Influenza A hemagglutinin-specific T cell clones strictly restricted by HLA-DR1 or HLA-DR7 molecules.

The antigenic specificities, major histocompatibility complex restrictions and functional properties of influenza virus-specific proliferative cloned cell lines have been studied. These lines were specific for the H3 hemagglutinin subtype of influenza A viruses. By using a large panel of HLA-phenotyped antigen-presenting cells, it was found that the polymorphic structures, defined as DR1 and DR7 molecules, or closely associated structures, function as the restricting elements. We excluded for these lines a possible restricting role of supertypic specificities, known cross-reacting elements on DR molecules, or products of other loci in known linkage disequilibrium with the HLA-DR molecules. Such exquisitely restricted clones might be of great help in the class II typing of antigen-presenting cells. Their specific activity was stable for several months. This has allowed the study of some functional properties of these long-term-cultured cloned cell lines: interleukin 2 sensitivity and production, helper function in specific antibody synthesis and ability to stimulate in mixed leukocyte reactions.