title: Bovine prion is endocytosed by human enterocytes via the 37 kDa/67 kDa laminin receptor.
abstract: Some forms of transmissible spongiform encephalopathies result from oral infection. We have thus analyzed the early mechanisms that could account for an uptake of infectious prion particles by enterocytes, the major cell population of the intestinal epithelium. Human Caco-2/TC7 enterocytes cultured on microporous filters were incubated with different prion strains and contaminated brain homogenates in the apical compartment. Internalization of infectious particles was analyzed by Western blotting and immunofluorescence. We observed internalization by enterocytes of prion particles from bovine spongiform encephalopathy brain homogenates but not from mouse-adapted scrapie-strain brain homogenates or purified bovine spongiform encephalopathy scrapie-associated fibrils. Bovine prion particles were internalized via endocytosis within minutes of infection and were associated with subapical vesicular structures related to early endosomes. The endocytosis of the infectious bovine PrP(Sc) was reduced by preincubating the cells with an anti-LRP/LR blocking antibody, identifying the 37 kDa/67 kDa laminin receptor (LRP/LR), which is apically expressed in Caco-2/TC7 cells, as the receptor for the infectious prion protein. Altogether, our results underscore a potential role of enterocytes in the absorption of bovine prions during oral infection through specific LRP/LR-dependent endocytosis.
authors.affiliation: UMR505 INSERM/UPMC, 15 rue de l'école de Médecine, 75006 Paris, France.
authors.forename: Etienne
authors.initials: E
authors.lastname: Morel
authors.forename: Thibault
authors.initials: T
authors.lastname: Andrieu
authors.forename: Fabrice
authors.initials: F
authors.lastname: Casagrande
authors.forename: Sabine
authors.initials: S
authors.lastname: Gauczynski
authors.forename: Stefan
authors.initials: S
authors.lastname: Weiss
authors.forename: Jacques
authors.initials: J
authors.lastname: Grassi
authors.forename: Monique
authors.initials: M
authors.lastname: Rousset
authors.forename: Dominique
authors.initials: D
authors.lastname: Dormont
authors.forename: Jean
authors.initials: J
authors.lastname: Chambaz
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015153:Blotting, Western; D018938:Caco-2 Cells; D002417:Cattle; D017097:Electric Impedance; D016643:Encephalopathy, Bovine Spongiform / Q000378:metabolism; D004705:Endocytosis; D020895:Enterocytes / Q000378:metabolism*; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008567:Membranes, Artificial; D018613:Microscopy, Confocal; D008970:Molecular Weight; D018621:PrPC Proteins / Q000235:genetics / Q000378:metabolism; D018620:PrPSc Proteins / Q000235:genetics / Q000378:metabolism; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D017474:Receptors, Laminin / Q000235:genetics / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D008567:Membranes, Artificial; D018621:PrPC Proteins; D018620:PrPSc Proteins; D011328:Prions; D017474:Receptors, Laminin; D007770:L-Lactate Dehydrogenase