According to a new study published in the journal PloS ONE, researchers from Mount Sinai School of Medicine discovered that marijuana-like compounds can inhibit the multiplication of human immunodeficiency virus (HIV) in late-stage AIDS by acting on viral receptors.
Medical marijuana is prescribed in diseases which are accompanied by appetite suppression or by sever weight loss also for management of chronic pain, symptoms that are usually present in late stages of AIDS. Through this study, scientists found out that on the surface of immune cells a type of receptors called cannabinoid receptors, CB1 and CB2, are triggered by marijuana-like compounds and can inhibit the dissemination of human immunodeficiency virus throughout the body. It is very important for scientists to understand what are the effects of activated CB1 and CB2 receptors, because in the future they hope to be able to develop new drugs that can slow the progression of HIV infection to AIDS.
"We knew that cannabinoid drugs like marijuana can have a therapeutic effect in AIDS patients, but did not understand how they influence the spread of the virus itself. We wanted to explore cannabinoid receptors as a target for pharmaceutical interventions that treat the symptoms of late-stage AIDS and prevent further progression of the disease without the undesirable side effects of medical marijuana.", leader of the study said.
When it enters the body, the HIV virus infects T helper lymphocytes (cells that are expressing CD4 receptor), making them ineffective in fighting infection. In order to disseminate, human immunodeficiency virus needs that inactive T helper lymphocytes to be activated by the immune system. In late-stages of AIDS, in viral genome mutations are produced in order to penetrate inactive T helper lymphocytes, action that is mediated by a signaling receptor called CXCR4. By using marijuana-like chemicals, cannabinoid receptor agonists which are able to activate CB2 receptors, researchers observed that activated CB2 receptor can block CXCR4 receptor, thus suppressing the spread of viral infection to inactive T helper lymphocytes.
By triggering CB1 receptors it was observed that marijuana-like compounds have the same effects as marijuana, causing unwanted side effects. Scientists want to develop marijuana-like compounds that are only triggering CB2 receptors, because this CB2 agonist reduce the infection of inactive T helper cells.
"Developing a drug that triggers only CB2 as an adjunctive treatment to standard antiviral medication may help alleviate the symptoms of late-stage AIDS and prevent the virus from spreading," researchers added.
It has been observed that HIV infects inactive T helper lymphocytes by using CXCR4 receptor only in advanced stages of AIDS, so marijuana-like compounds seem to be effective only in advanced stages of the disease.
Due to the fact that the results of this study were very promising in vitro, researchers want to develop a lab mouse model with late-stage of AIDS to test the effectiveness of marijuana-like compounds that are triggering CB2 receptors in vivo.