Figure 4

IFN-γ induced by RSV is predominantly produced by T cells. We confirmed that nude mice were deficient in CD3⁺ T cells (A) and found that IFN-γ was significantly increased at days 5 and 7 post-RSV infection in BALB/c mice, but was nearly negligible in nude mice (B). We further found that both CD3⁺CD4⁺IFN-γ⁺ Th1 cells and CD3⁺CD8⁺IFN-γ⁺ Tc1 cells were remarkably elevated at day 5 when IFN-γ levels peaked in BALB/c mice (C). Data are representative of two independent experiments performed on 6 animals per group. *, p < 0.05, **, p < 0.01, ***, p < 0.001 shown comparing the corresponding mice groups are connected by a line.