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Adhesion Frequency Assay for In Situ Kinetics Analysis of Cross-Junctional Molecular Interactions at the Cell-Cell Interface
Published on: November 2, 2011
Neutrophil adhesive contact dependence on impingement force
C M Spillmann1, E Lomakina, R E Waugh
1Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642, USA.
Biophysical Journal
|September 14, 2004
Summary
Neutrophil adhesion involves specific receptor bonds forming under force. This study shows that increasing contact force and area between neutrophils and ICAM-1 enhances bond formation probability, crucial for immune cell recruitment.
Area of Science:
- Immunology
- Cellular Biophysics
- Biochemistry
Background:
- Neutrophil recruitment relies on receptor-ligand bonds under hydrodynamic forces.
- Understanding these bonds is key to immune response and inflammatory diseases.
Purpose of the Study:
- To investigate the relationship between force, contact area, and bond formation between neutrophil beta2-integrins and ICAM-1.
- To determine how mechanical forces influence the kinetics of integrin-mediated adhesion.
Main Methods:
- Utilized micropipette force microscopy to control cell-substrate contact forces.
- Measured adhesion probability of neutrophils binding to immobilized ICAM-1 under varying forces (50-350 pN) and contact stresses.
- Employed magnesium to induce high-affinity integrin conformations.
Main Results:
- Adhesion probability increased proportionally with impingement force and contact area (from ~20% to 50%).
- For a fixed contact stress, bond formation rate increased linearly with contact area.
- Higher contact stress led to intrinsically higher rates of bond formation.
Conclusions:
- Neutrophil adhesion probability is modulated by both contact area and force.
- Contact area and contact stress are critical parameters influencing the efficiency of beta2-integrin/ICAM-1 bond formation.
- Findings provide insights into the biophysics of immune cell adhesion and recruitment.
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