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-gamma 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-gamma, 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.