DIFFERING SIGNAL REQUIREMENTS FOR THE ACTIVATION OF MACROPHAGES FROM C3H HEJ AND C3H/OUJ MICE/

Endotoxin-associated protein (EP) from Salmonella typhi stimulated the release of prostaglandin E2 (PGE2), interleukin-1 (lL-1), and interfe ron (IFN) activity in macrophages from the lipopolysaccharide (LPS) re sponder C3H/OuJ mouse strain. However, only PGE2 and IL-1 were stimula ted by EP in macrophages from the LPS nonresponder C3H/HeJ mouse strai n. LPS stimulated the release of PGE2, IL-1 and IFN activity in C3H/Ou J macrophages, but not in C3H/HeJ macrophages. The protein kinase C (P KC) activator phorbol myristic acid (PMA) stimulated PGE2 production i n both strains but not IL-1 production, suggesting that signalling pat hways other than PKC may be involved in IL-1 production. The calcium i onophore ionomycin stimulated PGE2 production in C3H/OuJ but not C3H/H eJ macrophages, suggesting a defective calcium-related pathway in the C3H/HeJ macrophages as compared to the C3H/OuJ cells.