Related Experiment Video
Updated: Aug 11, 2026
Assessment of Antibody-based Drugs Effects on Murine Bone Marrow and Peritoneal Macrophage Activation
Published on: December 26, 2017
IFN-gamma reduces specific binding of tumor necrosis factor on murine macrophages
1U 196 INSERM, Section de Biologie, Institut Curie, Paris, France.
Abstract:
Because IFN-gamma is the main cytokine activating macrophages and TNF cooperates in this activation, we assessed TNF binding capacity during the course of murine macrophage activation by IFN-gamma. TNF binding to elicited macrophages increased with time, was maximal by 8 h of culture, and required de novo protein synthesis. 125I-TNF bound to about 40,000 sites/cell with a Kd of 1 x 10(-9) M. Cross-linking experiments performed with a bifunctional cross-linking agent revealed a specific band with a m.w. of 94,000. Preincubation of macrophages with IFN-gamma prevented the binding of TNF to receptors. This effect was dose-dependent and maximal at 100 U/ml. IFN-gamma also reduced specific TNF binding to preexisting receptors (50% inhibition in 3 h), but IFN-gamma did not change the internalization rate of TNF. These studies showed that the number of TNF receptors increased on macrophages vs maturation in culture and was negatively controlled by IFN-gamma.
Insights
Interferon-gamma (IFN-gamma) negatively controls tumor necrosis factor (TNF) receptors on macrophages. While macrophage maturation increases TNF receptor numbers, IFN-gamma significantly reduces TNF binding capacity.
Area of Science:
- Immunology
- Cell Biology
- Cytokine Signaling
Background:
- Interferon-gamma (IFN-gamma) is a key cytokine for macrophage activation.
- Tumor necrosis factor (TNF) cooperates with IFN-gamma in macrophage activation.
- Understanding TNF receptor dynamics during macrophage activation is crucial.
Purpose of the Study:
- To investigate the binding capacity of TNF receptors on murine macrophages during IFN-gamma-induced activation.
- To determine the effect of IFN-gamma on TNF receptor expression and function.
Main Methods:
- Macrophage cultures were treated with IFN-gamma over time.
- 125I-TNF binding assays were performed to quantify TNF receptor number and affinity.
- Cross-linking experiments identified the molecular weight of the TNF receptor complex.
Main Results:
- TNF binding capacity increased with time during macrophage activation, peaking at 8 hours.
- TNF receptor expression requires de novo protein synthesis and involves approximately 40,000 sites/cell with a Kd of 1 x 10(-9) M.
- IFN-gamma preincubation dose-dependently inhibited TNF binding, reducing it by 50% within 3 hours without altering TNF internalization.
Conclusions:
- Macrophage maturation in culture leads to an increase in TNF receptor numbers.
- IFN-gamma negatively regulates the number of TNF receptors on macrophages.
- This study elucidates a novel regulatory mechanism of TNF signaling by IFN-gamma in macrophages.
More Related Videos
08:19Transfer of Manipulated Tumor-associated Neutrophils into Tumor-Bearing Mice to Study their Angiogenic Potential In Vivo
Published on: July 20, 2019
07:44Studying the Effects of Tumor-Secreted Paracrine Ligands on Macrophage Activation using Co-Culture with Permeable Membrane Supports
Published on: November 28, 2019
Related Concept Videos
02:26NF-κB-dependent Signaling Pathway
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
01:24Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF