How a harmless virus called GB Virus type C (GBV-C) protects against HIV infection is now better understood. Researchers at the Department of Veterans Affairs (VA) Iowa City Health Care System and the University of Iowa have identified a protein segment that strongly inhibits HIV from growing in cell models.

The team found that an 85-amino acid segment within a GBV-C viral protein called NS5A greatly slows down HIV from replicating in cells grown in labs. The study results will appear online this week in the Proceedings of the National Academy of Sciences.

The finding builds on earlier VA and UI work showing that people with HIV who also are infected GBV-C live longer than those infected only with HIV, said Jinhua Xiang, M.D., a VA research health scientific specialist, UI researcher and the current study's principal author.

GBV-C and its role in HIV infection have been studied for nearly a decade by Xiang, along with another study author Jack Stapleton, M.D., staff physician and researcher at the VA Iowa City Health Care System and professor of internal medicine at the UI Roy J. and Lucille A. Carver College of Medicine.

"Identifying a specific protein made by GBV-C that inhibits HIV growth in cell culture strengthens the argument that GBV-C is responsible for the prolonged survival observed in several studies of HIV-positive people," Xiang said. "Understanding how the protein works may allow us to develop target-specific therapies that can mimic these effects and inhibit HIV.

"Potentially these novel therapies would have certain advantages over current drugs, as the newer therapies would target the cell in which HIV can replicate and not the virus directly. Therefore, HIV should have more difficulty developing resistance to the effects of this protein," Xiang added.

Xiang previously discovered that GBV-C grows in the same type of white blood cells, CD4 T-cells, that HIV grows in and ultimately destro
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Contact: Becky Soglin
becky-soglin@uiowa.edu
319-335-6660
University of Iowa
9-Oct-2006