Specific Recognition of Macroscopic Objects by the Cell Surface: Evidence for a Receptor Density Threshold Revealed by Micrometric Particle Binding Characteristics
| Autor: | Frederic Pincet, David Pointu, Stéphanie Sarda, Nelly Henry |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Streptavidin
Lymphoma B-Cell Time Factors Surface Properties Antigens CD19 Analytical chemistry Biophysics Ligands Models Biological Diffusion Cell membrane chemistry.chemical_compound Cell surface receptor Cell Line Tumor Cell Adhesion medicine Humans Scattering Radiation Biotinylation Binding site Cell adhesion Receptor Cell Line Transformed Binding Sites Cell Membrane Temperature Flow Cytometry Kinetics medicine.anatomical_structure Microscopy Fluorescence chemistry Cell Biophysics Covalent bond Particle Stress Mechanical Protein Binding |
| Zdroj: | Biophysical Journal. 86(5):3291-3303 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/s0006-3495(04)74377-5 |
| Popis: | The establishment of specific molecular bonds between a cell and a facing surface is involved in many physiological and technological situations. Using micrometric magnetic particles, we have explored the formation of specific molecular bonds between the cell and surfaces bearing complementary ligands under passive conditions. Streptavidin-coated particles were targeted to the cell surface of a B-cell line through a specific biotinylated antibody against the CD19 receptor. Flow cytometry, optical microscopy, and micropipette experimental techniques have been used. Main findings have been that cell surface receptor density acted like a switch for particle capture with a threshold value found here equal to 1.6 x 10(3) receptor/ microm(2). This led to exclusion from binding of the cells of lowest receptor density. The density threshold was modulated by the length of the binding link and the physics of the cell/particle collision. We suggest that the shear stress is one of the main determinants of the characteristics of binding. We also show that several thousand receptors were involved in the cell particle contact at the end of the binding process, although only eight bonds are required for the initial capture of a particle. A passive binding inhibition process due to link concentration by the initial contact was proposed to account for the small number of particles per cell. |
| Databáze: | OpenAIRE |
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