IL-1 TYPE-I RECEPTOR MEDIATES ACUTE-PHASE RESPONSE TO TURPENTINE, BUTNOT LIPOPOLYSACCHARIDE, IN MICE

This study examined the role of the interleukin-1 (IL-1) type I recept or (IL-1RtI) in the acute phase response (APR) to inflammation in mice . Turpentine (100 mu l/mouse) injected subcutaneously induced fever, l ethargy, body weight loss, and anorexia in IL-1RtI wild-type mice. Kno ckout mice lacking the IL-1RtI were resistant to these effects of turp entine, supporting a role for this receptor in the APR to local inflam mation. The intraperitoneal injection of a low (50 mu g/kg) or high (2 .5 mg/kg) dose of lipopolysaccharide (LPS) induced similar APRs in IL- 1RtI wild-type and knockout mice. IL-1RtI knockout mice were resistant to the APR induced by peripherally injected murine IL-1 beta, suggest ing that it is not the interaction of endogenous IL-1 beta with IL-1Rt II that induces an APR to LPS in these mice. We speculate that the abs ence of IL-1RtI in these knockout mice results in the sensitization of other cytokine pathways to mediate the APR to LPS.