Effect of DDX3 inhibitors on CD4+ T cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE167553 | GEO | 2021/02/26
REPOSITORIES: GEO
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Project description:HIV-1 infected patients virally suppressed by antiviral treatment harbor a persistent reservoir of replication competent latent HIV-1 infected cells, which constitute the main roadblock to a cure. A main strategy for HIV cure aims to stimulate viral gene expression in latently infected cells so that they can be cleared. Crucial for the design of drugs referred to as “latency-reversing agents” (LRAs) is the identification of molecular targets for latency reversal. The regulatory factors physically associated with and repressing the latent HIV-1 promoter or 5’LTR would provide ideal putative molecular targets for latency reversal. However, due to technical limitations, the comprehensive and unbiased identification of host proteins associated with the latent or active integrated HIV LTR in infected cells not been possible. Here we use dCas9 targeted chromatin and histone enrichment strategy coupled to mass spectrometry (Catchet-MS), to purify the locus-associated dCas9 bait, guided downstream of the HIV-1 transcriptional start site (TSS) in latent and activated HIV-1 infected T cells to identify the 5’LTR bound latent and active regulatory complexes. Catchet-MS identified both previously described as well as novel host factors distinctly associated with the latent versus transcriptionally active HIV-1 5’LTR. Within the identified factors we find the transcription factor IKZF1 to be a novel repressor of the HIV-1 promoter required for maintenance of latency, and thus a molecular target for latency reversal. Finally, we identify the FDA approved drug, Iberdomide, which targets IKZF1 for degradation to be a novel LRA, which reversed latency in latent ex vivo HIV-1 infected primary CD4+ T cells and in cells isolated from HIV-1 infected, aviremic participants.
2022-05-31 | PXD032975 | Pride
Project description:The barrier to HIV-1 functional cure is caused by a small pool of latently infected resting CD4 T-cells that persist under antiretroviral therapy. Notably this latent reservoir of infected cells will produce replication-competent infectious virus once prolonged suppressive HAART is withdrawn. The reactivation of HIV-1 gene expression in T-cells harboring latent provirus in HIV-1 patients under HAART will likely result in depletion of this latent reservoir due to cytopathic effects and immune clearance. Many studies have investigated small molecules that reactivate HIV-1 gene expression but to date no latency reversal agent (LRA) has been identified to be specific, non-toxic, and effective in primary T-cells isolated from HIV-1 infected individuals undergoing long-term HAART. Stochastic fluctuations in HIV-1 tat gene expression have been attributed to be essential in the viral progression to latency. We hypothesized that exposing Tat to latently infected CD4 T-cells will result in potent latency reversal. Our results indicate the capacity of an engineered Tat to reactivate HIV-1 in latently infected cells from patients to a similar degree as the protein kinase C agonist PMA (Phorbol 12-Myristate 13-Acetate) while showing no T-cell activation nor any significant transcriptome perturbation in primary CD4 T-cells.
2023-09-05 | GSE235229 | GEO
Project description:Despite antiretroviral therapy (ART), HIV-1 persists in latently-infected CD4+ T cells, preventing cure. Antigen (Ag) drives proliferation of infected cells, preventing latent reservoir decay. However, the relationship between antigen recognition and HIV-1 gene expression is poorly understood since most studies of latency reversal use agents that induce non-specific global T cell activation. Here, we isolated rare CD4+ T cells responding to cytomegalovirus (CMV) or HIV-1 Gag antigens from participants on long-term ART and assessed T cell activation and HIV-1 RNA expression upon co-culture with autologous dendritic cells (DCs) presenting cognate antigens. Physiological presentation of cognate antigens induced broad T cell activation (median 42-fold increase in CD154+CD69+ cells) and significantly increased HIV-1 transcription (median 4-fold), mostly through the induction of rare cells with higher viral expression. Thus, despite low proviral inducibility, physiologic antigen recognition can promote HIV-1 expression, potentially contributing to spontaneous reservoir activity on ART and viral rebound upon ART interruption. Additionally, we observed striking differences in the transcriptome profiles of Ag-responding CD4+ T cells after stimulations with Ag or global T cell activators. This analysis revealed quantitative differences between NFAT and NFkB target genes and may guide future approaches to Ag-mediated HIV-1 latency reversal.
