title: Interferon-γ promotes gastric lymphoid follicle formation but not gastritis inHelicobacter-infected BALB/c mice.
abstract: BACKGROUND
  Mouse infection studies have shown that interferon-γ (IFN-γ), a T helper 1 (Th1) cytokine, is required for the development of severe pathology induced by chronicHelicobacterinfection. This finding is largely based on studies performed using mice that have polarised Th1 responses i.e. C57BL/6 animals. The current work aims to investigate the role of IFN-γ inHelicobacter-induced inflammation in BALB/c mice which have Th2-polarised immune responses.
  
  
  RESULTS
  At 7 months post-infection withHelicobacter felis,IFN-γ deficiency in BALB/c mice had no significant effect onH. feliscolonisation levels in the gastric mucosa, nor on humoral responses, or gastritis severity.Ifng-/-animals with chronicH. felisinfection did, however, develop significantly fewer lymphoid follicle lesions, as well as increased IL-4 splenocyte responses, when compared with infectedIfng+/+mice (P = 0.015 and P = 0.0004, respectively).
  
  
  CONCLUSIONS
  The work shows that in mice on a BALB/c background, IFN-γ is not required for bacterial clearance, antibody responses, nor gastric inflammation. Conversely, IFN-γ appears to play a role in the development of gastric lymphoid follicles, which are precursor lesions to mucosa-associated lymphoid tissue (MALT) lymphoma. This study highlights the importance of mouse host background on the susceptibility toHelicobacter-induced pathologies.
authors.affiliation: Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, VIC 3123 Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Chonwerawong
authors.affiliation: Unité de Recherche et d'Expertise Histotechnologie et Pathologie, Institut Pasteur, 25-28 Rue du Dr Roux, 75724 Paris, France ; Unité de Histopathologie Humaine et Modèles Animaux, Institut Pasteur, 25-28 Rue du Dr Roux, 75724 Paris, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Avé
authors.affiliation: Unité de Recherche et d'Expertise Histotechnologie et Pathologie, Institut Pasteur, 25-28 Rue du Dr Roux, 75724 Paris, France ; Département de Pathologie, Institut Curie, 26 Rue d'Ulm, 75248 Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Huerre
authors.affiliation: Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Monash University, 27-31 Wright Street, Clayton, VIC 3123 Australia ; Department of Microbiology, Monash University, Clayton, VIC Australia.
authors.forename: Richard L
authors.identifier: 0000-0001-6817-6211
authors.initials: RL
authors.lastname: Ferrero
keywords: BALB/c; Gastric inflammation; Helicobacter; Interferon-gamma; Lymphoid follicle; MALT lymphoma; Mucosa-associated lymphoid tissue; T helper response