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Antibody Binding Specificity for Kappa (Vκ) Light Chain-containing Human (IgM) Antibodies: Polysialic Acid (PSA) Attached to NCAM as a Case Study
Published on: June 29, 2016
Adsorbed IgG: a potent adhesive substrate for human macrophages
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Journal of Biomedical Materials Research
|March 29, 2000
Summary
Preabsorbed IgG significantly enhances macrophage adhesion to poor substrates. The Fab and F(ab'')(2) fragments are effective, but the Fc fragment is not, suggesting non-Fc receptor mechanisms.
Area of Science:
- Immunology
- Cell Biology
- Biomaterials Science
Background:
- Previous studies indicated IgG enhances macrophage adhesion in vitro.
- Human monocyte/macrophage cultures are typically poorly adherent to Plastek M (PM).
Purpose of the Study:
- Quantify the effect of adsorbed human IgG on human macrophage adhesion.
- Investigate the mechanisms underlying IgG-mediated macrophage adhesion.
Main Methods:
- Human monocyte/macrophage cultures on Plastek M (PM).
- Quantification of macrophage adhesion enhancement by preabsorbed IgG.
- Radioiodine ((125)I) adsorption studies of IgG and its fragments (Fab, F(abeitet')(2), Fc).
Main Results:
- Optimal IgG adsorption concentration determined as 200 microg/mL for consistent cellular response.
- IgG adsorption followed Langmuir-style kinetics at low concentrations without a clear maximum.
- IgG fragments (Fab, F(abeitet')(2), Fc) adsorbed at 20-40% of whole IgG levels.
- Fab and F(abeitet')(2) fragments enhanced adhesion similarly to whole IgG.
- Fc fragment showed no activity, ruling out Fc receptor involvement.
Conclusions:
- Adsorbed IgG significantly enhances macrophage adhesion to poor substrates like PM.
- The adhesion-enhancing activity resides in the Fab and F(abeitet')(2) regions, not Fc.
- Potential mechanisms may involve macrophage lectins, novel Fab receptors, or complement activation.
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