Cannabinoids lead to enhanced virulence of the smallpox vaccine (vaccinia) virus.
Indian hemp is used since thousands of years as herbal drug. We found that a single dose of cannabis resin was equally active as Δ9-tetrahydrocannabinol (THC) enhancing severity and duration of symptoms in vaccinia virus infected mice. Cowpox virus did not cause symptomatic disease, but some reduction of specific antibody production was observed in drug treated animals. In vitro cannabis was superior to THC alone at inhibiting mitogen stimulated proliferation of human and mouse spleen cells and peripheral blood mononuclear cells. Also resin sub-fractions other than THC, cannabidiol and cannabinol, recovered also from cigarette smoke, were found inhibitory, suggesting additional involvement of constituents other than psychoactive THC. The immunoregulatory effects must be differentiated from apoptotic effects on spleen cells and lymphocytic mouse cell lines, which were observed with resin and THC but not with cannabidiol or cannabinol. A significant contribution of cytotoxic effects seems unlikely as drug treated lymphocytes were still capable of producing cytokines after T-cell receptor-specific stimulation. Considering a recent case of unusually severe cowpox virus infection in a young drug taker these data confirm a risk of "soft drugs" for acquiring poxvirus infection or enhancing side effects of the smallpox vaccine and perhaps also other live vaccines.
Dept. of Hygiene, Microbiology & Social Medicine, Innsbruck Medical University, Austria. hartwig.huemer@i-med.ac.at
Hartwig P
HP
Huemer
Caroline
C
Lassnig
David
D
Bernhard
Sonja
S
Sturm
Norbert
N
Nowotny
Maria
M
Kitchen
Marion
M
Pavlic
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects; D002186:Cannabinoids / Q000494:pharmacology*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D015608:Cowpox virus / Q000187:drug effects / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D013759:Dronabinol / Q000494:pharmacology; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000037:antagonists & inhibitors; D011817:Rabbits; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D013154:Spleen / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014615:Vaccinia / Q000276:immunology / Q000503:physiopathology; D014616:Vaccinia virus / Q000187:drug effects* / Q000472:pathogenicity*; D014774:Virulence
D002186:Cannabinoids; D016207:Cytokines; D008934:Mitogens; D011948:Receptors, Antigen, T-Cell; D013759:Dronabinol