RESUMO
Objective:To investigate the effect of autophagy on the Treg/Th17 cell imbalance in mice with acute lung injury (ALI).Methods:Twenty-four male SD mice were randomly divided into the sham operation group (S group), sepsis group (Sep group) and autophagy inhibitor 3-methyladenine group (Sep +3-MA group). ALI model was prepared by LPS tracheal dripping method. The mouse pathological injury score mice were evaluated under light microscopy and the W/D ratio was calculated. The counts of Th17 cells and Treg cells in tracheoalveolar lavage fluid (BALF) of mice and the levels of related cytokines were detected by flow cytometry. The expressions of LC3-Ⅱ, Beclin-1 and p62 in Th17 cells and Treg cells in BALF were determined by Western blot.Results:CCompared with the S group, the lung histopathological score and W/D ratio of the Sep group and Sep+3-MA group increased ( P<0.05). Compared with the Sep group, the count of Th17 cells in BALF of the Sep +3-MA group decreased, while the count of Treg cells increased significantly with the progression of sepsis( P<0.05), and the levels of IL-17, IL-10 and TNF-α were significantly decreased ( P<0.05). TGF-β1 levels increased in the early stages of sepsis, but decreased significantly with the progression of sepsis( P<0.05). Compared with the Sep group, LC3-Ⅱ expression in BALF Th17 cells and Treg cells of the Sep+3-MA group showed a downward trend, but there was no statistical difference, while Beclin-1 expression significantly decreased ( P<0.05), and the expression of p62 significantly increased ( P<0.05). Conclusions:Abnormal activation of autophagy in Th17 cells and Treg cells is involved in the immune imbalance of Th17/Treg cells in ALI with sepsis. Inhibition of autophagy can restore the functions of Th17 cells and Treg cells, and improve the imbalance of Th17/Treg by inhibiting autophagy may become a new idea to control the pathogenesis and progression of immune disorders with sepsis.