title: Immune responses to Yersinia enterocolitica in susceptible BALB/c and resistant C57BL/6 mice: an essential role for gamma interferon.
abstract: Susceptibility of mice to infection with Yersinia enterocolitica has been shown to be related to neither the Ity locus encoding for resistance to Salmonella typhimurium and other pathogens nor the H-2 locus. Recent studies in our laboratory have demonstrated that T-cell-mediated immune responses are required for overcoming primary Yersinia infection. In the present study, we investigated the course of infection with Y. enterocolitica and the resulting immune responses in Yersinia-susceptible BALB/c and Yersinia-resistant C57BL/6 mice. In the early phase of infection, the clearance of the pathogen was comparable in both strains of mice, suggesting similar mechanisms of innate resistance. Splenic T cells from Yersinia-infected C57BL/6 mice exhibited marked proliferative responses and produced gamma interferon (IFN-gamma) upon exposure to heat-killed yersiniae. By contrast, the Yersinia-specific T-cell response in BALB/c mice was weak, and IFN-gamma production could not be detected before day 21 postinfection. T cells isolated from C57BL/6 mice 7 days after infection mediated immunity to Y. enterocolitica but those from BALB/c mice did not, while at 21 days postinfection T cells from both strains mediated protection. Neutralization of IFN-gamma abrogated resistance to yersiniae in C57BL/6 mice but to a far smaller extent in BALB/c mice. Administration of recombinant IFN-gamma or anti-interleukin-4 antibodies rendered BALB/c mice resistant to yersiniae, whereas this treatment did not significantly affect the course of the infection in C57BL/6 mice. These results indicate that the cellular immune response, in particular the production of IFN-gamma by Yersinia-specific T cells, is associated with resistance of mice to Y. enterocolitica.
authors.affiliation: Institute for Hygiene and Microbiology, University of Würzburg, Federal Republic of Germany.
authors.forename: I B
authors.initials: IB
authors.lastname: Autenrieth
authors.forename: M
authors.initials: M
authors.lastname: Beer
authors.forename: E
authors.initials: E
authors.lastname: Bohn
authors.forename: S H
authors.initials: SH
authors.lastname: Kaufmann
authors.forename: J
authors.initials: J
authors.lastname: Heesemann
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D007371:Interferon-gamma / Q000502:physiology*; D015847:Interleukin-4 / Q000502:physiology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000276:immunology; D015009:Yersinia Infections / Q000276:immunology*; D015008:Yersinia enterocolitica / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D016207:Cytokines; D015847:Interleukin-4; D007371:Interferon-gamma