Figure 1.

The expression of IFN-γ and IL-4 by PB and SF CD4⁺ and CD8⁺ T cells. PBMC or SFMC were activated for 5 hr in the presence or absence of PMA (10 ng/ml)⁺ ionomycin (0·5 μg/ml), or anti-CD3 mAb (1 μg/ml)⁺ anti-CD28 mAb (10 μg/ml). Brefeldin A (10 μg/ml) was added to the cultures to prevent cytokine secretion. Activated cells were stained with PerCP-conjugated anti-CD4 or anti-CD8 mAb, fixed, permeabilized in 0·1% saponin and stained with FITC-conjugated anti-human IFN-γ and PE-conjugated anti-human IL-4 mAb. CD4⁺ or CD8⁺ cells were gated and quadrants were set on the basis of FITC- and PE-conjugated IgG1 isotype controls. The values denote the percentage of cells in each quadrant.