Immunology Mechanism of CD4~+ CD25~+ T Regulatory Cells Acting on Effector T Cells

摘要

Objective: To detect the inhibiting co-stimulating molecule CTLA4 and cytokines secreted by Treg cells, and explore the immunology mechanism of T regulatory cells acting on effector T cells in co-cultured system(CCS) and separating-cultured system(SCS). Methods: Detecting the percentage of CTLA4 and CD28 expressed on the Treg cells and effector T cells, and then adding Treg cells to mixed lymphocyte reaction(MLR) system in CCS and TransWell Millicell-PCF SCS, at the same time, adding or not adding anti-IL-10 or anti-TGF-β1 to the reacting systems, examining the inhibitory capacity of Treg cells exerting on the MLR. Results: Compared with effector T cells, Treg cells expressed higher level CTLA4 and secreted much more IL-10 and TGF-β1(P < 0.01). The inhibitory capacity of Treg cells co-cultured with effector T cells is much stronger than that in separating cultured group(P < 0.01). Moreover, the inhibiting rate of Treg cells exerting on effector T cells through secreting IL-10 was more powerful than that through secreting TGF-β1(P < 0.01). Conclusion: Both cell-to-cell contact and cytokines secretion mechanisms are involved in CD4~+ CD25~+ Treg cells operating function. However, the former is more important. Intrestingly, we for the first time point found that IL-10 plays more powerful roles than TGF-β1 in the cytokines secretion mechanism.