Antigen-specific memory CD8⁺ T cells rapidly traffic into VacV-infected skin and provide protective immunity.

(A) Naïve P14 CD8+ T cells were transferred into B6 mice and infected with LCMV. At 75 days post LCMV-infection, mice were challenged with VacV-GP33 on the left ear skin and trafficking of memory P14 CD8+ T cells into the skin was quantified. (B) Proliferation of memory CD8+ T cells from (A) was analyzed in the indicated tissue by BrdU incorporation. (C) Quantification of (B). (D) Expression of CD127 and KLRG1 on memory P14 CD8+ T cells that trafficked in to the skin as shown in (A). (E) Quantification of (D). (F) Naïve and LCMV-immune mice were infected with 1 x 106 PFU of VacV-GP33 on the left ear skin. On the indicated day post-infection, viral load was quantified in the infected skin. LOD (limit of detection) is indicated by the dashed line.