Investigation of the immunosuppressive effects of Delta-9-Tetrahydrocannabinol on macrophage function

The macrophage is essential to the integrity of the immune system of multicellular organisms. These cells are involved in immune regulation, are responsible for engulfing and degrading invading pathogens, as well as eliminating cancerous cells. Delta-9- tetrahydrocannabinol (li9-THC), a psychoactive component of marijuana, is known to inhibit macrophage function. Consequently, depression of macrophage activity may have serious consequences for the host immune response. Through the development of a nonradioactive cytotoxicity assay that measures macrophage function, this study explores the effect of cannabinoid exposure on macrophage cytoltyic activity toward tumor target cells. Lipopolysaccharide-activated RA W264. 7 macrophages were exposed to physiologically attainable concentrations of li9-THC. Macrophage-conditioned media was added to L929 tumor target cells, and cell death was assessed through the Cyto Tox 96 assay. No significant differences were observed in cytotoxicity of LPS-activated, drug-treated macrophages