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Intraperitoneal Infection of Wild-Type Mice with Synthetically Generated Mammalian Prion.

Wang X, McGovern G, Zhang Y, Wang F, Zha L, Jeffrey M, Ma J - PLoS Pathog. (2015)

Bottom Line: However, whether the pathogenic properties of synthetically generated prion (rec-Prion) recapitulate those of naturally occurring prions remains unresolved.Detailed pathological analyses revealed that the nature of rec-Prion induced lesions, including spongiform change, disease specific prion protein accumulation (PrP-d) and the PrP-d dissemination amongst lymphoid and peripheral nervous system tissues, the route and mechanisms of neuroinvasion were all typical of classical rodent prions.Our results revealed that, similar to naturally occurring prions, the rec-Prion has a titratable infectivity and is capable of causing prion disease via routes other than direct intra-cerebral challenge.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, United States of America; Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America.

ABSTRACT
The prion hypothesis postulates that the infectious agent in transmissible spongiform encephalopathies (TSEs) is an unorthodox protein conformation based agent. Recent successes in generating mammalian prions in vitro with bacterially expressed recombinant prion protein provide strong support for the hypothesis. However, whether the pathogenic properties of synthetically generated prion (rec-Prion) recapitulate those of naturally occurring prions remains unresolved. Using end-point titration assay, we showed that the in vitro prepared rec-Prions have infectious titers of around 104 LD50/μg. In addition, intraperitoneal (i.p.) inoculation of wild-type mice with rec-Prion caused prion disease with an average survival time of 210-220 days post inoculation. Detailed pathological analyses revealed that the nature of rec-Prion induced lesions, including spongiform change, disease specific prion protein accumulation (PrP-d) and the PrP-d dissemination amongst lymphoid and peripheral nervous system tissues, the route and mechanisms of neuroinvasion were all typical of classical rodent prions. Our results revealed that, similar to naturally occurring prions, the rec-Prion has a titratable infectivity and is capable of causing prion disease via routes other than direct intra-cerebral challenge. More importantly, our results established that the rec-Prion caused disease is pathogenically and pathologically identical to naturally occurring contagious TSEs, supporting the concept that a conformationally altered protein agent is responsible for the infectivity in TSEs.

No MeSH data available.


Related in: MedlinePlus

Brain and spleen PrP-res accumulation in rec-Prion inoculated wild-type CD-1 mice.(A) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c rec-Prion inoculation as indicated. (B) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c inoculation of mouse brain homogenate (MBH) prepared from mice that received rec-Prion transmission. Two inoculated mice were sacrificed before any clinical signs (154 and 152 dpi), and their PK digested samples were separated in lanes 6 (brain) and 5 (spleen) of (A), and lanes 5 (brain and spleen) of (B). C, PK-digested brain or spleen homogenates prepared from age-matched wild-type CD-1 mice as controls.
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ppat.1004958.g002: Brain and spleen PrP-res accumulation in rec-Prion inoculated wild-type CD-1 mice.(A) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c rec-Prion inoculation as indicated. (B) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c inoculation of mouse brain homogenate (MBH) prepared from mice that received rec-Prion transmission. Two inoculated mice were sacrificed before any clinical signs (154 and 152 dpi), and their PK digested samples were separated in lanes 6 (brain) and 5 (spleen) of (A), and lanes 5 (brain and spleen) of (B). C, PK-digested brain or spleen homogenates prepared from age-matched wild-type CD-1 mice as controls.

Mentions: All inoculated CD-1 and C57BL/6 mice developed signs of prion disease and accumulated PrP-res (Fig 2A and 2B). Notably, at early stage of the disease, more PrP-res accumulated in the spleen than in the brain (Fig 2A lanes 6 (brain) and 5 (spleen); Fig 2B lanes 5 (brain and spleen). These two mice were sacrificed before clinical signs became apparent, suggesting that PrP-res may accumulate first in the spleen. The fact that spleen PrP-res accumulation was detected in both i.p. and i.c. challenged mice (Fig 2) suggests that the rec-Prion is a lymphotropic prion, which is able to replicate and accumulate in peripheral lymphoid organs. The accumulation of PrP-res in lymphoid organs following i.c. rec-Prion inoculation provides a disease phenotype that is similar to that of naturally occurring contagious prions [41–44].


Intraperitoneal Infection of Wild-Type Mice with Synthetically Generated Mammalian Prion.

