Figure 2.

Arenavirus-specific CD4⁺ T cells have a polyfunctional phenotype. Epitope-specific cytokine production (IFN-γ, TNF-α, and IL-2) from splenic CD4⁺ T cells of a group of three rVACV primed and peptide boosted HLA-DRB1*0101 transgenic mice was measured 11 to 14 days after peptide immunization. (A) The fraction of the total cytokine response comprising LCMV GPC_421-435, L_946-960, or NP_6-20-specific CD4⁺ T cells expressing all 3 cytokines, any 2 cytokines, or any 1 cytokine. (B) The frequency of LCMV GPC_421-435-specific CD4⁺ T cells expressing each of the seven possible combinations of IFN-γ, TNF-α, and IL-2. Results from one experiment are shown and are representative of at least two independent experiments. Error bars indicate SEM.