A human monoclonal antibody specific for the leucine-33 (P1A1, HPA-1a) form of platelet glycoprotein IIIa from a V gene phage display library.
IgG alloantibodies to polymorphic platelet glycoproteins (GPs) are known to be responsible for severe thrombocytopenia in the neonate and after transfusion. Platelet GPIIIa can have either a leucine or a proline at residue 33. The most immunogenic platelet alloantigen in thrombocytopenia is the leucine 33 form of GPIIIa. Here, we have generated human monoclonal antibody fragments that are specific for the leucine and not the proline form of GPIIIa and can inhibit the binding of polyclonal human IgG alloantibodies to GPIIIa leucine 33 on platelets. The antibody fragments were selected from a library of single chain Fv fragments displayed on the surface of filamentous phage. The VH gene repertoire was derived from the peripheral blood lymphocytes of an alloimmunized individual and recombined with a VL gene repertoire from a nonimmune source. Antibodies such as these, which are able to distinguish between two variant forms of a native antigen and which have been unobtainable by conventional hybridoma technology, have both diagnostic and potential therapeutic applications.
Division of Transfusion Medicine, University of Cambridge, UK.
H M
HM
Griffin
W H
WH
Ouwehand
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D000918:Antibody Specificity; D015703:Antigens, CD / Q000276:immunology*; D016824:Antigens, Human Platelet / Q000276:immunology*; D001483:Base Sequence; D003090:Coliphages / Q000235:genetics; D005260:Female; D005803:Genes, Immunoglobulin; D006650:Histocompatibility Testing / Q000379:methods*; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology; D007075:Immunoglobulin M / Q000235:genetics / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D039661:Integrin beta3; D007518:Isoantibodies / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D007930:Leucine; D008214:Lymphocytes / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology*; D010641:Phenotype; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology*; D011247:Pregnancy; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D016415:Sequence Alignment; D017385:Sequence Homology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016824:Antigens, Human Platelet; C061248:ITGB3 protein, human; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D039661:Integrin beta3; D007518:Isoantibodies; D010446:Peptide Fragments; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011993:Recombinant Fusion Proteins; D007930:Leucine