Protective autoimmunity: regulation and prospects for vaccination after brain and spinal cord injuries.

Neuronal degeneration after traumatic injury to the central nervous system (CNS) can be reduced by active immunization or passive transfer of T cells against CNS-associated myelin antigens. We propose that a protective autoimmunity is evoked by CNS insult when non-immunological local protective mechanisms cannot adequately buffer the injury-induced toxicity. The ability of a particular strain to develop a protective autoimmune response appears to be inversely related to its susceptibility to autoimmune disease. We also propose that vaccination with specific CNS-derived'safe' (non-pathogenic) peptides after traumatic CNS insult, and possibly at any stage of chronic neurodegenerative disease, can be used to boost the protective autoimmunity and thereby to reduce further injury-induced damage. Such therapeutic vaccination ensures that the augmented beneficial autoimmunity will be free of accompanying disease.