THE ROLE OF E-SELECTIN IN LYMPHOCYTE AND POLYMORPHONUCLEAR CELL RECRUITMENT INTO CUTANEOUS DELAYED-HYPERSENSITIVITY REACTIONS IN SENSITIZEDPIGS

We have studied the role of E-selectin in leukocyte accumulation into Ag-specific cutaneous delayed-type hypersensitivity reactions in pigs sensitized to the topical application of 2,4-dinitro-1-fluorobenzene o r to the intradermal injection of bacillus Calmette-Guerin. The delaye d-type hypersensitivity reactions were shown to be specific for the se nsitizing Ag and characterized by the up-regulation of E-selectin, as demonstrated by the uptake of tracer Tc-99m-labeled monoclonal anti-E- selectin mAb and entry df Cr-51-labeled PBL and (111)ln-labeled polymo rphonuclear cells (PMN), intravenous injection of 5 mg/kg of a F(ab')( 2) preparation of a monoclonal anti-E-selectin Ab at peak limes of leu kocyte entry resulted in a significant inhibition of entry of both PMN and lymphocytes, The anti-selectin Ab inhibited PMN recruitment by 70 to 90% and lymphocyte recruitment by 58 to 60%. in comparison, an ant i-CD18 treatment reduced PMN recruitment by 70 to 90% and lymphocyte r ecruitment by 60 to 70% in this model. These data confirm an important role for E-selectin in the recruitment of both PMN and lymphocytes to sites of immune-based dermal inflammation.