Concanavalin A-mediated binding and sphering of human red blood cells by homologous monocytes.
Human red blood cells sensitized with concanavalin A became bound to homologous peripheral blood monocytes. Binding occured at a concentration of 10(5) molecules of tetrameric Con A per red blood cell (RBC) and increased with additional Con A. RBC binding began within 5 min and was maximal at 90 min. Phagocytosis of sensitized RBCs was minimal. RBC attachment was prevented by 0.01 M alpha-methyl-D-mannopyranoside, and, once the RBC-monocyte rosette was established, bound RBCs were largely removed with this specific saccharide inhibitor of Con A. RBCs attached to monocytes became spherocytic and osmotically fragile. The recognition of concanavalin A (Con A)-coated RBCs was not mediated through the monocyte IgG-Fc receptor. These studies demonstrate that, like IgG and C3b, Con A is capable of mediating the binding of human RBCs to human monocytes. Red cells so bound are damaged at the monocyte surface.
D001665:Binding Sites; D002448:Cell Adhesion / Q000187:drug effects*; D003208:Concanavalin A / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G; D007700:Kinetics; D009000:Monocytes / Q000378:metabolism / Q000502:physiology*; D009994:Osmolar Concentration; D010587:Phagocytosis; D011952:Receptors, Concanavalin A / Q000378:metabolism
D007074:Immunoglobulin G; D011952:Receptors, Concanavalin A; D003208:Concanavalin A