Methamphetamine Doubly Dangerous For HIV

17 August 2006
Methamphetamine Doubly Dangerous For HIV
by George Atkinson

University at Buffalo (UB) researchers have uncovered evidence that the drug methamphetamine (also known as crystal meth or speed) increases production of a docking protein that promotes the spread of the HIV virus in infected users. Previous studies had shown that methamphetamine was a risk factor for HIV as it increased risky sexual behaviors, but this new study is the first to define the mechanism by which the drug actually makes the virus more potent.

Methamphetamine gives a boost to the virus by increasing expression of a receptor called DC-SIGN, a virus attachment factor, allowing more of the virus to invade the immune system. "This finding shows that using meth is doubly dangerous," said UB researcher Madhavan P.N. Nair. "Meth reduces inhibitions, thus increasing the likelihood of risky sexual behavior, and, at the same time, allows more virus to get into the cell."

Nair's study, appearing in the Journal of Neuroimmune Pharmacology, focused on dendritic cells, which serve as the first line of defense again pathogens, and two receptors on these cells - HIV binding/attachment receptors (DC-SIGN) and the meth-specific dopamine receptor. Dendritic cells overloaded with virus due to the action of methamphetamine can overwhelm the T cells, the major target of HIV, and disrupt the immune response, promoting HIV infection. "Now that we have identified the target receptor, we can develop ways to block that receptor and decrease the viral spread," explained Nair. "We have to approach this disease from as many different perspectives as possible. If we could prevent the upregulation of the meth-specific dopamine receptor by blocking it, we may be able to prevent the interaction of meth with its specific receptors, thereby inhibiting the virus attachment receptor."

But many questions remain to be answered. "Right now, we don't know how the virus-attachment receptor and meth-specific receptors interact with each other, leading to the progression of HIV disease in meth-using HIV-infected subjects. That is the next question we want to answer," said Nair, adding that "[the] use of dopamine receptor blockers during HIV infection in meth users could be therapeutically beneficial to reduce HIV infection in these high-risk populations."

Based on material from the University at Buffalo