Regulatory B cells contribute to the alleviation of colitis induced by Dextran Sulphate Sodium afterH.pyloriinfection

Background Epidemiological studies showed that there was an inverse relationship between Helicobacter pylori infection and the incidence of inflammatory bowel disease. Our previous research indicated that the regulatory immune responses induced by H.pylori infection were not limited to gastric mucosa, and the balance of intestinal mucosal immunity was influenced. In this study, we investigated the role of the regulatory B cells in the effects of the H.pylori infection on acute and chronic colitis induced by dextran sulphate sodium. Methods Mice were infected with H.pylori and then colitis was induced by 3% DSS, the CD19 + IL-10 + Breg cells and CD4 + CD25 + Foxp3 + Treg cells in blood、 spleen、 mesenteric lymph nodes (MLN)、 Peyer’s Patches (PP) and gastrointestinal mucosa were measured and examined. The anti– and pro-inflammatory cytokines were also detected at mRNA level. Results In the acute and chronic colitis groups, DAI and colonic histological scores reduced significantly and colon length shorted less; the anti-inflammatory cytokines mRNA expression upregulated while the pro-inflammatory cytokines mRNA expression downregulated in colonic mucosa; and the percentages of CD19 + IL-10 + Breg cells in blood spleen MLN、 PP were higher in the H.pylori /DSS co-treated group compared with the DSS treated group. Conclusion H.pylori infection can alleviate the acute and chronic colitis induced by DSS. CD19 + IL-10 + Breg cells may play a critical role in the alleviation of acute and chronic colitis following H.pylori infection.