title: Hapten-Ficoll conjugates induce T-cell-dependent IgM anti-hapten responses and T cells mediating hapten-specific delayed-type hypersensitivity.
abstract: It was generally believed until recently that the B-cell IgM response induced by type-II "thymus-independent" antigens, that are not mitogenic for B cells, was T cell independent. Neither has it been possible in the past to demonstrate that these antigens activate specific T cells. This has led to the general belief that type-II thymus-independent antigens have the anomalous property of not being able to activate such cells. Recent evidence has shown that the IgM response to hapten-Ficoll conjugates, the prototype of type-II thymus-independent antigens, is T cell dependent in at least some circumstances. Here evidence that these antigens activate T cells mediating hapten-specific delayed-type hypersensitivity (DTH) is presented. Furthermore, the conditions under which they do so are similar to those that allow thymus-dependent antigens to activate DTH-mediating T cells.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005362:Ficoll / Q000276:immunology*; D006241:Haptens / Q000276:immunology*; D006462:Hemolytic Plaque Technique; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D051379:Mice; D008808:Mice, Inbred CBA; D011134:Polysaccharides / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000939:Epitopes; D006241:Haptens; D007075:Immunoglobulin M; D011134:Polysaccharides; D014301:Trinitrobenzenes; D005362:Ficoll