<i>PrP</i>genetics in ruminant transmissible spongiform encephalopathies

Goldmann, Wilfred

doi:10.1051/vetres:2008010

Cited by 160 publications

(154 citation statements)

References 91 publications

(129 reference statements)

Supporting

Mentioning

139

Contrasting

Unclassified

Order By: Relevance

“…It has been known for a long time that within the same species, susceptibility to TSE is tightly controlled by natural variations in the PrP sequence. For example, sheep breeds exhibit variable susceptibilities to experimental or natural scrapie, and polymorphisms at codons 136, 154 and 171 of the ovine PrP gene are particularly important [79,80]. A/V/T, R/H/L and R/H/Q/K can be encoded at these positions, respectively.…”

Section: Influence Of the Prp Genementioning

confidence: 99%

Prion agent diversity and species barrier

2008

View full text Add to dashboard Cite

-Mammalian prions are the infectious agents responsible for transmissible spongiform encephalopathies (TSE), a group of fatal, neurodegenerative diseases, affecting both domestic animals and humans. The most widely accepted view to date is that these agents lack a nucleic acid genome and consist primarily of PrP Sc , a misfolded, aggregated form of the host-encoded cellular prion protein (PrP C ) that propagates by autocatalytic conversion and accumulates mainly in the brain. The BSE epizooty, allied with the emergence of its human counterpart, variant CJD, has focused much attention on two characteristics that prions share with conventional infectious agents. First, the existence of multiple prion strains that impose, after inoculation in the same host, specific and stable phenotypic traits such as incubation period, molecular pattern of PrP Sc and neuropathology. Prion strains are thought to be enciphered within distinct PrP Sc conformers. Second, a transmission barrier exists that restricts the propagation of prions between different species. Here we discuss the possible situations resulting from the confrontation between species barrier and prion strain diversity, the molecular mechanisms involved and the potential of interspecies transmission of animal prions, including recently discovered forms of TSE in ruminants.prion / strain / misfolding / species barrier / PrP Table of Mammalian prion diseases or transmissible spongiform encephalopathies (TSE) form a group of related, invariably fatal neurodegenerative disorders of both animals and humans. The brain pathology consists of spongiosis, astrocytosis, neuronal loss and neural tissue from affected individuals contains an infectious agent, the prion, setting these diseases apart from other neurodegenerative diseases. Prion replication is thought to involve in essence the self-perpetuating conversion of the host-encoded cellular prion protein (PrP C ) into a misfolded form (PrP Sc ) that tends to aggregate and may be neurotoxic (for reviews [1,157]). Prion replication may also occur in lymphoid tissues but is there poorly if not pathogenic (for review [126], [133]). PrP C is a protein with two variably occupied glycosylation sites. It is attached at the outer of the plasma membrane by a glycosylphosphatidylinositol anchor. Its secondary structure is rich in alpha-helix and the protein is likely to be in a monomeric state in mild detergents. While its precise physiological function has not been assigned, PrP C is essential for prion replication and neurotoxicity to occur [57,129]. Upon infection, PrP C is refolded -without apparent post-translational modification -into beta-sheet -rich PrP Sc , initially in the presence of exogenous PrP Sc and then by an autocatalytic process. It leads to the formation of aggregates, sometimes of amyloid type, that can be differentiated from PrP C because of their partial resistance to protease digestion and of their insolubility into non-denaturing detergents [153]. Proteinase K, the most commonly used protease, di...

show abstract

Section: Influence Of the Prp Genementioning

confidence: 99%

Prion agent diversity and species barrier

2008

View full text Add to dashboard Cite

show abstract

“…This is well established for sheep, but less well examined for goats [11]. The most common amino acid polymorphisms in British goat breeds are at codons 127 (glycine or serine), 142 (isoleucine or methionine), 143 (histidine or arginine) and 240 (proline or serine), and an association of polymorphisms at codons 142 and 143 with susceptibility and incubation period has been reported [1,2,10].…”

Section: Introductionmentioning

confidence: 99%

High prevalence of scrapie in a dairy goat herd: tissue distribution of disease-associated PrP and effect ofPRNPgenotype and age

González¹,

Martin²,

Sisó³

et al. 2009

Vet. Res.

Self Cite

View full text Add to dashboard Cite

-Following a severe outbreak of clinical scrapie in 2006-2007, a large dairy goat herd was culled and 200 animals were selected for post-mortem examinations in order to ascertain the prevalence of infection, the effect of age, breed and PRNP genotype on the susceptibility to scrapie, the tissue distribution of diseaseassociated PrP (PrP d ), and the comparative efficiency of different diagnostic methods. As determined by immunohistochemical (IHC) examinations with Bar224 PrP antibody, the prevalence of preclinical infection was very high (72/200; 36.0%), with most infected animals being positive for PrP d in lymphoreticular system (LRS) tissues (68/72; 94.4%) compared to those that were positive in brain samples (38/72; 52.8%). The retropharyngeal lymph node and the palatine tonsil showed the highest frequency of PrP d accumulation (87.3% and 84.5%, respectively), while the recto-anal mucosa-associated lymphoid tissue (RAMALT) was positive in only 30 (41.7%) of the infected goats. However, the efficiency of rectal and palatine tonsil biopsies taken shortly before necropsy was similar. The probability of brain and RAMALT being positive directly correlated with the spread of PrP d within the LRS. The prevalence of infection was influenced by PRNP genetics at codon 142 and by the age of the goats: methionine carriers older than 60 months showed a much lower prevalence of infection (12/78; 15.4%) than those younger than 60 months (20/42; 47.6%); these last showed prevalence values similar to isoleucine homozygotes of any age (40/80; 50.0%). Two of seven goats with definite signs of scrapie were negative for PrP d in brain but positive in LRS tissues, and one goat showed biochemical and IHC features of PrP d different from all other infected goats. The results of this study have implications for surveillance and control policies for scrapie in goats.scrapie / goat / prion disease / transmissible spongiform encephalopathy

show abstract

“…5 Disease manifestation is influenced by variations in the Prnp gene, which encodes PrP C . 6 Non-synonymous Single Nucleotide Polymorphisms (SNPs) present in the ovine Prnp have been strongly associated with resistance and were targeted by selective breeding strategies, resulting in significant reduction of disease prevalence. 7,8 Unfortunately, this has not yet been applied in the case of goats, as the most promising scrapie-protective allele(s) has not been determined yet.…”

Section: Introductionmentioning

confidence: 99%

“…Similarly to sheep, the caprine Prnp gene is highly polymorphic. 6,[9][10][11][12][13][14][15][16] Field studies, conducted in different countries on a variety of goat breeds, assigned some degree of protection against scrapie to the following alleles Met-142, Arg-143, Asp-146, Ser-146, His-154, Gln-211 and Lys-222. 11,13,14,[17][18][19][20][21][22][23] Among these, Met-142 is linked to prolonged incubation period, 13,17,21,23 while Arg-143 18 and His-154 14,18,19,21,23 are associated with moderate protection.…”

Section: Introductionmentioning

confidence: 99%