结直肠癌患者外周血CD4^+CD25^(high)调节性T细胞分析

CD4^+CD25^(high) regulatory cells in peripheral blood of patients with colorectal malignancy

目的探讨结直肠癌患者外周血高表达CD25的CD4+调节T细胞(CD4+CD25highTr)的比率变化特点及其临床意义。方法采用流式细胞术检测37例结直肠癌患者外周血CD4+CD25high调节T细胞水平,并进行分层分析。结果结直肠癌患者外周血高表达CD25T细胞水平占总CD4+T细胞的(4.59±1.62)%(n=37),与健康对照组比较(2.04±1.03)%(n=15),差异有统计学意义(t=2.007582;P=0.0000012)。该CD4+CD25highTr细胞低表达CD45RA,不表达CD69。Ⅰ~Ⅲ期结直肠癌患者外周血CD4+CD25highTr占总T细胞的(3.93±1.48)%(n=17),Ⅳ期结直肠癌患者外周血CD4+CD25highTr细胞占总T细胞的(5.18±1.54)%(n=20),明显高于Ⅰ~Ⅲ期患者,差异有统计学意义(t=2.08091;P=0.015)。结论结直肠癌患者外周血CD4+CD25highTr细胞比率明显升高,可能在结直肠癌的发生发展中起重要作用。

OBJECTIVE： To investigate and identify a CD4^＋ population of regulatory T（Tr） cells which express high levels of CD25 （CD4^＋ CD25^high） in the circulation of humans. METHODS.. The frequency of CD4^＋ CD25^high Tr cells in the peripheral blood of patients with colorectal malignancies and 15 healthy controls was determined by flow cytometry. RESULTS： Compared with healthy control （2.04±1.03）% （n=15）, the frequency of CD4＋CD25^high in the peripheral blood of patients with colorectal malignancies showed an increase of CD4^＋ CD25^high T ceils in the peripheral blood： （4.59± 1.62） % （n= 37）. The phenotic chacteristics of the CD4^＋ CD25^high Tr cells were low expression of CD45RA and lacked markers of recent activation （CD69）. The proportion of CD4^＋ CD25^high Tr cells in the patients with esophageal cancer in stage Ⅳ （5.18±1.54）% （n=20） was significantly higher than that in stage Ⅰ -Ⅲ （3.93±1.48）% （n=17） （P=0. 000 001 2）. CONCLUSION： There is an increased pool of CD4^＋ CD25^high in the peripheral blood of patients with colorectal cancers, the relative increase in CD4^＋ CD25^high Tr cells may be related to immunosuppression and tumor progress in colorectal cancer patients. These results demonstrate the role of CD4^＋ CD25^high Tr cells in tumor-induced immune tolerance and the interest of Tr cell depletion to sensitize colorectal cancers to irnmunotherapy.