Multiomic Profiling Reveals Unexpected Increased Chromatin Accessibility Downstream from the 3’ LTR OF Active HIV-1 Proviruses (Hi-C)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE189178 | GEO | 2022/08/26
REPOSITORIES: GEO
Similar Datasets
Project description:The restructuring of chromatin architecture following lentiviral integration is not well elucidated. We jointly interrogate (HIV-distal & -local) chromatin organization (via Hi-C & ATAC-seq) and the RNA landscape around defined sites of proviral integration using HIV-inducible cellular models. We report chromatin interaction networks and nuclear ultrastructure around integrated HIV-1 are predominantly preserved, suggesting HIV integration does not induce large scale remodeling of cellular chromatin. Instead, we find that induction of proviral transcription leads to stark local changes in nucleosome organization with chromatin accessibility increasing at the intergenic junction between the HIV-1 3’ LTR and flanking cellular genome. This result suggests subtle changes in chromatin structure may be mediating proviral activation. Using long-read Nanopore RNA-seq, we interrogate the local host & HIV transcriptomes, observing a small fraction of HIV-1 transcripts are chimeric read-through products, where transcription initiates at the HIV-1 5’ LTR promoter and continues extensively into the flanking cellular genome. Despite provirus-driven read-through, HIV-1 appears to have only a modest effect on the local transcriptional environment. The changes in chromatin accessibility and read-through at activated proviruses closely resembles lytic Herpes simplex virus type 1 (HSV-1) induced cellular chromatin reprogramming. We propose chromatin “opening” at the 3’ LTR HIV-host junction is important for sustained proviral activity, and overall, HIV proviruses do not significantly alter local host transcription and chromatin structure. Our studies provide the first in-depth integrative investigation of 3D chromatin organization, nucleosome density, and HIV-host transcriptomes at HIV-host genic boundaries.
2021-10-26 | GSE184345 | GEO
Project description:HIV-1 integration introduces ectopic transcription factor binding sites into host chromatin. We postulate that the integrated provirus serves as an ectopic enhancer that recruits additional transcriptional factors to the integration locus, increases chromatin accessibility, changes 3D chromatin interactions, and enhances both retroviral and host gene expression. We used 4 well-characterized HIV-1-infected cell line clones having unique integration sites and low to high levels of HIV-1 expression. Using single-cell DOGMA-seq, which captured the heterogeneity of HIV-1 expression and host chromatin accessibility, we found that HIV-1 transcription correlated with HIV-1 accessibility and host chromatin accessibility. HIV-1 integration increased local host chromatin accessibility within ~5–30 kb distance. CRISPRa and CRISPRi-mediated HIV-1 promoter activation and inhibition confirmed integration site-dependent HIV-1-driven changes of host chromatin accessibility. HIV-1 did not drive chromatin confirmation changes at the genomic level (by Hi-C) or the enhancer connectome (by H3K27Ac HiChIP). Using 4C-seq to interrogate HIV-1-chromatin interactions, we found that HIV-1 interacted with host chromatin ~100–300 kb from the integration site. By identifying chromatin regions having both increased transcription factor activity (by ATAC-seq) and HIV-1-chromtain interaction (by 4C-seq), we identified enrichment of ETS, RUNT, STAT, and ZNF transcription factor binding that may mediate HIV-1-host chromatin interactions. Our study found that HIV-1 promoter activity increased host chromatin accessibility, increased HIV-1-host chromatin interactions in an integration site dependent manner, within the existing chromatin boundaries without impacting broader host chromatin structure.
2023-05-01 | GSE230313 | GEO
Project description:HIV-1 integration introduces ectopic transcription factor binding sites into host chromatin. We postulate that the integrated provirus serves as an ectopic enhancer that recruits additional transcriptional factors to the integration locus, increases chromatin accessibility, changes 3D chromatin interactions, and enhances both retroviral and host gene expression. We used 4 well-characterized HIV-1-infected cell line clones having unique integration sites and low to high levels of HIV-1 expression. Using single-cell DOGMA-seq, which captured the heterogeneity of HIV-1 expression and host chromatin accessibility, we found that HIV-1 transcription correlated with HIV-1 accessibility and host chromatin accessibility. HIV-1 integration increased local host chromatin accessibility within ~5–30 kb distance. CRISPRa and CRISPRi-mediated HIV-1 promoter activation and inhibition confirmed integration site-dependent HIV-1-driven changes of host chromatin accessibility. HIV-1 did not drive chromatin confirmation changes at the genomic level (by Hi-C) or the enhancer connectome (by H3K27Ac HiChIP). Using 4C-seq to interrogate HIV-1-chromatin interactions, we found that HIV-1 interacted with host chromatin ~100–300 kb from the integration site. By identifying chromatin regions having both increased transcription factor activity (by ATAC-seq) and HIV-1-chromtain interaction (by 4C-seq), we identified enrichment of ETS, RUNT, STAT, and ZNF transcription factor binding that may mediate HIV-1-host chromatin interactions. Our study found that HIV-1 promoter activity increased host chromatin accessibility, increased HIV-1-host chromatin interactions in an integration site dependent manner, within the existing chromatin boundaries without impacting broader host chromatin structure.
