Wait, our immune systems can turn against us?
THE IMMUNE SYSTEM, WHICH IS MADE UP OF white blood cells, the spleen, and bone marrow, acts like an invisible cavalry in our bodies. When it spots an intruder like a virus, it dispatches Y-shaped antibody proteins that lock on to a particular baddie to mark it for attack. But the strategy isn’t exactly perfect.
Sometimes the microscopic defense revolts, and doctors are still baffled as to why. What they do know, though, is that when things go haywire, our internal fighters can destroy healthy cells and organs, causing lupus and other illnesses in at least 20 million Americans. Daniel Davis, a professor of immunology at the University of Manchester, says it’s possible that antibodies end up targeting the wrong bits because certain dastardly germs can resemble human proteins.
In other cases invaders might overwhelm the first line of attacking white blood cells, triggering a harmful overreaction. As long as our immune systems are constantly doing battle, they’re liable to mistake some friends for foes in the trenches.