Porphyromonas gingivalis LPS によるB細胞活性化におけるCD14の関与

The functional role of CD14 as well as Toll-like receptors (TLRs) in the Porphyromonas gingivalis (P. gingivalis) LPS-induced activation of B cells was assessed, using CD14-, TLR2- and/or TLR4-overexpressed murine B cells (CH12.LX). After stimulation with P. gingivalis LPS, both CD14- and TLR4-transfected (but not TLR2-transfected) CH12.LX cells showed higher induction of NF-κB activation than a parent vector-transfected cells, suggesting that P. gingivalis LPS could induce B cell activation in a CD14-dependent pathway through TLR4 and NF-κB activation. Furthermore, the control CH12.LX cells proliferated under stimulation with P. gingivalis LPS, accompanied by up-regulations of transforming growth factor (TGF)-β and intereleukin (IL)-6 mRNA. In contrast, the overexpression of CD14 resulted in enhancement of the up-regulations of TGF-β mRNA, but not IL-6 mRNA or proliferative responses to P. gingivalis LPS. These results suggest that P. gingivalis LPS could induce B cell activation both in CD14-dependent and independent pathways. In a CD14-dependent pathway, TGF-β production could be induced upon stimulation with P. gingivalis LPS through TLR4 and NF-κB activation. A CD14-independent pathway could also exist in the P. gingivalis LPS-induced activation of B cells that leads to proliferation and IL-6 production