Soon, pill to prevent and cure HIV

A team of scientists has created a potential long-acting HIV therapeutic.

New molecule, which shows promise for controlling HIV without daily antiretroviral drugs, foils a wider range of HIV strains in the laboratory than any known broadly neutralizing HIV antibody and is more powerful than some of the most potent of these antibodies.

In addition, the molecule safely protected monkeys from infection with an HIV-like virus during a 40-week study period. Together, the data suggest that the molecule could, with further research, be used to subdue HIV in humans.

The authors at National Institute Of Allergy And Infectious Diseases note that the molecule potentially could be used as both a preventative drug and as a treatment.

Researcher Anthony S. Fauci said that this innovative research holds promise for moving us toward two important goals: achieving long-term protection from HIV infection, and putting HIV into sustained remission in chronically infected people.

The new molecule is called eCD4-Ig and works by tightly binding to two unchanging sites on the surface of HIV that the virus uses to attach to receptors on cells called CD4 and CCR5. Typically, when HIV attaches to these receptors, it unlocks a door to the cell and gets inside. However, when eCD4-Ig binds to HIV, it effectively takes away the viru's key, locking it out of the cell and preventing it from multiplying.

To make eCD4-Ig, the scientists took an antibody-like molecule that latches onto the CD4 binding site but does not neutralize HIV on its own, and fused it with a short protein fragment that attaches tightly to the CCR5 binding site. Together, these two arms of the molecule are much more effective at stopping HIV than either one is alone.

Researcher Michael Farzan said that their molecule appears to be the most potent and broadest inhibitor of HIV entry so far described in a preclinical study and if one could inject either eCD4-Ig or our gene therapy tool into people with HIV infection, it might control HIV for extended periods in the absence of antiretroviral drugs. Further research will help illuminate the promise of these approaches.

The new findings appear in the journal Nature.