RESUMO
[Absract] Objective This paper was designed to reveal the new mechanism on ASI Ⅱ triggered CD4+T cells activation via regulating CD45 molecular and provide a basis for the theoretical foundation of antitumor immunotherapy of Astragalus.Methods The CD4+T cells were randomly divided into negative group,stimulated control group,ASI Ⅱ group,CD45 inhibitor group,and the combination of ASI Ⅱ and CD45 inhibitor group.Besides negative group,the cells from other groups were activated by anti-CD3/CD28 antibody.ASI Ⅱ group was treated with 10 nmol/L ASI Ⅱ,CD45 inhibitor group was treated with 0.8 μmol/L CD45 inhibitor,and the combination group were treated with 10 nmol/L ASI Ⅱ and 0.8 iμmol/L CD45 inhibitor.After 36h culture,the proliferation of CD4+T cells was detected by Ki-67 intracellular staining assay.Cytokine production of Th1 and Th2 were examined ELISA method.The proportion of surface marker (CD44 and CD25)and Th1 intracellular cytokines (IFN-γ) were detected by flow cytometry.Results Compared with stimulated group,Astragaloside Ⅱ group in CD4+Ki67+T positive proportion (5.37％ ± 0.92％ vs.1.19％ ± 0.23％),in CD4+CD25+ positive proportion (50.23％ ± 4.65 ％ vs.15.89％ ± 1.13％),in CD4+CD44+ positive proportion (33.16％ ± 6.08％ vs.15.36％ 4 1.45％),in CD4+IFN-γ+ positive proportion (1.42％ ± 0.44 ％ vs.0.38％ ± 0.06％) were significntly increased.And the secretion of IFN-γ,IL-4 and IL-2 in ASI Ⅱ group were higher than stimulated group.The anti-mouse CD45 Ab treatment markedly blocked the proliferation and Th1 cytokines production which induced by ASI Ⅱ.Furthermore,the anti-mouse CD45 Ab treatment significantly decreased the expression of surface marker (CD44 and CD25).Conclusions Activating CD45 protein tyrosine phosphatase may be involved in ASI Ⅱ triggered CD4+T cells activation.This study will provide a basis for antitumor immunotherapy of Astragalus.