肿瘤患者胸/腹水和外周血中TCR Vβ亚家族表达及调节性T细胞亚群的研究

目的:探讨肿瘤患者胸/腹水中肿瘤浸润性淋巴细胞(TIL)和外周血T细胞中T细胞受体(TCR)Vβ亚家族的表达变化情况、CD4/CD8细胞比例变化和Treg细胞的分布情况,分析肿瘤患者的免疫状态。方法:分离11例肿瘤患者胸/腹水和外周血以及4例健康人外周血的T细胞,采用流式方法检测Vβ24个亚家族及CD3、CD4、CD8、CD25、CD127的表达情况,统计分析T细胞中Vβ24个亚家族、Treg细胞的特点。结果:TCR Vβ亚家族的表达在肿瘤患者胸/腹水TIL中与血液淋巴细胞中存在着显著差异,其中肺癌患者(4/5)TIL中TCR Vβ8,结肠癌患者(3/4)TIL中TCR Vβ2等亚家族显著高表达;11例肿瘤患者胸/腹水样本中Treg的比例均比外周血高(P<0.05),其中5例肺癌患者胸腹水中CD8+T细胞比例降低。结论:肿瘤患者胸/腹水中的淋巴细胞TCR Vβ亚家族表达与外周血存在差异,表明肿瘤患者体内淋巴细胞发生了明显的优势取用和定向趋化。此外肿瘤微环境可能影响了TIL中CD4+细胞的分化导致胸腹水中Treg细胞的比例升高,同时伴随着CD8+T比例的下降,并可能因此影响到TIL中TCR Vβ亚家族的优势取用情况,且导致免疫耐受。

Study on the T cells receptor(TCR) Vβ repertoire and the expression profile of Treg between peripheral blood mononuclear cells and the tumor infiltrating lymphocytes(TIL) in patients with carcinoma

Objective:To analyze the T cells receptor(TCR) Vβ repertoire,CD4/CD8 ratio,and the expression profile of Treg between peripheral blood mononuclear cells and the tumor infiltrating lymphocytes(TIL) in patients with carcinoma.Methods:T cells were isolated from the pleural effusion or ascites of carcinoma patients,and from the peripheral blood of carcinoma patients and healthy individuals.The expressions of 24 TCR Vβ subfamilies,CD3,CD4,CD8,CD25,and CD127 were detected by flow cytometry(FCM).The T cells receptor(TCR) Vβ repertoire,CD4/CD8 ratio,and Treg expression profile were statistically analyzed.Results:There was a distinct difference in TCR Vβ repertoire between TILs from pleural effusion/ascites and T cells from peripheral blood in patients with carcinoma.TCR Vβ8 in TILs of lung carcinoma patients(4/5) and TCR Vβ2 in TILs of colon carcinoma patients(3/4) showed higher proportion than that in peripheral blood T cells of patients and healthy controls.The proportion of Treg was higher in pleural effusion/ascites than in peripheral blood of carcinoma patients or healthy controls(P<0.05).Correspondingly,the proportion of CD8+T cells was lower in pleural effusion than in peripheral blood in 5 lung carcinoma patients.Conclusion:The distinct differences in TCR repertoire between TILs and peripheral blood T cells imply that selective expansion and chemotaxis of T cells have occurred in carcinoma patients.In addition,the tumor microenvironment may affect the differentiation of CD4+ T cells and lead to the increased Treg and decreased CD8+ T cells in pleural effusion/ascites,which may also affect the selective expansion of TILs and led to immune tolerance.