L-selectin can mediate leukocyte rolling in untreated mesenteric venules in vivo independent of E- or P-selectin.
Granulocyte recruitment during the acute inflammatory response is initiated by their rolling along the endothelial lining of postcapillary venules. To determine whether expression of L-selectin alone is sufficient for rolling, the murine pre-B lymphocytic cell line 300.19, which does not bind E- or P-selectin, was transfected with human L-selectin cDNA, which led to stable L-selectin expression at a level similar to that of blood lymphocytes. Fluorescent-labeled cells were infused retrogradely into a side branch of the superior mesenteric artery of anesthetized rats. In venules of the mesenteric membrane, leukocyte rolling occurs without intentional stimulation. On average, 17% +/- 6% of L-selectin transfectants rolled in the observed venules, while mock-transfected cells did not roll. Rolling of L-selectin transfectants began approximately 20 minutes after surgery and continued for at least 120 minutes. In contrast, HL-60 promyelocytes, which express sialyl-Lewis(x) tetrasaccharide (sLe(x)) but not L-selectin and that bind to E- and P-selectin in vitro, did not roll between 20 and 120 minutes, but some HL-60 cells rolled at very early (< 20 minutes) and late (> 2 hours) time points. Pretreatment with either of two function-blocking monoclonal antibodies recognizing the lectin domain of L-selectin completely blocked rolling of L-selectin transfectants and sharply reduced (by 70%) rolling of isolated human granulocytes. Taken together, these results show that L-selectin can mediate leukocyte rolling by virtue of its lectin activity.
Ley
K
K
Freie Universität Berlin, Department of Physiology, Germany.
Tedder
T F
TF
Kansas
G S
GS
D000818:Animals; D000906:Antibodies / Q000502:physiology; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000494:pharmacology*; D002465:Cell Movement; D019040:E-Selectin; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D006098:Granulocytes / Q000166:cytology; D006801:Humans; D019041:L-Selectin; D037102:Lectins / Q000276:immunology; D007962:Leukocytes / Q000166:cytology / Q000502:physiology*; D008642:Mesenteric Veins / Q000502:physiology*; D019007:P-Selectin; D010641:Phenotype; D010980:Platelet Membrane Glycoproteins / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000166:cytology; D014699:Venules / Q000502:physiology
D000906:Antibodies; D015815:Cell Adhesion Molecules; D019040:E-Selectin; D037102:Lectins; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D019041:L-Selectin