Syngeneic sensitization of mouse lymphocytes on monolayers of thyroid epithelial cells. IX. Thyroid epithelial cells are antigen presenting cells.
We observed T lymphoblast generation after three days of culture of normal spleen lymphocytes on monolayers of syngeneic thyroid epithelial cells. It appears that only these T lymphoblasts sensitized on thyroid monolayers are specifically labelled by fluorescein-conjugated thyroglobulin. In this study, the role of thyroglobulin, and the manner in which it is presented to syngeneic T cells bearing receptors for thyroglobulin were investigated. It appears that thyroglobulin plays a key role in primary syngeneic sensitization of spleen cells in vitro, but its action is not exclusive. Proteins, which are encoded by a gene located in the I-A subregion level of the major histocompatibility complex, are capable of inducing a primary proliferative signal when the presentation of syngeneic class II antigens by syngeneic thyroid epithelial cells is simultaneous. In addition, thyroglobulin-pulsed macrophages are not able to do so. In contrast, once this primary syngeneic T cell proliferation has been accomplished, soluble thyroglobulin is sufficient to induce a secondary response by these syngeneic T cells.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D001667:Binding, Competitive; D002478:Cells, Cultured; D004847:Epithelial Cells; D004848:Epithelium / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008815:Mice, Inbred Strains; D013601:T-Lymphocytes / Q000276:immunology*; D013954:Thyroglobulin / Q000276:immunology; D013961:Thyroid Gland / Q000166:cytology / Q000276:immunology*
D001323:Autoantibodies; D013954:Thyroglobulin