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.