Tumor Necrosis Factor-α Induces Leukocyte Recruitment by Different Mechanisms in Vivo and in Vitro

Michael J. Hickey, Paul H. Reinhardt, Lena Ostrovsky, Ward M. Jones, Mark A. Jutila, Derrice Payne, John Francis Elliott, Paul Kubes

Research output: Contribution to journalArticleResearchpeer-review

41 Citations (Scopus)

Abstract

It is well established that E-selectin is the endothelial adhesion molecule that is primarily responsible for mediating leukocyte rolling on TNF-α-stimulated cultured endothelial cells. Despite this, few studies in in vivo inflammatory models have observed reduced leukocyte accumulation using mAbs against E-selectin. The objective of this study was to compare the function of E-selectin on endothelial cells in vitro with its role in TNF-α-induced leukocyte recruitment in vivo using EL246, a mAb that blocks the function of E-selectin on activated feline endothelial cells. In vitro experiments using feline endothelial cells showed that EL246 functionally inhibits E-selectin-dependent leukocyte recruitment induced by TNF-α, without affecting the function of other rolling mechanisms. Intravital microscopy of single 25- to 40-μm venules in the feline mesentery was then used to examine leukocyte rolling and adhesion in response to superfusion with TNF-α. TNF-α treatment significantly increased the number of both rolling and adherent leukocytes and significantly decreased leukocyte rolling velocity. Treatment with EL246 (1 mg/kg), either i.v. at the start of the TNF-α protocol or directly into the superior mesenteric artery after 3 h of TNF-α treatment, had no effect on leukocyte rolling, adhesion, or rolling velocity. However, treatment with the selectin-binding carbohydrate, fucoidan, reduced leukocyte rolling to below baseline levels. These results suggest that in contrast to its prominent role on cultured endothelial cells, E-selectin does not contribute to leukocyte recruitment in TNF-α-stimulated feline mesenteric venules in vivo.

Original languageEnglish
Pages (from-to)3391-3400
Number of pages10
JournalJournal of Immunology
Volume158
Issue number7
Publication statusPublished - 1 Apr 1997
Externally publishedYes

Cite this