Ever wonder why some people never seem to get sick but others get stuck in bed? Scientists say it might have to do with special immune cells that are more like jail cells, because they put the flu virus behind bars.
As reported in the journal Nature Medicine, researchers at Washington University in St. Louis discovered that these jail cells, formally known as macrophages, rely on a gene called CCL5 to stay alive even after a virus gets inside them.
When the flu virus infects our normal cells, they have to commit suicide to prevent the virus from spreading. But as Holtzman's team reported, the gene CCL5 blocks this process in macrophages. As a result, macrophages can pick up viruses, hold them inside their membranes, and help clear them from our bodies--without dying themselves.
To figure our how CCL5 works, the researchers created mice without the gene and compared them to mice that had it.
"We find that the mice who were missing it were dying from the viral infection whereas the ones who had it did perfectly fine," says Holtzman.
In a follow-up laboratory study, they compared human cells that had CCL5 to others that did not and saw the same thing. Without CCL5, the cells died.
Holtzman suspects that because we all have different gene combinations, those of us who have more of this gene may be less likely to get sick.