Central memory T cells (TCM cells) in the lymph nodes (LNs) and resident memory T cells (TRM cells) in peripheral tissues have distinct roles in protective immunity. In Nature Medicine, Kupper and colleagues use various models of skin immunization in mice and humans and high-throughput sequencing of the gene encoding the T cell antigen receptor β-chain (TCRβ) to investigate the clonal origin of TCM cells and TRM cells. After immunization, TCM cells and TRM cells with identical TCRβ CDR3 sequences are present with equal abundance in the LNs and skin, respectively. Multiple exposures to the same antigen lead to higher population expansion of skin TRM cells than of LN TCM cells. Parabiosis experiments show that TCM cells are freely migratory between LNs, where they are greatly outnumbered by naive T cells, while skin TRM cells are sedentary and make up most of the T cells in this location. These data are consistent with the existence of a common naive T cell precursor to TCM cells and TRM cells in various anatomic compartments.

Nat. Med. (11 May 2015) doi:10.1038/nm.3860