Lets Talk Cannabinoids……

Cannabinoids and the Immune System: What role in an infectious disease process?

By: Angel Lyn Horner, AP, DOM, DACM

Academic Cannabis Care Certificate from Pacific College of Health and Science

            Our innate immune system functions to help ward off invading foreign agents and pathogens, adapting as needed with a cascade of mechanisms to eliminate those that may harm us. These mechanisms wall off the infectious agents or pathogens by utilizing an inflammatory process to prevent replication, widespread invasion, and potential damage. It is a complex system of T-lymphocytes, B-lymphocytes, CD4+T helper cells, along with monocytes, neutrophils, eosinophils, macrophages, dendric, and natural killer cells, to name a few. In doing so, it responds to hormones, neurotransmitters, proteins, and lipids.  Some cells related to fats or lipids involve the endocannabinoid system (ECS). Namely the CB1 And CB2 receptors.   The activation of the endocannabinoid system may play a significant and determining factor in preventing or developing diseases (Hernandez-Cervantes, Mendez-Diaz, Prospero-Garcia, & Morales-Monto, 2017). Cannabinoid receptors on immune cells may have a modulating effect, and also immunosuppression is possible by their presence (McKallip, Lombard, Martin, Nargarkatti & Nargarkatti, 2002). The endocannabinoid system is directly involved in healing some 100 or more diseases and chronic symptoms (Blesching, 2015).  It is global and broad in its functions and found in all complex species in the animal kingdom, even fish. It also has a global and broad effect in humans (Backes, 2017). 

            The distribution of cannabinoid receptors is throughout the entire human body. There are endogenous cannabinoids, anandamide, and 2-AG found within the human organism. The body makes endogenous cannabinoids on its own to regulate, regain, and help maintain the health of the entire body. There are also cannabinoids from plant or phytocannabinoid origin and also cannabinoids from the synthetic sources that are humanmade (Hernandez-Cervantes, Mendez-Diaz, Prospero-Garcia, & Morales-Monto, 2017). Of some 100 cannabinoids identified in the cannabis plant, two significant cannabinoids to consider are 9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD). As these are the most well-known, we will examine the evidence-based research available on how they may influence the immune system. It is vital to consider because while Cannabis is helpful and is not considered dangerous, it is not harmless in some circumstances (Blesching, 2015).


It is the most well-known active compound found in Cannabis. It is usually also the most abundant. It is considered the “psychoactive component,” which produces a “euphoric high” and responsible for many of the medical and therapeutic effects (Konieczny & Wilson, 2018). 

THC has shown in studies to help with inflammation, analgesic for pain, reduce intraocular pressure, spasticity, and relieve muscle tension.

Selective breeding of cultivars can produce either high THC varieties or low THC varieties. High doses of THC over time may cause tolerance to THC, downregulation of CB receptors may result. A decline in the density of the CB receptors may affect the entire endocannabinoid system (Backes,2017). What have studies shown as regards to the immune system and THC?

Some studies have tested and shown THC in the presence of infections:

