For the first time, UCLA AIDS Institute scientists have demonstrated in an animal model that cocaine use dramatically accelerates the spread of HIV infection. Offering a useful tool for examining other HIV-related risk factors, their findings are reported today in the online edition of the Journal of Infectious Diseases.
“Cocaine not only influences risky behaviors,” explained Dr. Gayle C. Baldwin, associate professor of hematology-oncology and a member of the UCLA AIDS Institute. “It also has a direct and profound effect on the AIDS virus.”
Using mice specially bred without immune systems, Baldwin’s team inoculated the animals with human cells, then infected the cells with HIV.Four days following infection, the researchers gave half of the mice daily injections of liquid cocaine. The rest of the mice received a saline placebo.
After 10 days, the UCLA team harvested the human cells from the animals and counted the HIV-infected cells. They made three distinct discoveries that surprised them.
“We saw a 200-fold increase in AIDS viral load in the blood of the animals injected with cocaine compared to those that received the placebo,” said Baldwin. “In only two weeks, the drug radically stimulated the production and spread of HIV.”Secondly, the mice exposed to cocaine possessed more than double the number of HIV-infected cells than the mice injected with saline.
Finally, Baldwin’s team saw a significant nine-fold drop in CD4 T-cells — the immune cells that HIV targets to destroy the immune system — in the cocaine-exposed mice.”The cocaine increased HIV’s efficiency so dramatically that it nearly wiped out the CD4 T-cells,” observed Baldwin. “We found nine times fewer CD4 T-cells in the cocaine-treated mice than in the animals that received the placebo.”
“This means that the cocaine produced a spectacular double outcome,” she added. “Not only did the drug double the number of HIV-infected cells — it produced a nine-fold plunge in the number of T-cells that fight off the virus.”
Baldwin proposes that the mouse model provides a practical method for examining other factors that may influence how the AIDS virus affects the body, such as diet, alcohol and other drugs.”Cocaine doesn’t work in a vacuum,” Baldwin said. “We need a living host to examine its absorption rate in cells and tissue. Studying cells in a test tube won’t allow us to do this.”
The National Institute of Drug Abuse, UCLA AIDS Institute’s Center for AIDS Research and UCLA’s Jonsson Comprehensive Cancer Center provided financial and facility support for the study. Coauthors included Michael Roth, Donald Tashkin, Beth Jamieson, Jerome Zack and Ruth Choi.
—UCLA Health Sciences