Loss of myeloid cell Arg1 results in activation of virus-specific CD8⁺ T cells in inflamed muscle tissue.

<p>Three-to-four week-old WT (n = 8) and LysMcre;Arg1^F/F (n = 10) mice were inoculated with 10³ PFU of RRV-LCMV. At 10 dpi, leukocytes from quadriceps muscles (following enzymatic digestion) were isolated for flow cytometric analysis of CD11a and CD69 expression on virus-specific CD8⁺ T cells. Muscle-infiltrating leukocytes that were left unstained were utilized as a control for CD11a and CD69 staining. (A) Representative histograms demonstrating CD11a (left) and CD69 (right) expression on CD44⁺gp33⁺CD8⁺CD4^- T cells at 10 dpi. (B) Frequency of CD11a⁺ or CD69⁺ cells (of CD44⁺gp33⁺CD8⁺CD4^- T cells) in the muscle tissue of RRV-LCMV-inoculated WT mice and LysMcre;Arg1^F/F mice at 10 dpi. Data are represented as the arithmetic mean ± SEM and combined from two independent experiments. * <i>P</i> < 0.05 as determined by two-way ANOVA followed by a Bonferroni multiple comparison test.