[ODP-171] Effects of priming with proinflammatory factors on monocyte responses to Fusobacterium nucleatum LPS
Periodontopathic bacterial lipopolysaccharide (LPS) is a major virulent factor to stimulate migrated monocytes to induce proinflammatory responses. Host cells recognize LPS using three platforms, a Toll-like receptor (TLR) 4-associated platform on the cell surface and two cytosolic platforms, an NLRP3-associated platform, and an interferon (IFN)-induced guanylate-binding protein (GBP) platform. Proinflammatory factors can be thought to alter monocytic responsiveness against LPS, but detailed effects are largely unclear. In this study, we primed human monocytic THP-1 cells with IFN-γ, IL-17 or a synthetic bacterial lipopeptide, Pam3CSK4, to investigate responsiveness to LPS by measuring IL-1β production by ELISA and gene expression of three LPS-recognizing platforms by real-time RT-PCR. LPS was extracted from Fusobacterium nucleatum ATCC25586. Pam3CSK4 enhanced responsiveness to LPS through recognition by TLR4 and NLRP3, and induced gene expression of a TLR4-associated platform. IL-17 moderately affected responsiveness to LPS and gene expressions of three platforms. IFN-γ strongly enhanced responsiveness to LPS and gene expression of all of the platforms. Thus, priming with proinflammatory factors differently alters monocyte responsiveness to F. nucleatum LPS and gene expressions of LPS-recognizing platforms. Particularly, IFN-γ showed the most dynamic effects.