title: Recovery of small infectious PrP(res) aggregates from prion-infected cultured cells.
abstract: Prion diseases are characterized by deposits of abnormal conformers of the PrP protein. Although large aggregates of proteinase K-resistant PrP (PrP(res)) are infectious, the precise relationships between aggregation state and infectivity remain to be established. In this study, we have fractionated detergent lysates from prion-infected cultured cells by differential ultracentrifugation and ultrafiltration and have characterized a previously unnoticed PrP species. This abnormal form is resistant to proteinase K digestion but, in contrast to typical aggregated PrP(res), remains in the soluble fraction at intermediate centrifugal forces and is not retained by filters of 300-kDa cutoff. Cell-based assay and inoculation to animals demonstrate that these entities are infectious. The finding that cell-derived small infectious PrP(res) aggregates can be recovered in the absence of strong in vitro denaturating treatments now gives a biological basis for investigating the role of small PrP aggregates in the pathogenicity and/or the multiplication cycle of prions.
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France.
authors.forename: Zaira E Arellano
authors.initials: ZEA
authors.lastname: Anaya
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Savistchenko
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Massonneau
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Lacroux
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Andréoletti
authors.affiliation: From the Institut National Recherche Agronomique, Unité Mixte Recherche 1225, Interactions Hôtes-Agents Pathogènes, Université Toulouse, Institut National Polytechnique, Ecole Nationale Vétérinaire de Toulouse, F31076 Toulouse, France. Electronic address: d.vilette@envt.fr.
authors.forename: Didier
authors.initials: D
authors.lastname: Vilette
mesh_terms: D000818:Animals; D002460:Cell Line; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D018620:PrPSc Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity; D017096:Prion Diseases / Q000235:genetics / Q000378:metabolism*; D012756:Sheep
chemical_list: D018620:PrPSc Proteins