Alterations of the glycocalyx of Fc receptor-bearing cell lines during Fc receptor-ligand interactions.

The binding of IgG-coated erythrocytes to Fc receptors on both a lymphoblastoid and a macrophage-like cell line resulted in a decrease in thickness of the polyanionic, extracellular glycocalyx (cell coat) as determined by electron microscopic histochemistry. This decrease showed no correlation with ligand-binding sites and was considered to be a generalized extramembrane effect. Pretreatment of the cells with trypsin or neuraminidase produced decreases in thickness similar to those observed following ligand binding. The results suggest a possible role for enzymatic cleavage of extracellular constituents by morphologically and functionally different cell types and may represent an event common to cell-surface recognition.