Neutralizing epitopes specific for influenza B virus Yamagata group strains are in the 'loop'.
To study the neutralizing epitopes of influenza B virus Yamagata group strains, two monoclonal antibodies (mAbs) were used to select escape mutants of the virus. mAbs 5H4 and 3A12 were found to react with B/Yamagata group strains in haemagglutination inhibition and neutralization tests; no reactivity with B/Victoria group strains was observed. Most of the mutants reacted poorly to polyclonal ferret antibody against the 1998 isolate. Analysis of the deduced amino acid sequences identified a single amino acid substitution at residue 141 (Gly-->Arg) or 149 (Arg-->Gly) in 5H4-escape mutants and 141 (Gly-->Arg), 147 (Thr-->Ile) or 148 (Ser-->Gly) in 3A12-escape mutants. These residues are situated in close proximity in the 'loop' of the haemagglutinin molecule. These epitopes have been conserved in B/Yamagata group strains for almost 10 years in Japan but amino acid substitutions in the loop have been observed in clinical isolates only since 1999.
Nakagawa
Naoko
N
Department of Parasitic Agents, Kobe Institute of Health, 4-6, Minatojima-nakamachi, Chuo-ku, Kobe 650-0046, Japan.
Kubota
Ritsuko
R
Division of Virology, Department of Public Health, Osaka Prefectural Institute of Public Health, 3-69, 1-Chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
Nakagawa
Toshimasa
T
Department of Clinical Pathology, Osaka Medical College, 2-7 Daigaku-cho, Takatsuki 569-8686, Japan.
Okuno
Yoshinobu
Y
Division of Virology, Department of Public Health, Osaka Prefectural Institute of Public Health, 3-69, 1-Chome, Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology; D000939:Epitopes / Q000032:analysis* / Q000235:genetics; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D009981:Influenza B virus / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009500:Neutralization Tests; D013045:Species Specificity
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes