Effects of ConA on early activation and function of CD4~+CD25~+ Treg cells in mice

AIM To study the effects of ConA on the early activation and the immunosuppressive function of CD4+ CD25+ regulatory T cells. METHODS CD4+ CD25+ regulatory T cells and CD4+ CD25- effector T cells of BALB/c mice were separated by MACS immunomagnetic beads. After twelve hours of stimulation with different concentrations of ConA, the cells were collected and the percentage of CD69 expression was analyzed by flow cytometry. The CD4+ CD25- effector T cells were stained by CFSE and co-cultured with the CD4+ CD25+ regulatory T cells in a ratio of 2:1. After stimulation with ConA for 3 days, the proliferation of CD4+ CD25- effector T cells suppressed by CD4+ CD25+ regulatory T cells was analyzed by flow cytometry. RESULTS ConA dose-dependently increased the percentage of CD69 expression of both CD4+ CD25+ regulatory T cells and CD4+ CD25- effector T cells, and enhanced the expression of CD69 on these two groups of cells similarly. ConA also dose-dependently activated the suppressive function of CD4+ CD25+ regulatory T cells to inhibit the proliferation of CD4+ CD25- effector T cells. CONCLUSION ConA enhances the activation and the function of CD4+ CD25+ regulatory T cells in vitro. Considering that ConA can mimic the antigen to some extent, this system can be used to evaluate the drug influence on the activation and the function of the regulatory T cells.