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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.
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Objective:To evaluate the changes in CD4 + CD25 + regulatory T cells (Treg)/helper cell type 17 (Th17) during intestinal damage in septic rats. Methods:Forty-eight clean-grade Sprague-Dawley rats, aged 3 months, weighing 200-300 g, were divided into control group (group C)and sepsis group(group Sep), with 24 rats in each group.The modified cecal ligation and puncture method was used to establish the model of sepsis in anesthetized rats.Resuscitation was performed with normal saline after operation, and the right jugular vein catheterization was used for treatment of enteral nutrition in two groups.Six rats were sacrificed at 12, 24, 48 and 72 h after surgery (T 1-4), and mesenteric lymph nodes and colon were obtained.The percentage of Treg cells and Thl7 cells in mesenteric lymph nodes was detected by flow cytometry.The contents of interleukin-17 (IL-17), IL-23, transforming growth factor beta (TGF-β) and IL-10 in colon tissues were determined by enzyme-linked immunosorbent assay. Results:Compared with group C, the percentage of Treg cells was significantly decreased at T 1, the percentage of Treg cells at T 3, 4 and Th17 cells at T 2-4 were increased, the contents of IL-17 and IL-23 at T 1-4, TGF-β at T 3-4 and IL-10 at T 2-4 were increased, and TGF-β contents were decreased at T 2 in group Sep ( P<0.05). Conclusion:The mechanism of intestinal damage is related to Treg and Th17 cell imbalance in septic rats.
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Objective To evaluate the effect of thymosin α1 (Tα1) on sepsis in rats.Methods A total of 120 pathogen-free healthy male Sprague-Dawley rats,weighing 250-300 g,aged 7 weeks,were divided into 3 groups using a random number table method:sham operation group (group S,n =24),sepsis group (group CLP,n=48) and Tα1 group (group T,n=48).Sepsis was induced by modified cecal ligation and puncture in anesthetized rats,and vena cava cannula was placed through the right jugular vein to connect the micropump infusion device.In group S,the cecum was only turned without ligation and perforation,and total venous nutrient solution 60 ml was intravenously infused daily for 3 days.After successful establishment of the model,total venous nutrient solution 60 ml was intravenously infused daily for 3 days in group CLP.After successful establishment of the model in group T,Tα1 0.18 mg/kg was subcutaneously injected daily at a fixed time,and total venous nutrient solution 60 ml was intravenously infused daily for 3 days.Twenty-four rats in group CLP and group T were selected,and the survival rate were observed within 3 days after establishing the model.At 12,24,36 and 72 h after establishing the model,6 rats were selected from each group,and blood samples were collected from the jugular vein for determination of the levels of regulatory T cells (Tregs) and T helper cell 17 (Th17) (using flow cytometry) and serum interleukin-10 (IL-10),IL-17 and tumor necrosis factor-alpha (TNF-α) concentrations (by enzymelinked immunosorbent assay),and the IL-10/TNF-cα ratio was calculated.Results Compared with group S,the level of Tregs in peripheral blood was significantly decreased at 24 h after establishing the model and was increased at 36 and 72 h after establishing the model,and the level of Th17 in peripheral blood and serum IL-10,IL-17 and TNF-α concentrations were increased at each time point after establishing the model,and the IL-10/TNF-α ratio was increased at 36 and 72 h after establishing the model in group CLP,and the levels of Tregs and Th17 in peripheral blood were significantly increased at 72 h after establishing the model,the concentrations of serum IL-10 and IL-17 were increased at each time point after establishing the model,serum TNF-α concentrations were increased at 12 and 24 h after establishing the model,and the IL-10/TNF-α ratio was increased at 36 and 72 h after establishing the model in group T (P＜0.05).Compared with group CLP,the levels of Tregs and Th17 in peripheral blood were significantly decreased,the serum IL-10 and IL-17 concentrations and IL-10/TNF-α ratio were decreased at 36 and 72 h after establishing the model,serum TNF-α concentrations were decreased at 72 h after establishing the model,and the survival rate was increased within 3 days after establishing the model in group T (P＜0.05).Conclusion Tα1 can reduce sepsis through improving the cellular immune function in rats.