Atomic force microscopy measurement of leukocyte-endothelial interaction.
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.
Zhang
Xiaohui
X
Dept. of Physiology and Biophysics, Univ. of Miami School of Medicine, Miami, FL 33101-6430, USA.
Chen
Aileen
A
De Leon
Dina
D
Li
Hong
H
Noiri
Eisei
E
Moy
Vincent T
VT
Goligorsky
Michael S
MS
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
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