Figure 1.

IL-21Rα^−/− mice generate reduced antigen-specific primary CD8⁺ T-cell responses to virally encoded antigens. (A) WT and IL-21Rα^−/− mice were inoculated with rAd-gp140 and p18-specific CD8⁺ T cells in the peripheral blood of individual mice were quantitated with an H-2D^d/p18 tetramer. Data are presented as the percentages of CD8⁺ T cells that bind tetramer and represent the means of six mice per group ± SE and are representative of eight experiments. (B) WT and IL-21Rα^−/− mice were inoculated with rVac-gp160 and p18-specific CD8⁺ T cells in the peripheral blood of individual mice were quantitated with an H-2D^d/p18 tetramer. Data are presented as the percentages of CD8⁺ T cells that bind tetramer and represent the means of six mice per group ± SE and are representative of two experiments. (C) WT and IL-21Rα^−/− mice were inoculated with rAd-gp140 and sacrificed 44 days post-inoculation. Lymphocytes were isolated from peripheral blood, mesenteric lymph nodes and spleen, and p18-specific CD8⁺ T cells of individual mice were quantitated with an H-2D^d/p18 tetramer. Splenocytes from individual mice were counted to allow enumeration of the number of tetramer-positive cells per mouse. Data represent the means ± SE of 11 mice per group and are representative of three experiments. (D) In vivo expression of the luciferase protein from a recombinant adenovirus (rAd). WT and IL-21Rα^−/− mice were inoculated with rAd-luciferase. The levels of luciferase expression were measured over time in the inoculated mice using IVIS. Upper panel: Representative images of luciferase expression in the mice following priming inoculation. Lower panel: The mean values of the amount of luciferase expressed by groups of four mice ± SE following inoculation and are representative of two experiments. The Mann–Whitney test was used for statistical comparisons.