Cooperativity in adhesion cluster formation during initial cell adhesion.
We have studied the initial phase of cell adhesion as a function of the lateral organization of individual integrin molecules with single-cell force microscopy. Nanostructures, consisting of hexagonally ordered gold dots, were prepared with diblock-copolymer micelle lithography and functionalized with arginine- glycine-aspartate peptides, thus defining integrin position with nanometer resolution. Adhesion strength was characterized with an atomic force microscope and both cell detachment forces and work of detachment showed a reinforcement of adhesion if the distance between integrin molecules was <70 nm. This reinforcement had already occurred at cell-substrate contact times <5 min. We believe our results show quantitatively the relevance of the distance between adjacent integrin binding sites rather than their density. Furthermore, we propose a model describing the cooperative stabilization of early integrin clusters as a function of receptor patterning at the nanoscale.
Selhuber-Unkel
Christine
C
Department of New Materials and Biosystems, Max-Planck-Institute for Metals Research, Stuttgart, Germany. selhuber@nbi.dk
López-García
Mónica
M
Kessler
Horst
H
Spatz
Joachim P
JP
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002448:Cell Adhesion; D002460:Cell Line; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D016023:Integrins / Q000378:metabolism*; D008823:Micelles; D049329:Nanostructures; D010456:Peptides, Cyclic / Q000378:metabolism; D051381:Rats
D016023:Integrins; D008823:Micelles; D010456:Peptides, Cyclic; C507169:cyclic arginine-glycine-aspartic acid peptide