[Isolation and function analysis of rat CD4+ CD25+ regulatory T cells].

AIM: To investigate the isolation method and to analyze the function of rat CD4~+ CD25~+ regulatory T cells. METHODS: Lymphocytes were isolated from the rat spleens and then CD4~+ CD25~+ T cells were sorted by magnetic bead cell sorting (MACS) system. The purity and Foxp3 expression of CD4~+ CD25~+ T cells were analyzed by flow cytometry(FCM) and RT-PCR, respectively. The suppressive effect of CD4~+ CD25~+ T cells on the proliferation of CD4~+ CD25~- T cells was analyzed by mixed lymphocyte reaction. IL-2, IFN-γ and IL-10 levels in culture supernatant were detected by ELISA. RESULTS: The purity of CD4~+ CD25~+ T cells sorted by MACS was 86%-93%. The CD4~+ CD25~+ T cells could specifically express the Foxp3 gene as compared with CD4~+ CD25~- T cells. In vitro CD4~+ CD25~+ T cells could suppress the proliferation of CD4~+ CD25~- T cells and IFN-γ, IL-2 production, but they themselves could secrete IL-10. CONCLUSION: We established an effective procedure for enrichment of CD4~+ CD25~+ regulatory T cells by MACS with satisfactory cell purity, viability and function. CD4~+ CD25~+ T cells can suppress CD4~+ CD25~- T cells and specifically express Foxp3 gene.