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.
Project description:Human immunodeficiency viruses type 1 and 2 (HIV-1 and 2) are known to depend on cellular host machinery for their replication and survival. While most of the studies on cellular proteomic and transcriptomic changes focused on the late-phase of the infection, studies of those changes in the early time-points; especially in the case of HIV-2 infection, are widely lacking. Using 2nd generation HIV-1 and 2 VSV-G pseudotyped lentiviral vectors, we transduced HEK-293T cells, and carried out transcriptomic profiling and proteomic analysis of harvested cells at 2h time point, which is representative of the immediate early-phase events in the infection cycle.
Project description:HCT116 cells transfected with lentiviral vectors expressing two different N-BLR shRNAs (clones #3-1 and #4-7) and empty vector control
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.
Project description:Purpose: Study of transcriptomic changes upon depletion of USP7 Methods: Melanoma PDX cells were transduced with lentiviral vectors expressing Scrambled(shSCR) or USP7 targeting (shUSP7) shRNA
Project description:ImageMol is a Representation Learning Framework that utilizes molecule images for encoding molecular inputs as machine readable vectors for downstream tasks such as bio-activity prediction, drug metabolism analysis, or drug toxicity prediction. The approach utilizes transfer learning, that is, pre-training the model on massive unlabeled datasets to help it in generalizing feature extraction and then fine tuning on specific tasks. This model is fine tuned on 13 assays concerned with a number of target categories ranging from viral entry to toxicity in humans. These interactions are formulated as binary classification tasks.
Model Type: Predictive machine learning model.
Model Relevance: Probability of HIV inhibition.
Model Encoded by: Dhanshree Arora (Ersilia)
Metadata Submitted in BioModels by: Zainab Ashimiyu-Abdusalam
Implementation of this model code by Ersilia is available here:
https://github.com/ersilia-os/eos6hy3
Project description:This study was performed to check that ESR1 and BMI1 are biologically active after lentiviral transduction of primary human mammary epithelial cells (HMECs) with lentiviral vectors expressing ESR1 and BMI1 from the human PGK promoter. ESR1 targets like PGR, PRLR and GREB1, but not TFF1 and XBP1, were induced by estradiol in the ESR1-expressing cells. BMI1 targets like BMI1, NEFL and CCND2 were repressed in the BMI1-expressing cells. BMI1 suppressed genes associated with squamous and neural differentiation in the ESR1 plus BMI1-expressing cells. Experiment Overall Design: Infect with lentiviruses 24 hours after reduction mammmoplasty. Grow cells in human mammosphere medium: Hepes-buffered DMEM/F12 supplemented with 20 ng/ml EGF, 1x B-27 (GIBCO) plus 1 nM 17-β-estradiol or 1 uM fulvestrant (ICI 182,780). Experiment Overall Design: Lentiviral vectors: pSD-82, ESR1; pSD-84, BMI1; pSD-86, gusA.
Project description:This study was performed to check that ESR1 and BMI1 are biologically active after lentiviral transduction of primary human mammary epithelial cells (HMECs) with lentiviral vectors expressing ESR1 and BMI1 from the human PGK promoter. ESR1 targets like PGR, PRLR and GREB1, but not TFF1 and XBP1, were induced by estradiol in the ESR1-expressing cells. BMI1 targets like BMI1, NEFL and CCND2 were repressed in the BMI1-expressing cells. BMI1 suppressed genes associated with squamous and neural differentiation in the ESR1 plus BMI1-expressing cells. Keywords: Drug response