Figure 4

Assessment of the ability of MeV-specific T cells to produce effector cytokines over time by intracellular staining and multicolor flow cytometry. PBMCs were stimulated with pooled overlapping peptides from the MeV H or N proteins and IFN-γ-producing CD4⁺ cells (A) and CD8⁺ cells (B) were identified. The frequency of MeV specific IFN-γ-producing cells was determined by subtracting the spontaneous response. The polyfunctionality of the MeV-specific T cell response was assessed by determining the ability of CD3⁺ CD4⁺ cells to simultaneously express IFN-γ, TNFα, or IL-2 (C) and CD3⁺ CD8⁺ cells for their ability to simultaneously express IFN-γ, CD107a, TNFα, or IL2 (D). Pie charts show the functional composition of CD4⁺ and CD8⁺ T cells that simultaneously express one (gray), two (blue), three (green), or four (black) different functional markers at a given time point (C,D) (n = 4–5/time point).