Flow cytometry of pulmonary myeloid and lymphoid dendritic cells in mice infected with RSV/IL-4 or wt RSV. (A) Example of primary data from individual mice on day 4 following infection with the indicated virus. The population with high forward scatter (FSC) and side scatter (SSC) was gated (designated R1, left panel) and analyzed for CD11b versus CD11c expression. The CD11blow CD11chigh (designated R2) and CD11bhigh CD11chigh (designated R3) cell populations represent pulmonary lymphoid and myeloid dendritic cells, respectively (42), and the CD11bhigh CD11clow population (R4) represents mostly macrophages (42). The percentage of the total PMC is indicated for each cell population. (B) Amounts of myeloid and lymphoid dendritic cells on days 4, 5, 7, and 9 following primary infection with wt RSV or RSV/IL-4, expressed as the mean percentages of the total PMC, with standard errors based on five or six mice per group. The days when the difference was statistically significant (P < 0.05) are indicated by stars.