Epidermal resident memory T cell fitness requires antigen encounter in the skin.

Abstract

CD8+ tissue-resident memory T cells (TRM) develop from effectors that seed peripheral tissues where they persist providing defense against subsequent challenges. TRM persistence requires autocrine TGFβ transactivated by integrins expressed on keratinocytes. TRM precursors that encounter antigen in the epidermis during development outcompete bystander TRM for TGFβ resulting in enhanced persistence. ScRNA-seq analysis of epidermal TRM revealed that local antigen experience in the skin resulted in an enhanced differentiation signature in comparison with bystanders. Upon recall, TRM displayed greater proliferation dictated by affinity of antigen experienced during epidermal development. Finally,..