  • Harmful to influenza if a person is infected. Viral pathogens in contact with cannabinoids may negatively affect the immune response (Hernandez et al., 2017).
  • It has the potential to increase viral load in those infected with influenza and diminished lymphocyte and macrophage recruitment into the lungs (Buchweitz, Karmus, Williams, Harkema & Kaminski 2008).
  • In SIV (Simian immunodeficiency virus), a retrovirus that causes a disease similar to AIDS and closely related to HIV-2 in humans. Natural killer cells seem to show evidence of being inhibited, increasing mortality (Ongradi, Spector, Horvath, & Friedman 1998).
  • In vitro studies show HSV (Herpes Simplex Virus) may be prone to replication. HCV (Hepatitis C virus) also  was shown to replicate in the presence of cannabinoids that affected glucose metabolism and promote replication (Sun, Yu, Wan, Zhang, Shi & Chen 2014)
  • THC was shown to enhance the release of HSV-2 and found to increase the extracellular virus 100-fold (Cabral, McNerney & Mishkin, 1986).
  • Prenatal mice exposed to THC had lower T-cell production, suggesting that if one uses Cannabis in pregnancy, the unborn child may have a less effective immune system as an adult, an increased chance of infectious disease (Dong, C., Chen, J., Harrington, A., Vinod, K.Y., Hedge, M.L., & Hegde, V. L., 2019)
  • Legionella pnuemophilia symptoms are cough, fever, shortness of breath, body and muscle aches, with a headache. Usually found in water, with patients experiencing symptoms 2-10 days after being exposed.  L. pnuemophilia infected mice treated with THC showed it might suppress TH1, increasing 50% mortality (Klein, T.W. Newton, C., Widen, R., & Friedman, H., 1993). Contributing to immune system malfunction. If CB1 and CB2 receptors become downregulated, an ineffective immune response becomes induced (Klein, T.W., Newton, C., Widen, R., & Friedman, H., 1993).
  • THC is shown to have anti-bacterial effects in some bacteria. It is also able to have the opposite effect depending on the ECS signaling.  Up or downregulating of the CB1 and CB2 receptors. More human studies are needed (Appendino, G., Gibbons, S., Giana, A., Pagani, A., Grassi, G., Stayri, M., Smith, E., & Rahman, M. M., 2008).
  • Parasites in vivo and vitro showed inhibited proliferation when in contact with cannabinoids. THC extracts inhibited parasite growth and were nematicidal in nature. THC may act as a sort of “pesticide” (Hernandez-Cervantes et al., 2017).


      Cannabidiol or CBD is a phytocannabinoid found in the Cannabis Sativa family, commonly referred to as “Hemp.”  Interestingly, recent genetic research into Cannabis is pointing to the fact at some point, ancestral Cannabis may have only produced CBD as the enzyme involved with it predates THC. CBD does not produce “psychoactive” effects. However, mildly relaxing or calming while it also increases alertness. By calming responses to stress and engaging serotonin receptors, it produces the calming effect (Blesching, 2017). As there is a synergy between CBD/THC, it buffers or modulates the THC (Backes, 2017). It is analgesic, anti-inflammatory by producing an impact on mechanisms controlling inflammation, reduces pain, has potent antioxidant activity, and anticonvulsant effects. Neurodegenerative illnesses may prove to be one of the essential uses of CBD, as further studies produce evidence in humans (Blesching, 2017). 

Some studies have shown the effects of CBD on the immune system, and in the presence of infection or viral conditions:

  • A study using growth experiments used cannabidiol (CBD) with bacitracin. It potentiated bacitracin’s effect against S. aureus and Gram-positive bacteria. It did not affect gram-negative bacteria. (Wassmann, C.S., Hojrup, P, & Klitgaard, J.K., 2020).
  • A study in mice injected with pneumococcal meningitis, then given extended administration of cannabidiol-CBD, showed prolonged treatment with CBD demonstrated anti-inflammatory effects and also prevented memory impairment (Barrichello, T., Ceretta, R,., Generoso, J., Moreira, A., Simoes, L., Comim, C., Quevedo, J., Vilela, M., Zuardi, A., Crippa, J. & Teixeira, A., 2010).
  • In mice with cerebral malaria, CBD exhibited neuroprotective effects by decreasing levels of pro-inflammatory cytokines in the prefrontal cortex. It may prove to be helpful as adjunctive therapy in the prevention of neurological consequences and symptoms after cerebral malaria (Campos, A, Brant, F. Miranda, A., Machado, F. & Teixeira, A., 2014).
  • In a gene assay study, it found that CBD has a beneficial role in T cell memory and autoimmune diseases (Kozela, M., Juknat, A., Gao, F., Kaushansky, N., Coppola, G., & Vogel, Z. 2016).
  • Cannabidiol-CBD was shown in vivo to inhibit replication in Hepatitis C , it demonstrated to work against HCV, but not against Hepatitis B (Lowe, H., Toyang, N., Mclaughlin, W. 2017).

