The defective TCD8+ cell response of aged mice to ECTV is not T cell intrinsic. (A) Experimental design for the adoptive transfer of CFSE-labeled lymphocytes from young (B6-Thy1.1) and aged (B6-CD45.1) donor mice into young B6 (B6 CD45.2-Thy1.2) hosts followed by ECTV infection and flow cytometry analysis gating on CD8+ cells. (B) B6 mice, as in A, were euthanized on the indicated dpi. Cells from the D-LN and spleen were restimulated ex vivo for 5 h with infected cells in the presence of brefeldin A and stained for surface CD3, CD8, Thy1.1, and CD45.1 and for intracellular IFN-γ and GzB, followed by flow cytometry. Top graphs show the data for the D-LN and lower graphs for the spleen. Columns show the percentage of TCD8+Y (gray bars) or TCD8+A (white bars) cells that produced IFN-γ (left) or that proliferated as indicated by CFSE dilution (right). Data correspond to the mean ± SD of pooled organs of three mice per group from three individual experiments. (C) Representative plots from B corresponding to spleens of individual mice 7 dpi. Plots corresponding to an uninfected control mouse are also shown for comparison. Plots were gated on CD8+ cells. (D) Aged B6 mice were adoptively transferred with lymphocytes from young B6-CD45.1 and infected with ECTV in the footpad. 7 dpi, the host (TCD8+A) and donor (TCD8+Y) TCD8+ cell responses were determined in spleens. Representative plots are shown. Data correspond to the mean ± SD of pooled organs of three mice per group from three individual experiments.
