Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA.
Nat Immunol. 2012 Jan 19;13(2):121-8. doi: 10.1038/ni.2190.
The T cell repertoire is generated during thymic development in preparation for the response to antigens from pathogens. The T cell repertoire is shaped by positive selection, which requires recognition by the T cell antigen receptor (TCR) of complexes of self peptide and major histocompatibility complex proteins (self-pMHC) with low affinity, and negative selection, which eliminates T cells with TCRs that recognize self-pMHC with high affinity. This generates a repertoire with low affinity for self-pMHC but high affinity for foreign antigens. The TCR must successfully engage both of these ligands for development, homeostasis and immune responses. This review discusses mechanisms underlying the interaction of the TCR with peptide-major histocompatibility complex ligands of varying affinity and highlights signaling mechanisms that enable the TCR to generate different responses to very distinct ligands.
T 细胞受体库是在胸腺发育过程中产生的，为应对病原体抗原的反应做准备。T 细胞受体库由阳性选择和阴性选择塑造，前者需要 T 细胞抗原受体（TCR）识别低亲和力的自身肽和主要组织相容性复合物蛋白（自身-pMHC）复合物，后者消除了 TCR 识别自身-pMHC 具有高亲和力的 T 细胞。这产生了一个对自身-pMHC 亲和力低但对外国抗原亲和力高的受体库。TCR 必须成功地与这两种配体结合才能进行发育、维持和免疫反应。本综述讨论了 TCR 与不同亲和力的肽-主要组织相容性复合物配体相互作用的机制，并强调了使 TCR 能够对非常不同的配体产生不同反应的信号转导机制。
