The human immune system includes about a dozen major cell types with specialized roles in the body’s defenses. They serve as sentries, identify threats, mobilize troops, capture and transport invaders, interrogate and kill those deemed dangerous and clear the battlefield of casualties. This intricate command-and-control system is what enables us to fend off most of the dangerous bacteria and viruses that come our way.
But in patients who suffer from inflammatory bowel disease (IBD), the immune system itself becomes the enemy. Even when the body faces no threat, immune cells called “helper T cells” take up arms, resulting in a kind of perpetual warfare that — far from being helpful — causes collateral damage to the gut.
“The system goes into overdrive,” says Yu Hui Kang, an immunology graduate student at Harvard Medical School and a researcher at Boston Children’s Hospital. “These cells have gone too far, and they can’t stop.”
Now Kang and colleagues in the lab of Scott Snapper, MD, PhD, director of Boston Children’s Inflammatory Bowel Disease Center, may have found a way to turn the tables on the immune system by recruiting its own “natural killer” cells to wipe out the harmful T cells. Though clinical applications are years away, the work suggests new avenues for developing treatments for the debilitating disease.…