Marijuana and its CD4 Receptors: A New HIV Treatment Strategy?

“Drugs that target one of the two cellular receptors stimulated by the active ingredient in marijuana may prove to be effective at blocking a form of HIV that has been linked to faster disease progression during late stages of the infection.

Though the PLoS One research report highlighting these findings—published March 20 by a team of scientists at Mt. Sinai School of Medicine in New York—stops short of concluding that marijuana is one of nature’s best antiretrovirals, the authors suggest that further study of cannabinoids is needed to ultimately discover drugs with both antiviral and symptom-reducing properties.

Marijuana—purchased legally or illegally and either smoked or ingested—along with its synthetic counterpart Marinol (dronabinol) are used by many people living with HIV to manage various symptoms of illness, including pain, depression and weight loss.

The numerous effects of marijuana are the result of chemical interactions between the drug’s active ingredient, tetrahydrocannabinol (THC), and two receptors on a variety of cells in the body: cannabinoid receptor 1 (CR1) and cannabinoid receptor 2 (CR2)…

Using a cannabinoid receptor agonist—a THC-like compound—her team found that activation of CR2 inhibited CXCR4-tropic HIV infection. It did this, not by altering the number of CXCR4 receptors on CD4 cells—this is a therapeutic approach being explored by others—but rather by blocking the receptor’s “signaling process” and interaction with HIV. 

According to the PLoS One report, activation of CR2 blocked the ability of CXCR4-tropic virus to infect other cells by 30 to 60 percent. “This inhibition is pronounced in resting cells,” the researchers explain, “which are a target of CXCR4-tropic HIV.”

“Developing a drug that triggers only [CR2] as an adjunctive treatment to standard antiviral medication may help alleviate the symptoms of late-stage AIDS and prevent the virus from spreading,” said Dr. Costantino in an accompanying news announcement.”

More: http://www.aidsmeds.com/articles/hiv_marijuana_cannabinoids_1667_22119.shtml#.Ub8Pcix9Dhs.twitter

Marijuana Rivals Mainstream Drugs For HIV/AIDS Symptoms – MedicalNewsToday

“Those in the United States living with HIV/AIDS are more likely to use marijuana than those in Kenya, South Africa or Puerto Rica to alleviate their symptoms, according to a new study published in Clinical Nursing Research, published by SAGE. Those who did use marijuana rate it as effective as prescribed or over the counter (OTC) medicines for the majority of common symptoms, once again raising the issue that therapeutic marijuana use merits further study and consideration among policy makers.”

More: http://www.medicalnewstoday.com/releases/151972.php

Compounds That Stimulate The Cannabinoid Type 2 Receptor In White Blood Cells Can Weaken HIV-1 Infection – MedicalNewsToday

“A new use for compounds related in composition to the active ingredient in marijuana may be on the horizon: a new research report published in the Journal of Leukocyte Biology shows that compounds that stimulate the cannabinoid type 2 (CB2) receptor in white blood cells, specifically macrophages, appear to weaken HIV-1 infection. The CB2 receptor is the molecular link through which the pharmaceutical properties of cannabis are manifested. Diminishing HIV-1 infection in this manner might make current anti-viral therapies more effective and provide some protection against certain HIV-1 complications.”

More:  http://www.medicalnewstoday.com/releases/259885.php

Marijuana-Like Compounds Fight AIDS, Study Finds

“Marijuana-like drugs can do more for AIDS patients than simply help them with their nausea or loss of appetite, according to a new study.

Doctor Tipster found new research published in the medical journal PLoS One that suggests marijuana-like compounds actually fight the HIV virus in late-stage AIDS patients.

Researchers told Doctor Tipster that they already know “cannabinoid drugs” like marijuana can have a therapeutic effect in AIDS patients. But they wanted to further understand how they “influence the spread of the virus itself.”

The study found that “cannabinoid receptors” are triggered by marijuana-like compounds and can actually block the spread of the HIV virus throughout the body.”

More: http://www.huffingtonpost.com/2012/03/22/marijuana-fights-aids_n_1373224.html

Human Immunodeficiency Virus In Late-Stage AIDS Inhibited By Marijuana-Like Chemicals – MedicalNewsToday

“Mount Sinai School of Medicine researchers have discovered that marijuana-like chemicals trigger receptors on human immune cells that can directly inhibit a type of human immunodeficiency virus (HIV) found in late-stage AIDS, according to new findings published online in the journal PLoS ONE.

