卵巢癌细胞培养上清诱导CD4+CD25-T细胞分化为CD4+CD25+调节性T细胞

目的研究卵巢癌细胞培养上清液是否能诱导外周血CD4^＋CD25^- T细胞转变为CD4^＋CD25^＋调节性T细胞。方法将外周血CD4^＋CD25^- T细胞分离后，对照组用CD3和CD28单抗活化，实验组在对照基础上加用卵巢癌细胞株SKOV3培养上清，72h后分离各组的CD25^＋和CD25^-T细胞，溴化脱氧尿嘧啶掺入标记法测定增殖能力及对静息的自体同源CD4^＋CD25^- T细胞的增殖抑制能力，流式细胞仪测定细胞糖皮质激素诱发型TNF受体（glucocorticoid-induced TNFR,GITR）与CTLA-4分子的表达，RT-PCR检测细胞卿mRNA的表达。结果与对照组相反，实验组的CD4^＋CD25^＋T细胞具有免疫抑制功能，自身增殖能力下降，GITR和CTLA-4分子的表达和CD4^＋CD25^＋调节性T细胞相似，并被诱导表达转录因子Foxp3 mRNA。结论卵巢癌细胞分泌的可溶性物质能诱导外周血CD4^＋CD25^-T细胞转化为CD4^＋CD25^＋调节性T细胞。

Conversion of peripheral CD4+ CD25- naive T cells to CD4+ CD25+ regulatory T cells by ovarian carcinoma cell supernatants

Objective To investigate whether the supernatant from cultured ovarian carcinoma cell line SKOV3 could convert peripheral CD4~+CD25~- T cells into CD4~+CD25~+ regulatory T cells. Methods CD4~+CD25~- T cells isolated from the peripheral blood of healthy woman were activated with plate-bound anti-CD3 and anti-CD28, which were used as the control group. The supernatant of cultured ovarian carcinoma cell line was added to the activated cells as the experiment group. After 72 h, the cells of both groups were harvested separately and further sub-populated into CD25~- and CD25~+ T cells. The cell proliferation was determined by BrdU labelling. Expressions of glucocorticoid-induced TNFR (GITR) and CTLA-4 were tested by flow cytometry. Foxp3 mRNA expression was examined by RT-PCR. Results In contrast to the activated CD4~+CD25~+ T cells, the supernatant-induced CD25~+ T cells which exhibited reduced proliferation capacity and possessed immunosuppressive activity. The supernatant-induced CD25~+ T cells expressed Foxp3 mRNA, GITR and CTLA-4. Conclusion The supernatant derived from SKOV3 converts CD4~+CD25~- T cells into CD4~+CD25~+ regulatory T cells, which is probably responsible for the increasing number of CD4~+CD25~+ regulatory T cells in patients with ovarian carcinoma.