scholarly journals Quantifying the turnover of transcriptional subclasses of HIV-1-infected cells

2013 ◽  
Author(s):  
Christian L Althaus ◽  
Beda Joos ◽  
Alan S Perelson ◽  
Huldrych F Günthard
Keyword(s):  
Peripheral Blood ◽  
Chronic Infection ◽  
Burst Size ◽  
Acute Infection ◽  
The Body ◽  
Latent Reservoir ◽  
Published Data ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

Background: HIV-1-infected cells in peripheral blood can be grouped into different transcriptional subclasses. Quantifying the turnover of these cellular subclasses can provide important insights into the viral life cycle and the generation and maintenance of latently infected cells. Results: We used previously published data from five patients chronically infected with HIV-1 that initiated combination antiretroviral therapy (cART). Patient-matched PCR for unspliced and multiply spliced viral RNAs combined with limiting dilution analysis provided measurements of transcriptional profiles at the single cell level. Furthermore, measurement of intracellular transcripts and extracellular virion-enclosed HIV-1 RNA allowed us to distinguish productive from non-productive cells. We developed a mathematical model describing the dynamics of plasma virus and the transcriptional subclasses of HIV-1-infected cells. Fitting the model to the data allowed us to better understand the phenotype of different transcriptional subclasses and their contribution to the overall turnover of HIV-1 before and during cART. The average number of virus-producing cells in peripheral blood is small during chronic infection (25.7 cells per ml). We find that 14.0%, 0.3% and 21.2% of infected cells become defectively, latently and persistently infected cells, respectively. Assuming that the infection is homogenous throughout the body, we estimate an average in vivo viral burst size of 2.1 x 10^4 virions per cell. Conclusions: Our study provides novel quantitative insights into the turnover and development of different subclasses of HIV-1-infected cells. The model predicts that the pool of latently infected cells becomes rapidly established during the first months of acute infection and continues to increase slowly during the first years of chronic infection. Having a detailed understanding of this process will be useful for the evaluation of viral eradication strategies that aim to deplete the latent reservoir of HIV-1.

scholarly journals Similar frequency and inducibility of intact HIV-1 proviruses in blood and lymph nodes

2020 ◽  
Author(s):  
Alyssa R Martin ◽  
Alexandra M Bender ◽  
Jada Hackman ◽  
Kyungyoon J Kwon ◽  
Briana A Lynch ◽  
...  
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Cd4 T Cells ◽  
Viral Rna ◽  
Latent Reservoir ◽  
Similar Frequency ◽  
Latently Infected ◽  
Infected Cells ◽  
Secondary Lymphoid Organs ◽  
Hiv 1

Abstract Background The HIV-1 latent reservoir (LR) in resting CD4 + T cells is a barrier to cure. LR measurements are commonly performed on blood samples and therefore may miss latently infected cells residing in tissues, including lymph nodes. Methods We determined the frequency of intact HIV-1 proviruses and proviral inducibility in matched peripheral blood (PB) and lymph node (LN) samples from ten HIV-1-infected patients on ART using the intact proviral DNA assay and a novel quantitative viral induction assay. Prominent viral sequences from induced viral RNA were characterized using a next-generation sequencing assay. Results The frequencies of CD4 + T cells with intact proviruses were not significantly different in PB vs LN (61vs104/10 6CD4 + cells), and were substantially lower than frequencies of CD4 + T cells with defective proviruses. The frequencies of CD4 + T cells induced to produce high levels of viral RNA were not significantly different in PB vs LN (4.3/10 6 vs 7.9/10 6), but were 14-fold lower than the frequencies of cells with intact proviruses. Sequencing of HIV-1 RNA from induced proviruses revealed comparable sequences in paired PB and LN samples. Conclusions These results further support the use of PB as an appropriate proxy for the HIV-1 LR in secondary lymphoid organs

scholarly journals Humanized Mouse Model of HIV-1 Latency with Enrichment of Latent Virus in PD-1+and TIGIT+CD4 T Cells

2019 ◽  
Vol 93 (10) ◽  
Author(s):  
George N. Llewellyn ◽  
Eduardo Seclén ◽  
Stephen Wietgrefe ◽  
Siyu Liu ◽  
Morgan Chateau ◽  
...  
Keyword(s):  
T Cells ◽  
Mouse Model ◽  
Ex Vivo ◽  
Latent Reservoir ◽  
Humanized Mouse ◽  
Humanized Mouse Model ◽  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

