Tremella Polysaccharides attenuated sepsis through inhibiting abnormal CD4+CD25 high regulatory T cells in mice / 中国免疫学杂志

ABSTRACT

Objective:To determine the effects of TPS on peripheral blood Tregs in sepsis mouse induced by burn plus P.aeruginosa infection.Methods: The experimental mice were separated into five groups randomly ,including sham burn group ,burn plus P.aeruginosa infection group ,burn plus P.aeruginosa infection with TPS (50,100,200 mg/kg) treatment group.Peripheral blood Tregs were isolated with Magnetic Microbeads and cultured in vitro from the day after burn (PBD0) to 4 days after burn(PBD4).IL-10, IFN-γ,IL-4 levels in Tregs culture supernatants were determined by sandwich enzyme-linked immunosorbent assays ( ELISA ) . Purification of CD4+CD25high Tregs and CD4+T cells in C57BL/6 mice were administrated by magnetic beads sorting .Tregs and CD4+T cells were cultured in vitro after joining TPS to without TPS cells as a control .The phenotypes of Tregs were analyzed by flow cytometry , and cytokines were measured by ELISA .Results:Vis-a-vis the results of the untreated group ,TPS could markedly decrease IL-4 and IL-10 secretion level and significantly increase the secretion of IFN-γ,and the secretion of IL-10 level and concentration of TPS dose effect.Vis-a-vis the results of the untreated group ,in vitro experiment ,without stimulation of TPS ,CD4+T cell proliferation and IFN-γwere significantly reduced ( P<0.05 ) and IL-4 levels increased significantly;CD4+T cell proliferation and IFN-γwere significantly increased and IL-4 levels were significantly reduced in the group of TPS with antibody-1;there was no significant difference in CD 4+T cell proliferation and the levels of IFN-γand IL-4 in the group of TPS with antibody-2.Conclusion:TPS could inhibit the abnormal ac-tivities of CD4+CD25highTregs in burn with P.aeruginosa infection mice,at least in part via inhibiting IL-10 secretion,and trigger a shift of Th2 to Th1 with activation of CD4+T cells in burn with P.aeruginosa infection mice.