Humans inhale somewhere between 1,000 and 10 billion mold spores on an average day—let alone on days after catastrophic flooding or a Category 5 hurricane hits, when fungal flare-ups can ensue. Each one of those teeny spores has the potential to embed in our moist, warm lungs. There they can unfurl fungal tendrils that grow like kudzu, invading and engulfing our organs, slowly choking the life out of us as mold bursts from our seams.
Luckily, our immune systems keep most of us safe from such an agonizing death. But they don’t pull it off with a bloody, fungal massacre each day—no, they use a much more dignified defense, according to a new study.
In the lung, immune cells get cozy with invading fungal spores, then trick them into pushing their own self-destruct buttons, researchers reported Thursday in Science. When the researchers used genetic engineering to override the spore’s self-destruct system, immune cells in mice were powerless to stop the fungal infiltration.