ABSTRACTCombination anti-retroviral drug therapy (ART) potently suppresses HIV-1 replication but does not result in virus eradication or a cure. A major contributing factor is the long-term persistence of a reservoir of latently infected cells. To study this reservoir, we established a humanized mouse model of HIV-1 infection and ART suppression based on an oral ART regimen. Similar to humans, HIV-1 levels in the blood of ART-treated animals were frequently suppressed below the limits of detection. However, the limited timeframe of the mouse model and the small volume of available samples makes it a challenging model with which to achieve full viral suppression and to investigate the latent reservoir. We therefore used anex vivolatency reactivation assay that allows a semiquantitative measure of the latent reservoir that establishes in individual animals, regardless of whether they are treated with ART. Using this assay, we found that latently infected human CD4 T cells can be readily detected in mouse lymphoid tissues and that latent HIV-1 was enriched in populations expressing markers of T cell exhaustion, PD-1 and TIGIT. In addition, we were able to use theex vivolatency reactivation assay to demonstrate that HIV-specific TALENs can reduce the fraction of reactivatable virus in the latently infected cell population that establishesin vivo, supporting the use of targeted nuclease-based approaches for an HIV-1 cure.IMPORTANCEHIV-1 can establish latent infections that are not cleared by current antiretroviral drugs or the body’s immune responses and therefore represent a major barrier to curing HIV-infected individuals. However, the lack of expression of viral antigens on latently infected cells makes them difficult to identify or study. Here, we describe a humanized mouse model that can be used to detect latent but reactivatable HIV-1 in both untreated mice and those on ART and therefore provides a simple system with which to study the latent HIV-1 reservoir and the impact of interventions aimed at reducing it.

scholarly journals Antigen responsive CD4+ T cell clones contribute to the HIV-1 latent reservoir

2020 ◽  
Author(s):  
Pilar Mendoza ◽  
Julia R. Jackson ◽  
Thiago Oliveira ◽  
Christian Gaebler ◽  
Victor Ramos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Latent Reservoir ◽  
Small Subset ◽  
T Cell Clones ◽  
Cell Clones ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

AbstractAntiretroviral therapy suppresses but does not cure HIV-1 infection due to the existence of a long-lived reservoir of latently infected cells. The reservoir has an estimated half-life of 44 months and is largely composed of clones of infected CD4+ T cells. The long half-life appears to result in part from expansion and contraction of infected CD4+ T cell clones. However, the mechanisms that govern this process are poorly understood. To determine whether the clones might result from, and be maintained by exposure to antigen, we measured responses of reservoir cells to a small subset of antigens from viruses that produce chronic or recurrent infections. Despite the limited panel of test antigens, clones of antigen responsive CD4+ T cells containing defective or intact latent proviruses were found in 7 out of 8 individuals studied. Thus, chronic or repeated exposure to antigen may contribute to the longevity of the HIV-1 reservoir by stimulating the clonal expansion of latently infected CD4+ T cells.

scholarly journals VIP-SPOT: an Innovative Assay To Quantify the Productive HIV-1 Reservoir in the Monitoring of Cure Strategies

mBio ◽  
2021 ◽  
Author(s):  
Maria C. Puertas ◽  
Ángel Bayón-Gil ◽  
Maria C. Garcia-Guerrero ◽  
Maria Salgado ◽  
Víctor Urrea ◽  
...  
Keyword(s):  
The Body ◽  
Continuous Treatment ◽  
Viral Reservoir ◽  
Functional Cure ◽  
Viral Eradication ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

Current efforts aimed at finding a definitive cure for HIV-1 infection are hampered mainly by the persistence of a viral reservoir in latently infected cells. While complete viral eradication from the body remains elusive, finding a functional cure to enable control of viremia without the need for continuous treatment is a key goal.

scholarly journals Strength of T cell signaling regulates HIV-1 replication and establishment of latency

2018 ◽  
Author(s):  
M Gagne ◽  
D Michaels ◽  
GM Schiralli Lester ◽  
WW Wong ◽  
S Gummuluru ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Signaling ◽  
Latent Reservoir ◽  
Binding Affinities ◽  
Antigen Receptors ◽  
T Cell Signaling ◽  
Chimeric Antigen Receptors ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

