The Mechanism Underlying Protective Autoimmunity

Studies from several laboratories have shown that T cells patrol the healthy CNS, but do not accumulate there. The recent data suggest that, in the event of an acute injury or chronic neurodegenerative condition, T cells are recruited by and accumulate in the CNS (Hirschberg et al., 1998 Moalem et al., 1999a), where they might rescue neurons from degeneration if the damage caused by the toxic biochemical environment is not yet irreversible moreover, the recruited T cells will prevent further deterioration. It is also possible that this autoimmune protective mechanism also operates when the 

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