WEDNESDAY, Sept. 25, 2002 (HealthDayNews) -- An extremely rare genetic disorder has provided researchers with new knowledge about the human immune system and ways of fighting infection, says a study in tomorrow's issue of Nature.
Only two children, a brother and a sister, have the genetic condition. Through them, scientists at the National Institute of Allergy and Infectious Diseases (NIAID) and colleagues discovered something about the human immune system that applies to everyone.
They found that an enzyme, caspase-8, which helps trigger cell death, also helps activate immune system cells to fight infections. Their finding could help develop new drugs to treat immune system disorders.
"Previously, no one had ever shown that caspase-8 played this other role," says senior study author Dr. Michael Lenardo, of NIAID's immunology laboratory.
"Caspase-8 deficiencies might explain why some people don't respond as well as others to vaccines, or why some people's immune systems don't fight off infections as well as others. Caspase-8 might be a useful target for a new class of anti-inflammatory or immunosuppressive therapies," Lenardo says.
The NIAIDS scientists made their discovery after being called to examine a brother and sister with a puzzling immune system disorder. They suffered from recurrent viral infections and didn't respond well to vaccines.
"These kids were very sick, and their doctors were stymied about the cause of their illness and how to treat it," Lenardo says.
It took several years for the NIAIDS scientists to find that the children's problems were linked to a lack of caspase-8.
More information
The National Institute of Allergy and Infectious Diseases has more on the human immune system.
