[Mouse interleukin-1 production by Actinobacillus actinomycetemcomitans Y4 lipopolysaccharide and augmenting effect of indomethacin on its production].

The present study demonstrates the ability of Actinobacillus actinomycetemcomitans lipopolysaccharide (LPS) to elicite interleukin-1 (IL-1) production and then augmenting effect of indomethacin on this production. LPS was isolated from A. actinomycetemcomitans Y4 by the hot phenol-water procedure (A-LPS). A marked IL-1 production by peritoneal macrophages treated with A-LPS was observed in the cells from C3H/HeN mice, but not in those from C3H/HeJ mice. LPSs from A. actinomycetemcomitans ATCC 29522 and 29523 exhibited the same inducing activity for IL-1 production as did A-LPS. The IL-1 production with A-LPS was inhibited drastically when the LPS was pretreated with polymyxin B. A-LPS-induced IL-1 production was augmented significantly by treatment of the cells with a inhibitor, indomethacin, but not with a lipooxygenase inhibitor, nordihydroguariatic acid. The augmenting effect occurred as early as 3 hr after treatment of indomethacin. In light of recent studies showing that IL-1 plays a regulatory role in bone remodeling systems, the present result suggest the possibility that A-LPS-induced IL-1 may play a significant role in mechanism(s) of alveolar bone resorption in juvenile periodontitis and also that its production may be regulated by prostaglandins.