Analysis of the antigen specificity of influenza haemagglutinin-immune human T lymphocyte clones: identification of an immunodominant region for T cells.

Human T lymphocyte clones specific for the haemagglutinin (HA) molecule of A/Texas/1/77 were maintained in long-term culture with T cell-growth factor. The clones were analysed for their viral antigen specificity using serologically defined type A influenza subtypes and chemically synthesized peptides of the HA-1 molecule. With the exception of one T cell clone that recognized only the HA molecule used for immunization, the clones responded to determinants that showed partial or complete cross-reactivity amongst the strain A subtypes. The cross-reactive population of T cell clones were specific for peptides distinct from the antibody binding sites of HA. Furthermore, one peptide located at the carboxyl terminus of the HA-1 molecule appeared to be immunodominant, although the critical residues for T cell antigen recognition within that could not be identified.