RESUMEN
Mink enteritis virus (MEV) is one of the most important pathogens in the mink industry. Recent studies have shed light into the role of microRNAs (miRNAs), small noncoding RNAs of length ranging from 18-23 nucleotides (nt), as critical modulators in the host-pathogen interaction networks. We previously showed that miRNA miR-181b can inhibit MEV replication by repression of viral non-structural protein 1 expression. Here, we report that two other miRNAs (miR-320a and miR-140) inhibit MEV entry into feline kidney (F81) cells by downregulating its receptor, transferrin receptor (TfR), by targeting the 3' untranslated region (UTR) of TfR mRNA, while being themselves upregulated.
Asunto(s)
Antivirales/metabolismo , Regulación de la Expresión Génica , MicroARNs/metabolismo , Virus de la Enteritis del Visón/fisiología , Receptores de Transferrina/antagonistas & inhibidores , Receptores Virales/antagonistas & inhibidores , Internalización del Virus , Animales , Gatos , Línea Celular , Regulación hacia Abajo , MicroARNs/genética , Receptores de Transferrina/genética , Receptores Virales/genéticaRESUMEN
BACKGROUND: The avian influenza virus (AIV) causes frequent disease with high morbidity and mortality. RNA interference (RNAi) has been shown to provide an effective antiviral defense in animals, and several studies have focused on harnessing small interfering RNAs (siRNAs) to inhibit viral infections. In addition, single chain variable fragments (scFvs) contain the complete antigen binding site, and specific scFvs can bind to and neutralize viruses. RESULTS: Fourteen positive scFvs were selected by the yeast two-hybrid system. Using molecular docking technology, we selected the three highest affinity scFvs for further functional validation. Results of indirect ELISA and IFA showed that all three scFvs could bind to FJ13 strain and had neutralizing activity, decreasing the viral infectivity markedly. Chicken fibroblastic DF-1 cells were transfected with scFvs in combination with siRNA-NP604 (an siRNA of anti-AIV NP protein previously reported). Following infection with FJ13 virus, copy numbers of the virus were significantly reduced from 12 h to at least 60 h post-infection compared to that achieved in cells transfected with scFv or siRNA-NP604 separately. CONCLUSIONS: A novel combination of antiviral siRNAs expressed in chicken cells and chicken antibody single-chain variable fragments (scFvs) secreted from the cells has a synergistic inhibitory effect on the avian influenza viral proliferation in vitro. Intracellular application of scFvs and anti-viral siRNA may provide a new approach to influenza prevention and treatment.
Asunto(s)
Antivirales/metabolismo , Subtipo H5N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H5N1 del Virus de la Influenza A/crecimiento & desarrollo , ARN Interferente Pequeño/metabolismo , Anticuerpos de Cadena Única/metabolismo , Animales , Línea Celular , Pollos , Carga ViralRESUMEN
MicroRNAs (miRNAs) are small regulatory RNAs that play a significant role in eukaryotes by targeting mRNAs for cleavage or translational repression. Recent studies have also shown them to be associated with cellular changes following viral infection. Mink enteritis virus (MEV) is one of the most important viral pathogens in the mink industry. To study the involvement of miRNAs in the MEV infection process, we used Illumina's ultrahigh throughput approach to sequencing miRNA libraries from the feline kidney (F81) cell line before and after infection with MEV. Using this bioinformatics approach we identified 196 known mammalian miRNA orthologs belonging to 152 miRNA families in F81 cells. Additionally, 97 miRNA*s of these miRNAs were detected. As well as known miRNAs, 384 and 398 novel miRNA precursor candidates were identified in uninfected and MEV-infected F81 cells respectively that have not been reported in other mammals. In MEV-infected cells 3 miRNAs were significantly down-regulated and 4 up-regulated including 3 significantly. The majority (12 of 16) of randomly selected miRNA expression profiles by qRT-PCR were consistent with those identified by deep sequencing. A total of 88 miRNAs were predicted to target interferon-associated genes; 6 appear to target the 3'UTR of MEV-specific receptor transferring receptor mRNAs; and 8 to target the MEV mRNA coding region. No miRNAs coded by MEV itself were detected.
Asunto(s)
Biomarcadores/metabolismo , Panleucopenia Felina/genética , Perfilación de la Expresión Génica , Riñón/metabolismo , MicroARNs/genética , Enteritis Viral del Visón/genética , Virus de la Enteritis del Visón/patogenicidad , Animales , Gatos , Células Cultivadas , Biología Computacional , Panleucopenia Felina/virología , Riñón/virología , Enteritis Viral del Visón/virología , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Construction and characterization of a full-length infectious clone (pMEV) of mink enteritis virus are described. Feline kidney cells (F81) were transfected with pMEV containing an engineered BamHI site that served as a genetic marker. The rescued virus was indistinguishable from its parental virus. The availability of a MEV infectious clone will facilitate studies of viral replication and pathogenicity and will permit the elucidation of determinants of the host range of the parvovirus.
Asunto(s)
Virus de la Enteritis del Visón/crecimiento & desarrollo , Genética Inversa/métodos , Virología/métodos , Animales , Gatos , Línea Celular , Virus de la Enteritis del Visón/genéticaRESUMEN
Mink enteritis virus (MEV) is one of the most important viral pathogens in the mink industry. Recent studies have showed that microRNAs (miRNAs), small noncoding RNAs of length ranging from 18-23 nucleotides (nt) participate in host-pathogen interaction networks; however, whether or not miRNAs are involved in MEV infection has not been reported. Our study revealed that miRNA miR-181b inhibited replication of MEV in the feline kidney (F81) cell line by targeting the MEV non-structural protein 1 (NS1) messenger RNA (mRNA) coding region, resulting in NS1 translational repression, while MEV infection reduced miR-181b expression. This is the first description of cellular miRNAs modulating MEV infection in F81 cells, providing further insight into the mechanisms of viral infection, and may be useful in development of naturally-occurring miRNAs antiviral strategies.