The S128R polymorphism of E-selectin mediates neuraminidase-resistant tethering of myeloid cells under shear flow.
E-selectin mediates the rolling of circulating leukocytes on vascular endothelial cells. A polymorphism, in which serine is substituted for arginine at position 128 (S128R) in the EGF domain, has been associated with both early-onset atherosclerosis and SLE. We investigated whether the substitution alters the ligand-binding properties of E-selectin under shear flow by studying the capacity of Chinese hamster ovary cell transfectants expressing wild type (WT) or S128R E-selectin to support interactions of neutrophils, K562 cells or HL60 cells. We initially chose to study non-fucosylated K562 cells. No interactions were observed on WT E-selectin, whereas S128R supported a transient tethering interaction of K562 cells, which was resistant to digestion with either neuraminidase or O-sialoglycoprotein endopeptidase, and, in turn, could result in firm adhesion in the presence of a beta2-integrin. HL60 cells exhibited increased rolling on S128R E-selectin. Although neuraminidase treatment inhibited all HL60 interactions with WT E-selectin, it unmasked transient tethers on S128R. We further observed that S128R recruited significantly more neutrophils than WT E-selectin, without affecting neutrophil rolling velocity. This polymorphism may therefore amplify leukocyte-endothelial cell interactions and may be a factor linking the S128R polymorphism to vascular disease.
Rao
Ravi M
RM
BHF Cardiovascular Medicine, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
Clarke
Julia L
JL
Ortlepp
Susan
S
Robinson
Martyn K
MK
Landis
R Clive
RC
Haskard
Dorian O
DO
D000818:Animals; D001120:Arginine; D016466:CHO Cells; D006224:Cricetinae; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D020014:K562 Cells; D016169:Lymphocyte Function-Associated Antigen-1 / Q000235:genetics; D008666:Metalloendopeptidases / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D022423:Myeloid Cells / Q000378:metabolism / Q000502:physiology; D009439:Neuraminidase / Q000378:metabolism*; D020556:Neutrophil Infiltration; D010812:Physical Stimulation; D011110:Polymorphism, Genetic; D012694:Serine; D014162:Transfection
D019040:E-Selectin; D016169:Lymphocyte Function-Associated Antigen-1; D012694:Serine; D001120:Arginine; D009439:Neuraminidase; D008666:Metalloendopeptidases; C070738:O-sialoglycoprotein endopeptidase