Abstract:

Objective    To study the mechanism of Indirubin on immune thrombocytopenic purpura(ITP) mice model. Method    ITP animal model was established with CBA mice received Wastar rat platelet. At the fourth week after the Indirubin treatment, spleen cells isolated from ITP mice was detected with MTT for the proliferation, while the cell levels and phenotypes were observed under FCM. Immunoregulatory function of CD4+CD25+Treg cells isolated by MACS was evaluated with MLR. Result     Proliferation of spleen cells in the ITP mice treated with indirubin was significantly inhibited. The ratios of CD4+CD25+Treg cells or CD4+CD25+Foxp3+ Treg cells to CD4+T cells in spleens (P<0.01 ) enhanced by Indirubin were identified.  Meanwhile, splenic CD4+CD25+Foxp3+ Treg cells treated with Indirubin showed immunosuppressive ability on the immune response of T effector cells to alloantigens or mitogen as efficiently as the control, CD4+CD25+Treg cells,  in vitro. Conclusion     The present study indicates that Indirubin can induce the immune tolerance in ITP mice by excerting the effecs on the number and relative proportions of CD4+CD25+Treg cells.

Key words: Indirubin； Immune thrombocytopenic purpura； Regulatory T cell； Immune tolerance