A microscope powerful enough to capture a single molecule has taken the clearest picture yet of the immune system in action.
The technique, called superresolution single-molecule fluorescence microscopy, recently helped scientists at the University of Manchester in England track natural killer (NK) cells, which help destroy cancer and viruses.
NK cells have receptors that are clustered together at their surface, and these receptors target proteins on another cell’s surface to tell whether the contacting cell is diseased or healthy. When the NK cell is activated, the receptor clusters change in size and density, which could help NK cells recognize and eliminate infected cells — but spare healthy ones — next time around.
[This article originally appeared in print as "Immune Attack Up Close."]