title: Selective re-routing of prion protein to proteasomes and alteration of its vesicular secretion prevent PrP(Sc) formation.
abstract: Conversion of the cellular prion protein (PrP(C)) into the abnormal scrapie isoform (PrP(Sc)) is the hallmark of prion diseases, which are fatal and transmissible neurodegenerative disorders. ER-retained anti-prion recombinant single-chain Fv fragments have been proved to be an effective tool for inhibition of PrP(C) trafficking to the cell surface and antagonize PrP(Sc) formation and infectivity. In the present study, we have generated the secreted version of 8H4 intrabody (Sec-8H4) in order to compel PrP(C) outside the cells. The stable expression of the Sec-8H4 intrabodies induces proteasome degradation of endogenous prion protein but does not influence its glycosylation profile and maturation. Moreover, we found a dramatic diverting of PrP(C) traffic from its vesicular secretion and, most importantly, a total inhibition of PrP(Sc) accumulation in NGF-differentiated Sec-8H4 PC12 cells. These results confirm that perturbing the intracellular traffic of endogenous PrP(C) is an effective strategy to inhibit PrP(Sc) accumulation and provide convincing evidences for application of intracellular antibodies in prion diseases.
authors.affiliation: Department of Neuroscience and Laboratory of Clinical Biochemistry, University of Tor Vergata, Rome, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Filesi
authors.forename: Alessio
authors.initials: A
authors.lastname: Cardinale
authors.forename: Sonia
authors.initials: S
authors.lastname: Mattei
authors.forename: Silvia
authors.initials: S
authors.lastname: Biocca
mesh_terms: D000818:Animals; D002451:Cell Compartmentation; D002738:Chloroquine / Q000494:pharmacology; D007135:Immunoglobulin Variable Region / Q000276:immunology; D051379:Mice; D016716:PC12 Cells; D018621:PrPC Proteins / Q000276:immunology / Q000378:metabolism*; D018620:PrPSc Proteins / Q000096:biosynthesis* / Q000276:immunology; D017096:Prion Diseases / Q000517:prevention & control; D011480:Protease Inhibitors / Q000494:pharmacology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D051381:Rats
chemical_list: D007135:Immunoglobulin Variable Region; D018621:PrPC Proteins; D018620:PrPSc Proteins; D011480:Protease Inhibitors; D002738:Chloroquine; D046988:Proteasome Endopeptidase Complex