Chronic inflammatory disease alters adhesion molecule requirements for acute neutrophil emigration in mouse skin

Mutant mice triply deficient in ICAM-1, E-selectin, and P-selectin did not develop the neutrophilic skin lesions that spontaneously arise in mutants d oubly deficient in E-selectin and P-selectin. Thus, ICAM-1 is essential to skin disease resulting from endothelial selectin deficiency. During experim ental dermatitis, acute neutrophil emigration was completely prevented in y oung mice deficient in both selectins (E/P and E/P/I mutants). However, old er E/P mutants with spontaneous skin lesions displayed an endothelial selec tin-independent pathway for acute neutrophil emigration. Ln contract, emigr ation remained compromised in E/P/I mutants and CD18 mutants regardless of age or lesions. Experimentally induced chronic lesions elicited this pathwa y for acute emigration in young E/P mutants. Thus, an endothelial selectin independent pathway for acute neutrophil emigration is induced in E/P mice by chronic inflammation at distant sites, and this pathway may contribute t o skin disease resulting from endothelial selectin deficiency.