Interferon-γ-producing B cells induce the formation of gastric lymphoid follicles after Helicobacter suis infection.

Helicobacter (H.) suis is capable of infecting various animals including humans, and H. suis infections can lead to gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Recently, we reported that interferon-γ (IFN-γ) was highly expressed in the stomachs of H. suis-infected mice, but the direct relationship between the upregulation of IFN-γ expression and the formation of gastric lymphoid follicles after H. suis infection remains unclear. Here, we demonstrated that the IFN-γ produced by B cells plays an important role in the formation of gastric lymphoid follicles after H. suis infection. In addition, IFN-γ-producing B cells evoked gastric lymphoid follicle formation independent of T-cell help, suggesting that they are crucial for the development of gastric MALT induced by Helicobacter infection.