Eosinophil tethering to interleukin-4-activated endothelial cells requires both P-selectin and vascular cell adhesion molecule-1.
We examined the mechanisms used by eosinophils to tether and accumulate on interleukin-4 (IL-4)-stimulated human umbilical vein endothelial cells (HUVECs) under flow conditions. As previously reported, HUVECs treated for 24 hours with 20 ng/mL IL-4 had increased expression of P-selectin and vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin. We found that eosinophils tethered and rolled on IL-4-stimulated HUVECs at physiologic shear stresses. Eosinophil rolling was quickly followed by firm adhesion. Treatment with either an anti-P-selectin monoclonal antibody (MoAb) or an anti-VCAM-1 MoAb decreased both eosinophil tethering and accumulation at 2 dyn/cm2. VCAM-1 interacts with 4-integrins expressed on eosinophils. We found that an anti-4-integrin MoAb also blocked eosinophil tethering and accumulation at 2 dyn/cm2. None of these MoAbs alone had an impact on eosinophil accumulation at lower shear stresses, but when either an anti-VCAM-1 or an anti-4-integrin MoAb was used in combination with an anti-P-selectin MoAb, all eosinophil tethering and accumulation on IL-4-stimulated HUVECs were blocked. This was true at both high and low shear stresses. These data show that both P-selectin and VCAM-1 are required to tether eosinophils at high shear stresses, but at low shear stresses these adhesion proteins can act independently to recruit eosinophils to IL-4-stimulated HUVECs.
Patel
K D
KD
Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada.
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology; D018821:CD18 Antigens / Q000276:immunology / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D004804:Eosinophils / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D039441:Integrin alpha4; D015847:Interleukin-4 / Q000494:pharmacology*; D019007:P-Selectin / Q000276:immunology / Q000502:physiology*; D013314:Stress, Mechanical; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1 / Q000276:immunology / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018821:CD18 Antigens; D019007:P-Selectin; D019010:Vascular Cell Adhesion Molecule-1; D039441:Integrin alpha4; D015847:Interleukin-4