FIG 3.

T-cell proliferation as assessed by CFSE staining assays. Splenocytes from IBV-immunized chicks were stained with CFSE and then stimulated with ConA or one of four individual peptides for 4 days. Cell proliferation analysis was performed by flow cytometry. (A) Illustration of the gating for T-cell proliferation. Lymphocytes, single cells, live lymphocytes, and CD8⁺ T-cell or CD4⁺ T-cell subsets were gated as described in Fig. 2. (B and C) T cell proliferation was defined as CFSE low, CFSE^low CD8⁺ T cells (B), and CFSE^low CD4⁺ T cells (C) were gated based on the reduction in CFSE fluorescence in CD8⁺ T-cell and CD4⁺ T-cell subsets, respectively. (Left) FACS plots from a representative sample; the percentages of proliferated cells are shown in each gate. (Right) Bar graphs displaying the mean ± standard deviation. Statistically significant differences are indicated as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001.