Delta-9-tetrahydrocannabinol inhibits macrophage protein expression in response to bacterial immunomodulators

The objective of this study was to determine the effect of delta-9-tetrahydrocannabinol (delta-9-THC), the major psychoactive component of marihuana, on macrophage protein expression in response to bacterial immunomodulators. Peritoneal macrophages of (B6C3)F1 mice receiving Propionibacterium acnes exhibited a novel protein profile when compared to resident or vehicle-treated macrophages. In contrast, macrophages from mice treated with P. acnes in concert with delta-9-THC exhibited profiles for which the majority of protein species reverted to patterns seen in profiles of resident or vehicle-treated macrophages. Treatment of the murine macrophage line P388D1 (DBA/2) in vitro with bacterial lipopolysaccharide (LPS) resulted in the hyperproduction of a subset of proteins ranging from 73 to 18 kD relative molecular weight. Coexposure of the P388D1 cells to LPS and 10(-7) M to 10(-5) M delta-9-THC resulted in a dose-related depletion of these proteins. These results suggest that delta-9-THC suppresses the expression of proteins elicited by macrophage bacterial immunomodulators.