Defining the Effects of PKC Modulator HIV Latency-Reversing Agents on Natural Killer Cells
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PROVIDER: PRJNA1214395 | ENA |
REPOSITORIES: ENA
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Project description:Latency reversing agents (LRAs) such as protein kinase C (PKC) modulators can reduce rebound-competent HIV reservoirs in small animal models. Furthermore, administration of natural killer (NK) cells following LRA treatment improves this reservoir reduction. It is currently unknown why the combination of a PKC modulator and NK cells is so potent and whether exposure to PKC modulators may augment NK cell function in some way. Here, we compare the transcriptional profiles of PKC-treated NK and CD4+ T cells to assess their generalized cellular effects. Transcriptomic profiles from both cell types displayed signatures of cellular activation and enrichment of genes associated with the NFκB pathway. However, the transcriptomic effects of PKC stimulation on NK cells are much milder than that in CD4+ T cells. This finding, combined with our experimental data testing killing capacity of PKC-stimulated NK cells against K562 cells and infected CD4+ T cells suggests that their contribution in “kick and kill” strategies is primarily due to upregulating HIV expression in CD4+ T cells, rather than directly enhancing the effector functions of NK cells. This suggests that PKC modulators are primarily augmenting the “kick” rather than the “kill” arm of this HIV cure approach.
2025-01-23 | GSE287754 | GEO
Project description:HIV-1 persists in individuals on ART in infected central (CM), transitional (TM) and effector memory (EM) CD4+ T cells. We developed LARA (latency and reversion assay), which facilitates the examination of HIV latency reversal in CM, TM and EM subsets in a single assay. Studies with latency reversing agents (LRAs) revealed responses specific to each subset, including compounds that significantly reversed latency in all subsets but with a range of efficiency (bryostatin) to those that demonstrated subset specificity (IL-15). Significantly, LARA has allowed the demonstration that EM cells display a more activated profile compared to CM, which translated to enhanced efficiency in responsiveness to multiple LRAs and allowed the identification of mechanisms associated with the compounds that reactivate latent HIV in all subsets. Understanding the responsiveness of memory CD4+ T cells subsets to LRAs will accelerate the development of anti-latency therapy to interfering with viral persistence in vivo.
2018-01-26 | GSE94149 | GEO
Project description:HIV-1 persists in individuals on ART in infected central (CM), transitional (TM) and effector memory (EM) CD4+ T cells. We developed LARA (latency and reversion assay), which facilitates the examination of HIV latency reversal in CM, TM and EM subsets in a single assay. Studies with latency reversing agents (LRAs) revealed responses specific to each subset, including compounds that significantly reversed latency in all subsets but with a range of efficiency (bryostatin) to those that demonstrated subset specificity (IL-15). Significantly, LARA has allowed the demonstration that EM cells display a more activated profile compared to CM, which translated to enhanced efficiency in responsiveness to multiple LRAs and allowed the identification of mechanisms associated with the compounds that reactivate latent HIV in all subsets. Understanding the responsiveness of memory CD4+ T cells subsets to LRAs will accelerate the development of anti-latency therapy to interfering with viral persistence in vivo.
2018-01-26 | GSE94150 | GEO
Project description:NSC95397 is a Novel HIV Latency Reversing Agent
| PRJNA1008920 | ENA
Project description:Memory CD4+ T cell subsets show differential responses to HIV latency reversing agents
| PRJNA369088 | ENA
Project description:The latent viral reservoir represents one of the major barriers of curing HIV. Focus on the “kick and kill” approach, in which virus expression is reactivated then cells producing virus are selectively depleted, has led to the discovery of many latency reversing agents (LRAs) that can reactivate latently integrated virus and further our understanding of the mechanisms driving HIV latency and latency reversal. Thus far, individual compounds have yet to be robust enough to work as a therapy, highlighting the importance of identifying new compounds that target novel pathways and synergize with known LRAs. In this study, we identified a promising LRA, NSC95397, from a screen of ~4250 compounds in J-Lat cell lines. We validated that NSC95397 reactivates latent viral transcription and protein expression from cells with unique integration events. Co-treating cells with NSC95397 and known LRAs demonstrated that NSC95397 has the potential to synergize with different drugs under both standard normoxic and physiological hypoxic conditions. We showed that NSC95397 does not globally increase open chromatin, and bulk RNA sequencing revealed that NSC95397 does not greatly change cellular transcription. Instead, NSC95397 downregulates many pathways key to metabolism, cell growth, and DNA repair – highlighting the potential of these pathways in regulating HIV latency. Overall, we identified NSC95397 as a novel LRA that does not alter global transcription, that shows potential for synergy with known LRAs, and that may act through novel pathways not previously recognized for their ability to modulate HIV latency.
