THE ADHESION MOLECULES USED BY MONOCYTES FOR MIGRATION ACROSS ENDOTHELIUM INCLUDE CD11A CD18, CD11B/CD18, AND VLA-4 ON MONOCYTES AND ICAM-1, VCAM-1, AND OTHER LIGANDS ON ENDOTHELIUM/
J. Meerschaert et Mb. Furie, THE ADHESION MOLECULES USED BY MONOCYTES FOR MIGRATION ACROSS ENDOTHELIUM INCLUDE CD11A CD18, CD11B/CD18, AND VLA-4 ON MONOCYTES AND ICAM-1, VCAM-1, AND OTHER LIGANDS ON ENDOTHELIUM/, The Journal of immunology, 154(8), 1995, pp. 4099-4112
CD11/CD18 and VLA-4 integrins mediate interactions of monocytes with H
UVEC cultured on human amniotic tissue. In the present study, the role
s of individual CD11/CD18 integrins and endothelia[ adhesion molecules
were examined using blocking mAbs and peptides. After 20 min of incub
ation, monocyte adhesion to and migration across unstimulated endothel
ium was dependent primarily on CD11a/CD18. When incubation was extende
d to 2 h to allow for completion of migration, either CD11a/CD18 or CD
11b/CD18 could be used. Similarly, either CD11a/CD18 or CD11b/CD18 cou
ld be used by monocytes to bind to and traverse IL-l P-stimulated endo
thelium. Although both CD11a/CD18 and CD11b/CD18 are known to bind to
ICAM-1, results of Ab-mixing experiments suggest that alternative liga
nds on HUVEC for CD11/CD18 integrins also may be used during transendo
thelial migration of monocytes. Our previous studies indicate that VLA
-4 on monocytes interacts primarily with VCAM-1 on unstimulated endoth
elium. In contrast, migration of monocytes across IL-lp-stimulated end
othelium was less dependent on VCAM-1. mAbs directed against binding s
ites for VLA-4 in domain 1 and domain 4 of VCAM-1 did not, by themselv
es, inhibit interactions of monocytes with stimulated HUVEC. VLA-4-dep
endent migration across IL-lp-stimulated endothelium was markedly inhi
bited only when mAbs to VCAM-1 were added in combination with peptides
of fibronectin. Therefore, VLA-4 can interact with either VCAM-1 or a
lternative ligands on IL-1 beta-stimulated HUVEC-amnion cultures to me
diate transendothelial migration of monocytes.