Figure 5.

Interleukin-21 (IL-21) depletion in primed mice reduces FoxP3 expression by BAL CD4 T cells after respiratory syncytial virus challenge. Mice were immunized and challenged as described in Figure 2. Five days post challenge, bronchoalveolar lavage fluid (BALF) was harvested and CD4 T cells were stained for (a) FoxP3, (b) RORγt (related orphan receptor-γt), or (c) T-bet according to the manufacturer's instructions. The percentage of CD4 T cells expressing each transcription factor was determined by flow cytometry and is shown in each dotplot. Grouped data for (d) percentage and (e) total number are also shown. The graph is representative of two independent experiments of five mice per group. Student's t-test result; **P<0.01, ***P<0.001.