A recent paper by Christian Gawden-Bone from Professor Gillian Griffiths’ laboratory, CIMR, and published in Immunity, has identified the mechanism by which receptor-mediated recognition triggers localised changes in membrane composition to establish a zone for granule secretion. Cytotoxic T lymphocytes are key cells in the immune system, able to recognise and destroy both virally infected and cancerous cells.  The importance of these cells is highlighted by recent advances in immunotherapies that harness their powerful response to combat cancers.   This mechanism, which controls the “opening and closing” of the jaws of the killer, ensures an exquisite co-ordination between the receptor-mediated recognition and secretion.
 
This study used rapid 4D imaging of killer cells with bio-probes to see changes in membrane lipids.  The results identified an important role for PIP5 kinases in regulating the dynamic and localised changes in membrane composition at the immune synapse formed between cytotoxic T cells and their targets.