Figure 2.

The route of antigen exposure does not greatly impact the direct ex vivo functionality of antigen-specific cells

PBMCs were stimulated with C19 (YLQPRTFLL) or FLU (GILGFVFTL) peptide for 4 h in the presence of brefeldin A and analyzed by flow cytometry.

(A) Representative FACS plots (top row) and quantification of data (bottom row) are shown. Numbers indicate percentages within the quadrant. Cells are gated for live CD3⁺CD8⁺ cells. BrefA control, cells stimulated with brefeldin A only (n = 16).

(B) Donut graphs showing polyfunctional analysis of C19- and FLU-specific CD8⁺ T cells. Relative distribution of single or multiple cytokine-producing cells is shown for IL-2, IFNγ, and TNF (n = 16).

(C and D) PBMCs were stimulated with a peptide pool of immunodominant epitopes of the spike protein of SARS-CoV-2 or of influenza HA for 4 h in the presence of brefeldin A and analyzed by flow cytometry.

(C) Percentage of cells expressing the indicated activation-induced markers (AIMs) (n = 18).

(D) (Top row) Representative FACS plots and (bottom row) quantification of cytokine expression (n = 24). Indicated are means ± SEM.

Statistical significances at ^∗p < 0.05 and ^∗∗p < 0.01 using one-way ANOVA followed by Bonferroni post-testing (A, C, and D).

See also Figure S2.