Characterization of resident CD8+ Trm cell populations using whole-genome biomarker analysis

This study seeks a better understanding of the functional differences between naturally acquired murine CD8+ T resident memory (Trm) cells of three distinct mucosal environments; the small intestine, the lung and the liver. CD8+ Trm cells of healthy young adult mice were retrieved from their respective organ environments by automated organ disintegration and MACS sorting, and compared with each other by whole genome gene expression profiling. Peripheral blood derived circulating CD8+ Tem cells were also analyzed, serving as nonresident peripheral memory T cell controls, in an attempt to identify common characteristics of resident mucosal CD8+ Trm subsets, as well. The livers, lungs, and small intestines of 8-16 weeks old healthy wild type C57Bl/6 mice were isolated to collect CD8+ T resident memory (Trm) cells by MACS cell sorting (n=5-6). Cirulating CD8+ T effector memory (Tem) cells were also collected from the peripheral blood by MACS sorting to serve as a reference, representing a circulating, nonresident CD8+ T memory T cell control. Finally, whole organ lysates were also collected as controls for possible parenchymal cell contamination of MACS sorted cells (n=3)