The role of cytokines in a Porphyromonas gingivalis-induced murine abscess model.
BACKGROUND
Porphyromonas gingivalis is an important periodontopathic bacterium that is strongly associated with periodontal disease and is part of human dental plaque. Periodontal disease results from the interaction of the host with bacterial products, and T-cell-derived cytokines remain critical in the immunoregulation of periodontal disease.


METHODS
The aim of this study was to examine the role of T helper type 1 [interleukin-12p40 (IL-12p40), interferon-gamma, tumour necrosis factor (TNF)] and type 2 (IL-4, IL-10) cytokines in the immune response to a subcutaneous challenge with P. gingivalis using a well-established murine abscess model, in genetically modified cytokine-specific knockout mice.


RESULTS
IL-12p40(-/-) mice exhibited more advanced tissue destruction and a reduced inflammatory cell infiltrate after subcutaneous P. gingivalis challenge. Deficiency of IL-4 or IL-10 did not result in increased susceptibility to P. gingivalis-mediated tissue destruction. Furthermore, TNF deficiency appeared to reduce local tissue destruction. Interestingly, serum-specific antibodies suggested a strong T helper type 2 response.


CONCLUSIONS
The results of our study indicate an important role for IL-12 in a primary P. gingivalis subcutaneous challenge.
Alayan
J
J
Oral Biology and Pathology, School of Dentistry, University of Queensland, Brisbane, QLD, Australia.
Gemmell
E
E
Ford
P
P
Hamlet
S
S
Bird
P S
PS
Ivanovski
S
S
Farah
C S
CS
D000038:Abscess / Q000382:microbiology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016866:Bacteroidaceae Infections / Q000276:immunology*; D016207:Cytokines / Q000276:immunology*; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D005260:Female; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D053762:Interleukin-12 Subunit p40 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D016966:Porphyromonas gingivalis / Q000276:immunology*; D017192:Skin Diseases, Bacterial / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology