The central theme of the Research Project is the study of the mechanisms involved in the determination ofthe prion strain and phenotype in human prion diseases. The rationale of the proposal is based on the widelyaccepted notion that there is a close correlation between the conformation of the scrapie prion protein (PrPScor prion strain) and the disease phenotype. Therefore,the mechanisms determining PrPSc conformation anddisease phenotype can be traced to the same origin.
Five specific aims are proposed.
Specific Aim 1 investigates the role played by glycans in phenotypic determination. Disease phenotypes and PrPSocharacteristics will be investigated in PrP glycosylation incompetent transgenic (Tg) mice expressing humanPrP (humanized mice) following inoculation with PrPSc from a subtype of sporadic Creutzfeldt-Jakobdisease(sCJD) characterized by phenotypic and PrPSc features likely to be related to the presence of unusualglycans.
Specific Aim 2 addresses the issue of the infectivity and competenceto reproduce the phenotype ofhuman PrPSc in relation to its state of aggregation. PrPSc oligomers as well as small and large aggregates willbe separated by size exclusion chromatography and will be individually inoculated to humanized mice.Infectivity and disease phenotype will be determined.
Specific Aims 3 and 4 take advantage of the noveltechnique of protein misfolding cyclic amplification (PMCA) to assess: i) the role of the PrP genotype in prionstrain determination and ii) whether PMCA can be used to circumvent species barriers. The characteristics ofPMCA-generated PrPSc species will be compared after using normal or cellular PrP (PrPc) differing in aminoacid sequence at position 129 as substrate for the replication. PrPSc species that are difficult to transmit bybioassay, such as the PrPSc associated with chronic wasting disease and bovine spongiformencephalopathy, will be replicated by PMCA using humanized Tg mice as donors of the PrPc needed for theconversion and inoculated to humanized mice. Transmissibility of the novel bovine amyloidotic spongiformencephalopathy (BASE) to humanized mice will also be attempted.
Specific Aim 5 is dedicated to thecharacterization of a novel human prion disease we recently identified that, remarkably, is associated withprotease-sensitive PrPSc and lack mutations in the PrP gene coding region despite an often positive familyhistory. The proposed research will advance the current understanding of mechanisms of prion strain andphenotypic determination. Furthermore, it may develop procedures that overcomethe limitation of thebioassay and lead to the expression of new phenotypes relevant to prion zoonoses, opening newavenuesfor research on prion diseases.
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Moda, Fabio; Gambetti, Pierluigi; Notari, Silvio et al. (2014) Prions in the urine of patients with variant Creutzfeldt-Jakob disease. N Engl J Med 371:530-9 |
Cannon, Ashley; Bieniek, Kevin F; Lin, Wen-Lang et al. (2014) Concurrent variably protease-sensitive prionopathy and amyotrophic lateral sclerosis. Acta Neuropathol 128:313-315 |
Notari, Silvio; Xiao, Xiangzhu; Espinosa, Juan Carlos et al. (2014) Transmission characteristics of variably protease-sensitive prionopathy. Emerg Infect Dis 20:2006-14 |
Xiao, Xiangzhu; Yuan, Jue; Qing, Liuting et al. (2014) Comparative Study of Prions in Iatrogenic and Sporadic Creutzfeldt-Jakob Disease. J Clin Cell Immunol 5: |
Blase, Jennifer L; Cracco, Laura; Schonberger, Lawrence B et al. (2014) Sporadic fatal insomnia in an adolescent. Pediatrics 133:e766-70 |
Xiao, Xiangzhu; Yuan, Jue; Haïk, Stéphane et al. (2013) Glycoform-selective prion formation in sporadic and familial forms of prion disease. PLoS One 8:e58786 |
Kong, Qingzhong; Mills, Jeffrey L; Kundu, Bishwajit et al. (2013) Thermodynamic stabilization of the folded domain of prion protein inhibits prion infection in vivo. Cell Rep 4:248-54 |
Kim, Mee-Ohk; Cali, Ignazio; Oehler, Abby et al. (2013) Genetic CJD with a novel E200G mutation in the prion protein gene and comparison with E200K mutation cases. Acta Neuropathol Commun 1:80 |
Gambetti, Pierluigi (2013) Creationism and evolutionism in prions. Am J Pathol 182:623-7 |
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