Study On The Effect Of T Regulatory Cells On Antibiotic-Associated Colitis And Gastric Cancer

T regulatory cells(tregs)are also known as inhibitory T cells.As an important subgroup of T cells,Treg cells can play an important role in inhibiting excessive immune response,ensuring the immune system's tolerance to autoantigens and preventing autoimmune diseases.Treg cells mainly inhibit the activation and activity of effector T cells to achieve the function of immunosuppression.More and more studies have shown that T regulatory cells play an important role in tumors and autoimmune diseases.In the IL10 gene-deficient mice,which is a model of inflammatory bowel disease,the interaction between T regulatory cells and microbiota plays an important role in the development of colitis.For tumor cells,more and more studies have shown that Treg cells are usually highly expressed in gastric cancer,severely inhibiting tumor immune response.Therefore,we compared the interaction between Treg cells and microbiota in colitis and the important role of Treg cells in intestinal inflammation in antibiotic-associated colitis.At the same time,we also studied the expression of T regulatory cells in early gastric cancer and precancerous lesions,and combined with the recent studies on immune checkpoint PD-1 and PD-L1 to clarify the important role of immune suppression in the process of early gastric cancer and precancerous lesions.Our results showed that antibiotic-associated colitis was milder in IL10 gene-deficient mice and heavier in wild-type mice.The reason was that the decreased proportion of Bacteroides in IL10 gene-deficient mice was lower,which could promote the proliferation of T-regulatory cells.Because of its small decrease,antibiotic-associated colitis was milder;while Stentrophomonas and Xanthomonas were milder.The proportion of bacteria decreased more,alleviating intestinal inflammation.In gastric intraepithelial neoplasia and early gastric cancer,we found that T-regulatory cells were expressed in low-grade intraepithelial neoplasia,high-grade intraepithelial neoplasia and early gastric cancer,and there was a significant correlation between T-regulatory cells and pathological grade.The expression of PD-1/PD-L1 at immune checkpoint was also examined.PD-1/PD-L1 was also expressed in endothelial neoplasia and early cancer,but there was no significant correlation with the expression of CD8 positive T cells.The expressions of PD-1 and PD-L1 were significantly correlated with Helicobacter pylori infection.