G9a/GLP Inhibition Promotes T Cell Development from Pluripotent Stem Cells [RNA-Seq]

Elucidating mechanisms of T cell development can guide in vitro T cell differentiation from Pluripotent Stem Cells (iPSCs) and inform off-the-shelf T cell-based immunotherapies. Using a stroma-free human iPSC-T cell differentiation platform, we screened for epigenetic modulators that govern T cell specification and identified the H3K9-directed histone methyltransferases G9a/GLP as repressors of T cell fate. We show that G9a/GLP controls the cell fate decision between myeloid and lymphoid lineages in hematopoietic stem and progenitor cells (HSPCs). Inhibition of G9a/GLP promotes the production of lymphoid cells during zebrafish embryonic hematopoiesis, demonstrating the evolutionary conservation of G9a/GLP function. Importantly, chemical-induced epigenetic reprogramming via G9a/GLP inhibition facilitates the generation of robust iPSC-T cells that bear transcriptional similarity to peripheral blood aß T cells. When engineered to express Chimeric Antigen Receptors, the epigenetically engineered iPSC-T cells exhibit enhanced antitumor activity both in vitro and in a xenograft mouse model. Overall design: iPSC-derived T cells were treated with G9a/GLP inhibitor, UNC0224

阐明T细胞发育的调控机制，可指导从诱导多能干细胞（iPSCs）体外分化获得T细胞，并为通用型T细胞免疫治疗提供理论支撑。本研究采用无基质人iPSC-T细胞分化平台，筛选调控T细胞定向分化的表观遗传调控因子，鉴定出靶向H3K9的组蛋白甲基转移酶G9a/GLP作为T细胞命运的抑制因子。研究发现，G9a/GLP可调控造血干祖细胞（HSPCs）中髓系与淋巴系谱系间的细胞命运抉择。在斑马鱼胚胎造血过程中，抑制G9a/GLP可促进淋巴系细胞生成，证实了G9a/GLP功能在进化上的保守性。值得注意的是，通过抑制G9a/GLP实现化学诱导的表观遗传重编程，可助力生成具有成熟功能的iPSC-T细胞，其转录组特征与外周血αβ T细胞高度相似。当对这些细胞进行工程化改造以表达嵌合抗原受体（Chimeric Antigen Receptors, CAR）后，经表观遗传修饰的iPSC-T细胞在体外及异种移植小鼠模型中均展现出更强的抗肿瘤活性。实验整体设计：将诱导多能干细胞分化而来的T细胞用G9a/GLP抑制剂UNC0224进行处理。