title: T helper lymphocytes recognize the VL domain of the isologous mouse myeloma protein 315.
abstract: The localization of a major determinant on an isologous myeloma protein (M315) which stimulates BALB/c helper T cells was investigated. Augmentation of the adoptive secondary antibody response to NIP-M315 and the idiotype of M315 (Id315) was used as an indicator of helper effects. Spleen cells primed with the light chain of M315 (L315) and its V-domain (VL315) were highly efficient helpers; priming with the fragment containing the two V-domains of M315 (FV315) induced a somewhat weaker helper effect than L315 or VL315. The helper effect was abolished or markedly reduced by treating the primed cells with rabbit anti-brain theta + C. Cells primed with the heavy chain of M315 (H315) effected weak but significant help. The V-domain of H315 (VH315) was incapable of eliciting cells with detectable helper effect. The data indicate that the VL315 embodies a major determinant for T helper lymphocytes. This determinant is expressed on the free VL315 as well as on the complete M315. In contrast, previous studies have shown that BALB/c antibodies produced against Id315 recognize antigenic sites that are only displayed on associated (VL315 + VH315) domains.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000961:Antilymphocyte Serum / Q000494:pharmacology; D000939:Epitopes; D007114:Immunization; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009194:Myeloma Proteins / Q000276:immunology*; D009592:Nitrohydroxyiodophenylacetate / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000961:Antilymphocyte Serum; D000939:Epitopes; D009194:Myeloma Proteins; D009592:Nitrohydroxyiodophenylacetate