Killing the Killer

Dateline: 02/18/99

A newly developed protease inhibitor is effective against previously drug resistant strains of HIV. The inhibitor was able to effectively stop HIV.

By studying HIV proteases, scientists found that the proteases mutate quickly so that current drugs are not able to bind to the active site, thus rendering the drugs ineffective. The proteases seem to reduce the size of the binding site so that the drugs no longer fit.

Taking that work a step further, researchers hypothesized that a small inhibitor might be more effective. Drugs were designed to bind to a smaller part of the active site, thus circumventing the reduction in size of the binding sites. No resistant strains were found during the one-year test period. Researchers were optimistic that these results could lead to the development of drugs that will take much longer to resist.

Almost all current anti-HIV drugs work by binding to an enzyme that the virus needs to reproduce. This binding changes the nature of a key enzyme and disrupts the reproduction process. The problem lies in the virus's ability to become quickly resistant to a particular drug. The process can be as rapid as a matter of days or weeks.

Current therapies are most effective when several drugs are combined in a "cocktail" which doctors hope will overwhelm the virus. Even with this cocktail, the virus still develops some drug resistance over time.

Scientists hope to continue these studies, concentrating on the inhibitor effects over time. They are optimistic that the virus may not be able to adapt as quickly to these techniques.

Potentially, these techniques could also be used to treat FIV or feline immunodeficiency virus. Because FIV is notorious for having a small binding site on proteases, the new inhibitors may work well.

What do you think? How long will it take before there is a long-term effective treatment for HIV/AIDS? Is a cure imminent or is focusing on prevention the best method? Come over to the Biology Forum and share your thoughts, opinions, and feelings.

For related information, see:

• New Protease Inhibitor Could Thwart AIDS Resistance To Current Drugs
  News release from Science Daily.