Agonist-induced lipoxin A4 generation: Detection by a novel lipoxin A4-ELISA

Publisher Website
Google Scholar
Abstract
Lipoxin A4 (LXA4) possesses potent bioactions. To facilitate its detection, an enzyme-linked immunosorbent assay (ELISA) was developed that proved sensitive and selective. Quantitation by ELISA of LXA4 generated from cellular sources strongly correlated (r=0.99) with values obtained by high-pressure liquid chromatography (HPLC). We used this LXA4-ELISA to examine parameters influencing LXA4 generation from endogenous substrates during human platelet-neutrophil (PLT-PMN) interactionsin vitro. Agonist-induced LXA4 production was clearly evident at a PLT-PMN ratio of 10∶1, and recombinant human granulocyte/monocyte colony stimulating factor-priming of PMN augmented LXA4 generation 5–6 fold. The chemotactic peptide formylmethionyl-leucyl-phenylalanine, platelet-derived growth factor and arachidonic acid (20∶4n−6) each stimulated formation of immunoreactive LXA4 (iLXA4) in these co-incubations. The presence of iLXA4 was also evaluatedin vivo in aspirin-sensitive asthmatic patients who, in a randomized, double-blind crossover design, underwent nasal lavage after they each ingested a predetermined threshold dose of aspirin or placebo. Aspirin challenge provoked statistically significant increases in iLXA4 in each patient (P4. Furthermore, the use of this ELISA has allowed the first documentation of iLXA4 formation in human subjects with aspirin-sensitive asthma following specific antigenic challenge.