New drug treats West Nile virus in mice

NEW YORK (Reuters Health) - Continuous administration of a drug dubbed AMD3100 improves survival of mice infected with West Nile virus, scientists at Washington University School of Medicine have found.

The drug allows T cells of the immune system to cross the blood-brain barrier to combat the virus infecting the brain, Dr. Robyn S. Klein and associates explain in their report in the Proceedings of the National Academy of Sciences.

The St. Louis-based team found that, compared with placebo treatment, AMD3100 improved survival in mice infected with West Nile virus by 50 percent.

After 8 days of treatment, AMD3100-treated mice showed a 1000-fold decrease in infectious virus within the brain.

The researchers conclude that manipulation of the immune response in this way "can promote an early increase in immune cell trafficking that controls viral infection, ultimately leading to a rapid dampening of inflammation that can have pathologic consequences."

SOURCE: Proceedings of the National Academy of Sciences, online August 4, 2008.