AbstractA major barrier to curing HIV is the long-lived latent reservoir that supports re-emergence of HIV upon treatment interruption. Targeting this reservoir will require mechanistic insights into the establishment and maintenance of HIV latency. Whether T cell signaling at the time of HIV-1 infection influences productive replication or latency is not fully understood. We used a panel of chimeric antigen receptors (CARs) with different ligand binding affinities to induce a range of signaling strengths to model differential T cell receptor signaling at the time of HIV-1 infection. Stimulation of T cell lines or primary CD4+ T cells expressing chimeric antigen receptors supported HIV-1 infection regardless of affinity for ligand; however, only signaling by the highest affinity receptor facilitated HIV-1 expression. Activation of chimeric antigen receptors that had intermediate and low binding affinities did not support provirus transcription, suggesting that a minimal signal is required for optimal HIV-1 expression. In addition, strong signaling at the time of infection produced a latent population that was readily inducible, whereas latent cells generated in response to weaker signals were not easily reversed. Chromatin immunoprecipitation showed HIV-1 transcription was limited by transcriptional elongation and that robust signaling decreased the presence of negative elongation factor, a pausing factor, by more than 80%. These studies demonstrate that T cell signaling influences HIV-1 infection and the establishment of different subsets of latently infected cells, which may have implications for targeting the HIV reservoir.Author SummaryActivation of CD4+ T cells facilitates HIV-1 infection; however, whether there are minimal signals required for the establishment of infection, replication, and latency has not been explored. To determine how T cell signaling influences HIV-1 infection and the generation of latently infected cells, we used chimeric antigen receptors to create a tunable model. Stronger signals result in robust HIV-1 expression and an inducible latent population. Minimal signals predispose cells towards latent infections that are refractory to reversal. We discovered that repression of HIV-1 transcription immediately after infection is due to RNA polymerase II pausing and inefficient transcription elongation. These studies demonstrate that signaling events influence the course of HIV-1 infection and have implications for cure strategies. They also provide a mechanistic explanation for why a significant portion of the HIV latent reservoir is not responsive to latency reversing agents which function by modifiying chromatin.

scholarly journals Efficient Transendothelial Migration of Latently HIV-1-Infected Cells

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1589
Author(s):  
Reou Tanabe ◽  
Yuko Morikawa
Keyword(s):  
Lymph Nodes ◽  
Stromal Cells ◽  
Cell Subset ◽  
Transendothelial Migration ◽  
The Body ◽  
Lymphoid Tissues ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

A small fraction of HIV-1-infected T cells forms populations of latently infected cells when they are a naive T-cell subset or in transit to a resting memory state. Latently HIV-1-infected cells reside in lymphoid tissues and serve as viral reservoirs. However, whether they systemically recirculate in the body and re-enter the lymphoid nodes are unknown. Here, we employed two in-vitro cell coculture systems mimicking the lymphatic endothelium in lymph nodes and investigated the homing potential, specifically the transendothelial migration (TEM), of two latently HIV-1-infected cell lines (J1.1 and ACH-2). In trans-well coculture systems, J1.1 and ACH-2 showed higher TEM efficiencies than their parental uninfected and acutely infected cells. The efficiency of TEM was enhanced by the presence of stromal cells, such as HS-5 and fibroblastic reticular cells. In an in-vitro reconstituted, three-dimensional coculture system in which stromal cells are embedded in collagen matrices, J1.1 showed slightly higher TEM efficiency in the presence of HS-5. In accordance with these phenotypes, latently infected cells adhered to the endothelial cells more efficiently than uninfected cells. Together, our study showed that latently HIV-1-infected cells enhanced cell adhesion and TEM abilities, suggesting their potential for efficient homing to lymph nodes.

scholarly journals Expanded cellular clones carrying replication-competent HIV-1 persist, wax, and wane

2018 ◽  
Vol 115 (11) ◽  
pp. E2575-E2584 ◽  
Author(s):  
Zheng Wang ◽  
Evelyn E. Gurule ◽  
Timothy P. Brennan ◽  
Jeffrey M. Gerold ◽  
Kyungyoon J. Kwon ◽  
...  
Keyword(s):  
T Cell ◽  
Cellular Proliferation ◽  
Integration Site ◽  
Virus Production ◽  
Viral Reactivation ◽  
Latent Reservoir ◽  
Major Barrier ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

