Preparation of influenza virus subviral particles lacking the HA1 subunit of hemagglutinin: unmasking of cross-reactive HA2 determinants

Virology. 1983 Apr 15;126(1):106-16. doi: 10.1016/0042-6822(83)90465-8.


Acid treatment of influenza A and B virus preparations followed by addition of dithiothreitol (DTT) and centrifugation through a sucrose cushion removes the HA1 subunit of hemagglutinin from virus. Rabbit sera made against these subviral particles and untreated virus were tested in a radioimmune precipitation assay using [35S]cysteine-labeled virus. Conditions of the assay permitted discrimination of discrete HA1- and HA2-specific antibody populations. It was found that (a) sera raised to intact influenza A virus preparations contained both HA1- and HA-2 specific antibodies, (b) sera made to subviral particles of influenza A virus contained HA2-specific antibody but had little or no detectable HA1-specific antibody. (c) the HA2-specific antibodies were partially cross-reactive with the HA2 of an influenza A virus of a different subtype, and (d) sera raised against two strains of untreated influenza B viruses contained antibodies which were cross-reactive with the HA2 as well as the NP of influenza A viruses.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cross Reactions
  • Dithiothreitol / pharmacology
  • Epitopes
  • Hemagglutinins, Viral / immunology*
  • Hydrogen-Ion Concentration
  • Influenza A virus / classification
  • Influenza A virus / immunology*
  • Orthomyxoviridae / immunology*
  • Precipitin Tests


  • Epitopes
  • Hemagglutinins, Viral
  • Dithiothreitol