In Situ Tolerance within the Central Nervous System as a Mechanism for Preventing Autoimmunity

Brabb, Thea; von Dassow, Peter; Ordonez, Nadia; Schnabel, Bryan; Duke, Blythe; Goverman, Joan

It is not yet clear whether in situ tolerance induction is unique to the CNS and constitutes an aspect of immune privilege of this organ, or whether tissue-specific tolerance occurs in other organs as well. Exposure of naive T cells to antigens within parenchymal tissues has been suggested as a basis for some forms of neonatal tolerance. T cell trafficking through extra-lymphoid tissues is thought to occur more extensively in neonates than in adult mice. However, in at least one example the tolerance induced in neonates by increased trafficking of peripheral tissues was systemic tolerance and did not result in the presence of tolerant T cells exclusively in the relevant tissue (39) . In contrast to these findings, we demonstrate that the tolerance to MBP within the CNS is tissue-specific rather than systemic.