By Malorye A. Branca
August 15, 2003 | A major setback in AIDS research early on was the realization that chimpanzees can be infected with HIV but do not develop full-blown AIDS. That made the search for animal models of the disease more complicated. Now, scientists at Evolutionary Genomics hope to capitalize on that fact to find new anti-HIV treatments.
It’s believed that SIV -- HIV’s cousin that infects apes -- has been around for about 2 million years, which has given the animals time to adapt to it. “Chimps have some mechanism for dealing with the virus,” says Walter Messier, chief technology officer at Evolutionary Genomics. According to Messier, nearly 1,000 chimpanzees have been infected with the virus and a few seemed to progress to AIDS, but then all but one recovered.
The blood samples from some of those chimps are available, and Messier and his colleagues are studying them to try and find the proteins that enable chimps to beat HIV. The company was recently awarded a National Science Foundation Phase I Small Business Innovation Research grant to support this project.
Evolutionary Genomics’ Adapted Traits platform allows it to compare genes of closely related species and fish out those genes that have been highly “selected” -- that is, they confer a strong survival advantage. For the HIV study, they will start by looking for genes whose expression patterns change after infection with the virus. The company can then apply its bioinformatics platform to pick out those genes that seem to play important roles in protecting against progression. “That is a vanishingly small number,” Messier says. The trick will be finding them.
Chimps and humans are more than 99 percent identical in their genetic code, and their immune systems are similar. The fact that chimps do not progress to AIDS is one of the rare differences. Looking for genetic differences between the two species should be easier than looking for similarities, since the former are much rarer.
“I look at the genome like a phonebook,” Messier says. “There is a lot of information in it, but you have to use it correctly.” Comparative genomics is widely applied to target identification and validation in the pharmaceutical industry, but the Evolutionary Genomics bioinformatics platform is unique. “It is a rigorous algorithm that takes into account many things,” he says.
Ultimately, the company’s work could lead to the design of small molecules that will mimic the chimps’ natural defenses against AIDS.