PT  - JOURNAL ARTICLE
AU  - Hickey, M J
AU  - Reinhardt, P H
AU  - Ostrovsky, L
AU  - Jones, W M
AU  - Jutila, M A
AU  - Payne, D
AU  - Elliott, J
AU  - Kubes, P
TI  - Tumor necrosis factor-alpha induces leukocyte recruitment by different mechanisms in vivo and in vitro.
DP  - 1997 Apr 01
TA  - The Journal of Immunology
PG  - 3391--3400
VI  - 158
IP  - 7
4099  - http://www.jimmunol.org/content/158/7/3391.short
4100  - http://www.jimmunol.org/content/158/7/3391.full
SO  - J. Immunol.1997 Apr 01; 158
AB  - It is well established that E-selectin is the endothelial adhesion molecule that is primarily responsible for mediating leukocyte rolling on TNF-alpha-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-alpha-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-alpha, without affecting the function of other rolling mechanisms. Intravital microscopy of single 25- to 40-microm venules in the feline mesentery was then used to examine leukocyte rolling and adhesion in response to superfusion with TNF-alpha. TNF-alpha 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-alpha protocol or directly into the superior mesenteric artery after 3 h of TNF-alpha 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-alpha-stimulated feline mesenteric venules in vivo.