Fig. 4

Pulmonary virus-specific antibody, T cells, and eosinophil response evaluation. To confirm the levels of IgG and IgA antibody responses, lung supernatant samples were collected at 5 days post-challenge infection. RSV specific-IgG (A) and IgA (B) antibody responses in the lungs were determined from diluted lung homogenates (1:10 dilution) by ELISA. Lung cells were isolated and stimulated with RSV antigens prior to flow cytometry analysis (C). Cells were gated accordingly to quantify the changes in RSV-specific CD4⁺ and CD8⁺ T cell populations (D, E). Eosinophil influx into the lungs was quantified by flow cytometry following RSV rA2-line19F infection. Cells were stained with CD11b, Siglec F, and Ly6G antibodies and gated (F). Mean values of eosinophil percentages were presented for all groups used in this study (G). Data are presented as mean ± SD from experiments performed in triplicate and statistical significance was determined by one-way ANOVA with Tukey’s multiple comparisons post hoc test (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001)