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Updated: Aug 6, 2026
Quantitative In vitro Assay to Measure Neutrophil Adhesion to Activated Primary Human Microvascular Endothelial Cells under Static Conditions
Published on: August 23, 2013
Kinetics analysis of binding between melanoma cells and neutrophils
1Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania 16802-6804, USA.
Abstract:
It has been determined previously that polymorphonuclear leukocytes, or PMNs, can facilitate melanoma cell extravasation through the endothelium under shear conditions. The interactions between melanoma cells and PMNs are mediated by the beta2-integrins expressed by PMNs and intercellular adhesion molecules (ICAM-1) expressed on melanoma cells. In this study, the kinetics of these interactions was studied using a parallel plate flow chamber. The dissociation rates were calculated under low force conditions for ICAM-1 interactions with both beta2-integrins, LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18), together and separately by using functional blocking antibodies on PMNs. The kinetics of PMNs stimulated with IL-8 was also determined. It was concluded that the small number of constitutively expressed active beta2-integrins on PMNs are sufficient to bind to ICAM-1 expressed on melanoma cells and that the intrinsic dissociation rate for these adhesion molecules appear to be more dependent on what method is used to determine them than on what cells express them.
Insights
Polymorphonuclear leukocytes (PMNs) facilitate melanoma cell extravasation via beta2-integrins binding to ICAM-1. Dissociation rates are method-dependent, not cell-dependent, indicating constitutive PMN integrins are sufficient for melanoma cell adhesion.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Polymorphonuclear leukocytes (PMNs) are known to aid melanoma cell extravasation across the endothelium under shear stress.
- This interaction is primarily mediated by beta2-integrins on PMNs and intercellular adhesion molecule-1 (ICAM-1) on melanoma cells.
Purpose of the Study:
- To investigate the kinetics of interactions between melanoma cells and PMNs.
- To determine the dissociation rates of ICAM-1 interactions with beta2-integrins (LFA-1 and Mac-1) under low force conditions.
- To assess the effect of IL-8 stimulation on PMN kinetics.
Main Methods:
- Utilized a parallel plate flow chamber to study cell-cell interactions under shear conditions.
- Employed functional blocking antibodies on PMNs to isolate interactions with LFA-1 and Mac-1.
- Calculated dissociation rates for ICAM-1 and beta2-integrin interactions.
Main Results:
- The study found that a limited number of constitutively active beta2-integrins on PMNs are sufficient for binding to ICAM-1 on melanoma cells.
- Dissociation rates were found to be more influenced by the experimental method used for determination than by the expressing cell type.
- Kinetics of IL-8 stimulated PMNs were also characterized.
Conclusions:
- Constitutively expressed active beta2-integrins on PMNs play a sufficient role in melanoma cell adhesion.
- The intrinsic dissociation rate of these adhesion molecules is primarily method-dependent.
- Understanding these kinetics is crucial for deciphering melanoma cell metastasis mechanisms.
