Involvement of CD14 in LPS-induced liver injury in Propionibacterium acnes-primed mice

The size of granulomas induced by an intraperitoneal administration of Prop ionibacterium acnes in M14M mice 7 days after priming was smaller than that in non-transgenic mice. The number of CD14-positive cells in granulomas wa s fewer in M14M mice than in non-transgenic mice. An LPS challenge induced apoptotic and necrotic changes in hepatocytes in non-transgenic mice but no t in M14M mice. TNF alpha expression was found in monocytic cells in granul omas and Kupffer cells in non-transgenic mice 7 days after priming and was significantly upregulated after LPS injection, whereas the expression was v ery low in these cells in M14M mice. The expression of IFN-gamma, IL-12 and iNOS mRNAs produced by LPS challenge in M14M mice were low compared with t hose in non-transgenic mice. IL-18 mRNA expression was upregulated in P. ac nes-primed nontransgenic mice but not in M14M mice. The production of sCD14 was increased by both P. acnes priming and LPS challenge. The high sCD14 c oncentration may account for lethality without liver damage in M14M mice. T he levels of ELAM-1 mRNA expression in several organs in M14M mice 1-3 h af ter LPS challenge were, however, lower than those in non-transgenic mice.