Researchers’ ability to witness processes within white blood cells at the highest resolution to date may ultimately enable targeted killing of tumors, avoidance of transplant rejection, and treatment of some auto-immune diseases. The imaging technique combines optical laser tweezers and super-resolution microscopy. It allowed British scientists to see how a type of blood cell called a natural killer (NK) creates a hole through which it delivers enzyme-filled granules to destroy diseased tissue.1 NK cells identify and kill viruses and tumors—and may play a role in the outcome of bone marrow transplants, says Prof. Daniel Davis from the Department of Life Sciences at Imperial College London, who led the research.
The imaging technique, developed in collaboration with physicists at Imperial and the use of a super-resolution microscope at the University of Oxford, involved immobilizing an NK cell and its target using optical tweezers so that the microscope could capture all the action at the interface between the cells. The contact between an NK cell and its target is only about a hundredth of a millimeter across and the miniscule actin proteins and granules change position continuously over the few minutes from initial contact until the target is killed.
1. A.C.N. Brown et al., PLoS Biol. 9, 9, e1001152 (2011).