Antagonistic effect of astragaloside on immune response of regulatory T cells mediated by high mobility group box-1 protein in rats / 中华创伤杂志

ABSTRACT

Objective To investigate the antagonistic effect of different doses of astragaloside Ⅳ (AST Ⅳ) on immune function of regulatory T (Treg) cells mediated by high mobility group box-1 protein (HMGB1) in rats and the mechanism by which AST Ⅳ exerts its influence.Methods CD4 + CD25 +Treg cells isolated from the spleens of clean-grade BALB/c mice were seeded on 72-well culture plate.Cells were divided into four groups (18 wells per group) according to the random number table,i.e.normal control group (cells were cultured merely),HMGB1 (1 μg/ml) group,HMGB1 (1 μg/ml) + AST Ⅳ (50 μg/ml) group,and HMGB1 (1 μg/ml)+AST Ⅳ (100 μg/ml) group.Each group consisted of three subgroups (6 wells per group),from which the Treg cells were collected at post-stimulation hours 24,48 and 72 respectively.Foxp3 intracellular protein and mRAN expressions were detected by flow cytometry and quantitative fluorescent PCR.Contents of IL-10 and TGF-β released into the supernatants were determined by ELISA method.Results As compared with the control group,Foxp3 intracellular protein and mRAN expressions in the Treg cells were decreased at 24 hours to 72 hours after HMGB1 stimulation (P ＜ 0.01),with particular reduction at 72 hours.Additionally,changes of IL-10 and TGF-βin the supernatants presented the same trends with Foxp3.Foxp3 protein and mRAN expressions in AST Ⅳ group were markedly higher than that in HMGB1 group at 24-72 hours (P ＜ 0.05) and the expressions in AST Ⅳ(100 μg/ml) group were much more significant than that in AST Ⅳ (50 μg/ml) group (P ＜ 0.05).While contents of IL-10 and TGF-β in supernatants revealed the same trend with Fox3 as well.Conclusions AST Ⅳ antagonizes the impact of HMGB1 on the activity of the Treg cells in a dose-dependent manner in vitro.It is suggested that AST Ⅳ has a strong inhibitory effect on HMGB1-mediated inflammatory response.