The influence of genetic variation on the splenic T cell cytokine and specific serum antibody responses to Porphyromonas gingivalis in mice.
BACKGROUND
T cell cytokine profiles in the spleens and anti-Porphyromonas gingivalis antibodies in the sera of P. gingivalis-immunized BALB/c (H-2d), CBA/CaH (H-2k), C57BL6 (H-2b), and DBA/2J (H-2d, C5 deficient) mice were examined.


METHODS
Mice were immunized either by intraperitoneal injections of P. gingivalis outer membrane antigens and Freund's incomplete adjuvant weekly for 3 weeks or sham-immunized with PBS and adjuvant, followed by subcutaneous challenge with live organisms 1 week after the final immunization. Spleens were excised and blood samples collected by heart puncture at 0 and 7 days after challenge. Splenic CD4 and CD8 cells were stained for intracytoplasmic interleukin (IL)-4, interferon (IF)-gamma, and IL-10 and levels of anti-P. gingivalis antibodies in the serum samples determined by ELISA.


RESULTS
Lesion sizes in immunized BALB/c mice remained stable for the 7-day experimental period. Immunized CBA/CaH and C57BL6 mice exhibited large lesions at day 1 reducing by day 7 particularly in the latter strain. Lesions in immunized DBA/2J mice were still larger than the other strains at day 7. With the exception of DBA/2J mice, sham-immunized mice demonstrated lesions which did not show signs of healing by day 7. T cell cytokine responses in sham-immunized mice at day 0 were low, increasing to a variable degree by day 7 after challenge in the 4 strains. Immunized BALB/c mice demonstrated intermediate T cell responses while generally exhibiting a stronger IFN-gamma response than IL-4 or IL-10. Immunized CBA/CaH and C57BL6 mice showed weak T cell cytokine responses while immunized DBA/2J displayed the strongest T cell responses particularly in regard to IL-4 positive cells. Sham-immunized mice had low levels of serum anti-P. gingivalis antibody levels at day 0 with levels increasing significantly by day 7 after challenge. Antibody levels in immunized mice seemed to correlate with lesion sizes. Immunized C57BL6 mice had the highest antibody levels followed by CBA/CaH, BALB/c with DBA/2J exhibiting low levels. The T cell and B cell antibody responses in each strain appeared to exhibit an inverse relationship.


CONCLUSIONS
This study has shown that genetic differences at the level of H-2 haplotype induce variations in the local and T and B cell responses to P. gingivalis antigens. The responses of DBA/2J mice which have the same haplotype as BALB/c mice suggest that factors other than H-2 haplotype such as the C5 deficiency may influence this immune response. The significance of the specific antibody and T cell responses and of their inverse relationship to susceptibility to periodontal disease remains to be determined.
Gemmell
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Immunopathology Laboratory, Oral Biology and Pathology, School of Dentistry, University of Queensland, Brisbane, Australia. e.gemmell@mailbox.uq.edu.au
Winning
T A
TA
Grieco
D A
DA
Bird
P S
PS
Seymour
G J
GJ
D000704:Analysis of Variance; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001770:Blood Bactericidal Activity / Q000235:genetics*; D016516:CD4-CD8 Ratio; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D014644:Genetic Variation; D006183:H-2 Antigens / Q000235:genetics*; D007114:Immunization; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics; D016018:Least-Squares Analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D008817:Mice, Mutant Strains; D016966:Porphyromonas gingivalis / Q000276:immunology*; D013045:Species Specificity; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D016207:Cytokines; D006183:H-2 Antigens; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma