Immunology and Host Defense Group, Discipline of Infectious Diseases and Immunology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.
Tuberculosis Research Program, Centenary Institute, The University of Sydney, Sydney, NSW, Australia.
Front Immunol. 2020 May 19;11:624. doi: 10.3389/fimmu.2020.00624. eCollection 2020.
T cells are critical in orchestrating protective immune responses to cancer and an array of pathogens. The interaction between a peptide MHC (pMHC) complex on antigen presenting cells (APCs) and T cell receptors (TCRs) on T cells initiates T cell activation, division, and clonal expansion in secondary lymphoid organs. T cells must also integrate multiple T cell-intrinsic and extrinsic signals to acquire the effector functions essential for the defense against invading microbes. In the case of T helper cell differentiation, while innate cytokines have been demonstrated to shape effector CD4 T lymphocyte function, the contribution of TCR signaling strength to T helper cell differentiation is less understood. In this review, we summarize the signaling cascades regulated by the strength of TCR stimulation. Various mechanisms in which TCR signal strength controls T helper cell expansion and differentiation are also discussed.
T 细胞在协调对癌症和多种病原体的保护性免疫反应中起着关键作用。抗原呈递细胞 (APCs) 上的肽 MHC(pMHC) 复合物与 T 细胞上的 T 细胞受体 (TCR) 之间的相互作用启动了 T 细胞在次级淋巴器官中的激活、分裂和克隆扩增。T 细胞还必须整合多种内在和外在的 T 细胞信号，以获得对抗入侵微生物所必需的效应功能。在辅助性 T 细胞分化的情况下，虽然先天细胞因子已被证明可以塑造效应 CD4 T 淋巴细胞的功能，但 TCR 信号强度对辅助性 T 细胞分化的贡献了解较少。在这篇综述中，我们总结了 TCR 刺激强度调节的信号级联。还讨论了 TCR 信号强度控制辅助性 T 细胞扩增和分化的各种机制。
