T细胞受体Vβ链基因限制性取用与哮喘患者的关系

Restricted usage of repertoire of T-cell receptor V beta in Chinese asthmatics

目的 探讨T细胞受体 β链可变区 (TCRVβ)受体谱限制性取用与哮喘的相关性。 方法 采用荧光标记半定量逆转录聚合酶链反应 (RT PCR) ,借助 377DNA自动测序仪分析 36例哮喘患者外周血TCRVβ基因取用格局的变化 ,通过变性聚丙酰胺凝胶电泳及单链构象多态性分析 (SSCP) ,对哮喘患者优势取用的TCRVβ基因家族进行基因片段重组长度及碱基差异分析。 结果 TCRVβ 8在哮喘患者以及其中对屋尘螨过敏者外周血中被优势取用的次数 (13/ 36、10 / 2 4)与正常对照组 (1/ 16 )比较 ,差异有显著性 (P =0 0 2 30、0 0 147) ;TCRVβ 5 1在屋尘螨过敏哮喘者外周血中被优势取用的次数 (10 / 2 4)与正常对照组 (1/ 16 )比较 ,差异有显著性 (P =0 0 186 )。值得注意的是 ,36例哮喘患者中有 2例豚草过敏者均优势取用了Vβ 1。同时发现被哮喘患者优势取用的TCRVβ基因家族在正常人中均为多克隆扩增 ,同时哮喘患者的外周血中大多数亦为多克隆扩增 ,但有 5例哮喘患者Vβ 8为寡克隆扩增 ,出现限制性取用。结论 TCRVβ 8、5 1基因片段可能和哮喘患者屋尘螨过敏有关 ,哮喘患者的外周血TCRVβ基因家族呈寡克隆扩增趋势。

Objective To investigate the association of restricted usage of repertoire of T cell receptor V beta (TCR V β) with asthma Methods In 36 Chinese asthmatics, peripheral blood TCR V β was studied by means of fluorescein-labeled RT-PCR as well as genescan and genotype software analysis The clonality of the predominant usage T cell receptors was analyzed by denaturing gel electrophoresis and single strand conformation polymorphism (SSCP) by using genescan analysis (with 377 ABI DNA sequencer) Results The number of cases predominantly using TCRV β 8 gene families in asthmatics and those allergy to house dust mite (HDM) was significantly higher than that of normal controls( P =0 023 0, 0 014 7), and so the TCR V β 5 1 gene family for asthmatics allergic to HDM ( P =0 018 6) It is remarkable-that only two cases in 36 asthmatics were allergic to ragweed and both of them predominantly used TCR V β 1 gene families The TCR V β gene families predominantly used in asthmatics showed polyclonal expression in all normal controls and most asthmatics, but 5 asthmatics showed oligoclonal expression of TCR V β 8 gene families Conclusions TCRV β 8 and TCR V β 5 1 gene families may be associated with allergy to HDM in asthmatics TCR V β gene families in asthmatic peripheral blood showed oligoclonal expression tendency