Effects of Marijuana on Macrophage Function
Delta-9-tetrahydrocannabinol (THC) is the major psychoactive component of marijuana. This substance has been shown to elicit a spectrum of effects in vitro and in experimental animals. The drug decreases host resistance to viruses (1–3) and bacteria (1), alters cellular morphology and function (4–10), and inhibits RNA, DNA, and protein synthesis (11–13). These effects on macromolecular synthesis suggest that THC may elicit its immunosuppressive effects by altering the expression and/or secretion of effector molecules. Macrophages play a central role in the regulation of immune responsiveness. These cells act “early” in a primary viral infection by exerting intrinsic and extrinsic antiviral activities (17,18), and play a central role in host resistance by their capacity to produce interferons and monokines and to function as antigen-presenting cells (19,20). Responsive macrophages undergo a multi-step process to full activation (21–23). Each of these stages in the activation process is associated with discrete functional activities. Responsive macrophages ingest and degrade bacteria and viruses. A hallmark of fully activated macrophages, on the other hand, is their capacity to destroy tumor cells and virus-infected cells. These effector functions are induced in response to a variety of signals, including bacteria and bacterial cell wall products (i.e., lipopolysaccharide). The sequential development of responsive macrophages to full activation is accompanied by the expression of defined, quantifiable protein markers which reflect the potential of the macrophage to execute different functional activities.
KeywordsPeritoneal Macrophage VERO Cell Tumoricidal Activity Marijuana Smoke Macromolecular Synthesis
Unable to display preview. Download preview PDF.
- 4.W. Pereira, T. McLaughlin, M. T. Baranano, S. Dudley, D. O’Connell, M. Cutting, and G. Huber, The acute effect of marijuana smoke on antibacterial and defense mechanisms of lung, Clin. Res. 23:A351 (1975).Google Scholar
- 6.A. Chari-Bitron, Effect of 11tetrahydrocannabinol on red blood cell membranes and alveolar macrophages, in: “Marijuana: Chemistry, Biochemistry, and Cellular Effects,” G. G. Nahas, ed., Springer-Verlag, New York (1976).Google Scholar
- 7.C. R. McCarthy, M. B. Cutting, G. A. Simmons, W. Pereira, R. Laguarda, and G. L. Huber, The effect of marijuana on the in vitro function of pulmonary alveolar macrophages, in: “Pharmacology of Marijuana,” M. C. Braude and S. Szara, eds., Vol. 1, Raven Press, New York (1976).Google Scholar
- 9.G. L. Huber, J. W. Shea, W. C. Hinds, V. E. Pochay, and R. T. Weker, M. W. First, and G. C. Sornberger, The gas phase of marijuana smoke and intra-pulmonary bacterial defenses, Bull. Eur. Physiopathol. Resp. 15:491 (1979).Google Scholar
- 12.R. D. Blevins and J. D. Regan, Delta-9-tetrahydrocannabinol: Effect on macromolecular synthesis in human and other mammalian cells, Arch. Toxicol. 44:133 (1980).Google Scholar
- 24.C. Hamelin, A. Chagnon, and M. Farwel, Identification of atypical strains of herpes simplex virus using a simplified DNA finger printing method, Micro biol. Immunol. 28:723 (1984).Google Scholar
- 25.M. F. Ackerman, R. Mark, P. R. Chakraborty, and P. S. Morahan, Effects of Propionibacterium acnes immunomodulation: Inhibition of macrophage activation and antitumor activity, J. Leukocyte Biol. 40:549 (1986).Google Scholar
- 32.D. R. Wing, J. T. A. Leuschner, G. A. Brent, D. J. Harvey, and W. D. M. Paton, Quantification of in vivo membrane-associated delta-1-tetrahydrocannabinol and its effect on membrane fluidity, in:“Proceedings of the 9th International Congress of Pharmacology:3rd satellite symposium on cannabis,” D. J. Harvey, ed., IRL Press, Oxford (1985).Google Scholar
- 39.M. P. Holsapple, P. J. McNerney, E. M. Mishkin, and G. A. Cabral, In vivo and in vitro effects of delta-9-tetrahydrocannabinol on immune responsiveness and resistance to vaginal herpes simplex virus II (HSV2) infection by B6C3F1 mice, in: Proceedings of the Oxford Symposium on Cannabis, IRL Press, Oxford (1985).Google Scholar