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

Abstract

The size of granulomas induced by an intraperitoneal administration of Propionibacterium acnes in M14M mice 7 days after priming was smaller than that in non-transgenic mice. The number of CD14-positive cells in granulomas was fewer in M14M mice than in non-transgenic mice. An LPS challenge induced apoptotic and necrotic changes in hepatocytes in non-transgenic mice but not in M14M mice. TNFα expression was found in monocytic cells in granulomas and Kupffer cells in non-transgenic mice 7 days after priming and was significantly upregulated after LPS injection, whereas the expression was very low in these cells in M14M mice. The expression of IFN-γ, IL-12 and iNOS mRNAs produced by LPS challenge in M14M mice were low compared with those in non-transgenic mice. IL-18 mRNA expression was upregulated in P. acnes-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 concentration may account for lethality without liver damage in M14M mice. The levels of ELAM-1 mRNA expression in several organs in M14M mice 1—3 h after LPS challenge were, however, lower than those in non-transgenic mice.