Resumen de T cell receptor signalling in Yò cell development: strength isn't everything

Gleb Turchinovich, Daniel J. Pennington

• Yò cells have been conserved across 450 million years of evolution, from which they share the distinction, alongside alfa beta T cells and B cells, of forming antigen receptors by somatic gene recombination. However, much about these cells remains unclear. Indeed, although Yò cells display �innate-like� characteristics exemplified by rapid tissue-localised responses to stress-associated stimuli, their huge capacity for T cell receptor (TCR)Yò diversity also suggests �adaptive-like� potential. Clarity requires a better understanding of TCRYò itself, not only through identification of TCR ligands, but also by correlating thymic TCRYò signalling with commitment to Yò effector fates. Here, we propose that thymic TCRYò-ligand engagement versus ligand-independent signalling differentially imprints innate-like versus adaptive-like characteristics on developing Yò cells, which fundamentally dictate their peripheral effector properties.