Bcl-3通过mTORC1信号通路调节CD4+T细胞代谢及功能的机制研究

Bcl-3 plays an important role in effective adaptive and innate immune responses against pathogens and the prevention of autoimmune diseases, as well as in effector CD4+Tcell plasticity. However, Whether Bcl-3 affects the function of CD4+T cells by regulating their energy metabolism remains unclear. Our previous studies found that knockout of Bcl-3 gene can reduce glycolysis ability and ATP production, inhibit proliferation of Jurkat cells and promote original state and TCR-stimulated activation of Jurkat cells. Moreover, Bcl-3 interacts with Raptor, one component of mTORC1 complex. These results suggest that Bcl-3 mediates energy metabolism and affects cell's function. We will investigate the pathways and molecular mechanisms by which Bcl-3 regulates energy metabolism of CD4+Tcells, and the regulatory mechanism of Bcl-3-mediated metabolic pathway on CD4+Tcell differentiation and autoimmune diseases from molecular and cellular levels and in vivo and in vitro systems by the methods of immuno-precipitation,flow staining,EAE model and other techniques. It will be determined the regulatory mechanism of Bcl-3-mediated metabolic pathway on CD4+Tcell function, the results will provide new ideas for the prevention and treatment of immunological diseases.

Bcl-3在对抗病原体的有效适应性和先天免疫应答、自身免疫疾病预防及CD4+T细胞可塑性方面都起着重要作用。但是，Bcl-3是否通过调控能量代谢进而影响CD4+T细胞的功能仍不明确。前期预实验研究发现，敲除Bcl-3基因可降低Jurkat细胞的糖酵解能力和ATP产生，抑制Jurkat细胞的增殖，促进Jurkat细胞原始状态及TCR刺激下的活化，且Bcl-3与mTORC1复合物中的Raptor相互作用。提示Bcl-3介导糖代谢和影响细胞功能。我们拟采用免疫共沉淀、流式染色、EAE疾病模型等方法，从细胞和分子水平、动物体内和体外系统地探讨Bcl-3通过mTORC1调控CD4+T细胞糖代谢的途径和分子机制，以及Bcl-3介导的糖代谢途径对CD4+T细胞分化及自身免疫性疾病的调节机制，从而阐明Bcl-3基因介导的糖代谢途径对CD4+T细胞功能的调节机制，为探索相关的免疫性疾病的防治策略提供新思路。

Bcl-3是一种非典型的IkB家族成员通过与p50/p52同源二聚体亚基结合。虽然各种研究表明Bcl-3在生理功能中的重要作用，其在代谢中的作用尚不清楚。本项目以Bcl-3基因敲除小鼠为研究对象，借助代谢组学分析、单细胞转录组测序，结合体外及体内实验，系统地研究Bcl-3通过乳酸调节Th17细胞功能的机制。通过体内外实验，发现Bcl-3对自身免疫有代谢调节作用，并且Bcl-3可以影响Jurkat T 细胞线粒体能量代谢。Bcl-3敲除的小鼠能够抵抗EAE疾病的发生，抑制Th17细胞由外周向中枢神经系统的迁移。进一步借助代谢组学分析发现，该疾病的抵抗力与Th17细胞中乳酸水平的增加有关，乳酸可以减轻WT小鼠EAE发病程度。Bcl-3缺失有助于Th17细胞的分化，伴随着这些细胞的胞外酸化率增加，他们的极限呼吸率和呼吸储备能力也明显低于WT小鼠。同时，向Bcl-3缺失的Th17细胞添加GNE-140（LADH抑制剂）可以扭转这一现象，且补充乳酸盐可以提高WT小鼠的Th17细胞的糖酵解代谢。在机制上，Bcl-3可以通过ANK结构域与Raptor的RNC结构域发生相互作用。因此，Bcl-3通过促进Raptor介导的能量代谢来调节Th17的致病性，这揭示了适应性免疫的一种新的调节方式。为探索相关的免疫性疾病的防治策略奠定理论基础，为药物研发和临床治疗提供新思路和新靶点。