RESUMO
p53 is implicated in several cellular pathways such as induction of cell-cycle arrest, differentiation, senescence, and apoptosis. p53 is activated by a broad range of stress signals, including viral infections. While some viruses activate p53, others induce its inactivation, and occasionally p53 is differentially modulated during the replicative cycle. During calicivirus infections, apoptosis is required for virus exit and spread into the host; yet, the role of p53 during infection is unknown. By confocal microscopy, we found that p53 associates with FCV VP1, the protease-polymerase NS6/7, and the dsRNA. This interaction was further confirmed by proximity ligation assays, suggesting that p53 participates in the FCV replication. Knocked-down of p53 expression in CrFK cells before infection, resulted in a strong reduction of the non-structural protein levels and a decrease of the viral progeny production. These results indicate that p53 is associated with the viral replication complex and is required for an efficient FCV replication.
Assuntos
Calicivirus Felino/genética , Proteínas do Capsídeo/genética , Peptídeo Hidrolases/genética , RNA Viral/genética , Proteína Supressora de Tumor p53/genética , Replicação Viral/genética , Animais , Calicivirus Felino/metabolismo , Capsídeo/química , Capsídeo/metabolismo , Proteínas do Capsídeo/metabolismo , Gatos , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Rim/metabolismo , Rim/virologia , Modelos Moleculares , Peptídeo Hidrolases/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , RNA Viral/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Vírion/genética , Vírion/metabolismoRESUMO
Noroviruses and Sapoviruses, classified in the Caliciviridae family, are small positive-stranded RNA viruses, considered nowadays the leading cause of acute gastroenteritis globally in both children and adults. Although most noroviruses have been associated with gastrointestinal disease in humans, almost 50 years after its discovery, there is still a lack of comprehensive evidence regarding its biology and pathogenesis mainly because they can be neither conveniently grown in cultured cells nor propagated in animal models. However, other members of this family such as Feline calicivirus (FCV), Murine norovirus (MNV), Rabbit hemorrhagic disease virus (RHDV), and Porcine sapovirus (PS), from which there are accessible propagation systems, have been useful to study the calicivirus replication strategies. Using cell cultures and animal models, many of the functions of the viral proteins in the viral replication cycles have been well-characterized. Moreover, evidence of the role of viral proteins from different members of the family in the establishment of infection has been generated and the mechanism of their immunopathogenesis begins to be understood. In this review, we discuss different aspects of how caliciviruses are implicated in membrane rearrangements, apoptosis, and evasion of the immune responses, highlighting some of the pathogenic mechanisms triggered by different members of the Caliciviridae family.
Assuntos
Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Caliciviridae/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade , Imunomodulação , Imunidade Adaptativa , Animais , Peptídeos Catiônicos Antimicrobianos , Apoptose , Caliciviridae/genética , Infecções por Caliciviridae/metabolismo , Membrana Celular/metabolismo , Membrana Celular/virologia , Efeito Citopatogênico Viral , Suscetibilidade a Doenças , Regulação Viral da Expressão Gênica , Genoma Viral , Humanos , Evasão da Resposta Imune , Imunidade Inata , Interações Microbianas , Microbiota , Replicação ViralRESUMO
Cellular proteins have been identified to participate in calicivirus replication in association with viral proteins and/or viral RNAs. By mass spectrometry from pull-down assays, we identified several cellular proteins bound to the feline calicivirus (FCV) genomic RNA; among them the lipid raft-associated scaffold protein Annexin (Anx) A2. AnxA2 colocalizes with FCV NS6/7 protein and with the dsRNA in infected cells; moreover, it was found associated with the viral RNA in the membrane fraction corresponding to the replication complexes (RCs), suggesting its role during FCV replication. AnxA2-knockdown from CrFK cells prior to infection with FCV caused a delay in the cytopathic effect, a strong reduction of viral non-structural proteins and dsRNA production, and a decrease of FCV yield in both cell-associated and supernatant fractions. Taken together, these results indicate that AnxA2 associates to the genomic RNA of FCV and is required for an efficient FCV replication.