MONOCLONAL-ANTIBODIES TO VONWILLEBRANDS FACTOR - REACTIVITY WITH PORCINE AND HUMAN-ANTIGENS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 58  (3) , 530-536
Abstract
Monoclonal antibodies to porcine von Willebrand''s factor (vWf) were obtained from hybridomas derived from the fusion of [mouse] NS-1 plasmacytoma cells and spleen cells from immunized BALB/c mice. Twenty hybrids were positive in a radioimmunoassay (RIA) based on the ability of immobilized hybridoma antibodies to bind porcine vWf as detected by the subsequent binding of 125I-polyclonal rabbit anti-vWf. Growth of the hybridomas as ascitic tumors yielded fluids having titers in this assay ranging from 8 .times. 107 to 8 .times. 1011. All the antibodies were positive when normal, but not von Willebrand''s, plasma was used as the source of antigen in this RIA, and when normal, but not von Willebrand''s, acetone-fixed platelets were used in an indirect immunofluorescence assay. Two of these antibodies inhibited ristocetin-induced platelet aggregation and platelet aggregating factor. In a 2nd RIA, only 13 were able to bind to vWf adsorbed directly to polystyrene. Ten of the 20 antibodies were reactive with human vWf; 2 of these would not react with human antigen in the presence of 2 M NaCl. Based on these assays, 6 reactivity groups of antibodies were identified.