肿瘤细胞对CD4~+CD25~+Treg细胞数量和功能的影响

目的：探讨肿瘤细胞与免疫细胞相互作用对CD4+CD25+Treg细胞数量和功能的影响。方法：建立Lewis肺癌细胞与小鼠脾淋巴细胞共培养体系。Lewis肺癌细胞与不同浓度小鼠脾淋巴细胞共培养，分为4组：实验组Ⅰ（5×105个Lewis肺癌细胞与1×106个淋巴细胞共培养）、对照组Ⅰ（1×106个淋巴细胞单独培养）、实验组Ⅱ（5×105个Lewis肺癌细胞
与2×106个淋巴细胞共培养）、对照组Ⅱ（2×106个淋巴细胞单独培养）；Lewis肺癌细胞与
淋巴细胞共培养不同时间，采用3个时间点：24、48和72 h；Lewis肺癌细胞培养上清与淋巴细
胞共培养，选择培养上清浓度为20%和50%。采用流式细胞术检测了Lewis肺癌细胞与脾淋巴
细胞共培养系统中CD4+CD25+Treg细胞数量变化，通过RT-PCR方法检测了共培养对Foxp
3 mRNA表达的影响。结果：与对照组比较，实验组Ⅰ 中CD4+CD25+Treg细胞数量和Foxp3 mRN
A表达明显增强（P<0.05），实验组Ⅱ中CD4+CD25+Treg细胞数量和Foxp3 mRNA表达无明
显变化（P>0.05）；Lewis肺癌细胞与淋巴细胞培养24及48 h可见CD4+CD25+Treg细胞数量及Foxp3
mRNA表达明显升高（P<0.05），而72 h后变化不明显；20%和50% Lewis肺癌细胞培养上清
均可明显提高CD4+CD25+Treg数量及Foxp3 mRNA表达（P<0.05）。结论：肿瘤细胞及其培养
上清可诱导CD4+CD25+Treg细胞数量增加、功能增强，由肿瘤细胞所引起的CD4+CD25+Treg细
胞产生及功能增强可能是肿瘤逃避免疫监视机制之一。

Influence of tumor cells in number and function of CD4~+CD25~+Treg cells

Objective To explore the influence of tumor cells in the number and function of CD4~+CD25~+Treg cells.Methods Lewis lung cancer cells and mouse spleen lymphocytes co-culture system was established.Lewis lung cancer cells with different concentrations of lymphocytes co-cultured were divided into 4 groups:experimental group Ⅰ(5×10~5Lewis lung cancer cells and 1 × 10~6 lymphocytes co-culture),control group Ⅰ(1 × 10~6 lymphocytes culture),experimental group Ⅱ(5×10~5 Lewis lung cancer cells and 2 × 10~6 lymphocytes co-culture),control group Ⅱ(2×10~6 lymphocytes culture);Lewis lung cancer cells were co-cultivated with lymphocytes for different time,24,48,and 72 h three time points were selected.Lewis lung cancer cells culture supernatant was cocultivated with lymphocytes.the concentrations of culture supernatant were 20% and 50%.The number changes of CD4~+ CD25~+Treg cells in the co-culture system of Lewis lung cancer cells and splenic lymphocytes were detected by flow eytometry;the expression of Foxp3 mRNA after co-culture was detected by RT-PCR method.Results Compared with control group,the number of CD4~+CD25~+Treg cells and the expression of Foxp3 mRNA were significantly increased in experimental group Ⅰ(P<0.05),and there was no significant difference in experimental group Ⅱ(P>0.05);24 and 48 h after co-culture of Lewis lung cancer cells and lymphoeytes,the number of CD4~+CD25~+Treg cells and the expression of Foxp3 mRNA were significantly increased(P<0.05),and there was no significant changes at 72 h;20%and 50%Lewis lung cancer cells supernatant could significantly increase the number of CD4~+CD25~+Treg cells and Foxp3 mRNA expression(P<0.05).Conclusion Tumor cells and their supernatants could induce the increase of the number of CD4+CD25+Treg cells and their function,this might be one of mechanisms of tumor-induced immune tolerance.