Figure 2: Mucosal amph-vaccines elicit robust expansion of antigen-specific CD8⁺ T_RMs in the lungs.

C57BL/6 mice were immunized either s.c. or i.t. with 5 μg of free AL11 peptide and 8 μg CpG or equimolar doses of amph-AL11 combined with amph-CpG on days 0 and 14. (A) Representative flow cytometry plots of CD8⁺AL11-tetramer⁺ T cells in the blood (upper panel) and lung parenchyma (lower panel) at day 20. (B, C) Quantification of CD8⁺AL11-tetramer⁺ cells in the blood (B) and lung parenchyma (C). (D) Representative histograms of CD49a expression on CD8⁺ T cells and quantification of CD49a mean fluorescence intensity (MFI) following i.t. amph-vaccination. (E) Representative flow cytometry plots of CD69 and CD103 expression on CD8⁺AL11-tetramer⁺ T cells in the blood (left panel), lung vasculature (center panel) and lung parenchyma (right panel) following i.t. amph-vaccination. (F) Quantification of the percentage of lung CD8⁺AL11-tetramer⁺ T cells expressing CD69, CD103 or both. (G) WT and Batf3^−/− mice were vaccinated with amph-gp100 and amph-CpG i.t. following the schedule in (A). Quantification of cytokine⁺ CD8⁺ lung T cells. (H) WT and FcRn^−/− mice were vaccinated with amph-gp100 and amph-CpG i.t. following the schedule in (A) and lung antigen-specific CD8⁺ T cells were quantified. Data are shown are mean + SEM, **p<0.01, ***p<0.001, ****p<0.0001 as determined by one-way ANOVA. Data are representative of at least three independent experiments (n = 3 – 5 animals/group).