Figure 4.

IFN-γ, IL-2, TNF-α, and CD107a multifunctional cells detected by ICS in CD3⁺CD8⁺ and CD3⁺CD4⁺ populations. Mean percentage of quadruple (black), triple (dark gray), double (light gray), and single (white) functional cells detected within the CD8⁺ (A) and CD4⁺ (B) populations. Within the CD8⁺ population, the most frequently detected triple positive cells were CD107a⁺IFN-γ⁺TNF-α⁺; the most frequently detected double positive cells were CD107a⁺TNF-α⁺; and CD107a⁺ cells were the most frequently detected single positive cells. Within the CD4⁺ cells, the most frequently detected triple positive cells were CD107a⁺IFN-γ⁺IL-2⁺; the most frequently detected double positive cells were IFN-γ⁺IL-2⁺; and TNF-α⁺ cells were the most frequently detected single positive cells. At all time points the frequency of antigen-specific cytokine positive cells was greater in the CD8⁺ population (week 0, CD8⁺ = 1.92% and CD4⁺ = .12%; week 1, CD8⁺ = 2.43% and CD4⁺ = .58%; week 8, CD8⁺ = 3.96% and CD4⁺ = 1.19%).