Antigen/major histocompatibility complex-specific activation of murine T cells transfected with functionally rearranged T-cell receptor genes.

The genes encoding the alpha and beta chains of the T-cell antigen receptor isolated from a cytochrome c-specific, major histocompatibility complex (MHC)-restricted murine T-cell hybridoma were introduced into a mouse T-cell line of helper lineage by electroporation. In order to examine the contributions of those gene products to antigen and/or MHC specificity, the resultant transfectants were tested for functional antigen and/or MHC recognition. Only those transfectants that express both the introduced genes (alpha and beta) contributed by the normal T cell can respond specifically to the appropriate antigen/MHC pair. None of the transfectants that express only one of the introduced genes (alpha or beta) of the normal T cell, or paired hybrid genes (i.e., one gene from the normal T cell and the other from the fusion partner), can respond to the same combination of antigen and MHC product recognized by the donor T cell. However, one clone expressing the transfected genes that encode the alpha and beta chains of the fusion partner shows reactivity to the antigen-presenting cells even in the absence of the antigens. These data suggest that the alpha beta heterodimer of the T-cell receptor is required to define the fine specificity of a T cell.