AIDS research has been hampered because mice, which usually provide an excellent model for studying human disease, cannot be infected with HIV. Now, researchers have created a modified HIV strain that can infect mice.

Dr. Mary Jane Potash, at Columbia University Medical Center in New York, and colleagues swapped the HIV gene that encodes a surface protein called gp120, which recognizes human cells, with a gene for gp80 from a mouse leukemia virus.

 

The resulting “chimeric” virus, dubbed EcoHIV, infects about 75 percent of mice tested - an efficiency that is comparable to that of HIV in humans, the team report in the Proceedings of the National Academy of Sciences.

EcoHIV was observed in immune cells and white blood cells in the spleen, abdominal cavity, and the brain.

“In some mice the viral (level) is going up 5 months after infection, which means there is active replication going on,” Potash told Reuters Health. “And since we can detect virus in a week, when we have drugs to test we can potentially see an effect in vivo as fast as you can in culture.”

As for the development of an AIDS vaccine, Potash continued, “If there’s one place we ought to be able to discover how to get a good response it’s in a mouse where you have live virus infection that you might be able to control.”

She added, “One of the greatest advantages of this model is that the virus, at least in culture, does not infect human cells, so it ought to be a lot safer to use than HIV.”

SOURCE: Proceedings of the National Academy of Sciences, online February 22, 2005.