Adhesion molecule deficiencies increase Porphyromonas gingivalis-induced alveolar bone loss in mice.
Alveolar bone resorption can be induced in specific-pathogen-free mice by oral infection with Porphyromonas gingivalis (P. J. Baker, R. T. Evans, and D. C. Roopenian, Arch. Oral Biol. 39:1035-1040, 1994). Here we used a mouse strain, C57BL/6J, which is relatively resistant to P. gingivalis-induced bone loss to examine whether partial or complete deletion of various adhesion molecules would increase susceptibility. Complete deletion of P-selectin or nearly complete lack of expression of intercellular adhesion molecule 1 (ICAM-1) led to increased susceptibility to bone resorption after oral infection, while a hypomorphic defect in beta(2)-integrins did not. Both the total amount of bone lost and the number of sites at which there was significant loss were increased in mice deficient in either ICAM-1 or P-selectin. Each of the three adhesion molecule deficiencies was sufficient to decrease P. gingivalis-specific serum immunoglobulin G responses, but lower antibody titers did not lead to increased bone loss in partially beta(2)-integrin-deficient mice. In conclusion, P-selectin and ICAM-1 deficiencies increase susceptibility to and severity of alveolar bone loss after P. gingivalis infection. This finding underscores the importance of innate immunity in protection against P. gingivalis-induced alveolar bone resorption.
Baker
P J
PJ
Biology Department, Bates College, Lewiston, Maine 04240, USA. pbaker@bates.edu
DuFour
L
L
Dixon
M
M
Roopenian
D C
DC
D016301:Alveolar Bone Loss / Q000382:microbiology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016866:Bacteroidaceae Infections / Q000276:immunology / Q000473:pathology*; D018821:CD18 Antigens / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000235:genetics*; D007108:Immune Tolerance; D007113:Immunity, Innate; D007074:Immunoglobulin G / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D019007:P-Selectin / Q000235:genetics; D016966:Porphyromonas gingivalis / Q000276:immunology / Q000472:pathogenicity*
D000907:Antibodies, Bacterial; D018821:CD18 Antigens; D015815:Cell Adhesion Molecules; D007074:Immunoglobulin G; D019007:P-Selectin; D018799:Intercellular Adhesion Molecule-1