2024-08-07 | GSE273898 | GEO
Project description:HIV infection remains incurable due to the long-term persistence of latently infected cells, capable of refueling viremia upon antiretroviral therapy interruption. Shock-and-kill strategies aim to purge this latent reservoir by inducing the expression of viral genes, making infected cells visible for cleanup by the immune system. Here, we present a Tat mRNA formulation that, when combined with panobinostat, enables latency reversal at levels >3-fold higher than those reached with the most potent mitogens. We demonstrate that this mRNA formulation does not alter the transcriptome or phenotype of CD4 T cells, enabling the ex vivo assessment of infected cells upon latency reversal in a near-native state. Taking advantage of this characteristic, we show transcriptomic and proteomic differences between infected cells upon latency reversal and non-infected cells, including the upregulation of the cytotoxic protein granzyme A and a novel long non-coding RNA. Overall, we demonstrate that a Tat mRNA formulation enables potent reactivation of latent HIV, presenting a valuable research tool for studying the inducible HIV reservoir, as well as paving the way to a more effective shock-and-kill functional cure.
2023-11-09 | GSE247402 | GEO
Project description:Latency reversal and clearance strategies for HIV cure are beginning to employ IAP antagonists (IAPi) to induce unprecedented levels of latent reservoir expression without immunotoxicity during suppressive antiretroviral therapy (ART). However, full targeting of the reservoir may require combinatorial approaches. A Jurkat latency model screen for IAPi combination partners demonstrated synergistic latency reversal with Bromodomain and Extra-Terminal domain protein inhibitors (BETi). Mechanistic investigations using CRISPR-CAS9 and single cell-RNAseq informed comprehensive ex vivo evaluations of IAPi plus pan-BET, bromodomain (BD)-selective BET, or selective BET isoform targeting in CD4 T cells from ART-suppressed donors. IAPi+BETi treatment resulted in striking induction of cell-associated HIV gag RNA but lesser induction of fully elongated and tat-rev RNA, especially compared to T cell activation positive controls. IAPi/BETi resulted in HIV protein induction in bulk cultures of CD4 T cells using an ultrasensitive p24 assay, but did not translate to enhanced viral outgrowth frequency using a standard quantitative viral outgrowth assay. Overall, this study defines HIV transcriptional elongation and splicing as key barriers to latent HIV protein expression following latency reversal, delineates the roles of BET proteins and their bromodomains in HIV latency, and provides rationale for testing of IAPi+BETi in animal models of HIV latency.
2022-02-10 | GSE196091 | GEO
Project description:During HIV infection, a latent viral reservoir is formed that persists during antiretroviral therapy (ART) and is maintained by a heritable state of transcriptional repression. Recent findings indicate that much of the reservoir originates from infections occurring in the weeks near the time of ART initiation, raising the important possibility that interventions during this period might prevent reservoir seeding and substantially reduce reservoir size. Based on this concept, we tested the ability of compounds that target epigenetic machinery to prevent the establishment of latent HIV infection in primary CD4 T cells. We identified class 1 histone deacetylase inhibitors (HDACi) as potent agents of latency prevention, an activity distinct from latency reversal. Inhibiting HDACs in productively infected cells caused extended maintenance of HIV expression, even after HDACi withdrawal, and this activity was associated with persistently elevated H3K9 acetylation and reduced H3K9 methylation at the viral LTR promoter region. HDAC inhibition in HIV-infected CD4 T cells during effector-to-memory transition led to a striking change in the memory subset distribution indicating reprogramming of cell identity. Through knockout of individual HDACs and use of HDAC-selective inhibitors, we determined that HDAC1 and HDAC3 play crucial and distinct roles in proviral silencing initiation. Overall, this work indicates that a network of HDACs regulate a critical gateway process for HIV latency establishment and are required for the development of CD4 T-cell memory subsets that preferentially harbor long-lived, latent provirus. Epigenetic reprogramming by clinical targeting of HDACs during ART initiation may represent a novel way to prevent seeding of the HIV reservoir in vivo
2023-08-08 | GSE199946 | GEO
Project description:HIV latency is a major obstacle to curing infection. Current strategies to eradicate HIV aim at increasing transcription of the latent provirus. In the present study we observed that latently infected CD4+ T cells from HIV-infected individuals failed to produce viral particles upon ex vivo exposure to SAHA (vorinostat), despite effective inhibition of histone deacetylases. To identify steps that were not susceptible to the action of SAHA or other latency reverting agents, we used a primary CD4+ T cell model, joint host and viral RNA sequencing, and a viral-encoded reporter. This model served to investigate the characteristics of latently infected cells, the dynamics of HIV latency, and the process of reactivation induced by various stimuli. During latency, we observed persistence of viral transcripts but only limited viral translation. Similarly, the reactivating agents SAHA and disulfiram successfully increased viral transcription, but failed to effectively enhance viral translation, mirroring the ex vivo data. This study highlights the importance of post-transcriptional blocks as one mechanism leading to HIV latency that needs to be relieved in order to purge the viral reservoir.
2017-02-24 | GSE95297 | GEO
Project description:Suppressive HAART does not eradicate HIV-1 and viral DNA persists as a stably integrated form in the absence of viral particle production. As a consequence, latent reservoirs are refractory to antiretroviral drugs and invisible to immune surveillance. The largest latent reservoir consists of resting memory CD4+ T cells. These cells can resume viral infection when activated through antigen recognition, causing bursts of viremia (blips). Current therapies targeting latent HIV-1 have focused primarily on the M-bM-^@M-^\shock and killM-bM-^@M-^] approach, which employs M-bM-^@M-^\anti-latencyM-bM-^@M-^] drugs M-bM-^@M-^S most notably histone deacetylase (HDAC) inhibitors M-bM-^@M-^S to reactivate and flush latent provirus from its cellular reservoirs in the absence of global T cell activation. This approach is predicated on the notions that viral reactivation will lead to the demise of the infected cell, and that HAART will prevent spreading of the infection. On the contrary, recent evidence indicates that latently infected CD4+ T cells of HIV-1 patients on HAART survive in vitro viral reactivation with the HDAC inhibitor, SAHA, even when co-cultured with autologous CD8+ cytotoxic T lymphocytes (CTL). Moreover, it remains to be addressed the impact of anti-latency drugs on viral reservoirs undergoing low-level ongoing replication, inherently more resistant to the cytopathic effects of HIV-1 and residing in anatomical sites hard to reach for some antiretroviral drugs (e.g. macrophages). As a consequence, there is a need to develop alternative therapeutic approaches aimed at eliminating or decreasing the latent reservoir. Progress in that direction has been hindered by the lack of biomarkers uniquely or differentially expressed on latently infected compared to their uninfected counterparts. To gain insight into the cellular mechanisms that take place in the context of latency, and with the goal of identifying distinctive markers that distinguish latently infected CD4+ T cells, we have used an in vitro model developed in our laboratory to study the expression profile of latently infected CD4+ T cells by microarray analysis. We have used a culture system, previously established in our laboratory, to generate and isolate quiescent latently infected CD4+ T cells in vitro. In this in vitro HIV-1 latency model, CD4+ T cells are activated, infected with full length, replication competent HIV-1, and then returned to quiescence in the presence of IL-7, yielding a culture of quiescent latently infected and uninfected cells. We showed that HIV-1 p24gag expressed during viral replication persists in the cytoplasm of latently infected cells for several days before being degraded. Therefore, we exploited the presence of cytoplasmic p24gag to sort latently infected from uninfected cells by FACS from the same initial cell culture. Total RNA was isolated from sorted latently infected and uninfected cells generated from CD4+ T cells of four different donors. Paired RNA samples from infected and uninfected