中文摘要：

目的：了解急性单核细胞白血病（AML—M5）病人TCRVα29个亚家族的分布及其克隆性。方法：利用RT—PCR分别扩增8例M5病人外周血单核细胞的TCRVα29个亚家族基因的CDR3。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。9例健康人作为对照。结果：RT—PCR分析显示正常人表达绝大多数Vα亚家族基因，而8例M5病人外周血仅可以检测到1—10个Vα亚家族基因，出现频率最高的是Vα（6／8例，75％），其次为Vα12（5／8例，62．5％），有15个Vα亚家族表达缺失（Vα1、4、5、7、9、14—18、20、21、26、28和Vα29）。基因扫描分析显示：8例AML—M5病人中有6例存在克隆性增殖T细胞，其中，以Vα12亚家族出现克隆性增殖T细胞频率（3／5例）最高，有2例仅存在单一的克隆性增殖Vα3亚家族T细胞。正常人外周血各Vα亚家族T细胞主要呈多克隆性。结论：M5病人外周血Vα亚家族T细胞存在明显的选择性选用及克隆性增殖特点，这可能是机体T细胞受M5细胞刺激而引起机体产生相应的特异性免疫反应，同时T细胞TCRVα亚家族分布及克隆性增殖情况具有个体特异性。

英文摘要：

AIM： To investigate the distribution and clonal expansion of 29 T cell receptor （TCR） Vet subfamily T cells in patients with acute monoblastic leukemia （ AML - M5 ）. METHODS ： The CDR3 of TCR Vα 29 subfamily genes were amplified in peripheral blood mononuclear cells （PBMCs） from 8 cases with AML - M5 using RT - PCR,and the PCR products were further labeled with fluorescent and analyzed by genescan technique for the CDR3 size, to evaluate clonality of the detectable TCR Vet subfamily T cells. 9 normal individuals served as control. RESULTS ： Most Vet subfamily genes could be detected in PBMCs from normal individuals, whereas only 1 - 10 subfamily T cells were identified in 8 cases with AML - MS, the highest frequently expressed Vet subfamily was Vα3 （75%）, and Vα12 was the second （62. 5% ）, 15 Vet subfamilies （Vα1, 4, 5, 7, 9, 14 - 18, 20, 21, 26, 28 and Vα29） were absent. Genescan analysis showed that clonal expanded T cells were found in T cells from 6 out of 8 AML - M5 cases. The highest frequency of clonal expanded T cells predominated in Vα12 （3 out of 5 positive samples）. In PBMCs from two cases, clonal expanded Vα3 T cells were the unique detectable Vet subfamily T cells. CONCLUSION： The selected usage and clonal expansion of TCR Vet subfamily T cells from peripheral blood could be found in patients with AML - MS. It may be a specific immune response which the host T cells are activated by the M5 leukemia cells. The distribution pattern of Vet subfamily clonal expansion displays individual specificity.