Marijuana-Like Chemicals Inhibit Human Immunodeficiency Virus (HIV) in Late-State AIDS
Source: Mount Sinai Medical Center
3/20/2012 - Newswise - 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.
Funding for this study was provided to Drs. Chen and Devi by the National Institutes of Health in Bethesda, Maryland.
Dr. Costantino is supported by a National Institutes of Health Clinical and Translational Science Award grant awarded to Mount
Sinai School of Medicine.
About The Mount Sinai Medical Center
The Mount Sinai Medical Center encompasses both The Mount Sinai Hospital and Mount Sinai School of Medicine. Established in 1968, Mount
Sinai School of Medicine is one of the leading medical schools in the United States. The Medical School is noted for innovation in
education, biomedical research, clinical care delivery, and local and global community service. It has more than 3,400 faculty in
32 departments and 14 research institutes, and ranks among the top 20 medical schools both in National Institutes of Health
(NIH) funding and by US News and World Report.
The Mount Sinai Hospital, founded in 1852, is a 1,171-bed tertiary- and quaternary-care teaching facility and one of
the nation's oldest, largest and most-respected voluntary hospitals. In 2011, US News and World Report ranked The Mount Sinai
Hospital 16th on its elite Honor Roll of the nation's top hospitals based on reputation, safety, and other patient-care
factors. Of the top 20 hospitals in the United States, Mount Sinai is one of 12 integrated academic medical centers
whose medical school ranks among the top 20 in NIH funding and US News and World Report and whose hospital is on
the US News and World Report Honor Roll. Nearly 60,000 people were treated at Mount Sinai as inpatients last
year, and approximately 560,000 outpatient visits took place.
For more information, visit http://www.mountsinai.org/.
Find Mount Sinai on:
Facebook: http://www.facebook.com/mountsinainyc
Twitter: @mountsinainyc
YouTube: http://www.youtube.com/mountsinainy
###
Source: http://www.newswise.com/articles/chemicals-in-marijuana-inhibit-human-immunodeficiency-virus-hiv-in-late-state-aids
|
