Wang SX, Liu QY, Li Y. Lentinan ameliorates burn sepsis by attenuating CD4
+ CD25
+ Tregs.
Burns 2016;
42:1513-1521. [PMID:
27156806 DOI:
10.1016/j.burns.2016.04.003]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 12/15/2022]
Abstract
AIM
The aim of our study was to investigate the effect of lentinan on regulatory T cells (Tregs) in sepsis, especially on the generation of interleukin (IL)-10 via regulation of Erk-FoxO1 signaling.
METHODS
BalB/c mice were randomized into five groups: sham group, the group with burns plus Pseudomonas aeruginosa infection, and the groups with burns plus P. aeruginosa infection administered 40, 100, and 250mg/kg of lentinan. The mice were sacrificed on postburn days 0, 1, 2, 3, and 4, respectively, with eight animals per group at each time point. The peripheral blood CD4+ CD25+ Tregs and CD4+ T cells were isolated using magnetic microbeads. The phenotypes were analyzed by flow cytometry. The cytokine levels were determined with enzyme-linked immunosorbent assay (ELISA). Signal transduction was studied by Western blot, quantitative polymerase chain reaction (qPCR), and luciferase assay.
RESULTS
The IL-10-producing capacity of CD4+ CD25+ Tregs was significantly enhanced in the group with burns plus P. aeruginosa infection, compared with the sham group. Administration of lentinan significantly decreased IL-10 production and FoxP3 expression of CD4+ CD25+ Tregs. The proliferative activities of CD4+ T cells, however, were restored. Lentinan decreased lipopolysaccharide (LPS)-induced IL-10 production in the Tregs isolated from burned mice. In addition, lentinan attenuated LPS-stimulated Erk-FoxO1 activation.
CONCLUSIONS
Lentinan may improve the outcome of postburn sepsis by suppressing LPS-triggered Erk-FoxO1 activation. Consequently, the hyperfunction of CD4+ CD25+ Tregs is inhibited, leading to a shift in the inflammatory status from Th2 to Th1 in postburn sepsis.
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