Harnessing DNA May Protect Against HIV

A recent study revealed a better understanding of an ancient “error correction” system that helps protect against HIV. The findings lead to superior treatments for HIV infection.

"Through our research, we are gaining a better understanding of this interaction and how we may be able to harness it to help treat HIV in the future," said biochemist and virologist Linda Chelico.

This system is produced through 7 genes: APOBEC3-A, B, C, D, F, G, and H, and although the body uses these enzymes to fight back against HIV by scrambling the DNA to stop it from multiplying, the virus is able to block the enzymes at times.

In a study published in The Journal of Biological Chemistry performed at the University of Saskatchewan (U of S), 2 variations were studied called haplotype II and V, which were found to interfere with HIV but in different ways.

Preventing the Spread of HIV

"One of the interesting bits is that APOBEC3H is more resistant to viral suppression than other APOBEC3s," Chelico said.

The body evolved to suppress errors that were introduced by “junk” or “parasitic” DNA inserted into the human genome over millennia. The APOBEC3 genes and its products are part of this evolved system. A side effect of this is that the system attacks active viruses like HIV.

Researchers are now able to look into enhancing APOBEC3H performance. However, this can prove difficult because of the role in protecting against retrotransposons, a virus-like element.

"We have to be careful when designing an inhibitor," Chelico said. "It can bind the viral protein or bind the human protein, but interfere with function."

Now researchers are exploring the databases for peptides that might work. However, this method has proven to be a slow process.

"We use cell models," Chelico said. "There's never been a hit good enough to progress into animal models. But we're trying an approach that hasn't been done before."