Related Experiment Videos
Effect of polymeric IgG on human monocyte functions.
International Archives of Allergy and Applied Immunology
|January 1, 1987
Summary
Polymeric IgG down-modulates both Fc receptors and iC3b receptors on monocytes, impairing phagocytosis and bacterial killing. This receptor modulation affects crucial host defense mechanisms against pathogens.
Area of Science:
- Immunology
- Cell Biology
Background:
- Fc receptors (FcR) and complement fragment 3b/iC3b receptors (CR3) mediate critical phagocyte functions.
- These receptors are essential for immune adherence, phagocytosis, degranulation, and pathogen elimination.
Purpose of the Study:
- To investigate the effect of polymeric and monomeric IgG on Fc and iC3b receptor expression in human monocytes.
- To determine how IgG interactions modulate monocyte functions related to host defense.
Main Methods:
- In vitro treatment of human monocytes with polymeric and monomeric IgG.
- Analysis of Fc receptor (FcR) and iC3b receptor (CR3) expression.
- Assessment of monocyte functions including phagocytosis, oxygen metabolite release, and bacterial killing.
Main Results:
- Polymeric IgG in fluid phase induced concomitant down-modulation of both Fc and iC3b receptors on monocytes.
- Monomeric IgG only down-modulated Fc receptors when surface-bound, without affecting iC3b receptors.
- This receptor down-modulation correlated with reduced Fc receptor-mediated phagocytosis, decreased oxygen metabolite release, and impaired bacterial killing.
Conclusions:
- Down-modulation of Fc and iC3b receptors by fluid-phase polymeric IgG significantly impairs key monocyte functions.
- These findings highlight the potential impact on host defense mechanisms, as these receptors are vital for pathogen clearance.