Neutrophils are white blood cells produced in the bone marrow that can fight infection and inflammation by ingesting harmful microorganisms. But some evidence has suggested that if neutrophils do not die in a wound, they might leave and cause inflammation elsewhere in the body.
Now researchers have found that the cells sometimes return to the bone marrow and self-destruct.
Paul Kubes at the University of Calgary in Canada and his colleagues used fluorescence imaging to track the activity of these cells in mice with damage to the liver. They watched as neutrophils infiltrated wounds and cleaned up DNA fragments, as expected. But 24 hours later, many of the cells had returned to the bone marrow and initiated their own deaths. This round trip could be essential for the resolution of inflammation, the authors say.