title: Interferon-gamma deficiency attenuates local P. gingivalis-induced inflammation.
abstract: Infection with the periodontal pathogen Porphyromonas gingivalis causes a strong local inflammatory reaction. Using IFNgamma-deficient mice, we tested the hypothesis that the absence of IFNgamma would result in a reduction of the local pro-inflammatory response to P. gingivalis. Cytokine secretion by macrophages from IFNgamma(-/-) animals was significantly attenuated. Addition of IFNgamma restored cytokine secretion. In vivo injection of P. gingivalis into subcutaneous chambers increased the intra-chamber leukocyte counts and TNFalpha and IL-1beta levels. This increase was significantly lower in the IFNgamma(-/-) mice. Local reconstitution of IFNgamma(-/-) mice at the site of inflammation with the IFNgamma gene increased the levels of TNFalpha and decreased the IL-10 levels. Anti-P. gingivalis IgG1 levels, a marker of Th2 response, were higher in immunized IFNgamma(-/-) than in IFNgamma(+/+) mice. The results suggest that lack of IFNgamma reduced the amplitude of the local pro-inflammatory response without decreasing the humoral protective response. The higher IgG1/IgG2a ratio observed supports the possibility of a Th2-dominant response in IFNgamma-deficient animals.
authors.affiliation: Department of Periodontology, Faculty of Dental Medicine, Hadassah and Hebrew University Medical Centers, PO Box 12272, Jerusalem 91120, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Houri-Haddad
authors.forename: W A
authors.initials: WA
authors.lastname: Soskolne
authors.forename: E
authors.initials: E
authors.lastname: Shai
authors.forename: A
authors.initials: A
authors.lastname: Palmon
authors.forename: L
authors.initials: L
authors.lastname: Shapira
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D007249:Inflammation / Q000276:immunology / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism*; D007371:Interferon-gamma / Q000172:deficiency* / Q000502:physiology*; D007375:Interleukin-1 / Q000096:biosynthesis; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D016966:Porphyromonas gingivalis / Q000472:pathogenicity*; D013047:Specific Pathogen-Free Organisms; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D000907:Antibodies, Bacterial; D016207:Cytokines; D018836:Inflammation Mediators; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma