[The role of the immune system in the pathogenesis of prion diseases]

Prion diseases are disorders whose development is unclear. The incubation period of prion diseases is long and during this time there are distinct changes that can signal pathological changes in the organism. However, the appearance of the pathological form of the prion protein (PrP(Sc)) in the brain starts a rapid process of neurodegradation which always leads to death. In this article the participation of the immune system in the spread of prion diseases is discussed with special attention to the cells of this system and the substances they produce. Studies in this field apply to cells on which physiological prion protein (PrP(C)) appears or in which the accumulation of this protein has been observed. Many experiments show that first and principal center of pathological prion protein (PrP(Sc)) accumulation and replication is the immune system; however, no specific antibodies for PrP(Sc)protein have been found, though in many studies it was shown that elements of the immune system demonstrate major reactivity. In this article it is demonstrated that both immune system cells and substances produced by them are important in the development of prion diseases because they definitely contribute to PrP(Sc)spread in the infected organism.