Interleukin-1 gene expression in macrophages induced by surface protein components of Porphyromonas gingivalis: Role of tyrosine kinases in signal transduction

We examined interleukin-β (IL-1β) mRNA expression and protein tyrosine kinase activities induced by surface protein components of Porphyromonas gingivalis to gain insights into signaling pathways leading to macrophage responses. Reverse transcriptase-polymerase chain reaction analyses showed that native fimbriae, full-length recombinant fimbrillin, and a lectin-like 12-kDa antigen of P. gingivalis induced rapid expression of mRNA encoding IL-1β in BALB/c and lipopolysacharide-hyporesponsive C3H/HeJ peritoneal macrophages. The antigens also specifically activated tyrosine kinase(s) in macrophages. The ability of the surface protein components to induce the cytokine mRNA accumulation was markedly abrogated by tyrosine kinase inhibitors. The findings reported here suggest that IL-1β expression in macrophages is a functional consequence of tyrosine kinase activation by the P. gingivalis surface protein components.