title: Mechanical shedding of L-selectin from the neutrophil surface during rolling on sialyl Lewis x under flow.
abstract: The interaction of L-selectin expressed on leukocytes with endothelial cells leads to capture and rolling and is critical for the recruitment of leukocytes into sites of inflammation. It is known that leukocyte activation by chemoattractants, the change of osmotic pressure in cell media, or cross-linking of L-selectin all result in rapid shedding of L-selectin. Here we present a novel mechanism for surface cleavage of L-selectin on neutrophils during rolling on a sialyl Lewis x-coated surface that involves mechanical force. Flow cytometry and rolling of neutrophils labeled with Qdot(R)-L-selectin antibodies in an in vitro flow chamber showed that the mechanical shedding of L-selectin occurs during rolling and depends on the amount of shear applied. In addition, the mechanical L-selectin shedding causes an increase in cell rolling velocity with rolling duration, suggesting a gradual loss of L-selectin and is mediated by p38 mitogen-activated protein kinase activation. Thus, these data show that mechanical force induces the cleavage of L-selectin from the neutrophil surface during rolling and therefore decreases the adhesion of cells to a ligand-presenting surface in flow.
authors.affiliation: Departments of Biomedical Engineering, University of Rochester, Rochester, New York 14642.
authors.forename: Dooyoung
authors.initials: D
authors.lastname: Lee
authors.affiliation: Biochemistry and Biophysics, and Biomedical Engineering, University of Rochester, Rochester, New York 14642.
authors.forename: Joanne B
authors.initials: JB
authors.lastname: Schultz
authors.affiliation: Biochemistry and Biophysics, and Biomedical Engineering, University of Rochester, Rochester, New York 14642.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Knauf
authors.affiliation: Departments of Biomedical Engineering, University of Rochester, Rochester, New York 14642; Chemical Engineering Biomedical Engineering, University of Rochester, Rochester, New York 14642; Biomedical Engineering, University of Rochester, Rochester, New York 14642. Electronic address: mike_king@urmc.rochester.edu.
authors.forename: Michael R
authors.initials: MR
authors.lastname: King
mesh_terms: D006801:Humans; D019041:L-Selectin / Q000378:metabolism*; D036904:Leukocyte Rolling / Q000502:physiology*; D016256:Lewis X Antigen / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D033081:Shear Strength; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D016256:Lewis X Antigen; D008024:Ligands; D019041:L-Selectin; D048051:p38 Mitogen-Activated Protein Kinases; D019158:N-Acetylneuraminic Acid