T <sub>RM</sub> integrins CD103 and CD49a differentially support adherence and motility after resolution of influenza virus infection
Emma C. Reilly, Kris Lambert Emo, Patrick M Buckley, Nick Reilly, Ian Smith, Francisco A. Chaves, Hongmei Yang, Patrick W. Oakes, David J. Topham
Abstract
Tissue-resident memory CD8 T (T RM ) cells are a unique immune memory subset that develops and remains in peripheral tissues at the site of infection, providing future host resistance upon reexposure to that pathogen. In the pulmonary system, T RM 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 T RM cell surface phenotype develops by 2 wk postinfection, with the majority of the population expressing CD49a and a subset that is also positive for CD103. Despite a previously established role in retaining T RM in peripheral tissues, CD49a facilitates locomotion of virus-specific CD8 T cells, both in vitro and in vivo. These results demonstrate that CD49a may contribute to local surveillance mechanisms of the T RM population.