cells were labeled with Cy3 and Cy5 to allow dual-color competitive hybridization. Moreover, to control for the dye bias in our experiments, we implemented a dye swap protocol (reciprocal labeling) for paired RNA samples from 2 donors. Samples were analyzed by dual-color competitive hybridization on the Agilent whole human genome microarrays (41,000 unique probes). This is the first comparative genomic profiling of primary latently infected resting memory CD4+ T cells versus their uninfected counterparts sorted from the same culture. Microarray analyses performed in this study revealed profound differences between latently infected and uninfected cells. Of relevance are genes involved, not only in previously described pathways related with transcriptional and post-transcriptional regulation, but affecting proliferation, survival, cell cycle progression and cell metabolism. This could explain why latently infected cells have been resistant to reactivation with current anti-latency approaches. Thus, targeting of more downstream steps, such as the ones identified in this study, may be able to enhance viral flushing from refractory latent reservoirs. In addition, we identified a panel of surface makers differentially expressed in latently infected cells, which seem worth investigating for their potential use as biomarkers. Indeed, they might allow the enrichment of this latent reservoir for molecular in depth studies, for monitoring the size of the latent reservoir in the clinical setting, as well as for the development of new therapeutic strategies aimed at eradicating this reservoir.
2013-03-15 | E-GEOD-40550 | biostudies-arrayexpress
Project description:HSV-2 coinfection is associated with increased HIV-1 viral loads and expanded tissue reservoirs, but the mechanisms are not well-defined. HSV-2 recurrences result in an influx of activated CD4+ T cells to sites of viral replication and an increase in activated CD4+ T cells in peripheral blood. We hypothesized that HSV-2 induces changes in these cells that facilitate HIV-1 reactivation and replication and tested this hypothesis in human CD4+ T cells and 2D10 cells, a model of HIV-1 latency. HSV-2 promoted latency reversal in HSV-2 infected and bystander 2D10 cells. Bulk and single-cell RNA sequencing studies of activated primary human CD4+ T cells identified decreased expression of HIV-1 restriction factors and increased expression of transcripts including MALAT1 that could drive HIV replication in both the HSV-2-infected and bystander cells. Transfection of 2D10 cells with VP16, an HSV-2 protein that regulates transcription, significantly upregulated MALAT1 expression, decreased trimethylation of lysine 27 on histone H3 protein, and triggered HIV latency reversal. Knockout of MALAT1 from 2D10 cells abrogated the response to VP16 and reduced the response to HSV-2 infection. These results demonstrate that HSV-2 contributes to HIV-1 reactivation through diverse mechanisms including upregulation of MALAT1 to release epigenetic silencing.
2023-05-07 | GSE229390 | GEO
Project description:HSV-2 coinfection is associated with increased HIV-1 viral loads and expanded tissue reservoirs, but the mechanisms are not well-defined. HSV-2 recurrences result in an influx of activated CD4+ T cells to sites of viral replication and an increase in activated CD4+ T cells in peripheral blood. We hypothesized that HSV-2 induces changes in these cells that facilitate HIV-1 reactivation and replication and tested this hypothesis in human CD4+ T cells and 2D10 cells, a model of HIV-1 latency. HSV-2 promoted latency reversal in HSV-2 infected and bystander 2D10 cells. Bulk and single-cell RNA sequencing studies of activated primary human CD4+ T cells identified decreased expression of HIV-1 restriction factors and increased expression of transcripts including MALAT1 that could drive HIV replication in both the HSV-2-infected and bystander cells. Transfection of 2D10 cells with VP16, an HSV-2 protein that regulates transcription, significantly upregulated MALAT1 expression, decreased trimethylation of lysine 27 on histone H3 protein, and triggered HIV latency reversal. Knockout of MALAT1 from 2D10 cells abrogated the response to VP16 and reduced the response to HSV-2 infection. These results demonstrate that HSV-2 contributes to HIV-1 reactivation through diverse mechanisms including upregulation of MALAT1 to release epigenetic silencing.
2023-05-07 | GSE229391 | GEO