Characterization of young and aged lung tissue-resident influenza nucleoprotein-specific CD8 memory T cells

To identify the disparaties of D^b-nucleoprotein specific resident memory CD8 T cells between young and aged mice, we pooled n=11 aged or n=18 young lungs together after intraveounously labeling T cells and sorted ivCD90- CD8a+ CD44hi CD69+ D^b-NP tetramer (PE+ & APC+) cells. By scRNA-seq, we found the aged population was missing a cluster in the young population that resembled typical functional resident memory CD8 T cells indicating that aged resident memory CD8 T cells of this specificity would have poor recall function. Examined with lung-resident memory CD8+ T cells sorted from influenza PR8-infected young (2months at infection) or aged (22 months at infection) C57BL/6 mice (60 days post infection) by scRNA-seq