Regulation of PSGL-1 interactions with L-selectin, P-selectin, and E-selectin: role of human fucosyltransferase-IV and -VII.
P-selectin glycoprotein ligand-1 (PSGL-1) interactions with selectins regulate leukocyte migration in inflammatory lesions. In mice, selectin ligand activity regulating leukocyte recruitment and lymphocyte homing into lymph nodes results from the sum of unequal contributions of fucosyltransferase (FucT)-IV and FucT-VII, with FucT-VII playing a predominant role. Here we have examined the role of human FucT-IV and -VII in conferring L-selectin, P-selectin, and E-selectin binding activities to PSGL-1. Lewis x (Le(x)) carbohydrate was generated at the CHO(dhfr)(-) cell surface by FucT-IV expression, whereas sialyl Le(x) (sLe(x)) was synthesized by FucT-VII. Both human FucT-IV and -VII had the ability to generate carbohydrate ligands that support L-selectin-, P-selectin-, and E-selectin-dependent rolling on PSGL-1, with FucT-VII playing a major role. Cooperation was observed between FucT-IV and -VII in recruiting L-, P-, or E-selectin-expressing cells on PSGL-1 and in regulating cell rolling velocity and stability. Additional rolling adhesion assays were performed to assess the role of Thr-57-linked core-2 O-glycans in supporting L-selectin-, P-selectin-, and E-selectin-dependent rolling on PSGL-1. These studies confirmed that core-2 O-glycans attached to Thr-57 play a critical role in supporting L- and P-selectin-dependent rolling and revealed that additional binding sites support >75% of E-selectin-mediated rolling. The observations presented here indicate that human FucT-IV and -VII both contribute and cooperate in regulating L-selectin-, P-selectin-, and E-selectin-dependent rolling on PSGL-1, with FucT-VII playing a predominant role in conferring selectin binding activity to PSGL-1.
Martinez
Manuel
M
Service and Central Laboratory of Hematology, Centre Hospitalier Universitaire Vaudois, Bugnon 46, 1011 Lausanne, Switzerland.
Joffraud
Magali
M
Giraud
Sylvain
S
Baïsse
Bénédicte
B
Bernimoulin
Michael Pierre
MP
Schapira
Marc
M
Spertini
Olivier
O
D000818:Animals; D016466:CHO Cells; D002448:Cell Adhesion; D002478:Cells, Cultured; D006224:Cricetinae; D000939:Epitopes / Q000737:chemistry / Q000378:metabolism; D005434:Flow Cytometry; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D036904:Leukocyte Rolling; D016256:Lewis X Antigen / Q000737:chemistry / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D019087:Selectins / Q000235:genetics / Q000378:metabolism*; D000080506:Sialyl Lewis X Antigen; D014162:Transfection
D000939:Epitopes; D016256:Lewis X Antigen; D008562:Membrane Glycoproteins; D009844:Oligosaccharides; C084882:P-selectin ligand protein; D019087:Selectins; D000080506:Sialyl Lewis X Antigen; D005647:Fucosyltransferases