Role of PrP in prion spread and establishment of central nervous system infection

• Unité de recherche: PCRD EU
• Numéro de projet: 98.0185
• Titre du projet anglais: Role of PrP in prion spread and establishment of central nervous system infection

Mots-clé (Anglais)

Prions; BSE; Creutzfeldt-Jakob

Autre Numéro de projet (Anglais)

EU project number: FAIRJ-CT98-6022

Programme de recherche (Anglais)

EU-programme: 4. Frame Research Programme - 4.3 Biomedical/Health research

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

Coordinator: Commissariat ä l'Energie Atomique, Fontenay (F)

Résumé des résultats (Abstract) (Anglais)

Prion pathogenesis after intraperitoneal challenge requires intact lymphoreticular organs. Analogously, oral pathogenesis is thought to involve gut-associated lymphatic tissue, which includes Peyer's patches (PPs) and M cells. Homing of activated B lymphocytes to PPs requires a4b7 integrin: PPs of b7?/? mice are normal in number, yet atrophic and almost devoid of B cells. Here we studied oral prion pathogenesis in b7?/? mice. Minimal infectious dose, and disease incubation after exposure to logarithmic prion dilutions, were similar in b7?/? and wild-type mice. Although oral LD50 was 4 log higher than intraperitoneal LD50 in both genotypes, PPs of both b7?/? and wild-type mice contained 3-4 logLD50/g prion infectivity >125 days after challenge. Despite strongly depleted B cells, M cells were still present in b7?/? mice. Instead, mice deficient in tumor necrosis factor and lymphotoxin-a (TNFa?/? x LTa?/?) or in lymphocytes (RAG?1?/?, µMT), whose PPs were reduced in number, were highly resistant to oral challenge, and their intestine was virtually devoid of prion infectivity at all times after challenge. Therefore lymphoreticular requirements for enteric and for intraperitoneal uptake of prions are dramatically different from each other. Susceptibility to prion infection after oral challenge correlates with the number of PPs, but is independent of their proper equipment with lymphocytes.

Références bases de données (Anglais)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 98.0185