Druffner, S. R. | bioRxiv Science

bioRxiv2025

Endogenous glucocorticoids moderate the gastric inflammatory response to Helicobacter infection and protect from autoimmunity.

Background and AimsImmune responses to infection must balance pathogen clearance with minimizing tissue damage and autoimmunity. Chronic gastric inflammation caused by H. pylori damages the gastric mucosa and promotes carcinogenesis. Glucocorticoids are immunoregulatory hormones that limit immune activation in the stomach. This study aimed to determine how endogenous glucocorticoids regulate the gastric immune response to Helicobacter infection and their impact on preneoplastic lesion development. MethodsWe examined the role of endogenous glucocorticoids in shaping the gastric immune response to Helicobacter felis colonization. Gastric immune cell infiltration, atrophy, metaplasia, and preneoplastic lesion development were evaluated in adrenal-intact control mice and adrenalectomized (ADX) mice. Auto-reactive IgG antibodies were assessed using a mouse self-antigen array and by measuring their binding to healthy gastric tissue. ResultsLoss of endogenous glucocorticoids led to significantly increased H. felis-induced gastric T cell infiltration and proinflammatory cytokine expression compared to intact-infected controls. While all intact mice maintained chronic infection for up to 12 months, nearly all ADX mice eradicated H. felis within 2-3 weeks. Despite bacterial clearance, ADX mice continued to exhibit chronic gastric inflammation and developed dysplasia. Autoantibody profiling showed that both intact and ADX groups generated self-reactive IgG during active infection. However, only ADX mice sustained autoantibody production following bacterial eradication. ConclusionsEndogenous glucocorticoids attenuate gastric inflammation during Helicobacter infection, supporting bacterial persistence while maintaining immune tolerance. These findings suggest that heightened immune responses to H. pylori may trigger autoimmune gastritis (AIG) development, which can persist after H. pylori clearance and continue to drive gastric cancer risk.

immunology↗

bioRxiv2023

Comparison of gastric inflammation and metaplasia induced by Helicobacter pylori or Helicobacter felis colonization in mice

BackgroundGastric cancer is the fifth most diagnosed cancer in the world. Infection by the bacteria Helicobacter pylori (HP) is associated with approximately 75% of gastric cancer cases. HP infection induces chronic gastric inflammation, damaging the stomach and fostering carcinogenesis. Most mechanistic studies on Helicobacter-induced gastric cancer initiation are performed in mice and utilize either mouse-adapted strains of HP or the natural mouse pathogen Helicobacter felis (HF). Each of these infection models is associated with strengths and weaknesses. Here, we identified the differences in immunogenicity and gastric pathological changes associated with HP and HF infection in mice. Material and MethodsPMSS1 HP strain or with the CS1 HF strain were co-cultured with mouse peritoneal macrophages to assess their immunostimulatory effects. C57BL/6J mice were infected with HP or HF, and gastric inflammation, atrophy, and metaplasia development were assessed 2 months post-infection. ResultsHP and HF induced similar cytokine production from cultured mouse peritoneal macrophages. HP-infected mice caused modest inflammation within both the gastric corpus and antrum and did not induce significant atrophy within the gastric corpus. In contrast, HF induced significant inflammation throughout the gastric corpus and antrum. Moreover, HF infection was associated with significant atrophy of the chief and parietal cell compartments and induced expression of pyloric metaplasia markers. ConclusionsHP is poorly immunogenic compared to HF. HF induces dramatic CD4+ T cell activation, which is associated with increased gastric cancer risk in humans. Thus, HP studies in mice are better suited for studies on colonization, while HF is more strongly suited for pathogenesis and cancer initiation studies.

immunology↗