title: Vascular endothelial cell expression of ICAM-1 and VCAM-1 at the onset of eliciting contact hypersensitivity in mice: evidence for a dominant role of TNF-alpha.
abstract: We have studied vascular endothelial activation and increased expression of ICAM-1 and VCAM-1 at the onset of the elicitation phase of oxazolone contact hypersensitivity in mice. By measuring the local uptake of i.v. administered radiolabeled anti-ICAM-1 and anti-VCAM-1 mAb, we found that endothelial ICAM-1 and VCAM-1 was increased by 4 h after challenge, 2 h later than the first peak of ear swelling and 125I-labeled human serum albumen uptake. Increased expression of endothelial ICAM-1 and VCAM-1 was significantly greater in sensitized animals than in naive animals. Anti-TNF-alpha antiserum significantly inhibited both the increase in ear thickness (p < 0.01), and the up-regulation of ICAM-1 and VCAM-1 expression (p < 0.01 for both) at 4 h. In contrast, the combination of anti-IL-1alpha and IL-1beta had only a small inhibitory effect on ICAM-1 expression (p < 0.05) and no significant effect on increased ear thickness or on VCAM-1 expression. A mixture of anti-TNF-alpha, anti-IL-1alpha, and IL-1beta was no more inhibitory for endothelial ICAM-1 and VCAM-1 expression than anti-TNF-alpha alone. ICAM-1 and VCAM-1 expression at 4 h was unaffected by a combination of mAb against alpha4 and beta2 integrins, whereas expression at 24 h was significantly inhibited (p < 0.05), suggesting that the release of TNF-alpha and other cytokines involved in the initiation of the response may not require leukocyte traffic or other leukocyte functions involving these integrins. We conclude that the early up-regulation of endothelial ICAM-1 and VCAM-1 during the elicitation of contact hypersensitivity is primarily due to the immune-dependent local release of TNF-alpha.
authors.affiliation: British Heart Foundation Cardiovascular Medicine Unit, National Heart and Lung Institute, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom.
authors.forename: J F
authors.initials: JF
authors.lastname: McHale
authors.forename: O A
authors.initials: OA
authors.lastname: Harari
authors.forename: D
authors.initials: D
authors.lastname: Marshall
authors.forename: D O
authors.initials: DO
authors.lastname: Haskard
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D003877:Dermatitis, Contact / Q000209:etiology* / Q000276:immunology* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D010081:Oxazolone / Q000276:immunology / Q000633:toxicity; D012709:Serum Albumin / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis* / Q000276:immunology