Cannabis may accentuate the effects of HIV on the brain or perhaps may mitigate them because of its anti-inflammatory properties.
Despite advances in understanding the interconnections of the cells in the brain to cannabinoid exposure, there is little known today about what goes on with HIV infection on the cells in the brain.
The National Institute on Drug Abuse (NIDA), which is part of the National Institutes of Health, has awarded Weill Cornell Medicine a five-year, $11.6 million grant for research on a link between cannabis and the brains of those living with HIV.
Lishomwa Ndhlovu, M.D., Ph.D., professor of immunology in medicine at Weill Cornell Medicine in New York, is leading a five-year study on this topic and will use the grant money to get a better understanding of the issue.
Michael Corley, Ph.D., assistant professor of immunology in medicine at Weill Cornell Medicine and Dionna Whitney Williams, Ph.D., an assistant professor of molecular and comparative pathobiology at Johns Hopkins University School Medicine, are leading the cannabis research.
“We will be using the grant to study the effects cannabis (cannabinoids), including marijuana and compounds derived from it, may have on the brains of those living with HIV,” Ndhlovu said. “Cannabinoids may cause changes within the brain, but it remains unclear yet how the use of cannabis might interact with HIV infection. This support from NIDA will allow us to collect the data we need to explore this relationship.”
The project is the newest component of NIDA’s SCORCH program, which seeks to investigate how substances that might lead to addiction may modify the effects of HIV in the brain, at the level of individual cells.
This is an important study, Ndhlovu shared, because it will allow researchers to better understand the effects of cannabis on the brain in people with HIV and guide better treatments to improve brain health.
“We continue to investigate many assumptions on whether cannabis may exacerbate HIV’s effects on the brain, or whether it may protect against them,” he said.
He noted that although those with the virus can now live longer lifespans, HIV may still cause damage, including to the brain and that up to 50% of those living with HIV may experience declines in cognitive function, particularly in working memory and attention.
Previous studies have discovered that people living with HIV frequently use cannabis recreationally or to treat symptoms related to HIV. As a potentially addictive substance, it too alters the brain, and people with HIV may be at risk for cannabis use disorder.
However, cannabis may also offer benefits for those living with HIV, the researchers assert, as it has an anti-inflammatory effect that researchers speculate could tamp down the chronic, harmful inflammation caused by the virus.
“Findings from our lab and others demonstrate that inflammation can influence cognition in people living with HIV, and we’re aiming to understand whether cannabis can mitigate those effects and how it does this on a molecular level,” Williams said.
In the new study, the researchers will examine the interaction between cannabis and HIV, and will focus on several brain regions, including the hippocampus, where new neurons form in a process critical to learning and memory. Using brain tissue samples collected from human patients after death and from animal models, they will look at gene activity and the mechanisms controlling it within individual cells.
The information this project generates could, over the long-term, aid efforts to better prevent and treat HIV-related cognitive deficits and cannabis use disorder, Ndhlovu said.