Figure S1 - A Single E627K Mutation in the PB2 Protein of H9N2 Avian Influenza Virus Increases Virulence by Inducing Higher Glucocorticoids (GCs) Level

Analysis of T cells in blood and thymus of infected mice. Mice (n = 12/group) were infected i.n. with 10⁴ PFU of V_K627 (▪), rV_K627E (□), Ts_E627 (▾), and rTs_E627K (∇). Blood and thymuses from three mice per group per time point were collected. The percents of CD4⁺ and CD8⁺ T cells in blood (A) were analyzed by flow cytometry. The morphology of thymuses (B) was photoed and single cell suspension was prepared. The percentages of T cells (as determined by appropriate gating on labeled cells) were examined and the numbers of T cells (C) in thymus were calculated by multiplying the percentage of each cell type by the total number of viable thymus cells. Baseline from PBS inoculated mice is shown as a dashed line in each graph. The data shown in A and B represents mean ± SD for three independent experiments. *p<0.05 between V_K627 and rV_K627E; ˆp<0.05 between Ts_E627 and rTs_E627K.

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