Project description:Analysis of RISC bound short (s)RNAs in cells infected with HIV-1 reveals a contribution of 6mer seed toxicity to HIV-1 induced cytopathicity
Project description:Analysis of RISC bound short (s)RNAs in cells infected with HIV-1 reveals a contribution of 6mer seed toxicity to HIV-1 induced cytopathicity
Project description:Analysis of RISC bound short (s)RNAs in cells infected with HIV-1 reveals a contribution of 6mer seed toxicity to HIV-1 induced cytopathicity
Project description:Analysis of RISC bound short (s)RNAs in cells infected with HIV-1 reveals a contribution of 6mer seed toxicity to HIV-1 induced cytopathicity
Project description:Analysis of RISC bound short (s)RNAs in cells infected with HIV-1 reveals a contribution of 6mer seed toxicity to HIV-1 induced cytopathicity
Project description:The question of how HIV-1 interfaces with cellular microRNA (miRNA) biogenesis and effector mechanisms has been highly controversial. Here, we first used deep sequencing of small RNAs present in two different infected cell lines (TZM-bl and C8166) and two types of primary human cells (CD4+ PBMCs and macrophages) to unequivocally demonstrate that HIV-1 does not encode any viral miRNAs. Perhaps surprisingly, we also observed that infection of T cells by HIV-1 has only a modest effect on the expression of cellular miRNAs at early times after infection. Comprehensive analysis of miRNA binding to the HIV-1 genome using the photoactivatable ribonucleoside-induced crosslinking and immunoprecipitation (PAR-CLIP) technique revealed several binding sites for cellular miRNAs, a subset of which were shown to be capable of mediating miRNA-mediated repression of gene expression. However, the main finding from this analysis is that HIV-1 transcripts are largely refractory to miRNA binding, most probably due to extensive viral RNA secondary structure. Together, these data demonstrate that HIV-1 neither encodes viral miRNAs nor strongly influences cellular miRNA expression, at least early after infection, and imply that HIV-1 transcripts have evolved to avoid inhibition by pre-existing cellular miRNAs by adopting extensive RNA secondary structures that occlude most potential miRNA binding sites.
Project description:The epigenetic mechanisms established by histone modifications may affect the transcriptional silencing of HIV-1 and viral latency. A systematic epigenome profiling could be applicable to develop new epigenetic diagnostic markers for detecting HIV-1 latency. In this study, histone modification profiles of HIV-1 latency cell lines were compared with those of uninfected CD4+ T cell line. The HIV-1 latency gave rise to differential histone modification regions. The differential enrichment patterns helped us to define potential effector genes leading to the viral latency. The histone H3K4me3 and H3K9ac profiles were obtained from the HIV-1 latency cell lines (NCHA1, NCHA2, and ACH2) and control CD4+ T cell line (A3.01)
Project description:The heterogeneity and rarity of HIV-1-infected cells hampers effective cure strategies. We used single-cell DOGMA-seq to simultaneously capture transcription factor accessibility, transcriptome, 156 surface proteins, HIV-1 DNA, and HIV-1 RNA from six HIV-1+ individuals during viremia and after suppressive antiretroviral therapy. We identified 252 transcriptionally inactive (HIV-1 DNA+ RNA–) and 270 transcriptionally active (HIV-1 RNA+) HIV-1-infected cells from 82,549 memory CD4+ T cells. We identified increased transcription factor accessibility in HIV-1 DNA+ RNA– cells (RORC) and HIV-1 RNA+ cells (IRF and AP-1), in addition to CNC and MAF in both. Both HIV-1 DNA+ RNA– and HIV-1 RNA+ cells upregulate IKZF3 (Aiolos) that correlates with proliferation of HIV-1-infected cells. We revealed that the heterogeneous HIV-1-infected T cells comprise four distinct immune programs driven by epigenetic regulators – IRF-activation, Eomes-cytotoxic effector, AP-1-migration, and cell death. Our study revealed the single-cell epigenetic, transcriptional, and protein states of transcriptionally inactive and active HIV-1-infected cells.
Project description:We invesitgated cellular pathways required for HIV-1 activation using HIV-1-suppressing agents. Despite effective antiretroviral therapy, HIV-1-nfected cells continue to produce viral antigens and induce chronic immune exhaustion. Using a novel dual reporter system and a high-throughput drug screen, we identified FDA-approved drugs which can suppress HIV-1 reactivation in both cell line models and CD4+ T cells from virally suppressed, HIV-1-infected individuals. We identified 11 cellular pathways required for HIV-1 reactivation as druggable targets. Using differential expression analysis, gene set enrichment analysis and exon-intron landscape analysis, we examined the impact of drug treatment on the cellular environment at a genome-wide level.
