Treg is essential for the suppressive effects of Ad5-gsgAM on asthma. Six-week-old mice were sensitized with OVA, immunized with Ad5 or Ad5-gsgAM, inoculated with anti-CD25 antibody PC61 or isotype control (termed as OVA/gsgAM/PC61 or OVA/gsgAM/isotype, respectively), and then challenged with OVA. Twenty-four hours after the final challenge, the mice were sacrificed. a Schedules of OVA sensitization, immunization, antibody inoculation, OVA challenge, and detection. b, c The frequency of CD4+CD25+FoxP3+ cells in the spleen (b) and MLN (c) were examined by flow cytometry. d The contents of IgE in the serums were determined by ELISA. e The absolute numbers of total cells, eosinophils, and macrophages in the BALFs were counted based on H&E staining. f The percentages of total cells, eosinophils, and macrophages in the BALFs. g–j The contents of IL-5 (g), IL-13 (h), IL-33 (i), and sST2 (j) in the BALFs were determined by ELISA. Data are presented as the mean ± SEM (n = 5 to 7 mice per group). Representative results from one of three independent experiments are shown. *P < 0.05, **P < 0.01, ***P < 0.001. ns, no significance