弥漫性大B细胞淋巴瘤患者外周血T细胞受体Vα与T细胞受体Vβ亚家族T淋巴细胞的分布与克隆性增殖特点

摘要

目的 探讨弥漫性大B细胞淋巴瘤(DLBCL)患者外周血T淋巴细胞表达的T细胞受体(TCR)Vα与TCR Vβ亚家族基因谱系及克隆性增殖情况.方法 选取2006年4～5月及7月,于广州医科大学附属第一医院肿瘤血液科收治的3例DLBCL患者作为研究对象,并纳入研究组;选取同期于本院体检的3例健康个体纳入对照组.本研究遵循的程序符合广州医科大学附属第一医院人体试验委员会所制定的伦理学标准,得到该委员会批准,分组征得受试对象本人的知情同意,并与之签署临床研究知情同意书.两组受试对象性别与年龄等一般临床病历资料比较,差异无统计学意义(P＞0.05).通过本院检验科采集研究组与对照组血液10 mL,采用实时聚合酶链式反应(RT-PCR)方法扩增两组受试者外周血T淋巴细胞中29个TCRVα与24个TCR Vβ亚家族基因的互补决定区(CDR)3,采用基因扫描分析两组RT-PCR产物的CDR3序列及其长度.回顾性分析研究组和对照组的临床数据:对比分析TCR Vα与TCR Vβ亚家族基因在两组受试者T淋巴细胞中的表达情况,以及分析研究组T淋巴细胞克隆性增殖的特点.结果 ①与对照组外周血T淋巴细胞表达全部的29个TCR Vα与24个TCR Vβ亚家族基因不同,研究组3例DLBCL患者外周血T淋巴细胞表达TCR Vα亚家族基因成员的数量为20～22个,表达TCR Vβ亚家族基因成员的数量为9～17个.②3例DLBCL患者均存在寡克隆、双克隆或克隆性增殖趋势的T淋巴细胞,其中克隆性增殖T淋巴细胞表达TCR Vα亚家族基因成员主要为TCR Vα6、Vα8、Vα14、Vα15、Vα21、Vα22、Vα23及Vα25.克隆性T淋巴细胞表达TCR Vβ亚家族基因成员主要为TCR Vβ1、Vβ3、Vβ13、Vβ15及Vβ16.表达TCR Vα6、Vα8、Vα14、Vα15、Vα23及TCR Vβ13、Vβ15亚家族基因的T淋巴细胞均全部为克隆性增殖T淋巴细胞.TCR Vα6、Vα23亚家族T淋巴细胞与TCR Vβ3、Vβ13亚家族T淋巴细胞呈明显克隆性增殖,基因扫描分析所得图形接近单克隆图形.结论 DLBCL患者外周血TCR Vα与TCR Vβ亚家族T淋巴细胞均呈优势利用及克隆性增殖的特点.%Objective To investigate the situation of T cell receptor (TCR) Vα and TCR Vβ gene subfamily repertoire and clonal proliferation of T lymphocytes from peripheral blood of patients with diffuse large Bcell lymphoma (DLBCL).Methods April,May and July 2006,a total of three patients with DLBCL who were admitted in the First Affiliated Hospital of Guangzhou Medical University were collected in this study.Another of three healthy individuals who received medical examination in the same period were included into control group.The study protocol was approved by the Ethical Review Board of Investigation in Human Beings of the First Affiliated Hospital of Guangzhou Medical University.Informed consent was obtained from all participants.There were no significant differences of subjects' general clinical features between two groups (P＞0.05).The blood specimens (10 mL) from the subjects were collected at the clinical laboratory.The complementarity determining region 3 (CDR3) of 29 TCR Vα and 24 TCR Vβ subfamily genes in peripheral blood T lymphocytes were amplified by real-time polymerase chain reaction (RT-PCR).CDR3 sequence and length of RT-PCR products were analyzed by gene scan.The clinical data of two groups were retrospectively analyzed:The expression of TCR Vα and Vβ subfamily genes in T lymphocytes of two groups were compared,and clonal proliferation of T lymphocytes in study group was analyzed.Results ① Different from the control group,20-22 TCR Vα and 9-20 TCR Vβ subfamilies were identified in 3 DLBCL patients of study groups,respectively.② Oligoclonality,biclonality and oligoclonal tendency of one or more TCR Vα and TCR Vβ subfamilies T lymphocytes were observed in all 3 DLBCL patients.TCR Vα subfamily genes expressed in clonal proliferative T lymphocytes were TCR Vα6,Vα8,Vα14,Vα15,Vα21,Vα22,Vα23 and Vα25.TCR Vβ subfamily genes expressed in clonal proliferative T lymphocytes were TCR Vβ1,Vβ3,Vβ13,Vβ15 and Vβ16.T lymphocytes predominately expressed TCR Vα6,Vα8,Vα14,Vα15,Vα23 and TCR Vβ13,Vβ15 subfamily genes were all in clonal proliferation.TCR Vα6,Vα23 and TCR Vβ3,Vβ13 subfamily T lymphocytes were obviously monoclonal proliferation,and their gene scan results were all closely monoclonaliity shape.Conclusions TCR Vα and TCR Vβ subfamilies T lymphocytes from peripheral blood of patients with DLBCL showed characteristics of advantage utilization and clonal proliferation.