Proliferation of CD4+CD25+ T cells from PBMCs of the gastric cancer patients and inhibitory effect on CD4+CD25- T cells in vitro

AIM:To investigate the proliferation of CD4+CD25+ T cells from PBMCs of the gastric cancer patients and the inhibitory effect on CD4+CD25- T cells in vitro. METHODS:Magnetic activated cell sorting (MACS) method was used to separate CD4+CD25+T and CD4+CD25-T cells from peripheral blood monocytic lymphocytes in the gastric cancer patients, and then the purity and activity of CD4+CD25+T cells were analyzed with flow cytometer. After stimulated with anti-CD3 Ab, anti-CD28 Ab and rh IL-2, CD4+CD25- and CD4+CD25+ T cells were cocultured. The inhibitory effect of CD4+CD25+T on CD4+CD25-T cells was assayed by ［3H］ thymidine proliferation experiment. RESULTS:(1)After sorting, CD4+CD25+ T cells purity in healthy control and gastric cancer patients were 83.80%±1.84% and 84.13%±2.77%, respectively. No significant difference between the two groups (P>0.05) was observed. (2)The activity of CD4+CD25+ and CD4+CD25- T cells in healthy control and the gastric cancer patients after sorting were 98.52%±0.72% and 97.80%±0.95%. There was no significantly difference between the two groups (P>0.05). (3) CD4+CD25+ T cells obviously inhibited the CD4+CD25-T cell proliferation in vitro. The inhibition achieved to maximum in coculture of CD4+CD25+ T cells together with CD4+CD25- T cells (ratio of 1∶〖KG-*2〗1). CONCLUSION:The MACS system can effectively isolate CD4+CD25+ and CD4+CD25- T cells. After sorting, CD4+CD25+T cells obviously inhibit the proliferation of CD4+CD25- T cells in vitro and the inhibitory effect display an effect-target ratio relationship.