Prion strain-specific structure and pathology: A view from the perspective of glycobiology

Abstract

Prion diseases display multiple disease phenotypes characterized by diverse clinical symptoms, different brain regions affected by the disease, distinct cell tropism and diverse PrP Sc deposition patterns. The diversity of disease phenotypes within the same host is attributed to the ability of PrP C to acquire multiple, alternative, conformationally distinct, self-replicating PrP Sc states referred to as prion strains or subtypes. Structural diversity of PrP Sc strains has been well documented, yet the question of how different PrP Sc structures elicit multiple disease phenotypes remains poorly understood. The current article reviews emerging evidence suggesting that carbohydrates in the form of sialylated N-linked glycans, which are a constitutive part of PrP Sc , are important players in defining strain-specific structures and disease phenotypes. This article introduces a new hypothesis, according to which individual strain-specific PrP Sc structures govern selection of PrP C sialoglycoforms that form strain-specific patterns of carbohydrate epitopes on PrP Sc surface and contribute to defining the disease phenotype and outcomes. � 2018 by the authors. Licensee MDPI, Basel, Switzerland.