Preliminary experimental study on mechanism of intestinal mucosal damage induced by IgG immune complex in mice / 中国免疫学杂志

ABSTRACT

Objective:To study the cellular pathology and molecular mechanisms of intestinal mucosal damage induced by IgG immune complex in mice.And to explore the pathogenic mechanism and molecular diagnosis evidence of ulcerative colitis induced by food intolerance in clinical practice.Methods: Six weeks old BALB/c female mice were used to build animal model.All the mice were divided into four groups:the control group(group A),the rabbit intestinal mucosal protein immunized group(group B),the DSS induced group(group C),the rabbit intestinal mucosal protein immunized combined with DSS induced group(group D).After successful establishment of animal model,serum and colon tissues were collected to be performed relevant tests.Results: IgG level in serum and colonic mucosa of group B mice increased.And inflammatory cell infiltration and a small amount of mast cell activation were observed in intestinal mucosa;group C mice showed the typical acute ulcerative colitis:a large number of inflammatory cells infiltration,inflammatory factor levels increased in mucosa and mucosa lamina propria,and mucosal epithelial cells′ tight junction weakened;group D mice manifested both high level of IgG in serum and colonic mucosa and also typical acute ulcerative colitis.Besides,significant mast cell activation was observed in the intestinal mucosa.Conclusion: We infer from the experimental results that IgG immune complexes can induce the damage of intestinal epithelium by mediating activation of mast cells.And during the process,the level of inflammatory cytokines increased in intestinal mucosa and the expression of tight junction protein in epithelial cell decreased.These factors contribute to the promotion of intestinal mucosa damage induced by immune complexes.