THAT red, painful swelling around a wound is the body鈥檚 way of fighting infection. But too much inflammation can be bad news. It can kill flu victims, and chronic inflammation has been implicated in a range of illnesses, from eczema to Alzheimer鈥檚.
Now Charles Serhan and his colleagues at Harvard University have discovered how inflammation normally turns itself off once the crisis has passed. At the site of wound, molecules called chemokines rally white blood cells, or leukocytes, to fight infection. The leucocytes emit powerful germ-killing chemicals 鈥� and then commit suicide.
Serhan discovered that even when the leucocytes die they continue to soak up the chemokines that attracted them there in the first place. This feedback prevents too many white blood cells congregating in a wound, where their germicide could damage surrounding tissue.
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These self-destructing leukocytes are 鈥渢he ultimate scavenging entity鈥�, the team writes in Nature Immunology (DOI: 10.1038/ni13920). They hope a better understanding of this 鈥渙ff switch鈥� might enable them to fight disease by turning off dangerous inflammatory reactions.
