CD69+ memory CD8⁺ T cells that remain in the skin are protected from antibody-mediated depletion and produce IFNγ following topical peptide challenge.

(A) LCMV immune mice were infected with VacV-GP33. On day 40 post VacV-GP33 infection, mice received control IgG or anti Thy1.1 antibody as described in Materials and Methods. Seven days later, memory Thy1.1+ P14 CD8+ T cells from the skin were analyzed for expression of CD69 and CD103. (B) Quantification of frequencies of skin P14 CD8+ T cells from (A). (C,D) Quantification of total numbers of (C) CD69+ and (D) CD69- memory P14 CD8+ T cells from (A). (E) Naïve YFP-IFNγ P14 CD8+ T cells were transferred into B6 mice and infected with LCMV. On day 60 post-infection, mice were then infected with VacV-GP33 on the left ear skin. On day 40 after the VacV-GP33 infection, the ear skin was challenged with either GP33-41 peptide or control peptide (NP396-404). Expression of IFNγ (YFP) was analyzed 6 hours post-peptide challenge. (F,G) Quantification of (F) CD69 expression and (G) YFP expression from (E). (H) Same mice as (E) except ear skin swelling was quantified at 6 hours post-peptide challenge.