Immunoregulation of complement regulatory protein CD46 on CD4~+ T cells

Objective To investigate the immunoregulation of complement regulatory protein CD46 on CD4+ T cells and its mechanism. Methods CD4 + T cells were isolated from human peripheral blood T lymphocytes by magnetic-activated cell sorting. Then the effect of CD3, ConA, CD3/CD28, CD3/CD46, and CD3/CD28/CD46 costimulation on CD4+ T cells proliferation and levels of interleukin-2 (IL-2),γ-interferon (IFN-γ), interleukin-10 (IL-10), and transforming growth factor-β (TGF-β) in supernatant fluid were detected. Results As compared with CD3 group or negative control group, ConA, CD3 / CD28, CD3/CD46, and CD3/CD28/CD46 costimualtion can induce significant proliferation of CD4+ T cells (P0.05), especially in CD3/CD28/CD46 costimualtion group (vs CD3/CD28 or CD3/CD46 consitmulation groups, P0.05). Levels of IL-2 and IFN-γ were significantly increased in CD3/CD28 costimulation group than those in CD3 group and negative control group (P0.05). Levels of IL-10 and TGF-β were significant increased in CD3/CD46 costimulation group than those in negative control, ConA, CD3, and CD3/CD28 groups (P0.05). Conclusion Complement regulatory protein CD46 can induce CD4 + T cells proliferation and increase IL-10 and TGF-β, and may inhibit allograft immune response.