IL-27 restricts the development of MCMV-specific CD4 T cells displaying a cytotoxic phenotype.

<p>WT and <i>Il27ra</i>^<i>-/-</i> mice were infected with 1*10⁴ PFU MCMV and the proportion of polyclonal CD11a⁺CD49d⁺ CD4 T cells expressing KLRG1 were analyzed throughout the course of infection in the blood (A) and in the spleen at day 21 (B) and day 40 p.i. (C). (D) The proportion of KLRG1 expressing M09_133-147 specific CD4 T cells in the spleen at day 40 p.i. (E) Proportion of CD11a⁺CD49d⁺ CD4 T cells expressing granzyme A (GrzA) in the spleen at day 21 p.i. (F) The proportion of CD4 T cells that express CD107a upon PMA/ion stimulation in the spleen at day 7 p.i. (G-H) Proportion of polyclonal CD11a⁺CD49d⁺ CD4 T cells expressing NKG2D (G) and FasL (H) in the spleen at day 21 p.i. All data are representative of at least 2 independent experiments with n = 4–5 mice per group. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.