CML细胞诱导自体和脐血T细胞TCR Vβ谱系和杀伤性分析

TCR Vβ repertoire and cytotoxicity of T cells from patients with CML or cord blood induced by CML cells

目的 了解慢性粒细胞白血病 (CML)细胞诱导T细胞的TCRVβ亚家族限制性利用和克隆性增殖情况 ,及其对CML细胞的杀伤活性。方法 采用混合淋巴细胞 肿瘤细胞培养 (MLTC)方法 ,利用CML细胞体外诱导脐血或患者的T细胞增殖 ,用RT PCR和基因扫描分析MLTC前后T细胞的 2 4个TCRVβ亚家族基因的互补决定区 (CDR3) ,了解各Vβ亚家族的利用和T细胞克隆性特点。并利用LDH方法检测MLTC后T细胞的细胞毒性。结果 脐血T细胞表达 8～ 11个TCRVβ亚家族 ,经MLTC后 ,2～ 3个Vβ亚家族呈克隆性增殖 ,CML细胞诱导的自体T细胞的TCRVβ亚家族也类似。经MLTC后T细胞对原诱导细胞有较强的杀伤活性。结论 CML细胞可诱导脐血T细胞和自体T细胞TCRVβ优势利用和克隆性增殖 ,诱导后T细胞具有特异性杀伤CML细胞的作用。

Objective To investigate the restricted usage and clonal expansion of TCR Vβ subfamily T cells induced by chronic myelogenous leukemia (CML) cells, and to analyze the cytotoxicity of the T cells against CML cells. Methods The amplification of the T cells from patients with CML or cord blood were performed using mixed lymphocyte-tumor culture (MLTC) and CML cells in vitro. The complementarity determining region 3 (CDR3) of 24 TCR Vβ subfamily genes from the T cells was analyzed before and after MLTC using RT-PCR and genescan technique, to detect the usage and clonality feature of TCR Vβ subfamilies. The cytotoxicity of induced T cells (after MLTC) was detec- ted by lactate dehydrogenase (LDH) release assay. Results Only 8-11 TCR Vβ subfamilies were expressed in T cells from cord blood. Clonal expansion was identified in 2-3 TCR Vβ subfamilies T cells from cord blood after MLTC. The similar results were found in T cells from patients with CML induced by autologous CML cells. The high cytotoxicity of T cells against primary CML cells was found after MLTC. Conclusion The restricted usage and clonal expansion of TCR Vβ subfamily T cells from cord blood or patients with CML could be induced by CML cells, and the induced T cells have specific cytotoxicity against CML cells.