title: Surface expression and partial characterization of an arsonate hapten-specific idiotype-bearing T-cell receptor.
abstract: Anti-idiotype antibodies raised against the arsonate hapten idiotype have been used to detect arsonate-binding receptors on the surface of peripheral T cells of A/J mice and to isolate this material after biosynthetic labeling for partial chemical characterization. It was found that 2-3% of splenic T cells from arsonate-immune mice specifically bound the hapten using immunofluorescent keyhole limpet hemocyanin as a carrier. In double-immunofluorescence labeling experiments, a high proportion (approximately equal to 70%) of these cells also bound the (Fab')2 fragment of rabbit anti-idiotype antibody in exactly the same patches on the cell as the arsonate hemocyanin antigen. In addition, the anti-idiotype antibody inhibited the binding of the hapten-carrier complex to T cells by approximately equal to 70%. In parallel experiments, fowl antibodies against mouse (Fab')2 fragments bound to 100% of arsonate-binding T cells in the same cell-surface patches as the hapten, and were capable of inhibiting 100% of the hapten-binding cells. Capping, shedding, and resynthesis experiments indicated that the T cells synthesized their antigen-binding idiotype-bearing receptors. Immunoblots of unreduced detergent extracts of purified splenic T cells developed with anti-idiotype antibodies showed bands at 150,000 and 94,000 Da. Equal amounts of protein extracted from liver and analyzed in the same gels as the T-cell material failed to show any reactivity with anti-idiotype antibodies. To confirm the biosynthetic origin of the idiotype-positive materials, detergent extracts from 75Se-methionine- or [3H]leucine-labeled Con A-treated splenic T cells were reacted with anti-idiotype antibodies and the bound material was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the presence of 2-mercaptoethanol the major band was at 68,000 Da, with variable minor levels of material at 45,000 Da, while when hapten was used to isolate the receptor a dominant 25,000- to 30,000-Da band was seen. We believe that the higher-molecular-weight materials are multimers of the 25,000-30,000 subunit.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D001391:Azo Compounds / Q000276:immunology*; D002645:Chickens / Q000276:immunology; D003429:Cross Reactions; D006241:Haptens / Q000276:immunology; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D008024:Ligands / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D051379:Mice; D008805:Mice, Inbred A / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D010132:p-Azobenzenearsonate / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001391:Azo Compounds; D006241:Haptens; D007140:Immunoglobulin Fab Fragments; D007130:Immunoglobulin Idiotypes; D008024:Ligands; D011948:Receptors, Antigen, T-Cell; D010132:p-Azobenzenearsonate