Massing to Defend

On the front line of the immune system’s battle with pathogens, T cells raise the alarm and stimulate the body’s response to danger. They become activated when protein receptors on their surfaces detect an outsider, triggering a suite of cellular processes to eventually destroy the pathogen and promote its detection around the body. T-cell receptors are organised into minute nano-clusters, or protein islands, which, in cultured cells in the laboratory, are known to merge into larger micro-clusters when the cell becomes activated. For the first time, this behaviour has been observed in the cells’ natural environment, in a live animal, thanks to super-resolution microscopy; this image shows bright receptor micro-clusters in a mouse T cell. Researchers hope that a deeper understanding of T-cell activation will reveal ways of interfering with the responses of the immune system, in particular to tone them down in patients with autoimmune diseases.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

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• Image courtesy of The Salk Institute
• The Salk Institute for Biological Studies, La Jolla, CA, USA
• Image copyright held by original authors
• Research published in PNAS, June 2016