Measle's Spread Doesn't Depend on Airways
Instead, certain immune cells may be key, new study shows
FRIDAY, June 20, 2008 (HealthDay News) -- Measles may be one of the most common contagious diseases in the world, but new research shows that it does not spread through one's body via airways and the lungs, as long believed.
Mayo Clinic researchers, whose work was published in the June 20 online edition of The Journal of Clinical Investigation, reported that the measles virus instead spreads through immune system cells called lymphocytes. This new finding may help bring about more effective vaccines for viruses and might even help improve the effectiveness and safety of some cancer therapies, the researchers said.
"It has long been assumed that measles virus infects the airway epithelium [surface lining cells] before infecting immune cells," senior author Roberto Cattaneo, a Mayo Clinic virologist, said in a prepared statement. "But we've shown that replication in the airways is not required, and that a virus replicating only in immune cells causes measles in monkeys."
The team demonstrated its theory by developing a measles virus that cannot enter the airway epithelium. They then infected rhesus monkeys with the virus via the nasal passages.
The monkeys developed a rash and lost weight consistent with measles infection; however, tests showed that while the monkeys' lymph systems were infected, the virus never entered the airway epithelium. Also, the virus did not cross the respiratory epithelium and shed itself on its way out of the lungs.
The measles virus can be reprogrammed to eliminate cancer cells so, in addition to what the research can tell us about measles, the findings may also help doctors and scientists better understand how it can be used to treat cancer, the team said.
The U.S. Centers for Disease Control and Prevention has more about measles.