UCLA research offers more evidence for possible link between cocaine use and HIV infection

http://www.eurekalert.org/pub_releases/2015-06/uoc--uro061815.php

Public Release: 18-Jun-2015
University of California - Los Angeles Health Sciences

New UCLA research offers further evidence that cocaine use disrupts the immune system, making people who use it more likely to become infected with HIV.

In research published online June 18 in the peer-reviewed journal Scientific Reports, researchers with the UCLA AIDS Institute and Center for AIDS Research used an advanced form of humanized mice -- that is, immunodeficient mice engineered to have a human-like immune system -- to study the effects of cocaine. The findings suggest that using cocaine makes people significantly more susceptible to HIV infection.

'Substance use and abuse is a major issue, especially when it comes to HIV infection,' said Dimitrios Vatakis, the study's senior author and an assistant professor of medicine in the division of hematology/oncology at the David Geffen School of Medicine at UCLA. 'There has been a general attitude, especially in the scientific but also the general community, that risky behavior is the main reason for higher infections. This study shows that under the same transmission conditions, drug exposure enhances infection through a collective of biological changes.'

This study builds on previous research by Vatakis and others on his team showing that a three-day exposure to cocaine appears to make a unique population of immune cells called quiescent CD4 T cells, which are resistant to HIV, more susceptible to infection by stimulating two receptors in the cells, called σ1 and D4. Those findings suggested that cocaine use increases the pool of CD4 T cells in the human body that can become infected by the virus. As a result, the odds for productive infection and a larger viral reservoir increase.

That study, however, was based on in-vitro research -- that is, research done in a petri dish -- which could have skewed the results. The next step was to find the same effect in in-vivo studies -- that is, those conducted with living organisms, such as mice. This is what the current paper has done.

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