LIPOPOLYSACCHARIDES FROM PORPHYROMONAS-GINGIVALIS, PREVOTELLA-INTERMEDIA AND ACTINOBACILLUS-ACTINOMYCETEMCOMITANS PROMOTE OSTEOCLASTIC DIFFERENTIATION IN-VITRO

Bacterial lipopolysaccharides possess bone-resorbing activity. Here, l ipopolysaccharides from three putative periodontopathic bacteria were examined for effects on osteoclast-like cell formation of bone marrow cells from lipopolysaccharide-responsive C3H-HeN and non-responsive C3 H/HeJ mice. The bone marrow cells were cultured with or without variou s doses of lipopolysaccharide in the presence of 1,25-dihydroxyvitamin D-3 and dexamethasone. These lipopolysaccharide preparations signific antly increased the number of osteoclast-like cells formed in the cult ure of C3H/HeN marrow cells; the same as lipopolysaccharides from Esch erichia coli and a synthetic lipid A with E. coli-type structure (LA-1 5-PP), at doses from 0.1 to 1 mu g/ml. This stimulating effect of each lipopolysaccharides was uniformly abrogated by the addition of polymy xin B at 5 mu g/ml. All the lipopolysaccharide and the synthetic lipid A had no effect on osteoclast formation of the C3H/HeJ marrow cells, whereas lipopolysaccharide from Porphyromonas gingivalis and Prevotell a intermedin showed significant mitogenic activity on C3H/HeJ spleen c ells. it seems likely that the activity of lipopolysaccharides to augm ent osteoclast-like cell formation in the bone marrow cell cultures is derived from a common structure of the lipid A portion. Copyright (C) 1996 Elsevier Science Ltd.