Cross-reactivity for different type A influenza viruses of a cloned T-killer cell line

Spleen cytotoxic T cells killing influenza virus-infected target cells are cross-reactive for the different type A influenza viruses, in contrast to the circulating antibodies, which show fine specificity for each A virus subtype variant. This finding has raised the question of whether a single T cell can recognize cells infected with all type A viruses. T-killer cell lines with specificity for alloantigens and the male Y antigen can be selected by means of growth factors present in the supernatant of T cells stimulated with concanavalin A (refs 3-7). We report here that we have been able to establish clones of mouse T cells killing target cells infected with influenza virus. Our cell line maintains the same specificity as the heterogeneous spleen cell population from infected mice, in as far as the T-killer cells are specific for A influenza virus, but do not discriminate between the different type A viruses. The cell line maintains H-2 restriction and does not kill cells infected with B influenza virus. The cells grow in the presence of T-cell growth factor and do not require antigen for growth although they maintain their receptors for type A virus. They can also be stimulated by irradiated T-helper cells from mice primed by type A influenza infection in the presence of type A virus-infected cells.