Protective role of cytosolic prion protein against virus infection in prion-infected cells.
J Virol
; 98(9): e0126224, 2024 Sep 17.
Article
in En
| MEDLINE
| ID: mdl-39194237
ABSTRACT
Production of the amyloidogenic prion protein, PrPSc, which forms infectious protein aggregates, or prions, is a key pathogenic event in prion diseases. Functional prion-like protein aggregations, such as the mitochondrial adaptor protein MAVS and the inflammasome component protein ASC, have been identified to play a protective role in viral infections in mammalian cells. In this study, to investigate if PrPSc could play a functional role against external stimuli, we infected prion-infected cells with a neurotropic influenza A virus strain, IAV/WSN. We found that prion-infected cells were highly resistant to IAV/WSN infection. In these cells, NF-κB nuclear translocation was disturbed; therefore, mitochondrial superoxide dismutase (mtSOD) expression was suppressed, and mitochondrial reactive oxygen species (mtROS) was increased. The elevated mtROS subsequently activated NLRP3 inflammasomes, leading to the suppression of IAV/WSN-induced necroptosis. We also found that prion-infected cells accumulated a portion of PrP molecules in the cytosol, and that the N-terminal potential nuclear translocation signal of PrP impeded NF-κB nuclear translocation. These results suggest that PrPSc might play a functional role in protection against viral infections by stimulating the NLRP3 inflammasome-dependent antivirus mechanism through the cytosolic PrP-mediated disturbance of NF-κB nuclear translocation, which leads to suppression of mtSOD expression and consequently upregulation of the NLRP3 inflammasome activator mtROS. IMPORTANCE Cytosolic PrP has been detected in prion-infected cells and suggested to be involved in the neurotoxicity of prions. Here, we also detected cytosolic PrP in prion-infected cells. We further found that the nuclear translocation of NF-κB was disturbed in prion-infected cells and that the N-terminal potential nuclear translocation signal of PrP expressed in the cytosol disturbed the nuclear translocation of NF-κB. Thus, the N-terminal nuclear translocation signal of cytosolic PrP might play a role in prion neurotoxicity. Prion-like protein aggregates in other protein misfolding disorders, including Alzheimer's disease were reported to play a protective role against various environmental stimuli. We here showed that prion-infected cells were partially resistant to IAV/WSN infection due to the cytosolic PrP-mediated disturbance of the nuclear translocation of NF-κB, which consequently activated NLRP3 inflammasomes after IAV/WSN infection. It is thus possible that prions could also play a protective role in viral infections.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
NF-kappa B
/
Reactive Oxygen Species
/
Cytosol
/
Inflammasomes
/
NLR Family, Pyrin Domain-Containing 3 Protein
Limits:
Animals
/
Humans
Language:
En
Journal:
J Virol
Year:
2024
Type:
Article
Affiliation country:
Japan