脐血中TCRVβ亚家族T细胞的分布和克隆性分析

目的:了解正常脐血中TCR Vβ亚家族T细胞的分布和克隆性。方法:利用RT-PCR分别扩增13例正常脐血单个核细胞的TCR Vβ 24个亚家族基因的CDR3,了解各Vβ亚家族的表达情况。阳性的PCR产物进一步经荧光素标记和基因扫描分析产物的CDR3长度,了解T细胞克隆性。10例正常人外周血和T细胞株Molt-4及Jurkat作为对照。 结果:正常脐血T细胞仅选择性表达24个Vβ亚家族的38.78%±16.26%,以Vβ3、5、8、9和13为多见,而正常人外周血T细胞则表达全部24个Vβ亚家族。基因扫描显示正常脐血和正常人外周血的全部PCR产物均呈多峰图象。结论:正常脐血存在不完全TCR Vβ亚家族T细胞,所有TCR Vβ亚家族T细胞均呈多克隆性。

Analysis of the distribution and clonality of TCR Vβ T cells in cord blood

AIM:To investigate the distribution and clonality of TCR Vβ subfamily T cells in cord blood. METHODS:The CDR3 of TCR Vβ 24 subfamily genes were amplified in mononuclear cells from 13 cases of cord blood. To observe the usage of TCR Vβ repertoire, the PCR products were further labeled with fluorescent and analyzed by genescan technique for the CDR3 size, to evaluate clonality of the detectable TCR Vβ T cells. Peripheral bloods from 10 cases of normal individuals and T cell line Molt-4 and Jurkat served as controls. RESULTS:Only 38.78%±16.26% of 24 Vβ subfamily T cell were selectively expressed in cord blood, predominantly in Vβ 3, 5, 8, 9 and 13, whereas all 24 Vβ subfamilies could be detected in T cells from peripheral blood of normal individuals. Genescan analysis showed that all PCR products of TCR Vβ subfamilies from cord blood or normal individual peripheral blood displayed multi-peaks. CONCLUSION:Some TCR Vβ subfamily T cells were absent in cord blood. All TCR Vβ subfamily T cells in cord blood displayed polyclonality.