Figure 5.

(a) Cell viability and (b–d) de novo synthesis of sulfido-leukotrienes (sLT) from isolated blood leukocytes. (a,b) Leukocytes were simultaneously incubated without any pre-incubation (w/o pre-incubation) with either fMLP, C5a and 0.5 or 5 µM α-13’-COOH for 50 min. (c,d) Leukocytes were pre-incubated with (w/ pre-incubation) 0.5 or 5 µM α-13’-COOH or buffer (untreated) for 50 min. Leukocytes used as control were incubated with buffer only. Incubation with an anti-IgE Receptor mAb/fMLP solution is shown as positive control (mAb/fMLP). (c) A second unspecific stimulation was conducted either with fMLP (5 µM), C5a (10 nM), or buffer for a further 50 min. (d) A second specific stimulation was conducted with an extract from house dust mite (HDM) for specific IgE-mediated response for a further 50 min. Leukocytes from donor 1 and donor 2 were confirmed with a specific IgE level sensitized against HDM extract. HDM extract was applied at two concentrations (HDM low: 2 ng; HDM high: 20 ng). (a) Cell viability is presented as the amount of ATP release given as fold change of the control. (b–d) De novo synthesis of sLT is given as absolute amounts per defined cell number. (a–d) All data are presented as mean ± SEM. Two independent experiments were performed as replicates. Asterisks [*] indicate significant deviations from the untreated control (* p < 0.05, ** p < 0.01 and *** p < 0.001).