NADPH oxidase activity and phagocytosis of DHR-labeled C albicans in CARD9-deficient neutrophils. (A) To assess the effect of CARD9 deficiency on production of ROS, patient and control neutrophils were stimulated with various stimuli: zymosan, STZ, PMA, PAF followed by fMLP, Candida particles (ratio with neutrophils, 1:4) and heat-aggregated Ig, in the presence of Amplex Red and horseradish peroxidase. Means ± SEM of at least 3 different experiments. (B) The phagocytosis of DHR-labeled C albicans by the CARD9-deficient and control neutrophils was determined by flow cytometry. Results represent data from 2 different experiments. fMLP, formyl-Met-Leu-Phe; STZ, serum-treated zymosan.