title: Ku80 autoantigen as a cellular coreceptor for human parvovirus B19 infection.
abstract: Human parvovirus B19 (B19) infects human erythroid cells expressing P antigen. However, some cell lines that were positive for P antigen failed to bind B19, whereas some cell lines had an ability to bind B19 despite undetectable expression of P antigen. We here demonstrate that B19 specifically binds with Ku80 autoantigen on the cell surface. Furthermore, transfection of HeLa cells with the gene of Ku80 enabled the binding of B19 and allowed its entry into cells. Moreover, reduction of cell-surface expression of Ku80 in KU812Ep6 cells, which was a high-sensitive cell line for B19 infection, by short interfering RNA for Ku80 resulted in the marked inhibition of B19 binding in KU812Ep6 cells. Although Ku80 originally has been described as a nuclear protein, human bone marrow erythroid cells with glycophorin A or CD36, B cells with CD20, or T cells with CD3 were all positive for cell-surface expression of Ku80. B19 infection of KU812Ep6 cells and bone marrow cells was inhibited in the presence of anti-Ku80 antibody. Our data suggest that Ku80 functions as a novel coreceptor for B19 infection, and this finding may provide an explanation for the pathologic immunity associated with B19 infection.
authors.affiliation: Department of Rheumatology and Hematology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan. mnkt@mail.tains.tohoku.ac.jp
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Munakata
authors.forename: Takako
authors.initials: T
authors.lastname: Saito-Ito
authors.forename: Keiko
authors.initials: K
authors.lastname: Kumura-Ishii
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Takao
authors.initials: T
authors.lastname: Kodera
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ishii
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Hirabayashi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Koyanagi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D015703:Antigens, CD / Q000276:immunology; D034961:Antigens, Nuclear / Q000276:immunology*; D001854:Bone Marrow Cells; D002462:Cell Membrane / Q000276:immunology; D004268:DNA-Binding Proteins / Q000276:immunology*; D041905:Erythroid Cells / Q000276:immunology* / Q000821:virology; D005786:Gene Expression Regulation / Q000276:immunology; D006367:HeLa Cells; D006801:Humans; D000072200:Ku Autoantigen; D010127:P Blood-Group System / Q000097:blood / Q000276:immunology; D010322:Parvoviridae Infections / Q000097:blood / Q000276:immunology*; D016732:Parvovirus B19, Human / Q000276:immunology*; D011991:Receptors, Virus / Q000276:immunology*; D020298:U937 Cells
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D010127:P Blood-Group System; D011991:Receptors, Virus; C101479:parvovirus B19 receptor; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen