P-selectin, L-selectin, and alpha 4 integrin have distinct roles in eosinophil tethering and arrest on vascular endothelial cells under physiological flow conditions.
The adhesive interactions of eosinophils with purified E-, P-, and L-selectins; vascular cell adhesion molecule-1 molecule; and HUVEC were examined in shear flow. Compared with neutrophils, eosinophils showed markedly less binding to E-selectin, but significantly stronger avidity for P-selectin. Both cell types showed a similar level of tethering and rolling on L-selectin. Eosinophils tethered and arrested abruptly on vascular cell adhesion molecule-1. However, some of the tethers were detached within several seconds; this was prevented by stimulation with eotaxin. Eosinophils also showed immediate arrest on HUVEC stimulated with 100 U/ml TNF-alpha for 6 h. Treatment with L-selectin mAb decreased eosinophil accumulation on the HUVEC by abrogating secondary tethers through interactions between flowing and attached eosinophils. mAb to P-selectin but not to E-selectin strongly inhibited primary tethers and accumulation of eosinophils. mAb to the integrin alpha 4 subunit inhibited arrest, induced rolling or detachment of tethered eosinophils, and resulted in partial reduction of eosinophil accumulation. mAb to the integrin beta 2 subunit had only a slight effect, whereas treatment with mAb to the integrin alpha 4 and beta 2 subunits together abolished rolling interactions as well as arrest, and thus almost totally inhibited eosinophil accumulation. Our data indicate that P-selectin, but not E-selectin, is directly involved in eosinophil tethering on inflammatory endothelium while L-selectin mainly mediates intereosinophil interaction. VLA-4 has a crucial role in eosinophil arrest, and arrest is enhanced by exposure to chemoattractants.
Kitayama
J
J
Center for Blood Research, Howard Medical School, Boston, MA 02115, USA.
Fuhlbrigge
R C
RC
Puri
K D
KD
Springer
T A
TA
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D054413:Chemokine CCL11; D019742:Chemokines, CC; D002631:Chemotactic Factors, Eosinophil / Q000502:physiology; D016207:Cytokines / Q000494:pharmacology; D015194:Diffusion Chambers, Culture; D019040:E-Selectin / Q000276:immunology / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D004804:Eosinophils / Q000276:immunology / Q000502:physiology*; D018056:Hemorheology; D006801:Humans; D039441:Integrin alpha4; D019041:L-Selectin / Q000276:immunology / Q000502:physiology*; D019007:P-Selectin / Q000276:immunology / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1 / Q000502:physiology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D002631:Chemotactic Factors, Eosinophil; D016207:Cytokines; D019040:E-Selectin; D019007:P-Selectin; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D019041:L-Selectin; D039441:Integrin alpha4