Wang X, McGovern G, Zhang Y, Wang F, Zha L, Jeffrey M, Ma J - PLoS Pathog. (2015)

Brain and spleen PrP-res accumulation in rec-Prion inoculated wild-type CD-1 mice.(A) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c rec-Prion inoculation as indicated. (B) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c inoculation of mouse brain homogenate (MBH) prepared from mice that received rec-Prion transmission. Two inoculated mice were sacrificed before any clinical signs (154 and 152 dpi), and their PK digested samples were separated in lanes 6 (brain) and 5 (spleen) of (A), and lanes 5 (brain and spleen) of (B). C, PK-digested brain or spleen homogenates prepared from age-matched wild-type CD-1 mice as controls.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489884&req=5

ppat.1004958.g002: Brain and spleen PrP-res accumulation in rec-Prion inoculated wild-type CD-1 mice.(A) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c rec-Prion inoculation as indicated. (B) PrP-res in brain (top panel) and spleen (bottom panel) of mice that received i.p. or i.c inoculation of mouse brain homogenate (MBH) prepared from mice that received rec-Prion transmission. Two inoculated mice were sacrificed before any clinical signs (154 and 152 dpi), and their PK digested samples were separated in lanes 6 (brain) and 5 (spleen) of (A), and lanes 5 (brain and spleen) of (B). C, PK-digested brain or spleen homogenates prepared from age-matched wild-type CD-1 mice as controls.
Mentions: All inoculated CD-1 and C57BL/6 mice developed signs of prion disease and accumulated PrP-res (Fig 2A and 2B). Notably, at early stage of the disease, more PrP-res accumulated in the spleen than in the brain (Fig 2A lanes 6 (brain) and 5 (spleen); Fig 2B lanes 5 (brain and spleen). These two mice were sacrificed before clinical signs became apparent, suggesting that PrP-res may accumulate first in the spleen. The fact that spleen PrP-res accumulation was detected in both i.p. and i.c. challenged mice (Fig 2) suggests that the rec-Prion is a lymphotropic prion, which is able to replicate and accumulate in peripheral lymphoid organs. The accumulation of PrP-res in lymphoid organs following i.c. rec-Prion inoculation provides a disease phenotype that is similar to that of naturally occurring contagious prions [41–44].

Bottom Line: However, whether the pathogenic properties of synthetically generated prion (rec-Prion) recapitulate those of naturally occurring prions remains unresolved.Detailed pathological analyses revealed that the nature of rec-Prion induced lesions, including spongiform change, disease specific prion protein accumulation (PrP-d) and the PrP-d dissemination amongst lymphoid and peripheral nervous system tissues, the route and mechanisms of neuroinvasion were all typical of classical rodent prions.Our results revealed that, similar to naturally occurring prions, the rec-Prion has a titratable infectivity and is capable of causing prion disease via routes other than direct intra-cerebral challenge.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, Michigan, United States of America; Department of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, United States of America.

ABSTRACT
The prion hypothesis postulates that the infectious agent in transmissible spongiform encephalopathies (TSEs) is an unorthodox protein conformation based agent. Recent successes in generating mammalian prions in vitro with bacterially expressed recombinant prion protein provide strong support for the hypothesis. However, whether the pathogenic properties of synthetically generated prion (rec-Prion) recapitulate those of naturally occurring prions remains unresolved. Using end-point titration assay, we showed that the in vitro prepared rec-Prions have infectious titers of around 104 LD50/μg. In addition, intraperitoneal (i.p.) inoculation of wild-type mice with rec-Prion caused prion disease with an average survival time of 210-220 days post inoculation. Detailed pathological analyses revealed that the nature of rec-Prion induced lesions, including spongiform change, disease specific prion protein accumulation (PrP-d) and the PrP-d dissemination amongst lymphoid and peripheral nervous system tissues, the route and mechanisms of neuroinvasion were all typical of classical rodent prions. Our results revealed that, similar to naturally occurring prions, the rec-Prion has a titratable infectivity and is capable of causing prion disease via routes other than direct intra-cerebral challenge. More importantly, our results established that the rec-Prion caused disease is pathogenically and pathologically identical to naturally occurring contagious TSEs, supporting the concept that a conformationally altered protein agent is responsible for the infectivity in TSEs.

No MeSH data available.


Related in: MedlinePlus