CJD and BSE: an integrated molecular and experimental neuropathological analysis of prion neurodegeneration, strain variation and transmission risks

• Forschungsstelle: EU FRP
• Projektnummer: 96.0311
• Projekttitel Englisch: CJD and BSE: an integrated molecular and experimental neuropathological analysis of prion neurodegeneration, strain variation and transmission risks

Schlüsselwörter (Englisch)

BSE; prions; transgenic mice; neurodegeneration; neuropathology

Alternative Projektnummern (Englisch)

EU project number: BMH4CT972679

Forschungsprogramme (Englisch)

EU-programme: 4. Frame Research Programme - 4.2 Agriculture and agroindustry

Kurzbeschreibung (Englisch)

See abstract

Partner und Internationale Organisationen (Englisch)

Cordinator::Imperial College of Science (UK)

Abstract (Englisch)

The epithelium that lines the gut is impermeable to macromolecules and microorganisms, except in Peyer`s patches (PP) where the lymphoid follicle-associated epithelium contains membranous epithelial cells (M cells) that transport antigens and microorganisms. M cells are key sites of antigen sampling for the mucosal-associated lymphoid system (MALT) and have recently been recognized as major sites for adherance and major ports of entry for enteric pathogens in the gut.
For the investigation of possible prion passage via M-cells we established a co-culture technique as developed originally Kerneis et al. (1997). A subclone of the human differentiated absorptive enterocyte cell line Caco-2 is co-cultured on transwell filters together with Raji-cells, a human B cell line. The presence of B cells/Rajii-cells is known to induce a conversion of a fraction of epithelial cells into M cells, while lymphoid cells are migrating through the pores of the filter and settle into the epithelial monolayer. Successful conversion of epithelial cells into M cells within this co-culture system was demonstrated by three distinct features: a) high transepithelial electric resistance, b) 3H-Inulin transport and c) latex beads (0.2um) transport. Transepithelial electric resistance and inulin transport demonstrated integrity of the cellular layer, while presence of functional M cells is shown by latex beads transport - a distinct feature of M cells.
After having established the co-culture system, the upper chamber of co-cultures including functional M cells was incubated with the prion containing RML isolate of mouse-adapted scrapie at various concentrations (10-1 to 10-4) and compared with cultures without M cells. We investigated the medium from the basolateral compartment in regard to the amount of (M cell dependently transported) PrPsc by bioassay. The co-culture medium was transmitted into tg20 indicator mice in order to study the infectivity after passage though M cell-containing monolayer. We could clearly show that the transport of prions within this in vitro-culture systems depends on the presence of M cells since M cell-lacking control cultures could not transport infectivity. Surprisingly, no infectivity was found in PP of both M cell-deficient mice (RAG1-/-) and wild-type mice (C57B/L6) after 24 or 48 h of oral prion uptake indicating that longer contact time may be needed for prions to gain access into the PP.

Datenbankreferenzen (Englisch)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 96.0311