title: T-cell antigen receptors with identical variable regions but different diversity and joining region gene segments have distinct specificities but cross-reactive idiotypes.
abstract: The T-cell antigen receptor alpha-chain genes of an alloreactive, H-2Db-specific cytotoxic T-cell clone (3F9) are described. This study and our work on the 3F9 beta-chain genes reveal that the variable region gene segments for the alpha and beta chains expressed in 3F9 are identical to the ones used by a chicken erythrocyte-specific, I-Ab-restricted helper T-cell clone (LB2). These two clones differ, however, in the diversity and joining portions of the alpha and beta chains of their T-cell receptor molecules. The analysis of 3F9 and LB2 with monoclonal antibodies specific for the 3F9 T-cell receptor shows that these two T-cell clones share the same idiotype; however, 3F9 and LB2 do not exhibit any antigen and/or major histocompatibility complex cross-reactivity. This suggests that the diversity and joining regions of the T-cell receptor may play a key role in antigen and/or major histocompatibility complex recognition.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004247:DNA / Q000032:analysis; D005796:Genes; D007130:Immunoglobulin Idiotypes / Q000235:genetics* / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics* / Q000276:immunology; D008213:Lymphocyte Activation; D046911:Macromolecular Substances; D051379:Mice; D008807:Mice, Inbred BALB C; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D007130:Immunoglobulin Idiotypes; D007135:Immunoglobulin Variable Region; D046911:Macromolecular Substances; D011948:Receptors, Antigen, T-Cell; D004247:DNA