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Updated: Jul 5, 2026
Use of a Monocyte Monolayer Assay to Evaluate Fcγ Receptor-mediated Phagocytosis
Published on: January 2, 2017
Measurement of Fc gamma receptor-mediated binding and phagocytosis
Alexander D Politis1, Stefanie N Vogel
1National Institute of Health, Bethesda, Maryland, USA.
Insights
This study details functional assays to measure macrophage Fc gamma receptor (FcγR) surface expression. These methods use sheep red blood cells to quantify FcγR-mediated phagocytosis and binding, aiding in understanding immune responses.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Macrophage Fc gamma receptors (FcγRs) are critical for immune responses.
- Quantifying FcγR surface expression is essential for understanding macrophage function.
- Functional assays provide direct measurement of FcγR activity.
Purpose of the Study:
- To describe reliable functional assays for quantifying macrophage FcγR surface expression.
- To provide methods for assessing FcγR-mediated phagocytosis and binding.
- To enable discrimination between FcγR subclasses involved in immune cell interactions.
Main Methods:
- Utilizing IgG-opsonized sheep red blood cells (SRBC) labeled with Na2 51CrO4.
- Implementing a Basic Protocol to measure phagocytosis of target cells after modulating FcγR expression.
- Employing an Alternate Protocol to measure FcγR-mediated binding of target cells to macrophages.
Main Results:
- Demonstrated functional assays accurately quantify macrophage FcγR surface expression.
- Successfully measured FcγR-mediated phagocytosis and binding using labeled SRBC.
- Showcased the ability to differentiate FcγR subclass involvement through opsonin choice.
Conclusions:
- Functional assays provide a robust method for assessing macrophage FcγR activity.
- These assays are valuable tools for immunological research and drug discovery.
- Understanding FcγR expression is key to modulating immune cell interactions and responses.
Abstract:
This unit describes functional assays that quantify macrophage FcgammaR surface expression. In each assay, IgG-opsonized sheep red blood cells (SRBC) labeled with Na2 51CrO4 are used to detect interaction with macrophages. The Basic Protocol measures phagocytosis of target cells following treatment of macrophages with agents known to modulate FcgammaR expression. The Alternate Protocol describes a method that can be used to measure FcgammaR-mediated binding of target cells to macrophages. A choice of opsonin in both methods allows for some discrimination between subclasses of FcgammaRs that are responsible for the observed results.
