(A) Purified neutrophils from six birch pollen-allergic individuals were cultured in medium alone (0) or stimulated with titrated concentrations 10(1), 1(2), 0.1(3), and 0.01(4) ng/ml) of GM-CSF, IFN-γ, and IL-3. The percentage of HLA-DR-positive cells was assessed by flow cytometry at 24 (white), 36 (light gray) and 48 h (dark gray box plots); (B) Neutrophils were left in medium alone (white) or stimulated with a cocktail of GM-CSF (100 pg/ml), IFN-γ (10 ng/ml) and IL-3 (30 ng/ml, gray) according to published protocols 1. The percentage of HLA-DR-positive cells was assessed at indicated time points; (C) The percentage of HLA-DR-positive cells expressing CD80 and CD86 at 24 h, the dot blot shows one representative experiment. *P<0.05, Wilcoxon Signed Ranks test;