FRIDAY, Jan. 19, 2007 (HealthDay News) -- An immune system gene called interferon stimulated gene 15 (ISG15) helps fight viruses that cause both flu and herpes, U.S. researchers report.
The gene also combats Sindbis virus, prevalent in Africa and Asia, which causes brief colds, fevers and muscle aches, according to a team from the Washington University School of Medicine in St. Louis.
The findings were published online this week in the Proceedings of the National Academy of Sciences.
Earlier tests found that ISG15 was not effective against two kinds of viruses commonly used in research, vesicular stomatitis and lymphocytic choriomeningitis.
In this new study, researchers exposed mice that lacked ISG15 to different kinds of viruses. They found that mice that lacked the gene were more likely than normal mice to be killed by the influenza A and B, herpes simplex and Sindbis viruses.
For example, influenza type A killed 70 percent of the mice that lacked ISG15, compared to 23 percent of mice that had the gene.
Lead author Dr. Deborah Lenschow, an assistant professor of medicine at the school, said of the new findings that "ISG15's first tryout as an antiviral just hadn't tested it against the right opponents."
The gene's ability to fight only certain viruses may be due to a highly specialized approach to combating infection or the result of adaptations by some viruses that enable them to avoid the effects of ISG15, the study authors said.
The American Society for Microbiology has more about viruses.