2023-05-01 | GSE229928 | GEO
Project description:HIV-1 integration introduces ectopic transcription factor binding sites into host chromatin. We postulate that the integrated provirus serves as an ectopic enhancer that recruits additional transcriptional factors to the integration locus, increases chromatin accessibility, changes 3D chromatin interactions, and enhances both retroviral and host gene expression. We used 4 well-characterized HIV-1-infected cell line clones having unique integration sites and low to high levels of HIV-1 expression. Using single-cell DOGMA-seq, which captured the heterogeneity of HIV-1 expression and host chromatin accessibility, we found that HIV-1 transcription correlated with HIV-1 accessibility and host chromatin accessibility. HIV-1 integration increased local host chromatin accessibility within ~5–30 kb distance. CRISPRa and CRISPRi-mediated HIV-1 promoter activation and inhibition confirmed integration site-dependent HIV-1-driven changes of host chromatin accessibility. HIV-1 did not drive chromatin confirmation changes at the genomic level (by Hi-C) or the enhancer connectome (by H3K27Ac HiChIP). Using 4C-seq to interrogate HIV-1-chromatin interactions, we found that HIV-1 interacted with host chromatin ~100–300 kb from the integration site. By identifying chromatin regions having both increased transcription factor activity (by ATAC-seq) and HIV-1-chromtain interaction (by 4C-seq), we identified enrichment of ETS, RUNT, STAT, and ZNF transcription factor binding that may mediate HIV-1-host chromatin interactions. Our study found that HIV-1 promoter activity increased host chromatin accessibility, increased HIV-1-host chromatin interactions in an integration site dependent manner, within the existing chromatin boundaries without impacting broader host chromatin structure.
2023-05-01 | GSE229927 | GEO
Project description:HIV-1 integration introduces ectopic transcription factor binding sites into host chromatin. We postulate that the integrated provirus serves as an ectopic enhancer that recruits additional transcriptional factors to the integration locus, increases chromatin accessibility, changes 3D chromatin interactions, and enhances both retroviral and host gene expression. We used 4 well-characterized HIV-1-infected cell line clones having unique integration sites and low to high levels of HIV-1 expression. Using single-cell DOGMA-seq, which captured the heterogeneity of HIV-1 expression and host chromatin accessibility, we found that HIV-1 transcription correlated with HIV-1 accessibility and host chromatin accessibility. HIV-1 integration increased local host chromatin accessibility within ~5–30 kb distance. CRISPRa and CRISPRi-mediated HIV-1 promoter activation and inhibition confirmed integration site-dependent HIV-1-driven changes of host chromatin accessibility. HIV-1 did not drive chromatin confirmation changes at the genomic level (by Hi-C) or the enhancer connectome (by H3K27Ac HiChIP). Using 4C-seq to interrogate HIV-1-chromatin interactions, we found that HIV-1 interacted with host chromatin ~100–300 kb from the integration site. By identifying chromatin regions having both increased transcription factor activity (by ATAC-seq) and HIV-1-chromtain interaction (by 4C-seq), we identified enrichment of ETS, RUNT, STAT, and ZNF transcription factor binding that may mediate HIV-1-host chromatin interactions. Our study found that HIV-1 promoter activity increased host chromatin accessibility, increased HIV-1-host chromatin interactions in an integration site dependent manner, within the existing chromatin boundaries without impacting broader host chromatin structure.
2023-05-01 | GSE229926 | GEO
Project description:In order to identify novel factors associated with regulation of HIV-1 transcription, we completed a genome-wide CRISPRi screen in a monogenic model of HIV-1. We identified SLTM mediated suppression of HIV-1 transcription. We hypothesized that SLTM would alter the chromatin acessibility at the site of HIV-1 integration. We conducted ATAC-seq of CRISPR ready cells encoding a single HIV-1 provirus in the SPECC1 gene transduced with a gRNA targetting SLTM and a Non-Targeting gRNA. We found that SLTM knockdown increased HIV-1 proviral acessibility across the provirus and host acessibility downstream of the site of HIV-1 integration.
2022-05-20 | GSE203235 | GEO
Project description:Integration of the HIV-1 provirus in the host genome ensures a persistent supply of latently infected cells. This latent reservoir is recalcitrant to antiretroviral therapy (ART) making lifelong treatment the only option for patients. The â??shock and killâ?? strategy aims to eradicate latent HIV by reactivating proviral gene expression followed by ART treatment. Gene specific transcriptional activation can be achieved using the RNA-guided CRISPR-Cas9 system comprising small guide RNAs (sgRNAs) with a nuclease deficient Cas9 mutant (dCas9) fused to the VP64 transactivation domain (dCas9-VP64).  We engineered this system to target 23 sites within the LTR promoter of HIV-1 and identified a â??hotspotâ?? for activation. We studied the functionality of activating sgRNAs to transcriptionally modulate the latent proviral genome across multiple different in vitro latency cell models including several J-Lat, ACH2 J1.1 and the CEM T cell model comprising a single clonal population of integrated mCherry-IRES-Tat from a full-length HIV LTR (LChIT). While we observed variable responses of latent cell models to well-characterized chemical stimuli, we detected consistent efficient activation of latent virus mediated by activator sgRNAs. In addition, transcriptome analysis of chemically treated cells revealed massive non-specific gene dysregulation whereas by comparison, dCas9-VP64/sgRNAs induced specific activation of the integrated provirus. In conclusion, we show the potential for CRISPR-mediated gene activation systems to provide enhanced efficiency and specificity in a targeted latency reactivation strategy. This represents a promising approach to a â??functional cureâ?? of HIV/AIDS. Three experimental conditions (sgRNA control, TNF treated and sgRNA against the LTR of HIV-1) were analyzed in triplicate using two sequencing lanes
2016-08-20 | E-GEOD-72259 | biostudies-arrayexpress
Project description:A major pharmacological strategy toward HIV cure aims to reverse latency in infected cells as a first step leading to their elimination. While the unbiased identification of molecular targets physically associated with the latent HIV-1 provirus would be highly valuable to unravel the molecular determinants of HIV-1 transcriptional repression and latency reversal, due to technical limitations, this has been challenging. Here we use a dCas9 targeted chromatin and histone enrichment strategy coupled to mass spectrometry (Catchet-MS) to probe the differential protein composition of the latent and activated HIV-1 5'LTR. Catchet-MS identified known and novel latent 5’LTR-associated host factors. Among these, IKZF1 is a novel HIV-1 transcriptional repressor, required for Polycomb Repressive Complex 2 recruitment to the LTR. We find the clinically advanced thalidomide analogue iberdomide, and the FDA approved analogues lenalidomide and pomalidomide, to be novel LRAs that, by targeting IKZF1 for degradation, reverse HIV-1 latency in CD4+T-cells isolated from virally suppressed people living with HIV-1.
2022-02-06 | GSE196059 | GEO
Project description:Bovine Leukemia Virus (BLV)-induced tumoral development is a multifactorial phenomenon which remains incompletely understood. Here, we highlight the critical role of the cellular CCCTC-binding factor (CTCF) both in the regulation of BLV transcriptional activities and in the deregulation of the three-dimensional (3D) chromatin architecture surrounding the BLV integration site. We demonstrated the in vivo recruitment of CTCF to three conserved CTCF binding motifs along the BLV provirus. Next, we showed the localization of CTCF to transitions in the histone modifications profile along BLV genome as well as its implication in the repression the 5’Long Terminal Repeat (LTR) promoter activity, thereby contributing to viral latency, while favoring the 3’LTR promoter activity. Finally, we demonstrated that BLV integration deregulated host cellular 3D chromatin organization through the formation of viral/host chromatin loops. Altogether, our results highlight CTCF as a new critical effector of BLV transcriptional regulation and BLV-induced physiopathology.
2022-02-18 | GSE178483 | GEO
Project description:Bovine Leukemia Virus (BLV)-induced tumoral development is a multifactorial phenomenon which remains incompletely understood. Here, we highlight the critical role of the cellular CCCTC-binding factor (CTCF) both in the regulation of BLV transcriptional activities and in the deregulation of the three-dimensional (3D) chromatin architecture surrounding the BLV integration site. We demonstrated the in vivo recruitment of CTCF to three conserved CTCF binding motifs along the BLV provirus. Next, we showed the localization of CTCF to transitions in the histone modifications profile along BLV genome as well as its implication in the repression the 5’Long Terminal Repeat (LTR) promoter activity, thereby contributing to viral latency, while favoring the 3’LTR promoter activity. Finally, we demonstrated that BLV integration deregulated host cellular 3D chromatin organization through the formation of viral/host chromatin loops. Altogether, our results highlight CTCF as a new critical effector of BLV transcriptional regulation and BLV-induced physiopathology.
2022-02-18 | GSE178482 | GEO