The effects of exogenous interleukin-12 on the induction of immune response to Porphyromonas gingivalis in vivo in mice.

ABSTRACT

The effects of treatment with exogenous interleukin-12 (IL-12) on the induction of immune response to Porphyromonas gingivalis, a black pigmented periodontopathic oral bacterium in mice, were determined in the present study. An increased footpad swelling representing a delayed type hypersensitivity (DTH) response to P. gingivalis in IL-12-treated mice could be observed, although increasing doses of IL-12 did not produce cumulative effects on this cellular Immune response. Multiple injections with IL-12 also resulted in elevated serum IFN-gamma levels. Treatment with this cytokine the day before, on and after immunization with heat-killed P. gingivalis augmented the levels of serum antigen-specific IgG2a and IgG3 antibodies, but had obviously little or no effects on those of serum antigen-specific IgG1 and IgG2b antibodies. The results of this study suggest that treatment with exogenous IL-12 In P. gingivalis-immunized mice may enhance DTH response and Th1 cell-associated antibody production.