DHR oxidation by GOL-loaded CGD granulocytes.

(A) (Ai indicates mean fluorescence; Aii, fluorescence-positive cells.) Cells were preincubated with GOLs (EPC:EPG:Chol, both 4:3:3 mole ratio, 1 mM) in PBS at 37°C for 15 minutes. Nonincorporated liposomes were washed out and the incubation was followed for different time periods (5-240 minutes) in PBS plus glucose. Subsequently, DHR was added. Diffusion of extracellular H₂O₂ was reduced by addition of catalase (50 U/mL) at time point 0 of the cellular incubation. Mean of 2 independent experiments with CGD granulocytes of 2 different patients; ▪ indicates fluorescence without catalase; ■, fluorescence with addition of catalase. (B) Effect of different concentrations of catalase over 30 minutes of incubation. Values are expressed as percentage of remaining DHR oxidation of CGD cells under the influence of catalase; mean of 3 independent experiments with granulocytes of different donors, mean ± SD.