Dependence of phagocytosis on strength of phagocyte-particle interaction

Sheep erythrocytes were pretreated with concanavalin A (Con-A-SRC), or glutaraldehyde (G-SRC), or specific rabbit immunoglobulin G (IgG-SRC), or specific rabbit immunoglobulin M and complement (C-SRC). Each erythrocyte type was made to adhere to rat peritoneal cells and adhesion was measured; binding decreased as follow: conA-SRC greater than IgG-SRC greater than less than G-SRC greater than C-SRC Peritoneal cell-erythrocyte complexes were then submitted to a laminar shear flow, and resistance of binding was assayed. Binging strength decreased in the following order: G-SRC greater than C-SRC greater than IgG-SRC greater than ConA-SRC Cell suspensions were incubated at 37 degrees, and phagocytosis was measured. Ingestion decreased in the following order: G-SRC greater than IgG-SRC greater than C-SRC greater than ConA-SRC It is concluded that: Binding strength may be of importance in triggering phagocytosis; when immunocytoadherence is studied, two independent parameters should be considered: binding and binding strength. This report describes a new method that may allow discrimination between different cell subpopulations of similar binding specificities.