Maintenance of immunologic self-tolerance by nonimmunogenic forms of antigen.

Immunologic tolerance to EAE in guinea-pigs appears to be a function of a determinant distinct from the encephalitogenic region of the myelin basic protein molecule. In Lewis rats (in which species the molecular sites for disease-induction and tolerance have not been completely characterized) the mechanism underlying this state of immunologic tolerance involves suppressor cell regulation of the autoimmune response. On the basis of these experimental findings we postulate that natural self-tolerance is maintained by suppressor T cells which are stimulated by nonimmunogenic fragments of self-antigen released during protein turnover.