Medical Research Council - London Institute of Medical Sciences

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Host Guards

T cells of the immune system found to self-activate via interaction of two proteins – B7 and CD28 – displayed on their surface

22 May 2023

Host Guards

Our cell membranes look “like a coastline with lots of coves and bays” says Enfu Hui, lead of a team of scientists who recently found a secret on the shores of this T cell (highlighted with fluorescent stains). A vital step in our immune response, T cells respond when presented with suspicious proteins called antigens found on the outside of pathogens like viruses, or cancers. A protein called B7 triggers another called CD28 on the T cells and they set off in pursuit of the pathogen. The team found that T cells can make their own supply of B7 and, using the folds and crevices on their membranes, bring it into contact with CD28. This 'self-activation' might help scientists design drugs to 'top up' T cells with B7 while on protective missions inside our bodies, or even intercept overzealous T cells, such as those found in auto-immune diseases.

Written by John Ankers

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