T cells can sometimes acquire properties of a memory cell without encountering foreign antigen. Miller et al. now show that development of such ‘memory phenotype’ (MP) CD8+ T cells starts with recognition of self-ligands in the thymus, and finishes in peripheral tissues. These cells respond rapidly during infection, and infiltrate tumors, where they express high amounts of PD-1.
Bibliographical noteFunding Information:
This work was supported by National Institutes of Health grant AI39560 (to K.A.H.).
© 2020 Elsevier Ltd
Copyright 2020 Elsevier B.V., All rights reserved.