Hu Q, Bazemore Walker C R, Girao C, Opferman J T, Sun J, Shabanowitz J, Hunt D F, Ashton-Rickardt P G
Gwen Knapp Center for Lupus and Immunology Research, Department of Pathology, University of Chicago, Illinois 60637, USA.
Immunity. 1997 Aug;7(2):221-31. doi: 10.1016/s1074-7613(00)80525-7.
To understand how thymic selection gives rise to T cells that are capable of major histocompatibility complex (MHC)-restricted recognition of antigen but are tolerant of self, we directly examined how peptide/MHC ligands expressed on thymic epithelial cells trigger the positive selection of immature thymocytes. We demonstrate that abundant self-peptides, purified from the H-2D(b) molecules of thymic epithelial cells, are specifically recognized during the positive selection of CD8+ T cells, implying that positive selection generates a repertoire of T cells that is weakly self-reactive. We also found that this recognition is somewhat cross-reactive, thereby providing an explanation for how the specific recognition of a limited repertoire of thymic self-peptides can select a diverse repertoire of T cells.
为了理解胸腺选择如何产生能够对主要组织相容性复合体（MHC）限制的抗原进行识别但对自身耐受的T细胞，我们直接研究了胸腺上皮细胞上表达的肽/MHC配体如何触发未成熟胸腺细胞的阳性选择。我们证明，从胸腺上皮细胞的H-2D(b)分子中纯化的大量自身肽在CD8+T细胞的阳性选择过程中被特异性识别，这意味着阳性选择产生了一组弱自身反应性的T细胞库。我们还发现这种识别具有一定的交叉反应性，从而解释了对有限的胸腺自身肽库的特异性识别如何能够选择多样化的T细胞库。
