NATURAL KILLER CELLS

Scientists have discovered how immune system cells called Natural Killer cells function to destroy diseased cells, while leaving normal cells alone. Natural Killer cells are a type of white blood cell that contain granules with chemicals inside. When they come across a tumor cell or a cell that is infected by a pathogen, they surround and destroy the diseased cell by releasing the chemicals. These chemicals break-down the cell membrane of the diseased cell, ultimately causing it to burst. Using high speed microscopy imaging techniques, the researchers were able to observe how Natural Killer cells distinguish a healthy cell from a diseased one. Receptors on the surface of the killer cell interact with proteins on any cell it comes in contact with. If the cell triggers more of the Natural Killer cell's activator receptors, the killing mechanism will be turned on. If the cell however triggers more inhibitor receptors, the Natural Killer cell will leave the cell alone.