胎儿胸腺发育过程中T细胞抗原受体的表达

Expression of T cell receptor in fetal thymus

目的：检测不同胎龄胎儿胸腺组织内T细胞抗原受体（TCR）的表达及发育规律.方法：18～40周胎儿胸腺组织,采用免疫组织化学SP法检测TCRαβ和TCRγδ的表达. 结果：胚胎21周,胸腺组织开始出现TCRαβ和TCRγδ阳性细胞.TCRαβ阳性细胞主要分布被膜下及小叶间隔中,围绕血管成群分布.TCRγδ阳性细胞的分布与TCRαβ阳性细胞相似, 但细胞数量较TCRαβ阳性细胞少.38周以后胎儿胸腺内TCR阳性细胞主要分布在皮髓质交界处,被膜下及小叶间隔中的TCR阳性细胞较早期少.结论：TCR阳性细胞在胚胎早期开始出现,其分布部位提示局部微环境有利于这些细胞的分化发育.

Objective： To observe the expression of T cell receptor （TCR）in the development of fetal thymus. Methods： Thymus of human fetal （from 18^th week to 40^th week of gestation） were obtained. The expressions of TCRαβ and TCRγδ were examined by using immunohistochemical S-P method. Results： TCR positive cells were expressed in fetal thymus from the 21^th week. The TCRαβ immunoreactive cells were：distributed mainly in the capsule and interlobular septum, and surrounded the blood vessels. The distribution of TCRγδ positive cells was similar to that of the TCRαβ, but the cell number was less than that of TCRαβ. At the 38^th week and thereafter, the TCR positive cells were predominantly located in corticomedullary junction zone. Conclusion： TCRαβ and TCRγδ express in the early embryonic period. The distribution of TCR positive cells indicates that the local micro environment favored differentiation of these cells.