Figure 4: Frequency of intracellular cytokine positive cells on ALL and ALL + gated cells. Freshly purified CD4+ T cells were incubated with ALL-Biotin followed by CyChrome-streptavidin incubation and stained with monoclonal antibodies against IL-4, IL-10, IFN-γ, or TGF-β. Cells were analyzed by flow cytometry and gated on ALL or ALL + cells. Percentages of cells positive to intracellular cytokines are shown in histograms.