P. Mansson et al., Critical role of P-selectin-dependent rolling in tumor necrosis factor-alpha-induced leukocyte adhesion and extravascular recruitment in vivo, N-S ARCH PH, 362(2), 2000, pp. 190-196
Leukocyte-endothelium interactions are dependent on a coordinated expressio
n and function of specific adhesion molecules. The objective of the present
study was to examine the role of selectin function and leukocyte rolling i
n tumor necrosis factor-alpha (TNF-alpha)-induced leukocyte adhesion and ex
travasation in venules in vivo.
For this purpose, we used intravital microscopy in the mouse cremaster musc
le stimulated for 2-3 h with TNF-alpha intrascrotally. Pretreatment with fu
coidan, which inhibits P- and Lselectin, and a P-selectin monoclonal antibo
dy (RB40.34) abolished TNF-alpha-stimulated leukocyte rolling. This great r
eduction in rolling caused a marked attenuation of firm adhesion and extrav
ascular accumulation of leukocytes. When fucoidan and RB40.34 were administ
rated after stimulation with TNF-alpha, it was found that leukocyte rolling
was greatly reduced whereas the number of firmly adherent leukocytes was c
ompletely unchanged, suggesting that the inhibitory effect of blocking P-se
lectin function on firm leukocyte adhesion and recruitment was due to the r
eduction in leukocyte rolling along the endothelium. Moreover, pretreatment
with a monoclonal antibody against intercellular adhesion molecule-1 (ICAM
-1) and a platelet-activating factor (PAF)-receptor antagonist had no effec
t of TNF-alpha-induced leukocyte rolling and adhesion, indicating that mole
cules other than ICAM-1 and PAF mediate firm adhesion and recruitment of le
ukocytes in TNF-alpha-activated tissues.
Taken together, our data demonstrate that P-selectin function plays an impo
rtant role in TNF-alpha-induced inflammatory cell recruitment by mediating
leukocyte rolling as a precondition for cytokine-provoked firm adhesion and
transmigration in vivo. These findings, thus, suggest that inhibition of P
-selectin may be a central target for pharmacological intervention in infla
mmatory diseases.