immune pathogenesis of prion diseases

Prion infections do not elicit immune responses: antibodies to the prion protein are typically undetectable, and transmissble spongiform encephalopathies do not go along with conspicuous inflammatory infiltrates. However, prions accumulate in lymphoid organs. Most interestingly, various states of immune deficiency prevent peripheral prion infection. This review revisits the current evidence of the involvement of the immune system in prion diseases, and traces the mechanisms by which peripherally administered prions invade the brain and provoke damage