Extended Data Fig. 2: Aging leads to expansion of memory CD8⁺ T cells in circulation.

Representative flow cytometry plots of T cells for young WT, aged WT, and young Ldlr^-/- mice after PCSK9-AAV and 10-weeks of western diet feeding. Representative flow cytometry plots demonstrating increased frequency of central memory CD8⁺ T cells in aged C57BL/6 WT mice and young Ldlr^-/- mice compared to young C57BL/6 WT mice, increased frequency of effector memory CD8⁺ T cells in aged C57BL/6 WT mice versus young C57BL/6 WT and Ldlr^-/- mice, and greater frequency of naive CD8⁺ T cells in young C57BL/6 WT mice and young Ldlr^-/- mice compared with aged C57BL/6 WT mice. Aged WT mice also demonstrate greater frequency of PD1⁺ EM CD8⁺ T cells and granzyme K⁺ PD1⁺ EM CD8⁺ T cells compared to young WT and Ldlr^-/- mice. PCSK9 = proprotein convertase subtilisin/kexin type 9 serine protease, AAV = adeno-associated virus, CM = central memory, EM = effector memory.