title: Antigenic variants with amino acid deletions clarify a neutralizing epitope specific for influenza B virus Victoria group strains.
abstract: To study the neutralizing epitopes of influenza B virus Victoria group strains, two monoclonal antibodies (MAbs) were used to select antigenic variants of the virus. MAbs 10B8 and 8E6 were found to react with B/Victoria group strains in three tests, peroxidase-antiperoxidase staining, haemagglutination inhibition and neutralization tests; no reactivity with B/Yamagata group strains was observed. Analysis of the deduced amino acid sequences of 10B8-induced variants identified a single amino acid deletion at residue 165 or 170, as well as a single amino acid substitution at residues 164 (Asp-->Tyr), 165 (Asn-->Ser or Thr) or 203 (Lys-->Thr or Asn). A single amino acid substitution at residue 241 (Pro-->Ser) was observed in 8E6-induced variants. Three-dimensional analysis showed that the epitopes for both MAbs were situated in close proximity to each other. Since B/Yamagata group strains are characterized by amino acid deletions at residues 164-166, the epitope for MAb 10B8 is strictly specific for B/Victoria group strains.
authors.affiliation: Division of Virology, Department Public Health, Osaka Prefectural Institute of Public Health, 3-69 1-Chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan1.
authors.forename: Naoko
authors.initials: N
authors.lastname: Nakagawa
authors.affiliation: Division of Virology, Department Public Health, Osaka Prefectural Institute of Public Health, 3-69 1-Chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan1.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Kubota
authors.affiliation: Department of Clinical Pathology, Osaka Medical College, 2-7 Daigaku-cho, Takatsuki 569-8686, Japan2.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Division of Virology, Department Public Health, Osaka Prefectural Institute of Public Health, 3-69 1-Chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan1.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Okuno
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000276:immunology*; D007124:Immunoenzyme Techniques; D009981:Influenza B virus / Q000145:classification / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D013329:Structure-Activity Relationship
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus