Phenotypic Similarity of Transmissible Mink Encephalopathy in Cattle and L-type Bovine Spongiform Encephalopathy in a Mouse Model

Thierry Baron,Eric Morignat,Anna Bencsik,Anne-Gaëlle Biacabe,Richard A Bessen

doi:10.3201/eid1312.070635

Abstract

Transmissible mink encepholapathy (TME) is a foodborne transmissible spongiform encephalopathy (TSE) of ranch-raised mink; infection with a ruminant TSE has been proposed as the cause, but the precise origin of TME is unknown. To compare the phenotypes of each TSE, bovine-passaged TME isolate and 3 distinct natural bovine spongiform encephalopathy (BSE) agents (typical BSE, H-type BSE, and L-type BSE) were inoculated into an ovine transgenic mouse line (TgOvPrP4). Transgenic mice were susceptible to infection with bovine-passaged TME, typical BSE, and L-type BSE but not to H-type BSE. Based on survival periods, brain lesions profiles, disease-associated prion protein brain distribution, and biochemical properties of protease-resistant prion protein, typical BSE had a distint phenotype in ovine transgenic mice compared to L-type BSE and bovine TME. The similar phenotypic properties of L-type BSE and bovine TME in TgOvPrP4 mice suggest that L-type BSE is a much more likely candidate for the origin of TME than is typical BSE.

Highlights

Transmissible mink encephalopathy (TME) is a rare prion disease in ranch-raised mink (Mustela vison) in North America and Europe [1,2,3,4]
Transmission of transmissible spongiform encephalopathy (TSE) Isolates in TgOvPrP4 Mice To determine the ability of the 4 bovine TSE isolates to cause a TSE in a common host species, they were inoculated into TgOvPrP4 mice (Table)
The shortest survival period was observed in mice infected with the typical bovine spongiform encephalopathy (BSE) isolate (421 ± 48 days), compared with 436 ± 77 days or 627 ± 74 days in TgOvPrP4 mice inoculated with bovine TME or L-type BSE, respectively

Summary

Introduction

Transmissible mink encephalopathy (TME) is a rare prion disease in ranch-raised mink (Mustela vison) in North America and Europe [1,2,3,4]. The H-type and L-type BSEs have been shown to differ from typical BSE with respect to incubation periods, vacuolar pathologic changes in the brain, and biochemical properties of PrPres in mice on transmission into wild-type or transgenic mice that express the bovine prion protein gene [14,15,16,17,18] The origin of these BSE cases is unknown, but researchers have proposed that they represent a spontaneous form of TSE in cattle that is distinct from typical BSE; alternative hypotheses have been considered, for example, cross-species contamination by another TSE source such as scrapie [15]. The implications of these findings with respect to the origin of TME are discussed

Methods

Results

Discussion

Conclusion