scholarly journals A Comparison of Different Immune Activation Strategies to Reverse HIV-1 Latency

2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Caroline C Garliss ◽  
Abena K Kwaa ◽  
Joel N Blankson
Keyword(s):  
T Cells ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
Low Frequency ◽  
Calcium Ionophore ◽  
Latent Reservoir ◽  
People Living With Hiv ◽  
Activation Markers ◽  
Proviral Dna ◽  
Latently Infected

Abstract Resting CD4+ T cells are the best characterized component of the latent reservoir. Activation of these CD4+ T cells is needed to optimize transcription and viral replication, and this strategy has been used to measure the inducible reservoir. There are several methods that can be used to activate CD4+ T cells, and in this study, we compared 3 different strategies: the combination of the lectin phytohaemagglutinin (PHA) and irradiated allogeneic feeders, a combination of PHA and a superagonistic anti-CD28 antibody, and the combination of the protein kinase C agonist phorbol 12-myristate 13-acetate and the calcium ionophore ionomycin. We show that each strategy induces a different pattern of expression of activation markers on CD4+ T cells. However, the different activation strategies induced similar frequencies of latently infected CD4+ T cells from people living with HIV on suppressive antiretroviral therapy regimens to produce replication-competent virus. Furthermore, the frequency of infectious units per million induced by each regimen was positively correlated with the copies of intact proviral DNA per million CD4+ T cells. Our results suggest that no single pattern of activation marker expression is most associated with latency reversal and demonstrate that different immune activation strategies reverse latency in a low frequency of CD4+ T cells that harbor intact proviral DNA.

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 Clonal Expansion of Infected CD4+ T Cells in People Living with HIV

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2078
Author(s):  
John M. Coffin ◽  
Stephen H. Hughes
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Large Fraction ◽  
Latent Reservoir ◽  
People Living With Hiv ◽  
Resting Cells ◽  
Hiv Rna ◽  
Art Initiation ◽  
Infected Cells ◽  
Living With Hiv

HIV infection is not curable with current antiretroviral therapy (ART) because a small fraction of CD4+ T cells infected prior to ART initiation persists. Understanding the nature of this latent reservoir and how it is created is essential to development of potentially curative strategies. The discovery that a large fraction of the persistently infected cells in individuals on suppressive ART are members of large clones greatly changed our view of the reservoir and how it arises. Rather than being the products of infection of resting cells, as was once thought, HIV persistence is largely or entirely a consequence of infection of cells that are either expanding or are destined to expand, primarily due to antigen-driven activation. Although most of the clones carry defective proviruses, some carry intact infectious proviruses; these clones comprise the majority of the reservoir. A large majority of both the defective and the intact infectious proviruses in clones of infected cells are transcriptionally silent; however, a small fraction expresses a few copies of unspliced HIV RNA. A much smaller fraction is responsible for production of low levels of infectious virus, which can rekindle infection when ART is stopped. Further understanding of the reservoir will be needed to clarify the mechanism(s) by which provirus expression is controlled in the clones of cells that constitute the reservoir.

Nonproliferating Bystander CD4+T Cells Lacking Activation Markers Support HIV Replication During Immune Activation

2001 ◽  
Vol 166 (10) ◽  
pp. 6437-6443 ◽  
Author(s):  
David Scales ◽  
Houping Ni ◽  
Farida Shaheen ◽  
John Capodici ◽  
Georgetta Cannon ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
Hiv Replication ◽  
Activation Markers

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

2020 ◽  
Vol 217 (7) ◽  
Author(s):  
Pilar Mendoza ◽  
Julia R. Jackson ◽  
Thiago Y. Oliveira ◽  
Christian Gaebler ◽  
Victor Ramos ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Half Life ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Latent Reservoir ◽  
T Cell Clones ◽  
Cell Clones ◽  
Latently Infected ◽  
Hiv 1

Antiretroviral 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 mo 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 seven of eight 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 Intragenic proviral elements support transcription of defective HIV-1 proviruses

2021 ◽  
Author(s):  
Jeffrey Kuniholm ◽  
Elise Armstrong ◽  
Brandy Bernabe ◽  
Carolyn Coote ◽  
Anna Berenson ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Treatment Interruption ◽  
Regulatory Elements ◽  
Host Cells ◽  
People Living With Hiv ◽  
Latently Infected ◽  
Infected Cells ◽  
Living With Hiv ◽  
Hiv 1

