转录因子Zfp281在T淋巴细胞功能的机制研究

T cell activation is a tightly regulated process at molecular level。Related researches are being the hot spots of immunology. Transcription factor Zfp281 known as one key factor to sustain the multipotency of embryo stem cells was highly expressed in T lymphocytes in this study. We constructed Zfp281 conditional knockout mice with Cre-Loxp system to explore the role of Zfp281 played in T lymphocytes development and function. In our project, we found that Zfp281 was required for the activation and immune responses of CD4+ T cells, while it was dispensable for T cell development. Thus, we will detect related TCR signaling pathways, and establish animal models responding to bacterial to confirm the phenotype. The target genes will be determined by omics analysis including RNA-seq and ChIP-seq. Furthermore, we will construct the transgenic mice of target genes to determine their functions on T cell activation. Taken together, the objective of this project is to illuminate the molecular mechanism of Zfp281 in regulating T cell activation. The immunomodulatory properties of Zfp281 also suggest that their application might be beneficial in diagnosis and treatment of patients with T cell-mediated immunopathologies such as bacterial infection

T细胞活化受到分子水平的精细调控。相关研究一直是免疫学研究的重点和热点。本课题组发现转录因子Zfp281这一维持胚胎干细胞多潜能性的重要基因在T细胞中高表达。通过CD4cre+ Zfp281fl/fl小鼠表型分析，显示Zfp281缺失对T细胞的发育影响甚微，但外周T 细胞活化明显受损。本项目通过信号通路检测、OTII小鼠杂交及动物感染模型证实Zfp281对T细胞活化的影响。并结合RNA-seq和ChIP-seq等组学方法，确定靶基因，揭示分子调控机制。进一步构建靶基因的T 细胞特异性转基因小鼠以分析表型，确定其对T细胞活化功能的影响。上述结果有望为现有的T 细胞活化分子调控机制提供补充，同时我们也将进一步研究Zfp281缺失对小鼠整体免疫反应，特别是对肿瘤免疫和感染免疫的影响，从而为阐明人类相关临床疾病的发病机制和为这类疾病提供诊断及治疗手段提供理论依据。

Zfp281 作为转录因子，是一种 C2H2 锌指蛋白，负向调控胚胎干细胞多能性。然而，尚未研究 Zfp281 在分化细胞中的功能。鉴于Zfp281 全基因组敲除具有胚胎致死性，将Zfp281fl/fl与CD4-Cre 转基因小鼠杂交，从而获得了Zfp281 在T 细胞中特异性敲除的小鼠CD4-Cre Zfp281fl/fl，表型分析发现Zfp281 敲除不影响T 细胞发育及外周CD4+ T 细胞增殖，但小鼠分泌细胞因子能力下降，T 细胞活化受损，小鼠清除李斯特菌感染的能力下降，且这种效应是TCR 特异性的。进一步机制研究发现Zfp281 在T细胞活化中发挥抑制作用是通过靶向共抑制分子CTLA-4，直接抑制Ctla-4 转录而促进T 细胞活化。本课题进一步补充了共抑制受体，CTLA-4在效应T细胞上的表达的转录调控的关键机制。成果也于2019年9月发表在Cellular &Molecular Immunology 期刊上。培养博士生2名和1名硕士生。除此之外，依托该基金项目的支持，课题组继续得以研究T细胞发育和活化的非转录性调控机制的研究。而这衍生的课题再次获得国家自然基金重点项目的支持，本人作为第一参与人，部分总结的结果正积极投稿中