Figure 6

Granzyme B release by stimulated LAK cells measured in the ELISPOT assay. Human peripheral blood mononuclear cells (PBMC) were cultured with 100 U/ml of IL-2 for 5–6 days to induce LAK cells. LAK cells (1 × 10³, 3 × 10³ or 1 × 10⁴ cells per well) were incubated with K562 (5 × 10⁴ cells per well) for 4 h at 37°C. Effector:target cell ratios are in brackets. Data are presented as average number of spots per well ± SD and are representative of 5 experiments with similar results. A significant correlation between the number of spots per well and effector cell number was observed (R² = 0.94).