ABSTRACTHIV-establishes a persistent proviral reservoir by integrating into the genome of infected host cells. Current antiretroviral treatments do not target this persistent population of proviruses which include latently infected cells that upon treatment interruption can be reactivated to contribute to HIV-1 rebound. Deep sequencing of persistent HIV proviruses has revealed that greater than 90% of integrated HIV genomes are defective and unable to produce infectious virions. We hypothesized that intragenic elements in the HIV genome support transcription of aberrant HIV-1 RNAs from defective proviruses that lack long terminal repeats (LTRs). Using an intact provirus detection assay, we observed that resting CD4+ T cells and monocyte-derived macrophages (MDMs) are biased towards generating defective HIV-1 proviruses. Multiplex reverse transcription digital drop PCR identified Env and Nef transcripts which lacked 5’ untranslated regions (UTR) in acutely infected CD4+ T cells and MDMs indicating transcripts are generated that do not utilize the promoter within the LTR. 5’UTR-deficient Env transcripts were also identified in a cohort of people living with HIV (PLWH) on ART, suggesting that these aberrant RNAs are produced in vivo. Using 5’ rapid amplification of cDNA ends (RACE), we mapped the start site of these transcripts within the Env gene. This region bound several cellular transcription factors and functioned as a transcriptional regulatory element that could support transcription and translation of downstream HIV-1 RNAs. These studies provide mechanistic insights into how defective HIV-1 proviruses are persistently expressed to potentially drive inflammation in PLWH.Author SummaryPeople living with HIV establish a persistent reservoir which includes latently infected cells that fuel viral rebound upon treatment interruption. However, the majority of HIV-1 genomes in these persistently infected cells are defective. Whether these defective HIV genomes are expressed and whether they contribute to HIV associated diseases including accelerated aging, neurodegenerative symptoms, and cardiovascular diseases are still outstanding questions. In this paper, we demonstrate that acute infection of macrophages and resting T cells is biased towards generating defective viruses which are expressed by DNA regulatory elements in the HIV genome. These studies describe an alternative mechanism for chronic expression of HIV genomes.

scholarly journals Antiretroviral Therapy Dampens Mucosal CD4+ T Lamina Propria Lymphocytes Immune Activation in Long-Term Treated People Living with HIV-1

2021 ◽  
Vol 9 (8) ◽  
pp. 1624
Author(s):  
Alessandro Lazzaro ◽  
Giuseppe Pietro Innocenti ◽  
Letizia Santinelli ◽  
Claudia Pinacchio ◽  
Gabriella De Girolamo ◽  
...  
Keyword(s):  
T Cells ◽  
Antiretroviral Therapy ◽  
Lamina Propria ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
People Living With Hiv ◽  
Living With Hiv ◽  
Lamina Propria Lymphocytes ◽  
Hiv 1

HIV infection is characterized by a severe deterioration of an immune cell-mediated response due to a progressive loss of CD4+ T cells from gastrointestinal tract, with a preferential loss of IL-17 producing Th cells (Th17), a specific CD4+ T cells subset specialized in maintaining mucosal integrity and antimicrobial inflammatory responses. To address the effectiveness of antiretroviral therapy (ART) in reducing chronic immunological dysfunction and immune activation of intestinal mucosa, we conducted a cross-sectional observational study comparing total IFN-γ-expressing (Th1) and IL-17-expressing (Th17) frequencies of CD4+ T lamina propria lymphocytes (LPLs) and their immune activation status between 11 male ART-naïve and 11 male long-term ART-treated people living with HIV-1 (PLWH) who underwent colonoscopy and retrograde ileoscopy for biopsies collection. Flow cytometry for surface and intracellular staining was performed. Long-term ART-treated PLWH showed lower levels of CD38+ and/or HLA-DR+ LPLs compared to ART-naïve PLWH. Frequencies of Th1 and Th17 LPLs did not differ between the two groups. Despite ART failing to restore the Th1 and Th17 levels within the gut mucosa, it is effective in increasing overall CD4+ T LPLs frequencies and reducing mucosal immune activation.

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

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.

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