells, particularly in the central memory (TCM) cell subset. TNand TCMcells are distinct cell populations distinguished by many phenotypic and physiological differences. In this study, we used a primary cell model of HIV-1 latency that utilizes direct infection of highly purified TNand TCMcells to address differences in the establishment and reversal of HIV-1 latency. Consistent with what is seenin vivo, we found that HIV-1 infected TNcells less efficiently than TCMcells. However, when the infected TNcells were treated with latency-reversing agents, including anti-CD3/CD28 antibodies, phorbol myristate acetate/phytohemagglutinin, and prostratin, as much (if not more) extracellular virion-associated HIV-1 RNA was produced per infected TNcell as per infected TCMcell. There were no major differences in the genomic distribution of HIV-1 integration sites between TNand TCMcells that accounted for these observed differences. We observed decay of the latent HIV-1 cells in both T cell subsets after exposure to each of the latency-reversing agents. Collectively, these data highlight significant differences in the establishment and reversal of HIV-1 latency in TNand TCMCD4+T cells and suggest that each subset should be independently studied in preclinical and clinical studies.IMPORTANCEThe latent HIV-1 reservoir is frequently described as residing within resting memory CD4+T cells. This is largely due to the consistent finding that memory CD4+T cells, specifically the central (TCM) and transitional memory compartments, harbor the highest levels of HIV-1 DNA in individuals on suppressive therapy. This has yielded little research into the contribution of CD4+naive T (TN) cells to the latent reservoir. In this study, we show that although TNcells harbor significantly lower levels of HIV-1 DNA, following latency reversal, they produced as many virions as did the TCMcells (if not more virions). This suggests that latently infected TNcells may be a major source of virus following treatment interruption or failure. These findings highlight the need for a better understanding of the establishment and reversal of HIV-1 latency in TNcells in evaluating therapeutic approaches to eliminate the latent reservoir.

Download Full-text

The CCL2 Chemokine Promotes Early Seeding of the Latent HIV Reservoir

10.1101/2021.02.25.432826 ◽

2021 ◽

Author(s):

Thomas A. Packard ◽

Roland Schwarzer ◽

Eytan Herzig ◽

Deepashri Rao ◽

Xiaoyu Luo ◽

...

Keyword(s):

T Cells ◽

Inflammatory Response ◽

Hiv Infection ◽

Cd4 T Cells ◽

Central Memory ◽

Humanized Mice ◽

Hiv Reservoir ◽

Latent Hiv ◽

Memory Cd4 T Cells

ABSTRACTHIV infects long-lived CD4 memory T cells establishing a latent viral reservoir that necessitates lifelong anti-retroviral therapy (ART). How this reservoir is formed so swiftly remains unknown. We now show the innate inflammatory response to HIV infection results in CCL2 chemokine release, which can drive recruitment of cells expressing the CCR2 receptor including a subset of central memory CD4 T cells. Supporting a role for the CCL2/CCR2 axis in rapid reservoir formation, we find 1) treatment of humanized mice with anti-CCL2 antibodies during HIV infection decreases reservoir seeding and 2) CCR2/5+ cells from the blood of HIV-infected individuals on long term ART contain significantly more provirus than CCR2/5-negative memory or naïve cells. Together, these studies support a model where the host’s innate inflammatory CCL2 response to HIV infection recruits CCR2/5+ central memory CD4 T cells to zones of virus-associated inflammation likely contributing to rapid formation of the latent HIV reservoir.GRAPHICAL ABSTRACTWhy is the latent HIV reservoir established so early following infection? An innate immune response occurs during acute infection that establishes a “zone of inflammation” (step 1). The CCL2 chemokine is produced in part through IFI16 sensing of HIV DNA in abortively infected cells. CCL2 promotes rapid recruitment of CCR2/5+ memory CD4 T cells (step 2). Many of these cells become productively infected (step 3) and a fraction become latently infected (step 4). Thus, HIV hijacks the host inflammatory response to rapidly establish the latent reservoir. In support of this model, we find HIV reservoir reduction in humanized mice treated with anti-CCL2 antibodies during early infection. Further, we find that CCR2/5+ CD4 T cells harbor a substantial fraction of detectable proviruses in the blood of HIV-infected individuals on long-term suppressive ART.Abstract Figure

Download Full-text

Systems analysis by mass cytometry identifies susceptibility of latent HIV-infected T cells to targeting of p38 and mTOR pathways

10.1101/371922 ◽

2018 ◽

Author(s):

Linda E. Fong ◽

Victor L. Bass ◽

Serena Spudich ◽

Kathryn Miller-Jensen

Keyword(s):

T Cells ◽

T Cell ◽

Cd4 T Cells ◽

Ex Vivo ◽

Viral Reactivation ◽

Latent Reservoir ◽

Kinase Signaling ◽

Mass Cytometry ◽

Latently Infected ◽

Latent Hiv

AbstractEfforts to cure HIV are hindered by viral persistence in latently infected memory CD4+ T cells. Targeting T cell death pathways dysregulated by HIV infection offers a novel approach for eradication of the latent reservoir. To identify potential therapeutic targets, we compared signaling and apoptosis in uninfected and latently infected primary cultured CD4+ central memory T cells by mass cytometry following T cell receptor stimulation. We found that HIV-infected cells were sensitized to activation of pro-apoptotic p38 kinase signaling via p53, and to inhibition of anti-apoptotic mTOR kinase signaling, even without HIV protein expression. Simultaneous targeting of p38 and mTOR kinases in resting CD4+ T cells from virally-suppressed HIV+ patientsex vivoreduced cell-associated HIV RNA and DNA. Our results demonstrate how systems biology approaches are useful for identifying novel therapeutic approaches to treat HIV latency, and further suggest that it may be possible to deplete latent HIV-infected T cells without viral reactivation.

Download Full-text

Increases in T Cell Telomere Length in HIV Infection after Antiretroviral Combination Therapy for HIV-1 Infection Implicate Distinct Population Dynamics in CD4+ and CD8+ T Cells

Clinical Immunology ◽

10.1006/clim.1999.4726 ◽

1999 ◽

Vol 92 (1) ◽

pp. 14-24 ◽

Cited By ~ 22

Author(s):

Sumesh Kaushal ◽

Alan L. Landay ◽

Michael M. Lederman ◽

Elizabeth Connick ◽

John Spritzler ◽

...

Keyword(s):

T Cells ◽

Population Dynamics ◽

T Cell ◽

Combination Therapy ◽

Hiv Infection ◽

Telomere Length ◽

Cd8 T Cells ◽

Distinct Population ◽

Hiv 1

Download Full-text

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

Journal of Virology ◽

10.1128/jvi.79.5.3195-3199.2005 ◽

2005 ◽

Vol 79 (5) ◽

pp. 3195-3199 ◽

Cited By ~ 15

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.

Download Full-text