title: The use of specific helper T cell clones to study the regulation of isotype expression by antigen-stimulated B cell clones.
abstract: In order to determine the mechanism by which helper T cells regulate the production of the various immunoglobulin (Ig) classes, a number of helper T cell clones specific for keyhole limpet hemocyanin (KLH) were generated. These helper T cell clones then were used in a modified splenic fragment system whereby cloned helper T cells and a source of B cells were limit-diluted into naive, lethally irradiated recipients. The B cell clones that were subsequently stimulated in such an assay system by the addition of the antigen 2,4-dinitrophenol (DNP)-KLH then were tested for the various isotypes produced. The results of these studies indicate that the use of a single helper T cell clone could result in the production of all known Ig isotypes including IgE. Moreover, the use of a single helper T cell clone could result in multiple isotype production by a single B cell clone. However, a comparison of the isotypes secreted by a number of different B cell clones that were stimulated with the same helper T cell clone indicated that a variety of isotypic patterns could be obtained. In addition, it was found that the majority of B cell clones produced in the presence of T cell clones secrete fewer numbers of different isotypes compared with B cell clones generated with a heterogeneous population of T cells. Finally, no evidence could be found for isotype-specific helper T cell clones, although a few of the T cell clones appeared to induce a somewhat restricted isotype pattern in which only two or three different isotypes were observed.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D004136:Dinitrobenzenes / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes / Q000276:immunology; D005260:Female; D006183:H-2 Antigens / Q000235:genetics; D006433:Hemocyanins; D006462:Hemolytic Plaque Technique; D007126:Immunoglobulin Allotypes / Q000032:analysis / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000941:Antigens; D004136:Dinitrobenzenes; D000939:Epitopes; D006183:H-2 Antigens; D007126:Immunoglobulin Allotypes; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin