Bovine spongiform encephalopathy infection alters endogenous retrovirus expression in distinct brain regions of cynomolgus macaques (Macaca fascicularis)
- Equal contributors
1 Leibniz-Institute for Zoo and Wildlife Research, Alfred-Kowalke Str. 17, D-10315 Berlin, Germany
2 Institute of Virology, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Germany
3 German Primate Center, Leibniz-Institute for Primate Research, Unit of Infection Models, D-37077 Göttingen, Germany
4 III Medizinische Universitätsklinik, Medizinische Fakultät Mannheim der Universität Heidelberg, D-68305 Mannheim, Germany
5 Institute of Toxicology, Helmholtz Zentrum München, Ingolstaedter Landstr. 1, D-85764 Neuherberg, Germany
6 Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
Molecular Neurodegeneration 2011, 6:44 doi:10.1186/1750-1326-6-44Published: 23 June 2011
Prion diseases such as bovine spongiform encephalopathies (BSE) are transmissible neurodegenerative diseases which are presumably caused by an infectious conformational isoform of the cellular prion protein. Previous work has provided evidence that in murine prion disease the endogenous retrovirus (ERV) expression is altered in the brain. To determine if prion-induced changes in ERV expression are a general phenomenon we used a non-human primate model for prion disease.
Cynomolgus macaques (Macaca fasicularis) were infected intracerebrally with BSE-positive brain stem material from cattle and allowed to develop prion disease. Brain tissue from the basis pontis and vermis cerebelli of the six animals and the same regions from four healthy controls were subjected to ERV expression profiling using a retrovirus-specific microarray and quantitative real-time PCR. We could show that Class I gammaretroviruses HERV-E4-1, ERV-9, and MacERV-4 increase expression in BSE-infected macaques. In a second approach, we analysed ERV-K-(HML-2) RNA and protein expression in extracts from the same cynomolgus macaques. Here we found a significant downregulation of both, the macaque ERV-K-(HML-2) Gag protein and RNA in the frontal/parietal cortex of BSE-infected macaques.
We provide evidence that dysregulation of ERVs in response to BSE-infection can be detected on both, the RNA and the protein level. To our knowledge, this is the first report on the differential expression of ERV-derived structural proteins in prion disorders. Our findings suggest that endogenous retroviruses may induce or exacerbate the pathological consequences of prion-associated neurodegeneration.