NOD1 is required for Helicobacter pylori induction of IL‐33 responses in gastric epithelial cells

• Published in: Cellular microbiology Vol. 20; no. 5; pp. e12826 - n/a
• Main Authors: Tran, Le Son, Tran, Darren, De Paoli, Amanda, D'Costa, Kimberley, Creed, Sarah J., Ng, Garrett Z., Le, Lena, Sutton, Philip, Silke, J., Nachbur, U., Ferrero, Richard L.
• Format: Journal Article
• Language: English
• Published: England Hindawi Limited 01.05.2018
• Subjects: Animals; Carcinogenesis; Carcinogens; Cell Line; Chronic infection; Epithelial cells; Epithelial Cells - microbiology; Epithelial Cells - pathology; Gastric Mucosa - immunology; Gastric Mucosa - microbiology; Helicobacter Infections - genetics; Helicobacter Infections - immunology; Helicobacter Infections - microbiology; Helicobacter pylori; Helicobacter pylori - genetics; Helicobacter pylori - immunology; Helicobacter pylori - pathogenicity; Humans; Immune response; Immunity, Mucosal - genetics; Infections; Inflammation - genetics; Inflammation - immunology; Inflammation - microbiology; Interferon; Interferon-gamma - genetics; Interleukin-33 - genetics; Interleukins; Kinases; Mice; Mucosa; Nod1 protein; Nod1 Signaling Adaptor Protein - genetics; Pathogens; Protein-serine/threonine kinase; Receptors, Interleukin-13 - genetics; Signal transduction; Signaling; Spleen; Th2 Cells - immunology; Th2 Cells - microbiology
• ISSN: 1462-5814; 1462-5822
• DOI: 10.1111/cmi.12826

Helicobacter pylori (H. pylori) causes chronic inflammation which is a key precursor to gastric carcinogenesis. It has been suggested that H. pylori may limit this immunopathology by inducing the production of interleukin 33 (IL‐33) in gastric epithelial cells, thus promoting T helper 2 immune responses. The molecular mechanism underlying IL‐33 production in response to H. pylori infection, however, remains unknown. In this study, we demonstrate that H. pylori activates signalling via the pathogen recognition molecule Nucleotide‐Binding Oligomerisation Domain‐Containing Protein 1 (NOD1) and its adaptor protein receptor‐interacting serine–threonine Kinase 2, to promote production of both full‐length and processed IL‐33 in gastric epithelial cells. Furthermore, IL‐33 responses were dependent on the actions of the H. pylori Type IV secretion system, required for activation of the NOD1 pathway, as well as on the Type IV secretion system effector protein, CagA. Importantly, Nod1+/+ mice with chronic H. pylori infection exhibited significantly increased gastric IL‐33 and splenic IL‐13 responses, but decreased IFN‐γ responses, when compared with Nod1−/− animals. Collectively, our data identify NOD1 as an important regulator of mucosal IL‐33 responses in H. pylori infection. We suggest that NOD1 may play a role in protection against excessive inflammation.