2024-08-31 | GSE241617 | GEO
Project description:The switch between HIV latency and productive transcription is regulated by an auto-feedback mechanism initiated by the viral trans-activator Tat, which functions to recruit the host transcription elongation factor P-TEFb to proviral HIV. A heterodimeric complex of CDK9 and one of three cyclin T subunits, P-TEFb is expressed at vanishingly low levels in latently infected memory CD4+ T cells and cellular mechanisms controlling its availability for proviral transcription are not well-defined. Using a well-characterized primary T-cell model of HIV latency alongside healthy donor memory CD4+ T cells, we sought to identify specific T-cell receptor (TCR) signaling pathways that regulate the generation of transcriptionally active P-TEFb, defined as the coordinate expression of cyclin T1 and phospho-Ser175 CDK9. Unexpectedly, cellular treatment with diacylglycerol-mimicking protein kinase C (PKC) agonists in the absence of intracellular calcium mobilization with an ionophore was sufficient to stimulate active P-TEFb expression and reactivate latent HIV with minimal cytotoxicity. Furthermore, inhibition-based experiments demonstrated that PKC agonists and TCR-mobilized diacylglycerol signal through MAP kinases ERK1/2 rather than through PKC to effect the reactivation of both P-TEFb and latent HIV. Single-cell RNA-seq analysis revealed that of the four known isoforms of RasGRP, the diacylglycerol-dependent Ras guanine nucleotide exchange factor RasGRP1 is by far the predominantly expressed isoform in memory CD4+ T cells and should therefore mediate the activation of ERK1/2 upon TCR co-stimulation or PKC agonist challenge. Combined inhibition of the PI3K-AKT-mTORC1/2 pathway alongside the ERK1/2 activator MEK prior to TCR co-stimulation abrogated active P-TEFb expression and strongly suppressed latent HIV reactivation. Therefore, contrary to prevailing models, the coordinate reactivation of P-TEFb and latent HIV in primary T cells in response to either TCR co-stimulation or PKC agonist challenge is largely independent of PKC activity but rather primarily involves two complementary signaling arms of the TCR cascade namely RasGRP1-Ras-Raf-MEK-ERK1/2 and PI3K-AKT-mTORC1/2.
2021-09-07 | GSE167916 | GEO
Project description:Human T-cell leukemia virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), is a retrovirus, which integrates into the host genome and persistently infects CD4+ T-cells. Virus propagation is stimulated by (1) clonal expansion of infected cells and (2) de novo infection. Viral gene expression is induced by the transactivator protein Tax, which recruits host factors like positive transcription elongation factor b (P-TEFb) to the viral promoter. Since HTLV-1 gene expression is repressed in vivo by viral, cellular, and epigenetic mechanisms in late phases of infection, HTLV-1 avoids an efficient CD8+ cytotoxic T-cell (CTL) response directed against the immunodominant viral Tax antigen. Hence, therapeutic strategies using latency reversing agents (LRAs) sought to transiently activate viral gene expression and antigen presentation of Tax to enhance CTL responses towards HTLV-1, and thus, to expose the latent HTLV-1 reservoir to immune destruction. Here, we review strategies that aimed at enhancing Tax expression and Tax-specific CTL responses to interfere with HTLV-1 latency. Further, we provide an overview of LRAs including (1) histone deacetylase inhibitors (HDACi) and (2) activators of P-TEFb, that have mainly been studied in context of human immunodeficiency virus (HIV), but which may also be powerful in the context of HTLV-1.
| S-EPMC8197370 | biostudies-literature
Project description:To delineate the mechanism driving JAK2 inhibitors´ induced effects on HIV-1 latency, whole transcriptome profiling was performed in the HIV-1 latency model HL-HIG, treated with the LRA fedratinib, the LPA pacritinib, the pan-JAKi ruxolitinib and PMA as a positive control of latency reactivation and immune activation.
2022-08-24 | GSE195855 | GEO
Project description:PKC modulator bryostatin-1 therapeutically targets CNS innate immunity to attenuate neuroinflammation and promote remyelination
| PRJNA1179434 | ENA