ABOVE: A human natural killer cell
FLICKR, NIAID
Scientists have long believed that humans and many other mammals have two types of immune systems: innate and adaptive. The former is driven by natural killer (NK) cells, which attack any cell it identifies as non-self, the latter by B and T cells that form long-term memories of particular antigens they meet so they are more prepared to fight that antigen in the future.
The NK cells are thought to form the first barrier of defense against any incoming pathogen, poking holes in the cells to kill them. Several years ago, researchers discovered that these NK cells may be able to form “memories” of previous antigen exposures and play a role in adaptive immunity, independent of B and T cells—in mice, at least.
Today (May 10), researchers report in Science Immunology the first observation of this NK function in humans, too.
“We were ...
