A new twist on HIV vaccines shows results in monkeys, study says

An effective vaccine for HIV has eluded researchers for several decades, due to the pathogen's infamous shape-shifting abilities.

Even though researchers have identified certain broadly neutralizing antibodies that can conquer multiple strains of the human immunodeficiency virus, many strains of rapidly mutating HIV remain resistant to the these super antibodies.

In recent years however,researches have proposed a new method of battling the virus that involves gene therapy.

Instead of using a vaccine to stimulate the body's own immune system, so that it produces HIV antibodies, scientists are bypassing the immune system entirely.

In experiments involving rats and monkeys, the researchers have used non-life-threatening viruses to alter the animals' genome so that its cells produce designer molecules capable of neutralizing HIV.

In a paper published Wednesday in the journal Nature, a team of researchers said they had used the technique to protect rhesus macaques from repeated intravenous injections of a SHIV, a combination of simian immunodeficiency virus and humanimmunodeficiency virus.

The technique, researchers said, "can function like an effective HIV-1 vaccine." (HIV-1 is the main family of the virus, and accounts for most infections worldwide.)

When HIV enters the body, it attacks specific immune cells. As the virus copies itself over and over, and kills more and more host cells, the immune system grows progressively weaker. If left untreated, this progressive weakening will give rise to AIDS.

In most cases, the HIV virus begins its attack by latching onto two separate protein structures on the surface of its target white blood cells. One of these structures is called CD4, and the other is called CCR5.

In the Nature study, researchers set out to engineer an antibody-like molecule that would mimic both of these proteins, so that it would act as decoy of sorts for the virus. Instead of latching onto a host cell, HIV would latch onto a specially enhanced protein molecule, or eCD4-Ig, that was released by the cell.

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A new twist on HIV vaccines shows results in monkeys, study says