[Immunoregulatory function of rat bone marrow mesenchymal stem cells on spleen mononuclearcell.]

Study the immunoregulatory function of rat bone marrow mesenchymal stem cells on spleen mononuclearcell (MNC) in vitro, and investigate the immunological regulation mechanism initially.

MSCs from bone marrow of rat were isolated and cultured in vitro. The morphological charactcrization of MSCs was observed after Wright-Giemsa's staining and the typical molecule on the cell surface were identified by flow cytometry(FCM). ConA was taken as stimuli origin. Effect of MSCs on proliferation of spleen MNC was determined by MTT method.Effect of MSCs on IL-2 and IL-10 secretion of spleen MNC was determined by ELISA.Analyze the effect of MSCs on MNC cell cycle distribution by FCM.Study the effect of MSCs on p27 and cyclin E expression of MNC by FCM. Investigate the effect of MSCs on spleen MNC killing colon26 and H22 by LDH release method.

Compared with positive control, proliferation of spleen MNC decreased obviously, when cultured with different number of MSCs (P<0.01), and the proliferation of MNC was inhibited markedly in a dose-dependent manner (P<0.01). After treated by MSCs, the level of IL-2 secreted by spleen MNC decreased, but the level of IL-10 increased markedly (P<0.01), and this function was also in a dose-dependent manner. MSCs could arrest spleen MNC to G(0);/G(1); phase (P<0.01), and inhibit spleen MNC entering S phase, when stimulated by ConA. MSCs could upregulate p27 expression and downregulate cyclin E expression of spleen MNC (P<0.05).After culturing with MSCs, ability of spleen MNC killing colon26 and H22 was impaired, compared with group cultured alone (P<0.05).

MSCs could inhibit spleen MNC proliferation in vitro, and this effect was related to that MSCs could alter cytokine secretion and regulate cell cycle distribution of MNC.