Herpes Drug Could Be Model For Future HIV Treatments

The anti-herpes drug acyclovir has been found to slow down HIV infection, researchers report in this week's JBC. This beneficial effect does pose a risk though, as HIV-infected cells treated with acyclovir promote the emergence of drug resistant strains of the virus.

HIV and herpes (HSV) are two of the most common sexually transmitted diseases worldwide, and individuals frequently become co-infected with both. In such cases, the two viruses interact with each other; the presence of HIV often results in more frequent HSV lesion outbreaks, while HSV can speed up the progression of HIV to AIDS.

Considering their interaction, recent studies showing that acyclovir treatment could reduce HIV viral load in co-infected patients were not surprising, and attributed to an indirect effect of HSV suppression. However, Moira McMahon and colleagues at Johns Hopkins decided to look whether the effects on HIV might be direct.

However, acyclovir treatment had some unexpected results; as early as five days after initial infection and subsequent treatment with acyclovir, a mutant (and potentially drug resistant) version of HIV appeared in the cells, and within 94 days spread to comprise over 90% of the viral population. The tests were conducted in the laboratories of Johns Hopkins.

What this means, the authors note, is that acyclovir could be a great model for designing future HIV treatments, but also could be a risky drug if given to HSV patients co-infected with HIV by potentially promoting cross-resistance to current treatments. Courtesy American Society for Biochemistry and Molecular Biology and Johns Hopkins University.