A critical role for IL-713 signaling in the development of Helicobacter felis-induced gastritis in mice

Background & Aims: Interleukin (IL)-7 is a critical cytokine in the develop ment of T and B cells and is involved in gastrointestinal pathophysiology. The aim of this study was to investigate the involvement of IL-7 receptor ( IL-7R) signaling in Helicobacter-induced gastritis. Methods: C57BL/6 mice ( n = 40) were inoculated with H. felis. Twenty mice were injected intraperit oneally with neutralizing IL-7R antibody (A7R34) every seventh day for 3 mo nths. Histology, serum anti-H. felis antibody, and gene expression of IL-7, IL-7R, and proinflammatory cytokines in the gastric mucosa were evaluated. Results: Seventeen of 20 (85%) infected mice without A7R34 developed sever e atrophic gastritis, whereas there was no gastritis in A7R34-treated infec ted mice. There was no difference in the serum levels of anti-H. felis anti body between the 2 groups. IL-7, IL-7R, IL-1 alpha, tumor necrosis factor a lpha, and interferon gamma messenger RNA expressions were up-regulated in c ontrol infected mice, whereas only IL-7 messenger RNA was up-regulated in A 7R34-treated infected mice. Immunohistochemistry indicated positive cytopla smic staining of IL-7 in the gastric epithelial cells. Conclusions: These d ata suggest a critical role for IL-7 receptor signaling in the development of Helicobacter-induced gastritis in mice.