A monoclonal antibody produced during infection which recognizes an epitope of influenza hemagglutinin only in the context of H-2k MHC class I antigen.

A hybridoma prepared from cells isolated from the lungs of H-2k mice infected with influenza virus (A/WSN) produces a monoclonal IgM (LM41) which recognizes an epitope of the A/WSN hemagglutinin (HA) Ag only when it is expressed in H-2k cells, as shown by Ag binding and complement-mediated lysis. However, it did not bind to the native HA of virus particles or any form of HA protein present on A/WSN-infected H-2d cells. LM41 inhibited Ag-specific, MHC class I-restricted lysis of H-2k target cells infected with a vaccinia recombinant virus expressing the HA of A/WSN by CTL from A/WSN virus-infected H-2k mice. We conclude that LM41 has a similar Ag specificity to the HA-specific TCR.