Analysis of cell surface molecules on human platelets with monoclonal antibodies. II. Diversity of antibody-binding sites on molecules and its relation to platelet function.
The effects of 18 monoclonal antibodies (alpha-GPIb, alpha-GPIIb-IIIa, alpha-gp78, and alpha-p151) on platelet function were examined. Four anti-GPIIb-IIIa antibodies and twelve anti-GPIb antibodies were classified into two groups depending on their binding specificities in assays of antibody binding blocking. Of the four anti-GPIIb-IIIa antibodies, three completely inhibited platelet aggregation induced with ADP or collagen, while the other caused only partial inhibition. The first three antibodies showed identical specificity in antibody binding blocking assays. Of the twelve anti-GPIB antibodies, 4 completely inhibited platelet aggregation induced with ristocetin, 2 inhibited it partially, and the other 6 antibodies did not inhibit it at all. No direct correlation was observed between the ability of the antibodies to inhibit platelet aggregation and their binding specificities. The monoclonal antibodies anti-gp78 and anti-p151 did not affect any of the platelet functions examined.
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000936:Antigen-Antibody Complex; D000954:Antigens, Surface / Q000276:immunology*; D001777:Blood Coagulation; D001792:Blood Platelets / Q000502:physiology*; D002462:Cell Membrane / Q000276:immunology; D006023:Glycoproteins / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology / Q000502:physiology*; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D000954:Antigens, Surface; D006023:Glycoproteins; D008565:Membrane Proteins; D010980:Platelet Membrane Glycoproteins