title: Atomic force microscopy measurement of leukocyte-endothelial interaction.
abstract: Leukocyte adhesion to vascular endothelium is a key initiating step in the pathogenesis of many inflammatory diseases. In this study, we present real-time force measurements of the interaction between monocytic human promyelocytic leukemia cells (HL-60) cells and a monolayer of human umbilical vein endothelial cells (HUVECs) by using atomic force microscopy (AFM). The detachment of HL-60-HUVEC conjugates involved a series of rupture events with force transitions of 40-100 pN. The integrated force of these rupture events provided a quantitative measure of the adhesion strength on a whole cell level. The AFM measurements revealed that HL-60 adhesion is heightened in the borders formed by adjacent HUVECs. The average force and mechanical work required to detach a single HL-60 from the borders of a tumor necrosis factor-alpha-activated HUVEC layer were twice as high as those of the HUVEC bodies. HL-60 adhesion to the monolayer was significantly reduced by a monoclonal antibody against beta1-integrins and partially inhibited by antibodies against selectins ICAM-1 and VCAM-1 but was not affected by anti-alphaVbeta3. Interestingly, adhesion was also inhibited in a dose-dependent manner (IC50 approximately 100 nM) by a cyclic arginine-glycine-aspartic acid (cRGD) peptide. This effect was mediated via interfering with the VLA-4-VCAM-1 binding. In parallel measurements, transmigration of HL-60 cells across a confluent HUVEC monolayer was inhibited by the cRGD peptide and by both anti-beta1 and anti-alphaVbeta3 antibodies. In conclusion, these data demonstrate the role played by beta1-integrins in leukocyte-endothelial adhesion and transmigration and the role played by alphaVbeta3 in transmigration, thus underscoring the high efficacy of cRGD peptide in blocking both the adhesion and transmigration of monocytes.
authors.affiliation: Dept. of Physiology and Biophysics, Univ. of Miami School of Medicine, Miami, FL 33101-6430, USA.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.forename: Aileen
authors.initials: A
authors.lastname: Chen
authors.forename: Dina
authors.initials: D
authors.lastname: De Leon
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Eisei
authors.initials: E
authors.lastname: Noiri
authors.forename: Vincent T
authors.initials: VT
authors.lastname: Moy
authors.forename: Michael S
authors.initials: MS
authors.lastname: Goligorsky
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000276:immunology; D002450:Cell Communication; D002465:Cell Movement / Q000187:drug effects; D020099:Coated Materials, Biocompatible; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D018922:HL-60 Cells; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000276:immunology; D019012:Integrin beta1 / Q000276:immunology; D018625:Microscopy, Atomic Force / Q000295:instrumentation; D009000:Monocytes / Q000502:physiology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D019087:Selectins / Q000276:immunology; D014471:Umbilical Veins; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D000906:Antibodies; D015815:Cell Adhesion Molecules; D020099:Coated Materials, Biocompatible; D039302:Integrin alphaVbeta3; D019012:Integrin beta1; D010456:Peptides, Cyclic; D019087:Selectins; D019010:Vascular Cell Adhesion Molecule-1; C119707:cyclo(S,S)KYGCRGDWPC