Clonal origin

Central memory T cells (T_CM cells) in the lymph nodes (LNs) and resident memory T cells (T_RM 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 T_CM cells and T_RM cells. After immunization, T_CM cells and T_RM 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 T_RM cells than of LN T_CM cells. Parabiosis experiments show that T_CM cells are freely migratory between LNs, where they are greatly outnumbered by naive T cells, while skin T_RM 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 T_CM cells and T_RM cells in various anatomic compartments.

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