人胎儿胸腺细胞表型分析

The phenotypic analysis of Human fetal thymocytes

利用流式细胞计分析了人中期妊娠引产胎儿胸腺细胞的某些表面分子的表达,结果表明从胎儿发育的第17周直到儿童期,胸腺细胞 CD1、CD2、CD3、CD4、CD8、CD38、TCR 以及 HLA 抗原的表达无明显变化.在这一发育阶段,胸腺细胞表型呈现以下特征:1.CD3/TCRαβ分子的表达呈现从弱到强的连续性分布,可以分为三个亚群,从弱到强依次称为 L-CD3/TCRαβ、M-CD3/TCRαβ和 H-CD3/TCRαβ.个体之间三个亚群含量差异很大.2.大部分单阳性成熟型胸腺细胞也表达 CD1抗原.3.HLA Ⅰ类抗原在胸腺细胞上表达呈现密度不等的变化.大部分胸腺细胞为弱阳性,少部分为强阳性.HLA Ⅰ类抗原表达量和胸腺细胞成熟度相关.4.根据胸腺细胞比重将胸腺细胞分为 Thy-L 和 Thy-H2个亚群.Thy-L 亚群中成熟型和早期胸腺细胞含量较多,而 Thy-H 主要由中间发育阶段的胸腺细胞构成.

The phenotypes of human fetal thymocytes has been analysed with fflowcytometry.The findings suggest that the composition of thymocyte subsets shows no obvious changes from the 17th week of gestation to birth.In the pieriod of human fetus,features of thymocyte phenotypes are showed:1.Expression density of CD3/TCRαβ shows a continuous distribution from low to high.According to the density of D3/TCRαβ,tyhmocytes can be divided into three subsets,that is,L—CD3/TCRαβ(low—density),M—CD3/TCRαβ medium—density)and H—CD3/TCRαβ(high— density).The proportion of three subsets is different in different fetuses.2.Single positive thymocytes express CD1 antigens.H—CD3/TCRαβ thymocytes also express CD1 antigens.But,Part of those thymocytes express low—density of CD1 antigens,other part of the hymocytes express high—density of CD1 antigens.3.HLA class Ⅰ antigen density varies with thymocytes.Most thymocytes express low density of HLA class Ⅰ antitgens,minor thymocytes express high density of HLA class Ⅰ antigens.HLA class Ⅰ antigen density correlates with maturity of thymocytes.4.Thymocytes can be divided into two subsets:Thy-L and Thy-H on the basis of thymocyte special density by means of density gradient centrifugation.Thy-L subset includes more mature and early thymocytes than Thy-H subset,while thy-H subset includes much more common thymocytes than Thy-L subset.