The role of RAGE in high mobility group box-1 protein1-mediated CD4+T cells differentiation to Th1/Th2 / 中华急诊医学杂志

ABSTRACT

Objective To explore the role of receptor for advanced glycation end products (RAGE) in HMGBl-mediated CD4+ T cells differentiation to Th1/Th2.Methods CD4+ T lymphocytes isolated from the spleens of male BALB/C mice by magnetic beads were suspended in RPMI-1640 with 10％ FCS in 2× 106cell/well on 96-well cell culture plates in vitro.The cells were randomly divided 4 groups according to concentration of HMGB1 treatmentcontrol group,10 ng/mL group,100 ng/mL group,1 000 ng/mL group after stimulation with ConA in 3 μg/mL for 12 hours.IL-4 and IFN-γ levels in culture supernatants were quantitated by ELISA kits after HMGB1 stimulation for 12,24,and 48 h.According to the results,cultured cells were exposed to HMGB1 in 100 ng/mL for 24 h in the following experiments.The cells were randomly divided into 4 groupscontrol group,A group,B group,C group,and each group were cultured with ConA in 3 μg/mL for 24 h.The cells of control group and other three groups were stimulated with PBS or 100 μg/L HMGB1 for 24 h.The cells of B,C groups were incubated with 1/200 diluted 5 μg/L anti-RAGE Abs (anti-bodies) or PBS for 2 h before HMGB1 stimulation.The cell suspension was obtained to detect the levels of IL-4 and IFN-γ by EILSA and the protein levels and mRNA expressions of RAGE,CATA-3 were detected by western-blot and real-time fluorescent quantitative PCR,respectively.ResuRs Compared with control group,CD4+ T cells incubated with increasing concentrations of HMGB1 (100,1 000 ng/mL) for 24 h resulted in a decrease in IFN-γ/IL-4 ratio (P＜0.05).When CD4+ T cells were exposed to 100 ng/mL HMGB1 for 12 h,IFN-γ/IL-4 ratio was markedly increased.However,CD4+ T cells treated with 100 ng/mL HMGB1 for 24,48 h,IFN-γ/IL-4 ratio was markedly inhibited (P＜0.05).Compared with control group,protein levels and mRNA expressions of RAGE and GATA3 of cells in A group were significantly increased (P＜0.05),and IFN-γ/IL-4 ratio of cell suspension in A group and B group was significantly down-regulated (P＜0.05).Compared with A group,IFN-γ/IL-4 ratio of cell suspension in C group was increased (P＜0.05),and expression of GATA3 mRNA was down-regulated (P＜0.05).Compared with A group,protein level of RAGE of cells in C group was significantly down-regulated (P＜0.05),but protein level of RAGE of cells in C group was still increased compared with control group (P＜0.05).Conclusion Th1/Th2 differentiation induced by HMGB1 on CD4+ T lymphocytes in vitro was at least partly mediated by over-activating RAGE/GATA3 pathway.