Constantly under surveillance for signs of trouble, diseased cells in our body get sent to their death at the hand of our immune system by T-cells. The T-cell pictured (left), with CD8 protein that distinguishes it highlighted in white, is locking on to its target cell (both nuclei stained blue) and injecting it with a cluster of toxic packages. These lytic granules (here labelled red) are precisely positioned inside the T-cell by the centrosome (where the cell’s skeletal elements are made). Attaching to the inside of the T-cell’s membrane the cell’s skeletal fibres pull granules towards it. Knocking-out a gene called Lck, stops the centrosome docking on the membrane (right-hand image) and lytic granules spill out into the fluid between cells. Mapping the labyrinth of molecular pathways that control centrosome docking provides scientists with more understanding of how cells of the immune system work in health and disease.
Written by Emma Stoye
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences (the new name for the MRC Clinical Sciences Centre) the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.