title: Cross-reaction of antibody against Helicobacter pylori urease B with platelet glycoprotein IIIa and its significance in the pathogenesis of immune thrombocytopenic purpura.
abstract: Many clinical investigations have suggested that Helicobacter pylori (H. pylori) infection might be associated with immune thrombocytopenic purpura (ITP), but its role in the pathogenesis of ITP is unsettled. In this study, we cultured H. pylori, produced recombinant H. pylori urease (ure) B, and then prepared monoclonal antibody (MoAb) against ureB, 1F11, both 1F11 and MoAb against human platelet glycoprotein (GP) IIIa, SZ21, could bind to the band of GP IIIa of normal platelet lysate, but not to that from a patient with Glanzmann thrombasthenia (GT) whose GP IIb-IIIa complex was absent. Flow cytometry showed that normal platelets were reacted with 1F11 and SZ21, while GT platelets were not. In immuno-radiometric assay, the binding of (125)I-labeled 1F11 to GP IIIa was higher than that to GP Ib, GP IIb, GP VI, and P-selectin. 1F11 could partly compete with SZ21 in a binding to platelet surface. In addition, 1F11 inhibited platelet aggregation induced by adenosine diphosphate, but had no effect on platelet P-selectin expression or Thromboxane B(2) production of platelets. These results indicate that H. pylori ureB antibody could cross-react with human platelet GP IIIa and partly inhibit platelet aggregation. UreB may be a crucial component of H. pylori involved in the pathogenesis of a subset of ITP.
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China. zwang11@sina.com.
authors.forename: Zhaoyue
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Bai
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Cao
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China.
authors.forename: Changgeng
authors.initials: C
authors.lastname: Ruan
mesh_terms: D000914:Antibodies, Viral; D003429:Cross Reactions / Q000276:immunology*; D016480:Helicobacter pylori / Q000201:enzymology / Q000276:immunology*; D006801:Humans; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000276:immunology*; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000209:etiology* / Q000276:immunology / Q000821:virology; D014510:Urease / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D014510:Urease