The latent reservoir for HIV-1 in resting CD4+ T cells is a major barrier to cure. Several lines of evidence suggest that the latent reservoir is maintained through cellular proliferation. Analysis of this proliferative process is complicated by the fact that most infected cells carry defective proviruses. Additional complications are that stimuli that drive T cell proliferation can also induce virus production from latently infected cells and productively infected cells have a short in vivo half-life. In this ex vivo study, we show that latently infected cells containing replication-competent HIV-1 can proliferate in response to T cell receptor agonists or cytokines that are known to induce homeostatic proliferation and that this can occur without virus production. Some cells that have proliferated in response to these stimuli can survive for 7 d while retaining the ability to produce virus. This finding supports the hypothesis that both antigen-driven and cytokine-induced proliferation may contribute to the stability of the latent reservoir. Sequencing of replication-competent proviruses isolated from patients at different time points confirmed the presence of expanded clones and demonstrated that while some clones harboring replication-competent virus persist longitudinally on a scale of years, others wax and wane. A similar pattern is observed in longitudinal sampling of residual viremia in patients. The observed patterns are not consistent with a continuous, cell-autonomous, proliferative process related to the HIV-1 integration site. The fact that the latent reservoir can be maintained, in part, by cellular proliferation without viral reactivation poses challenges to cure.

scholarly journals A Critical Review of the Evidence Concerning the HIV Latency Reversing Effect of Disulfiram, the Possible Explanations for Its Inability to Reduce the Size of the Latent Reservoir In Vivo, and the Caveats Associated with Its Use in Practice

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Harry D. J. Knights
Keyword(s):  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Latent Reservoir ◽  
Major Barrier ◽  
Latently Infected ◽  
Shock And Kill ◽  
Infected Cells ◽  
Hiv 1

Combination antiretroviral therapy (cART) effectively suppresses the replication of human immunodeficiency virus type 1 (HIV-1), improves immune function, and decreases the morbidity of acquired immune deficiency syndrome (AIDS). However, it is unable to eradicate the virus because it does not eliminate latently infected cells. The latent reservoir poses the major barrier to an HIV-1 cure. The “shock and kill” strategy aims to reactivate the virus and destroy latently infected cells. Many latency reversing agents (LRAs) reactivate HIV in vitro, but the absence of damaging side-effects and efficacy in vivo make disulfiram particularly promising. However, in clinical trials to date, disulfiram treatment has not resulted in a reduction in the size of the latent reservoir. In this article I will therefore discuss the evidence for the latency reversing effect of disulfiram, the possible explanations for its inability to reduce the size of the latent reservoir in vivo, and the caveats associated with its use in practice. These considerations will help to inform judgements about the prospect of an HIV cure from disulfiram based treatments.

scholarly journals CD161+ CD4+ T Cells Harbor Clonally Expanded Replication-Competent HIV-1 in Antiretroviral Therapy-Suppressed Individuals

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Xiaomin Li ◽  
Zhaoli Liu ◽  
Qijuan Li ◽  
Ronglin Hu ◽  
Lu Zhao ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Clonal Expansion ◽  
Latent Reservoir ◽  
Term Stability ◽  
Long Term Stability ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT The presence of an extremely stable latent reservoir of HIV-1 is the major obstacle to eradication, despite effective antiretroviral therapy (ART). Recent studies have shown that clonal expansion of latently infected cells without viral reactivation is an important phenomenon that maintains the long-term stability of the reservoir, yet its underlying mechanism remains unclear. Here we report that a subset of CD4+ T cells, characterized by CD161 expression on the surface, is highly permissive for HIV-1 infection. These cells possess a significantly higher survival and proliferative capacity than their CD161-negative counterparts. More importantly, we found that these cells harbor HIV-1 DNA and replication-competent latent viruses at a significantly higher frequency. By using massive single-genome proviral sequencing from ART-suppressed individuals, we confirm that CD161+ CD4+ T cells contain remarkably more identical proviral sequences, indicating clonal expansion of the viral genome in these cells. Taking the results together, our study identifies infected CD161+ CD4+ T cells to be a critical force driving the clonal expansion of the HIV-1 latent reservoir, providing a novel mechanism for the long-term stability of HIV-1 latency. IMPORTANCE The latent reservoir continues to be the major obstacle to curing HIV-1 infection. The clonal expansion of latently infected cells adds another layer maintaining the long-term stability of the reservoir, but its mechanism remains unclear. Here, we report that CD161+ CD4+ T cells serve as an important compartment of the HIV-1 latent reservoir and contain a significant amount of clonally expanded proviruses. In our study, we describe a feasible strategy that may reduce the size of the latent reservoir to a certain extent by counterbalancing the repopulation and dissemination of latently infected cells.

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