Macrophage Surface Affinity Changes During Phagocytosis
We have used a combination of surface thermodynamic, spectro-photometric and morphometric techniques to investigate the mechanism of particle ingestion (phagocytosis) by isolated alveolar macrophages. We studied the time and dose-dependence of the effects on macrophages of both structurally specific particles (serum complement-opsonised zymosan) and non-specific particles (non-opsonised silica). Particle exposure increased the cell affinity for the dextran phase of 4% Dextran 2M/4% PEG 20K phases in a dose-and opsonin-dependent manner which correlated well with biochemical and morphological assessment of cell activation. We do not yet know the structural basis of the cell surface changes which are responsible for the alterations in polymer phase affinity, but likely candidates are phagocytosis-induced changes in the amount, conformation or molecular weight of membrane glycoproteins.
KeywordsContact Angle Alveolar Macrophage Aryl Sulfatase Interfacial Free Energy Cell Surface Area
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