Project description:A major obstacle for HIV eradication is the persistence of latent reservoirs, cells harboring replication competent yet transcriptionally silent proviruses. These reservoirs, composed primarily of CD4+ T cells, cannot be targeted by the host immune system or by combination anti-retroviral therapy (cART). Upon cessation of cART, a rapid viral rebound occurs. In order to develop effective HIV cure therapies, a better understanding of the factors and host programd governing latency establishment and/or maintenance must be obtained. To achieve this goal, we treated a CD4+T cell-based model of latency (J-Lat 10.6) with Latency Reversing Agents (LRAs) and performed bulk RNA-seq to predict host transcriptional programs activated, and potentially involved, in latent HIV reactivation. Our findings suggest that a novel small molecule (EPH-334) reactivates latent HIV by activating an oxidative stress transcriptional program linked to activation of MAPKs and downstream master regulators. Interestingly, the pan histone deacetylase inhibitor SAHA also induces oxidative stress programs potentially linking sensing of redox state aletartions with activation of cell signaling and transcriptioonal programs culminating on latent HIV reactivation.
Project description:Upon antigen-specific T Cell Receptor (TCR) engagement, human CD4+ T cells proliferate and differentiate, a process associated with rapid transcriptional changes and metabolic reprogramming utilizing aerobic glycolysis together with maintenance of oxidative phosphorylation1,2. However, the role of glycolytic-reprogramming during T-cell activation remains largely unclear3,4,5. Here, we show that maintenance of cytosolic pyruvate production is an essential requirement for remodeling of the CD4+ T cell epigenome after TCR-engagement. Furthermore, we provide evidence that the local inflammatory environment sustains metabolic reprogramming of CD4+ T-cells and impacts histone modification in a pyruvate-dependent manner. Mechanistically, we demonstrate that rapid and sustained generation of cytosolic, but not mitochondrial, pyruvate is an essential step for acetyl-coA production and subsequent H3K27ac epigenome remodeling. TCR-activation was found to induce nuclear import of pyruvate dehydrogenase (PDH) and its association with both the p300 acetyltransferase and histone H3K27ac. Disrupting PDH nuclear import impacted expression of activation-induced genes. These results reveal a direct connection between CD4+ T cell metabolic reprogramming and transcriptional regulation, with the generation of cytosolic pyruvate being an essential step in T cell activation. These data support tight integration of metabolic enzymes and histone modifying enzymes, allowing metabolic reprogramming to fuel CD4+ T cell activation.
Project description:Pluripotent stem cells can be generated by pure small molecule compounds. However, only fibroblasts, a heterogeneous cell population, were reported for use in chemical reprogramming, and the efficiency is relatively low, raising the possibility that chemically induced pluripotent stem cells (CiPSCs) are derived from a specific cell subpopulation residing in fibroblast culture. Thus, it is of interest to know whether chemical reprogramming can be induced in other cell types, even using the same chemical cocktail. Here, using lineage tracing, we verify the generation of CiPSCs from fibroblasts. We further demonstrate that neural stem cells (NSCs) and small intestinal epithelial cells (IECs), cell types from the ectoderm and endoderm, respectively, can be chemically reprogrammed into pluripotent stem cells. CiPSCs derived from NSCs and IECs resemble mouse embryonic stem cells (ESCs) in terms of proliferation rate, global gene expression profiling, epigenetic status, self-renewal and differentiation capacity, and germline transmission competency. Interestingly, in the chemical reprogramming process from different cell types, a pluripotency gene Sall4 was commonly expressed in the initial stage, and the same core small molecules were required, suggesting conservatism underlying chemical reprogramming from different cell types. Moreover, the use of these small molecules should be fine-tuned to meet the requirement of reprogramming from different cell types. Together, these findings demonstrate that our reported chemical reprogramming approach can be reproduced in different cell types and suggest that chemical reprogramming is a promising strategy with the potential to be extended to more initial cell types. We analyzed the gene expression profiles of NSC-derived CiPSCs and IEC-derived CiPSCs ,using RNA-Sequencing. NSCs, IECs, and embryonic stem cells (R1) are controls.
Project description:Pluripotent stem cells can be generated by pure small molecule compounds. However, only fibroblasts, a heterogeneous cell population, were reported for use in chemical reprogramming, and the efficiency is relatively low, raising the possibility that chemically induced pluripotent stem cells (CiPSCs) are derived from a specific cell subpopulation residing in fibroblast culture. Thus, it is of interest to know whether chemical reprogramming can be induced in other cell types, even using the same chemical cocktail. Here, using lineage tracing, we verify the generation of CiPSCs from fibroblasts. We further demonstrate that neural stem cells (NSCs) and small intestinal epithelial cells (IECs), cell types from the ectoderm and endoderm, respectively, can be chemically reprogrammed into pluripotent stem cells. CiPSCs derived from NSCs and IECs resemble mouse embryonic stem cells (ESCs) in terms of proliferation rate, global gene expression profiling, epigenetic status, self-renewal and differentiation capacity, and germline transmission competency. Interestingly, in the chemical reprogramming process from different cell types, a pluripotency gene Sall4 was commonly expressed in the initial stage, and the same core small molecules were required, suggesting conservatism underlying chemical reprogramming from different cell types. Moreover, the use of these small molecules should be fine-tuned to meet the requirement of reprogramming from different cell types. Together, these findings demonstrate that our reported chemical reprogramming approach can be reproduced in different cell types and suggest that chemical reprogramming is a promising strategy with the potential to be extended to more initial cell types.
Project description:Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Chemicals' acronyms: V, VPA; C, CHIR; 6, 616452; T, tranylcypromine; F, FSK; Z, DZNep; P, PGE2; R, RG108; S, SRT1720; M, 2-Me-5HT; D, D4476; B, Sodium butyrate.
Project description:Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Chemicals' acronym: V, VPA; C, CHIR; 6, 616452; T, tranylcypromine; F, FSK; Z, DZNep; P, PGE2; R, RG108; S, SRT1720; M, 2-Me-5HT; D, D4476; B, Sodium butyrate. mRNA expression analysis of mouse embryonic fibroblasts (MEFs), GFP- cells, GFP+ clusters,GFP+ colonies, embryonic stem cells (ESCs) and CiPSCs by RNA sequencing.
Project description:High throughput phenotypic screen and transcriptional analysis identify new compounds, targets and pathways for macrophage reprogramming
Project description:Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Chemicals' acronym: V, VPA; C, CHIR; 6, 616452; T, tranylcypromine; F, FSK; Z, DZNep; P, PGE2; R, RG108; S, SRT1720; M, 2-Me-5HT; D, D4476; B, Sodium butyrate.
Project description:We analyzed the transcriptional profile of small-intestinal lamina propria (SI-LP) CD4+ T cells isolated from germ-free and mice monocolonized with Bifidobacterium adolescentis, SFB, and Nexabiotic (a 23-strain, Th17-inducing, probiotic mix).