Medical Research Council - London Institute of Medical Sciences

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Watching immune cells weigh-up threats before they attack

28 May 2019

Bullet Time

Trained assassins swarm through our body, on the lookout for any unwelcome invaders. These specialised cells of our immune system are on the constant lookout for trouble, and have lethal techniques to see it off, but how do they make sure they only pick a fight with dangerous invaders, not our own healthy cells or helpful members of our personal microbiome? Keen to understand the details of how our immune system works so they can exploit it for new treatments such as cancer immunotherapy, researchers filmed one particular part: the membrane attack complex (MAC). The researchers watched as MACs assemble and fire deadly bullet holes in the skins of threatening cells over time (shown in the video), and saw that the process pauses, allowing potential victims one last chance to prove they're harmless by displaying a particular protein, before striking a killing blow to those that can’t prove their allegiance.

Written by Anthony Lewis

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