INDUCTION OF SYSTEMIC MURINE B-CELL RESPONSES BY FUSOBACTERIUM-NUCLEATUM AND PORPHYROMONAS-GINGIVALIS

The purpose of this study was to examine the antigenic abilities of Fu sobacterium nucleatum strain ATCC 25586 and Porphyromonas gingivalis s train W50 black inbred BALB/cABom mice immunized subcutaneously. Furth ermore, we aimed to analyze whether the outer membranes (OM) and whole cells (WC) of F. nucleatum? or P. gingivalis had an effect on the lev els of antibody response and whether a combination of both could eithe r enhance or suppress the B-cell response. A single-cell assay, solid- phase enzyme-linked immunospot (ELISPOT), was used to analyze the sple nic B-cell response (immunoglobulin A (IgA), IgG and IgM). Enzyme-link ed immunosorbent assay (ELISA) and immunoblotting were used to verify the specific antibody response in the sera. A statistically significan t lower level of spontaneous antibody production was observed in the g roup immunized with P. gingivalis OM compared with groups immunized wi th F. nucleatum and saline. The specific antibody titers measured by E LISA indicated that the bacterial preparations were able to induce IgG and IgM response. The preparations containing P. gingivalis OM induce d higher humoral response than the preparations containing P. gingival is WC, but for F. nucleatum such a difference was not observed. The pr ominent proteins revealed had apparent molecular masses of 40 kDa for F. nucleatum and 115, 55-56 and 43 kDa for P. gingivalis, whereas the immunoreactive proteins were 70, 65 and 40 kDa for mice immunized with F. nucleatum and 115, 55-56, 43 and 33-34 kDa for mice immunized with P. gingivalis. Quantitative analysis of B-cell response at the single cell level with ELISPOT revealed that some component(s) of P. gingiva lis OM may have a suppressive ability on splenocytes incubated for a s hort time.