Figure 4.

Expansion of transferred CD8⁺ T cells in PD-L1^−/− mice. CD8⁺ T cells were isolated from CD45.1 × TCR Tg mice and adoptively transferred into WT and PD-L1^−/− mice. Recipient animals were infected with FV on the next day after CD8⁺ T cell transfer (A). Flow cytometry was used to detect the transferred donor CD8⁺ T cells (CD8⁺ CD45.1⁺). A representative dot plot shows the IgG isotype control for CD45.1 and PD-1 stining on CD8⁺ T cells, CD8⁺ T cells from the spleen of WT and PD-L1^−/− recipient mice on day 8 after FV infection (B). The frequency of CD45.1⁺ CD8⁺ donor cells in the spleen (C) and bone marrow (D), and frequency of CD45.1⁺ CD8⁺ donor cells expressing granzyme B in the spleen (E) and bone marrow (F) of 8- and 12-day infected recipient mice were determined. Mean numbers plus SD of 4–7 mice are shown. Data was pooled from two independent experiments with similar results. Unpaired t-test was used for the analysis of differences at every time point. Statistically significant differences between the groups are indicated (*p < 0.05).