Medical marijuana is prescribed to treat pain, debilitating weight loss and appetite suppression, side effects that are common in advanced AIDS. This is the first study to reveal how the marijuana receptors found on immune cells – called cannabinoid receptors CB1 and CB2 – can influence the spread of the virus. Understanding the effect of these receptors on the virus could help scientists develop new drugs to slow the progression of 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,” said study author Cristina Costantino, PhD, Postdoctoral Fellow in the Department of Pharmacology and Systems Therapeutics at Mount Sinai School of Medicine. “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.”

HIV infects active immune cells that carry the viral receptor CD4, which makes these cells unable to fight off the infection. In order to spread, the virus requires that “resting” immune cells be activated. In advanced AIDS, HIV mutates so it can infect these resting cells, gaining entry into the cell by using a signaling receptor called CXCR4. By treating the cells with a cannabinoid agonist that triggers CB2, Dr. Costantino and the Mount Sinai team found that CB2 blocked the signaling process, and suppressed infection in resting immune cells.

Triggering CB1 causes the drug high associated with marijuana, making it undesirable for physicians to prescribe. The researchers wanted to explore therapies that would target CB2 only. The Mount Sinai team infected healthy immune cells with HIV, then treated them with a chemical that triggers CB2 called an agonist. They found that the drug reduced the infection of the remaining 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,” said Dr. Costantino. Because HIV does not use CXCR4 to enhance immune cell infection in the early stages of infection, CB2 agonists appear to be an effective antiviral drug only in late-stage disease.

As a result of this discovery, the research team led by Benjamin Chen, MD, PhD, Associate Professor of Infectious Diseases, and Lakshmi Devi, PhD, Professor of Pharmacology and Systems Therapeutics at Mount Sinai School of Medicine, plans to develop a mouse model of late-stage AIDS in order to test the efficacy of a drug that triggers CB2 in vivo. In 2009 Dr. Chen was part of a team that captured on video for the first time the transfer of HIV from infected T-cells to uninfected T-cells.”

http://www.medicalnewstoday.com/releases/243183.php

Medicinal Marijuana Effective For Neuropathic Pain In HIV – MedicalNewsToday

“In a double-blind, placebo-controlled clinical trial to assess the impact of smoked medical cannabis, or marijuana, on the neuropathic pain associated with HIV, researchers at the University of California, San Diego School of Medicine found that reported pain relief was greater with cannabis than with a placebo. The study, sponsored by the University of California Center for Medical Cannabis Research (CMCR) based at UC San Diego, will be published on line, in the journal Neuropsychopharmacology.

Led by Ronald J. Ellis, M.D., Ph.D., associate professor of neurosciences at UCSD School of Medicine, the study looked at 28 HIV patients with neuropathic pain not adequately controlled by other pain-relievers, including opiates. They took part in the controlled study as outpatients at the UCSD Medical Center. The proportion of subjects achieving pain reduction of 30 percent or more was greater for those smoking cannabis than those smoking the placebo.

“Neuropathy is a chronic and significant problem in HIV patients as there are few existing treatments that offer adequate pain management to sufferers,” Ellis said. “We found that smoked cannabis was generally well-tolerated and effective when added to the patient’s existing pain medication, resulting in increased pain relief.””

More:  http://www.medicalnewstoday.com/releases/117509.php

Medicinal Marijuana Effective For Neuropathic Pain In HIV, Study Finds – ScienceDaily

“In a double-blind, placebo-controlled clinical trial to assess the impact of smoked medical cannabis, or marijuana, on the neuropathic pain associated with HIV, researchers at the University of California, San Diego School of Medicine found that reported pain relief was greater with cannabis than with a placebo.

The study’s findings are consistent with and extend other recent research supporting the short-term efficacy of cannabis for neuropathic pain,

“This study adds to a growing body of evidence that indicates that cannabis is effective, in the short-term at least, in the management of neuropathic pain,” commented Igor Grant, M.D., professor of psychiatry and director of the CMCR.

