Abstract
Background: Mast cells and eicosanoid mediators play an important role in asthma. There are few studies comparing eicosanoid release from different human mast cell models.
Objective: We characterized release of eicosanoids from the LAD2 human mast cell line and primary cultured-human mast cells from cord blood (CBMC) and peripheral blood (PBMC).
Methods: Mast cells were stimulated with anti-human IgE via cross-linking of IgE antibodies for 30 minutes, and β-hexosaminidase, cysteinyl leukotrienes (CysLTs), LTB4, prostaglandin D2 (PGD2) were measured, and expression of cyclooxygenase (COX)-1 and COX-2 were studied by western blot.
Results: LAD2 released β-hexosaminidase and PGD2 after stimulation with anti-human IgE in a dose-dependent manner, but not CysLTs or LTB4. CBMC and PBMC showed significant increase of cysLTs and LTB4 in addition to β-hexosaminidase and PGD2 after stimulation. IL-4 priming did not enhance CysLTs release in any of the mast cell models. IL-4 primed LAD2 however showed significant enhancement of PGD2 release. The PGD2 release from the three human mast cell models was consistently abolished by the selective COX-1 inhibitor, FR122047 (p<0.001), but not by the COX-2 inhibitor, etoricoxib. There was strong COX-1 expression in LAD2 which showed significant inhibition of PGD2 release after treatment with COX-1 siRNA.
Conclusion: LAD2 is a good model for studies of PGD2 release, but not for CysLTs. The PGD2 release from the isolated human mast cells is dependent on COX-1, in line with recent in vivo findings in asthmatics (Daham K et al. Clin Exp Allergy 2011;41:36-45)
This abstract was supported by ERS/Marie Curie joint research fellowship (MC 1549-2010).
- © 2011 ERS