[Comparative study of the myoid cells of human embryonal and adult thymus by the indirect immunofluorescence method].

The indirect immunofluorescence method showed that decreased (in comparison with myoid cells of adult human thymus) content of muscle antigens in the myoid elements of the embryonic organ caused a greater secretory activity of these elements at the early embryogenesis. Due to increased secretory activity of the myoid cells internal medium of the embryonic thymus contained more antigens common to the muscle tissue than the adult human thymus. The fact that during the ontogenesis the functional activity of the myoid cells correlated with the rate of lymphoid tissue formation favours a suggestion that heteroorganic antigens provide the thymus lymphocytes with information concerning the autoantigen structure necessary to induce natural immunological tolerance.