title: The idiotypic network and the internal image: possible regulation of a germ-line network by paucigene encoded Ab2 (anti-idiotypic) antibodies in the GAT system.
abstract: Heavy and light chain variable regions from eight monoclonal Ab2 (anti-idiotypic) antibodies of the GAT antigen, a (Glu60 Ala30 Tyr10)n co-polymer, have been analyzed by direct mRNA sequencing. Three mAb2s were directed against private idiotopes and used various VH-D-JH and Vk-Jk combinations. By contrast, the five 'anti-public' mAb2 antibodies used a very restricted repertoire, including all gene segments. Interestingly, within their D regions, Glu-Glu-Tyr or Tyr-Tyr-Glu sequences were reminiscent of the original (GAT) antigen and may act as possible internal images. A striking observation was that two mAb2 antibodies shared the same V-D-J sequence although derived from separate fusions. As this D sequence, 33 nucleotides long, has not been described so far, it is suggested that it may be encoded by a new germ-line D gene, acting as a crucial regulatory element in a GAT germ-line idiotypic network. An alternative model that may lead to the construction of this D segment by 'odd' rearrangements from pre-existing already reported sequences is also presented.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001483:Base Sequence; D005796:Genes; D006825:Hybridomas / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007130:Immunoglobulin Idiotypes / Q000235:genetics*; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D007143:Immunoglobulin Heavy Chains; D007130:Immunoglobulin Idiotypes; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D010455:Peptides; C022204:anti-GAT antibodies, idiotypic