Chen Weifeng
Department of Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100083, China.
Cell Mol Immunol. 2004 Feb;1(1):3-11.
After positive selection and lineage commitment, the TCR alphabeta+ CD4/CD8 SP medullary thymocytes migrate into and reside in thymic medulla, where they undergo an ordered program of late stage of T cell functional maturation and negative selection to delete self-reactive clones by apoptosis. Accomplishment of this final differentiation pathway, a physiological T cell repertoire is formed: T cells acquire immunocompetence to respond to foreign antigens and tolerance to self-antigens, ready for the emigration to homing to the T cell regions of peripheral lymphoid organs and tissues. In this review, emphases are put on introducing the approaches applied in this area and our own observations. Basically, we have analyzed the late stage of medullary thymocyte phenotypic differentiation pathways of both CD4 SP and CD8 SP medullary thymocytes and the concomitant functional maturation pathway, in particular, of CD4 SP thymocytes. It is to provide a standard to compare the functional capacity of the cells at the developmental stages induced by different conditions. The cellular and molecular basis of this differentiation process has been partially described.
经过阳性选择和谱系定向后，TCRαβ⁺ CD4/CD8 单阳性髓质胸腺细胞迁移至胸腺髓质并定居于此，在其中经历 T 细胞功能成熟后期的有序程序以及阴性选择，通过凋亡清除自身反应性克隆。完成这一最终分化途径后，形成了生理性 T 细胞库：T 细胞获得免疫能力以对外源抗原作出反应，并对自身抗原产生耐受性，准备迁移至外周淋巴器官和组织的 T 细胞区域并归巢于此。在本综述中，重点在于介绍该领域所应用的方法以及我们自己的观察结果。基本上，我们分析了 CD4 单阳性和 CD8 单阳性髓质胸腺细胞的髓质胸腺细胞表型分化途径的后期以及伴随的功能成熟途径，特别是 CD4 单阳性胸腺细胞的功能成熟途径。目的是提供一个标准，用于比较在不同条件诱导的发育阶段细胞的功能能力。该分化过程的细胞和分子基础已得到部分描述。
