Pyruvate dehydrogenase complex integrates the metabolome and epigenome in memory CD8+ T cell differentiation in vitro [RNA-Seq]. Pyruvate dehydrogenase complex integrates the metabolome and epigenome in memory CD8+ T cell differentiation in vitro [RNA-Seq]

Modulation of metabolic flux through pyruvate dehydrogenase complex (PDC) plays an important role in T cell activation and differentiation. PDC sits at the transition between glycolysis and the tricarboxylic acid cycle and is a major producer of acetyl-CoA, marking it as a potential metabolic and epigenetic node. To understand the role of pyruvate dehydrogenase complex in T cell differentiation, we generated mice deficient in T cell pyruvate dehydrogenase E1A (Pdha) subunit using a CD4-cre recombinase-based strategy. Herein, we show that genetic ablation of PDC activity in T cells (TPdh-/-) leads to marked perturbations in glycolysis, the tricarboxylic acid cycle, and OXPHOS. Due to depressed OXPHOS, TPdh-/- T cells became dependent upon substrate level phosphorylation via glycolysis. Due to the block of PDC activity, histone acetylation was reduced, including H3K27, a critical site for CD8+ T cell memory differentiation. Transcriptional and functional profiling revealed abnormal CD8+ memory T cell differentiation in vitro. Collectively, our data indicate that PDC integrates the metabolome and epigenome in memory T cell differentiation. Targeting this metabolic and epigenetic node can have widespread ramifications on cellular function. Overall design: RNA-Seq contributor: NISC Comparative Sequencing Program

丙酮酸脱氢酶复合物（pyruvate dehydrogenase complex, PDC）所介导的代谢流调控，在T细胞活化与分化过程中发挥关键作用。PDC位于糖酵解与三羧酸循环的代谢交汇节点，同时是乙酰辅酶A的主要合成来源，因此被视作潜在的代谢与表观遗传调控节点。为阐明丙酮酸脱氢酶复合物在T细胞分化中的功能，我们借助基于CD4-cre重组酶的基因工程策略，构建了T细胞特异性丙酮酸脱氢酶E1α（Pdha）亚基缺陷小鼠。本研究显示，T细胞中PDC活性的基因敲除（TPdh-/-）会显著扰动糖酵解、三羧酸循环与氧化磷酸化（OXPHOS）通路。由于氧化磷酸化功能受抑，TPdh-/- T细胞转而依赖糖酵解途径的底物水平磷酸化获取能量。因PDC活性被阻断，组蛋白乙酰化水平显著降低，其中包括CD8+ T细胞记忆分化关键位点H3K27的乙酰化。体外转录组与功能分析显示，TPdh-/- T细胞的CD8+记忆T细胞分化存在异常。综上，本研究数据证实PDC可在记忆T细胞分化过程中整合代谢组与表观基因组。靶向这一代谢与表观遗传调控节点，可对细胞功能产生广泛影响。实验整体设计：RNA测序（RNA-Seq）数据由NISC比较测序项目（NISC Comparative Sequencing Program）提供。