Effects of 1,25-dihydroxyvitamin D_3 on regulatory T cells and airway inflammation in asthmatic rats / 上海第二医科大学学报

ABSTRACT

Objective To investigate the effects of 1,25-dihydroxyvitamin D3[1,25(OH)2D3] on regulatory T cells(CD4+CD25+ Foxp3+ T cell)and airway inflammation in asthmatic rats. Methods Asthmatic models were established in 28 rats with ovalbumin as sensitinogen,and four groups were randomly divided(n=7).1,25(OH)2D3 was orally administered 1 h before challenge in treatment group 1,dexamethasone was subcutaneously injected 1 h before challenge in treatment group 2,both 1,25(OH)2D3 and dexamethasone were given 1 h before challenge in treatment group 3,while no medicine was administered 1 h before challenge in group 4(asthmatic control group).The levels of IL-4 and IL-10 in bronchoalveolar lavage fluid(BALF) were detected,the total cell numbers were obtained and the eosinophil count was performed.The ratios of Treg to CD4+ T cells in peripheral blood and spleen mononuclear cells were measured with flow cytometry,and the mRNA expression of IL-10 and Foxp3 in lung tissues was detected.Wistar rats without asthma were served as normal controls(n=7). Results There were significant differences between asthmatic control group and normal control group in each parameter.Compared with asthmatic control group,the total cell number and eosinophil count decreased,the level of IL-4 decreased and the level of IL-10 increased in BALF in treatment groups.The ratios of Treg to CD4+ T cells in peripheral blood and spleen mononuclear cells significantly increased,and the mRNA expression of IL-10 and Foxp3 in lung tissues increased in treatment groups compared with asthmatic control group.There was no significant difference between treatment groups and normal control group in each parameter. Conclusion Administration of 1,25(OH)2D3 increases the proportion of Treg and expression of Foxp3 mRNA in peripheral blood and spleen in asthmatic rats.1,25(OH)2D3 has a regulatory effect on Treg,and may serve as a potential therapeutic approach against asthma.