Tremella Polysaccharides attenuated sepsis through inhibiting abnormal CD4+CD25high regulatory T cells in mice

• The changes of IL-10 secreted by CD4+CD25high Tregs induced by Tremella Polysaccharides (TPS) in model mice.
• The influences of TPS on the activation and differentiation of CD4+T cell collected from sepsis mice.
• TPS promoted CD4+T cells proliferation and oriented CD4+T cells to Th1 differentiation.
• TPS could improve the lethality of mice suffered from burn plus P. aeruginosa infection.

Tremella Polysaccharides (TPS) have been reported to play an important role in regulating immune responses. Tregs are widely identified as the critical reason for immune dysfunction during sepsis. However, whether TPS could influence the immunomodulatory activities of Tregs in post-burn sepsis mice remains unclear. In this experiment, we researched the effects of TPS on peripheral blood Tregs in sepsis mouse induced by burn plus Pseudomonas aeruginosa infection. Results showed that TPS reversed the influences of Tregs on CD4+T cells proliferation and polarization and declined the level of IL-10 in burn plus P. aeruginosa infection mice. In addition, TPS notably reduced the mortality of post-burn sepsis mice. Therefore, TPS could inhibit the abnormal activities of CD4+CD25high Tregs 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.