中文摘要：

目的了解急性B淋巴细胞白血病(B-ALL)患者外周血T细胞的T细胞受体(TCR)Vγ和Vδ亚家族的T细胞谱系分布和克隆性增殖情况。方法利用反转录-多聚酶链反应(RT-PCR)方法检测14例B-ALL患者外周血单个核细胞中3个TCR Vγ和8个TCR Vδ亚家族基因谱系的分布情况;进一步经荧光素标记和基因扫描分析TCR Vγ和TCR Vδ亚家族基因的互补决定区3(CDR3),以检测T细胞克隆性。10例健康成人外周血作为对照。结果 B-ALL患者外周血中TCR Vγ亚家族表达率降低,其中VγII亚家族表达率降低与健康对照组的差异具有统计学意义(P=0.006)。B-ALL患者外周血中Vδ1(57.1%)、Vδ2(42.9%)和Vδ3(14.3%)亚家族表达率均低于健康对照组,且差异有统计学意义(P=0.024,0.006,0.001)。此外,在B-ALL患者外周血中可以检测到在健康人中未检测到的Vδ4(14.3%)和Vδ5(14.3%)亚家族;且Vδ6(28.6%)、Vδ7(21.4%,)和Vδ8(35.7%)亚家族表达率也高于健康对照组。B-ALL患者外周血中存在克隆性增殖的Vγ和Vδ亚家族T细胞,其中,Vδ8亚家族T细胞寡克隆增殖的发生频率最高(35.7%),其次为Vδ6(28.6%)和Vδ7(21.4%)亚家族T细胞。结论 B-ALL患者外周血TCR Vγ和TCR Vδ亚家族T细胞出现限制性表达和克隆性增殖,其中高频率出现的寡克隆性增殖的Vδ亚家族T细胞可能与体内存在的白血病抗原相关。

英文摘要：

The study aimed to investigate the distribution and clonality of T cells receptor(TCR) Vγ and Vδ subfamily T cells in patients with acute B lymphoblastic leukemia(B-ALL).Peripheral blood mononuclear cells(PBMCs) from 14 patients with untreated B-ALL were amplified by using RT-PCR to observe the distribution of TCR Vγ and Vδ repertoire,while ten healthy individuals served as normal controls.Then the positive PCR products were further labeled with fluorescent and analyzed by genescan technique to determine the size of complementarity determining region 3(CDR3) of TCR Vγ(I-III) and Vδ(1-8) subfamilies genes and to evaluate the clonality of the detectable TCR Vγ and Vδ cells.Compared with the healthy controls,B-ALL patients demonstrated lower expression frequencies of TCR Vγ subfamilies,especially the expression frequency of Vγ2 subfamily(P=0.006);the expression frequencies of Vδ1(57.1%),Vδ2(42.9%) and Vδ3(14.3%) subfamilies in PBMCs of B-ALL patients were significantly lower than that in healthy individuals(P=0.024,0.006,0.001,respectively).Expressions of Vδ4 and Vδ5 subfamilies,which were not detected in normal PBMCs,were detectable in peripheral blood of B-ALL patients(14.3% and 14.3%,respectively),while high expression frequencies of Vδ6(28.6%),Vδ7(1.4%) and Vδ8(35.7%) subfamilies were observed in B-ALL patients.Furthermore,oligoclonality of TCR subfamilies of γ/δ T cells were detected in all of the 14 B-ALL patients,and the frequency of occurrence of oligoclonal proliferation of Vδ8 subfamily was the highest(35.7%),followed by that of Vδ6(28.6%) and Vδ7(21.4%).We concluded that the highfrequency expression of oligoclonal proliferation of Vδ subfamilies T cells might be related to the host immune response for B-ALL associated antigen.