Prior to Foxp3⁺ regulatory T-cell induction, interleukin-10-producing B cells expand after Helicobacter pylori infection.

Regulatory T (Treg) cells play a critical role in Helicobacter pylori immune evasion and persistent infection. In addition to Treg cells, it is still unknown whether a newly defined B-cell subset, interleukin (IL)-10-producing B cells, is involved. Using a mouse model of H. pylori infection, we investigated the dynamic changes of IL-10-producing B cells and Foxp3(+) Treg cells in gastrointestinal mucosa, spleen and mesenteric lymph nodes following H. pylori infection. We observed that in addition to Foxp3(+) Treg cells, IL-10-producing B cells could also be induced after H. pylori infection and they expanded earlier than Foxp3(+) Treg cells did. Moreover, the regulatory immune responses induced by H. pylori were not limited to gastric mucosa. Our findings may provide new clues for further research on H. pylori immune evasion and diseases associated with H. pylori infection.