Characterization of Variable-Region Genes and Shared Crossreactive Idiotypes of Antibodies Specific for Antigens of Various Influenza Viruses

Several syngeneic monoclonal anti-idiotypic antibodies were obtained against PY206, a monoclonal antibody specific for X-31 (H₃N₂) influenza virus hemagglutinin. This idiotype was found in the sera of BALB/c mice immunized with various influenza viruses. Adsorption experiments indicated that the PY206 Id was borne by antibodies specific for viral hemagglutinin (HA) and/or neuraminidase (NA). This idiotype was identified on other monoclonal antibodies specific for various influenza HAs (H₃ and H₁). Study of the variable-region (V) genes of these monoclonal antibodies showed that its expression is independent of variable kappa (V_k)21 light-chains and that the heavy-chains of the strongly idiotype-positive hybridomas derive from either the variable heavy (V_H) J558 or V_H 7183 family. Finally, Western blot analysis demonstrated that PY206 idiotypic determinants are located exclusively on the heavy chain.