The effection of heat stress on cell immunology in rats / 重庆医学

ABSTRACT

Objective To investigate the effect of heat stress on the expression of Toll-like receptor 4 (TLR4) and peripheral blood T regulatory cells (Treg) in splenic cells of rats.Methods Senventy-two SD rats were divided into 20 ℃ control group and 37 ℃ group.Each group was divided into non stimulation,bacterial lipopolysaccharide (LPS) stimulation and concanavin A (Con-A) stimulation subgroup.Each subgroup had 1,12,48 h and 168 h observation points,and flow cytometry was used to determine the level of TLR4 and Treg.Results The TLR4+ immunocompetent cells in the spleen was decreased from 1 h to 168 h in every subgroup of the 37 ℃ group compared to the 20 ℃ control group (P＜0.05).The level of CD4+CD25+ Treg in the peripheral blood in rats from 1 to 48 h was significantly decreased (P＜0.05) and slightly increased at 168 h in LPS stimulation subgroup in the 37 ℃ group compared to the 20 ℃ control group.The level of CD4+ CD25+ Foxp3+ Treg in the peripheral blood in rats at 12 h were significantly increased in non-stimulation and concanavalin A (Con-A) stimulation subgroups in the 37 ℃group,and were significantly decreased at 168 h in every subgroup of the 37 ℃ group compared with 20 ℃ control group (P＜0.05).The level of CD8+CD25+ Treg in the peripheral blood in rats was significantly increased at 1 h and 168 h in the 37 ℃ hot and humid group in the every subgroup whencompared with the 20 ℃ control group (P＜0.05).The level of CD8+ CD25+Foxp3+ Treg in the peripheral blood in rats was significantly decreased at 1 h and 48 h in the every subgroup,and was significantly increased at 12 h and 168 h in the non-stimulation and LPS stimulation subgroups in the 37 ℃ group compared to the 20 ℃ control group (P＜0.05).Conclusion High temperature and damp heat can destroy the innate immunity and alter the functional state of adaptive immunity in rats.