Thymic myoid cells as a myasthenogenic antigen and antigen-presenting cells.

We investigated immune property of a myoid cell line, established from Fisher rat thymus. Immunization of syngeneic rats with the myoid cells induced anti-rat acetylcholine receptor (AChR). Implantation of them into the thymus failed to induce typical thymic pathology of human myasthenia gravis (MG) or anti-AChR responses. We also demonstrated that the myoid cells were able to present exogenous antigens to T cells and induce antigen-specific T cell proliferation. These results suggest that myoid cells have the potential antigenicity to induce anti-AChR and the functions of antigen-presenting cells, but their expansion in the thymus may not directly cause MG.