Grant noted that this is the fourth CMCR sponsored study to provide convergent evidence that cannabis can help in relieving these types of pain…”

More: http://www.sciencedaily.com/releases/2008/08/080806113135.htm

Medical Marijuana Might Reduce Nerve Pain Among People Living With HIV/AIDS, Study Says – MedicalNewsToday

“Medical marijuana might reduce the pain of peripheral neuropathy, a type of nerve damage, among people living with HIV/AIDS, according to a study published in the Feb. 13 issue of the journal Neurology, the Washington Post reports (Weiss, Washington Post, 2/13). Donald Abrams of the University of California-San Francisco and colleagues examined the effects of smoking medicinal marijuana among people living with HIV/AIDS during a two-year period beginning in May 2003, the San Francisco Chronicle reports.

The results are “evidence, using the gold standard for clinical research, that cannabis has some medical benefits for a condition that can be severely debilitating,” Abrams said.”

More:  http://www.medicalnewstoday.com/releases/62955.php

Synthetic Agents Related To Active Ingredient In Marijuana Weaken HIV Infection – MedicalNewsToday

“HIV, the virus that causes AIDS, is notorious for hiding within certain types of cells, where it reproduces at a slowed rate and eventually gives rise to chronic inflammation, despite drug therapy. But researchers at Temple University School of Medicine’s Department of Pathology and Laboratory Medicine and Center for Substance Abuse Research (CSAR) recently discovered that synthetic anti-inflammatory substances distantly related to the active ingredient of marijuana may be able to take the punch out of HIV while inside one of its major hideouts – immune cells known as macrophages.

The breakthrough comes at a crucial time in the HIV/AIDS pandemic…

To better understand the connection between inflammation and neurocognitive conditions linked to long-term exposure to HIV, Ramirez and colleagues looked specifically at the CB2 receptor, a protein located on the surface of macrophages. CB2 is a binding site for substances called cannabinoids, the primary active compounds of cannabis (marijuana), and it may play a role in blocking inflammation in the CNS. Unlike its counterpart, the CB1 receptor, which is found primarily on neurons in the brain, CB2 does not mediate the psychoactive effects for which cannabis is popularly known.

Ramirez explained that there has been much pharmacological interest in developing agents that selectively target CB2. Ideally, these compounds would help limit chronic inflammatory responses and would not bind to CB1.

The most promising compounds are those derived from THC (tetrahydrocannabinol), the main active substance in cannabis.”

More: http://www.medicalnewstoday.com/releases/259980.php

Synthetic derivatives of THC may weaken HIV-1 infection to enhance antiviral therapies – MedicalXpress

“A new use for compounds related in composition to the active ingredient in marijuana may be on the horizon: a new research report published in the Journal of Leukocyte Biology shows that compounds that stimulate the cannabinoid type 2 (CB2) receptor in white blood cells, specifically macrophages, appear to weaken HIV-1 infection. The CB2 receptor is the molecular link through which the pharmaceutical properties of cannabis are manifested. Diminishing HIV-1 infection in this manner might make current anti-viral therapies more effective and provide some protection against certain HIV-1 complications.

“The synthetic compounds we used in our study may show promise in helping the body fight HIV-1 infection,'” said Yuri Persidsky, M.D., Ph.D., a researcher involved in the work from the Department of Pathology and Laboratory Medicine at Temple University School of Medicine in Philadelphia, PA. “As compounds like these are improved further and made widely available, we will continue to explore their potential to fight other viral diseases that are notoriously difficult to treat.”

To make this discovery, scientists used a cell culture model to infect human macrophages with HIV-1 and added synthetic compounds similar to the active ingredient in marijuana to activate the CB2 receptor. At different times during the infection, samples from the culture were taken to see if the replication of the HIV virus was decreased. The researchers observed diminished HIV growth and a possible protective effect from some HIV-1 complications.

“HIV/AIDS has posed one of the most significant health challenges in modern medicine,” said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. “Recent high profile vaccine failures mean that all options need to be on the table to prevent or treat this devastating infection. Research on the role of cannabinoid type 2 receptors and viral infection may one day allow targeting these receptors to be part of combination therapies that use exploit multiple weaknesses of the virus simultaneously.””

http://medicalxpress.com/news/2013-04-synthetic-derivatives-thc-weaken-hiv-.html