Methods are provided for treating injury to or disease of the central or peripheral nervous system. In one embodiment, treatment is effected by administering activated T cells that recognize an antigen of Cop 1 or a Cop 1-related peptide or polypeptide to promote nerve regeneration or to prevent or inhibit neuronal degeneration within the nervous system. In another embodiment, treatment involves administering Cop 1 or a Cop 1-related peptide or polypeptide to promote nerve regeneration or to prevent or inhibit neuronal degeneration in the nervous system, either the central nervous system or the peripheral nervous system. The activated T cells, which have been activated by the presence of Cop 1 or a Cop 1-related peptide or polypeptide, can be administered alone or in combination with Cop 1 or a Cop 1-related peptide or polypeptide.