中文摘要：

目的：研究肺癌患者外周血（PBMC）及肿瘤浸润淋巴细胞（TIL）中CD4^＋ CD25^high Foxp3^＋调节性T细胞（Treg）的比例改变，探讨其在抗肿瘤免疫中的调节作用。方法：分离肺癌患者PBMC及TIL，FACS分析CD4^＋／CD8^＋T细胞的比值及CD4^＋ CD25^highT细胞占CD4^＋T细胞的比例。Real-time PCR检测Treg特异性转录因子Foxp3基因在PBMC及TIL中的表达。结果：肺癌患者PBMC及TIL中CD4^＋／CD8^＋比值降低；而CD4^＋ CD25^high T细胞在CD4^＋T细胞中所占比例升高；Foxp3基因仅在TIL中高表达，而在PBMC中低或不表达，表明肿瘤局部的CD4^＋ CD25^high T细胞主要是CD4^＋ CD25^high Foxp3^＋ Treg。结合临床资料分析显示Treg在肺腺癌比例较高。结论：CD4^＋ CD25^high Foxp3^＋ Treg在肺癌患者肿瘤浸润淋巴细胞中明显升高，可能与其通过细胞与细胞间接触抑制CD8^＋T细胞的杀伤效应，最终发挥免疫抑制效应相关。

英文摘要：

Objective：To study whether the change of CD4^＋ CD25^high Foxp3^＋ Treg cells in lung cancer patients influences the immune response and is associated with the tumor development. Methods： Lymphocytes isolated from blood and tumor mass of lung cancer patients were analyzed for the ratio of CD4 ^＋ vs CD8 ^＋ T cells and the proportion of CD4^＋ CD25^high T cells by flow cytometry, lymphocytes from health adults were served as control. The mRNA expression of Foxp3 which is the specific marker of T regular ceils, was detected by real-time PCR. Results： Compared to the control, a decreased ratio of CD4 ^＋ vs CD8 ^＋T ceils and an increased proportion of CD4 ^＋ CD25^high T cells were observed in PBMC and tumor infiltrated lymphocytes（TILs） of lung cancer patient. However, the Foxp3 expression was greatly increased only in the TILs, indicating more CD4^＋ CD25^high Foxp3 ^＋Treg cells aggregated in the tumor mass. Combined with clinical information, data showed that enhanced proportion of CD4^＋ CD25^high Foxp3 ^＋ Treg ceils is associated with the pathologic classification of lung cancer. Conclusion：The proportion of CD4^＋ CD25^high Foxp3 ^＋ Treg ceils was increased in lung cancer patients, which consequently resulted in the inhibition of immune response and tumor development.