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 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(P0.05) 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 (P0.05).(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∶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.