苯接触工人外周血T细胞受体TCRV_β亚家族基因多态性分析

Gene polymorphism of peripheral blood TCR V_β subfamily in benzene-exposed workers

目的 了解苯接触工人外周血TCRVβ 亚家族T细胞的分布及其克隆性 ,寻找防治苯中毒的免疫指标。方法 采用RT PCR扩增 6例不同工龄低浓度苯接触工人外周血单核细胞的TCRVβ2 4个亚家族的互补决定区 3(CDR3) ,产物进一步经基因扫描分析确定T细胞的克隆性 ,并与 8名健康人作对照。结果 8名健康者表达全部Vβ 亚家族 ,PCR产物呈多峰图像 (多克隆 )。苯接触工人随工龄不同 ,外周血损伤的情况不同而出现Vβ 表达减少 ,PCR产物出现寡克隆或双克隆改变。结论 低浓度苯接触工人的外周血T细胞的TCRVβ 亚家族表达出现限制性 ,部分Vβ 亚家族呈克隆性增殖 ,可能由于苯损害T细胞而造成机体免疫的不同改变。

Objective To investigate the distribution and clonal efficiency of peripheral blood TCR V β subfamily in benzene-exposed workers,thereby find out an immune index for the prevention and therapy of benzene poisoning.Method The complementarity determining region 3(CDR3)of TCR V β with variable region genes in T cells from the mononuclear cells(MNC)of peripheral blood in 6 cases of low concentration benzene-exposed workers were amplified using RT-PCR,the products were further analyzed for identifying the clonal efficiency of T cells with genescan.As control,MNCs from healthy donors (n=8) were analyzed.Result 24 TCR V β subfamilies were all expressed in T cells from healthy donors, the PCR products showed multi-peak feature in genescan.Whereas,the number of expressed TCR V β subfamilies was obviously reduced in that of benzene-exposed workers with the time of benzene exposure and the injury of hemopoietic function. Oligoclonal and biclonal phenomena in T cells from benzene-exposed workers could be seen by genescan.Conclusion The restricted expression of TCR V β subfamilies was found in T cells from low concentration benzene-exposed workers and there was some clonal expansion of partially TCR V β subfamilies,which might be a specific immune response after T cells damaged by benzene.This change probably becomes a helpful immune index to the prevention and therapy of benzene poisoning.