Captured in 3D: Cancer-killing white blood cells in action

Daily Mail : Natural killer (NK) cells are white blood cells that identify and destroy diseased tissue in the body. Now, Daniel Davis of Imperial College London and colleagues have captured images of NK cells at work and revealed intracellular events that were previously undetectable. The interface between an NK cell and its target is about a hundredth of a millimeter wide; Davis used optical laser tweezers to immobilize the killer cells and their targets so that a high-resolution microscope could resolve the interface between the two. He and his colleagues then watched as protein scaffolding within the NK cells rearranged to form portals in the cell membrane, and granules containing deadly enzymes moved to the opening and then onto the target cell. The granules changed position continuously from initial contact until the target was killed. Learning more about how NK cells identify which tissues to attack could aid in the development of targeted cancer therapies and prevent unwanted tissue destruction by NK cells that occurs in transplant rejection and some autoimmune diseases.