SPLENIC B-CELL ACTIVATION IN LIPOPOLYSACCHARIDE-NON-RESPONSIVE C3H HEJ MICE BY LIPOPOLYSACCHARIDE OF PORPHYROMONAS-GINGIVALIS/

Porphyromonas gingivalis 381 lipopolysaccharide (LPS) definitely exhib ited mitogenic activity in purified B-cells, separated from spleens of LPS-responsive C3H/HeN mice and LPS-non-responsive C3H/HeJ mice by us ing a magnetic cell sorting system. The mitogenic activity induced by P. gingivalis LPS was incompletely inhibited by polymyxin B. P. gingiv alis LPS also induced a higher production of interleukin-6 (IL-6) in s plenic B-cells of C3H/HeN mice as compared with Escherichia coli LPS. Furthermore, P. gingivalis LPS, but:not E. coli LPS, induced definite IL-6 production in C3H/HeJ mice. P. gingivalis LPS increased tyrosine, serine/threonine phosphorylation of proteins with various major induc ed bands in splenic B-cells of both C3H/HeN and C3H/HeJ mice. Addition ally, radioiodinated P. gingivalis LPS, similarly to E. coli LPS, boun d to a 73-kDa protein on C3H/HeJ as well as C3H/HeN B-cells. Thus P. g ingivalis LPS may activate B-cells of C3H/HeJ as well as C3H/HeN mice via the LPS-specific binding protein on the cells.