Apoptotic cell death of T-lymphocytes in experimental autoimmune neuritis of the Lewis rat.

The present study describes apoptosis of T-lymphocytes in the sciatic nerve in experimental autoimmune neuritis (EAN), a T-cell mediated disorder of the peripheral nervous system (PNS). Morphological signs characteristic for apoptotic cell death were found from day 4 onwards, peaking at day 7. Apoptosis of T-cells could be detected throughout the subsequent recovery period. In situ nick translation (ISNT) followed by immunocytochemical analysis confirmed the presence of DNA fragmentation in T-lymphocytes. We thus show for the first time that apoptosis is not a unique elimination mechanism of inflammatory T-cells in the central nervous system (CNS), but is operative in the PNS as well although at a lesser degree. Identifying the underlying mechanisms may provide a basis for the development of new therapeutic strategies in autoimmune disorders.