FIG. 3.

Neonatal T-cell responses are altered by viral cytokine expression. Four-day-old BALB/c mice were infected with 8 × 10⁴ FFU of RSV/wt, RSV/IFN-γ, or RSV/IL-4 i.n. or left naïve. (A and B) Cells were taken from lungs, and total numbers of CD4 (A) and CD8 (B) T cells were measured on days 4, 7, and 14 postinfection by flow cytometry. (C to F) CD62l⁻ CD44⁺ memory (C and E) and CD69⁺-activated (D and F) CD4 and CD8 cells, respectively, were also measured at the same time points. Data are representative of two experiments, and points represent data for five mice per group ± SEM.