The percentages of IFN-γ+CD4+T cells and IFN-γ+CD8+T cells in spleen. The percentages of IFN-γ+CD4+ T cells (A) and IFN-γ+CD8+ T cells (B) were assayed using anti-CD3, anti-CD4, anti-CD8b and anti-IFN-γ mAb by flow cytometry. The frequencies of CD3+CD4+ and CD3+CD8+ splenocytes were determined by intracellular IFN-γ staining. (a, as compare with group 4 (PBS-H1N1), P < 0.05; b, as compare with group 3 (H1N1- H1N1), P < 0.05.). n = 3/group.