One must take a moment and consider the evidence-based literature about the effects of THC on the immune system and infectious disease as most of this testing is in vivo and in vitro, with the use of synthetic THC.  More research is required in human subjects consuming Cannabis either as a medicine or recreationally and the immune effects, especially during a viral or bacterial type of disease process. One needs to tread very carefully so as not to interrupt balance in the body. There may be some instances when an infection either viral or bacterial is present one would consider taking a break from Cannabis, especially cultivars high in THC or any synthetic source of THC so as not to suppress the innate immune system. There are potential deleterious effects involving cannabis use, as there are also beneficial uses of Cannabis and cannabinoids (Cabral, G., Roger, T., Lichtman, A., 2015). This evidence does not affect the impact a low THC/High CBD cultivar or cannabis-based medicine may have on innate immune system function as CBD is known to modulate and buffer THC effects.  More human research in the future is needed. It would be suitable for one to keep a record or a cannabis diary if utilizing Cannabis in any form while an infection, flu, or viral or parasitic condition exists. It would be recommended for practitioners also to make a note of the effects on a patient who has chosen to utilize medical Cannabis for practical case by case studies and comparison. The patient should endeavor to use, organic cultivars, with a third-party analysis and a chemovar for the product they use.  Street cannabis may have synthetic THC added, increasing the effects of THC. As Cannabis is moved more into the medical and treatment realm, human studies using full plant medicine, with the “entourage effect” of the entire plant, with terpenes, is what is needed to fully assess how Cannabis plays a role in helping or hindering immune system function.

Angel Lyn Horner is a licensed Massage therapist and Acupuncturist in the State of Florida.  She is a Graduate of Dragon Rises College of Oriental Medicine, and also a Graduate of Pacific College of Oriental Medicine (now Pacific College of Health and Science) in San Diego having completed the Doctorate of Acupuncture and Chinese Medicine. After graduation from Pacific college she also completed the rigorous Academic Cannabis Care Certificate program.  She utilizes Shen Hammer Pulse in her practice and has had training with the Upledger Institute and The Vodder Schule of Lymphatic Studies in Austria.  She endeavors to help her patients in any way she can, and also recommends a Whole Foods approach to diet, with Traditional Foods.  She enjoys art, cycling, reading and cooking.

Email for inquiries is: angel@angelhorner.com

For Angels lectures on Cannabinoids and Cannabis, and the Endocannabinoid System visit: http://countryside-acupuncture.teachable.com/




Appendino, G., Gibbons, S., Giana, A., Pagani, A., Grassi, G., Stavri, M., Smith, E., & Rahman,

 M.M., (2008). Antibacterial cannabinoids from Cannabis sativa: a structure-activity

 study. Journal of natural products71(8), 1427–1430. https://doi.org/10.1021/np8002673

Barichello, T., Ceretta, R. A., Generoso, J. S., Moreira, A. P., Simões, L. R., Comim, C. M.,

Quevedo, J., Vilela, M. C., Zuardi, A. W., Crippa, J. A., & Teixeira, A. L. (2012). Cannabidiol reduces host immune response and prevents cognitive impairments in Wistar rats submitted to pneumococcal meningitis. European journal of pharmacology697(1-3), 158–164. https://doi.org/10.1016/j.ejphar.2012.09.053

Backes, M. (2017) Cannabis pharmacy: The practical guide to medical marijuana, New York,

 NY. Black Dog & Leventhal.

Blesching, U. (2013) The Cannabis Health Index, Berkley, CA. USA. North Atlantic Books.

Buchweitz J.P., Karmaus P.W., Williams K.J., Harkema J.R., Kaminski N. E., (2008)

Targeted deletion of cannabinoid receptors CB1 and CB2 produced enhanced inflammatory responses to influenza A/PR/8/34 in the absence and presence of delta-9-tetrahydrocannabinol. J Leukoc Biol 2008; 83:785-796.

Cabral G.A., McNerney P.J., Mishkin E.M. (1986) Delta-9-tetrahydrocannabinol enhances the 

release of Herpes simplex virus type 2. J Gen Virol,1986;67(Pt 9):2017-2022.

Cabral, G. A., Rogers, T. J., & Lichtman, A. H. (2015). Turning Over a New Leaf: Cannabinoid

and Endocannabinoid Modulation of Immune Function. Journal of neuroimmune pharmacology: the official journal of the Society on NeuroImmune Pharmacology10(2), 193–203. https://doi.org/10.1007/s11481-015-9615-z

Campos, A. C., Brant, F., Miranda, A. S., Machado, F. S., & Teixeira, A. L. (2015). Cannabidiol 

increases survival and promotes rescue of cognitive function in a murine model of 

cerebral malaria. Neuroscience289, 166–180. 

Dong, C., Chen, J., Harrington, A., Vinod, K. Y., Hegde, M. L., & Hegde, V. L. (2019). 

Cannabinoid exposure during pregnancy and its impact on immune function. Cellular and molecular life sciences: CMLS76(4), 729–743. https://doi.org/10.1007/s00018-018-2955-0

Hernández-Cervantes R., Méndez-Díaz M., Prospéro-García Ó., Morales-Montor, J. (2017).

Immunoregulatory Role of Cannabinoids during Infectious Disease.    

Neuroimmunomodulation, 2017; 24:183-199. DOI: 10.1159/000481824


Konieczny, E. (2018) Healing with CBD, Discover Cannabis Therapeutics for: Anxiety

Depression, Migraines, FibromyalgiaSeizures, Cancer and More. Berkley, CA. Ulysses Press.

Klein, T. W., Newton, C., Widen, R., & Friedman, H. (1993). Delta 9-tetrahydrocannabinol

injection induces cytokine-mediated mortality of mice infected with Legionella pneumophila. The Journal of pharmacology and experimental therapeutics267(2), 635–640.

 Kozela, E., Juknat, A., Gao, F., Kaushansky, N., Coppola, G., & Vogel, Z. (2016). Pathways and 

gene networks mediating the regulatory effects of cannabidiol, a nonpsychoactive cannabinoid, in autoimmune T cells. Journal of neuroinflammation13(1), 136. 


Lowe, H. I., Toyang, N. J., & McLaughlin, W. (2017). Potential of Cannabidiol for the 

Treatment of Viral Hepatitis. Pharmacognosy research9(1), 116–118.


McKallip R.J., Lombard C., Martin B.R., Nagarkatti M., Nagarkatti P. (2002). Delta-(9)-

tetrahydrocannabinol-induced apoptosis in the thymus and spleen as a mechanism of   

Immunosuppression in vitro and in vivo. J Pharmacol Exp Ther 2002; 302:451-465.

Ongrádi J., Specter S., Horváth A., Friedman H. (1998) Combined in vitro effect of marijuana

And Retrovirus on the activity of mouse natural killer cells. Pathol Oncol Res, 1998; 4:191-199.

Wassmann, C. S., Højrup, P., & Klitgaard, J. K., (2020). Cannabidiol is an effective helper

compound in combination with bacitracin to kill Gram-positive bacteria. Scientific reports10(1), 4112. https://doi.org/10.1038/s41598-020-60952-0

Rieder, S.A., Chauhan A., Singh U., Nagarkatti, M., Nargarkatti, P., (2010). Cannabinoid-

induced apoptosis in immune cells as a pathway to immunosuppression. Immunobiology,

 2010: 215:598-605.

Sun L.J., Yu J.W., Wan L., Zhang X.Y., Shi Y.G., Chen M.Y. (2014) Endocannabinoid system

activation contributes to glucose metabolism disorders of hepatocytes and promotes hepatitis C virus replication. Int J Infect Dis, 2014; 23:75-81.

 WHO (2016) Management of substance abuse: Cannabis, World Health Organization; Available

at: www.who.int/substance_abuse/facts/cannabis/en.2016