Role of selectins on IgE-mediated skin reaction

1 Selectins play an important role on leukocytes infiltration into inflamma tory tissues. To understand the role of selectins, we investigated the effe cts of selectin-IgG chimeras and anti selectin antibodies on the murine IgE -mediated skin inflammation model. 2 Biphasic skin reactions were induced by intradermal challenge with ovalbu min (OA) to ears of actively sensitized mice. This reaction was characteriz ed by immediate and late phase responses observed as which were induced via a rapid increase in capillary permeability and leukocyte infiltration, res pectively. The expression of E-selectin mRNA was significantly increased to reach its highest level at 2 h after OA challenge. 3 E-, P-, and L-selectin-IgG chimeras inhibited the late phase responses, i .e. ear swelling, neutrophil infiltration and eosinophil infiltration at 24 h after OA challenge in a dose-dependent manner at dose range of 0.1-10 mg kg(-1), i.v. Antiselectin antibodies did not inhibit the increase of ear s welling. But anti E- and P-selectin antibodies significantly inhibited neut rophil infiltration and eosinophil infiltration. 4 These results indicate that selectins play an important role on the late phase response of the murine IgE-mediated skin inflammation model by mediat ing inflammatory cell adhesion to endothelium.