Tissue resident memory CD8 T (TRM) cells are a unique immune memory subset that develops and remains in peripheral tissues at the site of infection, providing future host resistance upon re-exposure to that pathogen. In the pulmonary system, TRM are identified through S1P antagonist CD69 and expression of integrins CD103/β7 and CD49a/CD29(β1). Contrary to the established role of CD69 on CD8 T cells, the functions of CD103 and CD49a on this population are not well defined. This study examines the expression patterns and functions of CD103 and CD49a with a specific focus on their impact on T cell motility during influenza virus infection. We show that the TRM cell surface phenotype develops by two-weeks post-infection and that each integrin contributes a distinct function regulating CD8 T cell motility both in vitro and in vivo, with CD49a facilitating migration and CD103 limiting motility through tethering. These results demonstrate for the first time how CD103 and CD49a differentially impact adherence and migration in the tissue, likely affecting overall retention, maintenance of TRM, and host protection.

TRM Integrins CD103 and CD49a Differentially Support Adherence and Motility After Resolution of Influenza Virus Infection