Risk assessment

Bohutohu

Comparison of Bovine BSE-L and Human CJD prions phenotypic traits upon transmission To Human PrP transgenic mice

2008: 1 year / Grant: 70 000 euros

Project: It is now well established that vCJD is due to BSE exposure through contaminated food. However atypical forms of BSE such as BSE-L and BSE-H have been discovered and have been considered as sporadic BSE strains. Since many clues seem to converge to suggest that sporadic CJD- type 2a could be due L-BSE, the aim of“Bohutohu” wasto decipher the potential link between L-BSE and human prion diseases.

Main results and related published data: Transgenic mice expressing human PRNP were inoculated with known sCJD (17 cases) and L-BSE infected brain homogenates. Iterative subpassages were performed (3 or 4 times). Even if similar strain PrPTSE signatures with cortical MM2-sCJD prions(resistance to guanidinium chloride treatment, lymphotropism, and deposition) were observed, there was no evidence of L-BSE responsibility in the etiology of the known form of sCJD, since the incubation periods and the differential resistance to PK digestion were notcompatible. However, as this study revealed, there was no significant barrier of transmission of L-BSE in transgenic mice expressing human PrP, it appearsstill important to maintain surveillance and measuresto avoid food contamination by this L-BSE agent.