title: A new autoreactive monoclonal antibody specific for the Thy-1 antigen.
abstract: The present study describes the development of a new IgM monoclonal autoantibody reactive with the Thy-1 antigen. The C16-31 monoclonal antibody (mAb) was considered as autoreactive because it reacted with thymus cells of both the C3H and BALB/c strains, which were involved in the development of the antibody. The antibody was reactive with thymus cells in both immunofluorescent and cytotoxic tests. It also showed a weak immunofluorescent reactivity with peripheral T-lymphocytes. The identification of the specificity detected by the C16-31 mAb as the Thy-1 antigen was based on the following criteria: C16-31 mAB displayed a preferential reactivity with Thy-1.2 bearing thymus cells, rather than with Thy-1.1 bearing thymus cells. The tissue distribution of the antigen detected by the C16-31 antibody by direct tests and by direct tests and by adsorption experiments was in accordance with that characteristic for Thy-1. It was high on brain tissue and on thymus cells, and considerably lower on peripheral T-lymphocytes. Coating of thymocytes with C16-31 antibody blocked their reactivity with other monoclonal Thy-1 antibodies. Conversely, coating of thymus cells with rabbit anti-brain serum (RABR) inhibited the binding of C16-31. The C16-31 mAb differed from the Thy-1 autoantibodies described previously in its relatively strong reactivity with brain tissue and its considerably weaker reactivity with peripheral T-lymphocytes. Moreover, C16-31 mAb showed a preferential allospecificity for Thy-1.2, only in its reactivity with thymocytes. In contrast, it reacted equally well with brain tissue from either Thy-1.2 or Thy-1.1 mice.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D001667:Binding, Competitive; D001921:Brain / Q000276:immunology; D003429:Cross Reactions; D003601:Cytotoxicity Tests, Immunologic; D005455:Fluorescent Antibody Technique; D006825:Hybridomas / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D018800:Thy-1 Antigens