baCD3/CD28-TK⁺ human lymphocytes are unpolarized cells that produce IL-2. At day 10, aCD3-TK⁺ or baCD3/CD28-TK⁺ lymphocytes were compared with the corresponding PBLs for cytokine production at a single cell level. (A) After gating for CD3 in the case of PBLs, and for LNGFR in the case of TK⁺ cells, cells were analyzed by flow cytometry for IFN-γ and IL-4 production (dot plots). Quadrants were set according to isotype-control staining. The inserts report the percentages of cells for each quadrant. Results with cells from one representative donor of 4 are shown. Averages ± SD of the relative distribution of IFN-γ⁺IL-4⁺, IFN-γ^-IL-4⁺, or IFN-γ^-IL-4^- are reported for CD4⁺ (top histograms) or CD8⁺ cells (lower histograms) in PBLs or aCD3- or baCD3/CD28-TK⁺ lymphocytes. (B) Cells were also analyzed by flow cytometry for IFN-γ and IL-2 production (dot plots). Quadrants and percentages were set according to isotype-control staining. The inserts report the percentages of cells for each quadrant. Results with cells from one representative donor of 4 are shown. Averages ± SD of the relative distribution of IFN-γ⁺IL-2⁺, IFN-γ^-IL-2⁺, or IFN-γ^-IL-2^- cells are reported for CD4⁺ (top histograms) or CD8⁺ cells (bottom histograms) in PBLs or aCD3- or baCD3/CD28-TK⁺ lymphocytes. Symbols overlying aCD3- or baCD3/CD28-TK⁺-related bars are for statistical comparison with the corresponding PBL-related bars (^*P < .05; ^**P < .01; ^***P < .005).