ACTINOBACILLUS-ACTINOMYCETEMCOMITANS SEROTYPE B-SPECIFIC POLYSACCHARIDE ANTIGEN STIMULATES PRODUCTION OF CHEMOTACTIC FACTORS AND INFLAMMATORY CYTOKINES BY HUMAN MONOCYTES

Serotype b-specific polysaccharide antigen (SPA) was extracted from wh ole cells of Actinobacillus actinomycetemcomitans Y4 by autoclaving an d purified by chromatography on DEAE-Sephadex A-25 and Sephacryl S-300 . SPA induced the release of monocyte and leukocyte chemotactic factor s by human monocytes. Polymyxin B had almost no effect on the release of monocyte chemotactic factor, but a monoclonal antibody against SPA markedly inhibited it. Human monocytes stimulated with SPA exhibited t he increased mRNA expression of monocyte chemoattractant protein 1 (MC P-1) and a neutrophil chemotactic factor, interleukin-8 (IL-8). On the other hand, SPA induced the release of IL-1, IL-6, and tumor necrosis factor (TNF) and enhanced the expression of IL-1 alpha, IL-1 beta, IL -6, and TNF alpha (TNF-alpha) mRNAs. Human monocytes expressed MCP-1 a nd IL-8 mRNAs when stimulated by human recombinant IL-1 alpha, IL-1 be ta, IL-6, and TNF-alpha, suggesting that these inflammatory cytokines induced by SPA might participate in the production of chemotactic fact ors in human monocytes.