脐血中TCR Vβ亚家族T细胞的增殖特点

The Feature of TCR Vβ Subfamily T Cells Expansion in Cord Blood

目的 了解脐血T细胞体外诱导后TCRVβ亚家族的分布和克隆性增殖特点 .方法 利用T淋巴细胞液体培养法 ,在不同刺激源 (rhIL - 2、抗CD3 单抗、PHA、AML -M5细胞和bcr -abl多肽 )条件下诱导脐血T细胞扩增 ,并利用RT -PCR分别扩增培养前后脐血T细胞的TCRVβ 2 4个亚家族基因的CDR3片段 ,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 .结果 脐血T细胞仅表达部分Vβ亚家族 ,但经体外培养后 ,可检测到绝大多数TCRVβ亚家族T细胞 ,而经AML -M5细胞和bcr-abl多肽诱导后 ,TCRVβ亚家族T细胞呈限制性表达和Vβ亚家族克隆性增殖 .结论 脐血T细胞具备产生各TCRVβ亚家族T细胞的潜能 ,在白血病相关抗原诱导下 ,具有限制性和克隆性增殖的能力 .

Objective To investigate the distribution and clonal expansion of TCR Vβ subfamily T cells in cord blood after T cell culture in vitro. Methods T cells from cord blood induced by different stimulators (IL-2, PHA, anti-CD 3 antibody, AML-M 5 cells and bcr-abl peptide) were amplified in vitro by liquid T cell culture method. By using the RT-PCR, the CDR3 segments of T cell antigen receptor (TCR) 24 variable region gene was analyzed in T cells from 4 cases of cord blood before and after T cell culture, 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 evaluating clonality of the detectable TCR Vβ T cells. Results Only a part of 24 Vβ subfamily T cell were expressed in cord blood, but the most TCR Vβ subfamily T cells could been detected after T cell culture, whereas the restricted expression of TCR Vβ subfamilies and Vβ21 clonal expansion T cells were found in culture T cells induced by AML-M 5 cells or bcr-abl peptide. Conclusions T cells from cord blood may have the potential capability of proliferation in different TCR Vβ subfamily T cells, and the ability of restricted expression and clonal expansion, when T cells were induced by leukemia associated antigen.