Project description:To find out differently expressed circRNAs during Orf virus infection of GSF cells and their potential roles in response to ORFV infection
Project description:Contagious ecthyma (Orf) is a contagious disease with worldwide distribution, caused by the epitheliotropic Orf virus (ORFV), a member of the genus Parapoxvirus. In the current study, we collected the oral mucosa tissues samples (T0, T3, T7 and T15) from sheep at 0, 3, 7 and 15 days post ORFV infection, respectively. To explore the changes of comprehensive transcriptome of host cells from oral mucosa tissues post ORFV infection, the RNA-seq transcriptome comparisons were performed on these samples. It showed that 1928, 3219 and 2646 differentially expressed genes (DEGs) were identified among T3 vs. T0, T7 vs. T0, T15 vs. T0 respectively. Through Gene Ontology (GO) analyses of the DEGs from these comparisons, it revealed that ORFV provoked the vigorous immune response of the host cells during the early stage of infection. Moreover, GO and network analysis revealed that positive and negative regulative mechanisms of apoptosis worked as whole in the host cells, in order to reach a homeostasis of oral mucosa tissues.
Project description:Reverse genetics has been widely used to investigate function of viral genes. In the present study we investigated the gene expression profile of a primary ovine cell (OFTu) in response to infection with the wild type (OV-IA82) and deletion mutant virus (OV-IA82Δ024) aiming to determine possible functions for ORFV024 during ORFV infection. We used microarray analysis to investigate gene expression profile of OFTu with ORFV OV-IA82 and OV-IA82Δ024.
Project description:Using RNA sequencing technology, we compared specific changes in the transcriptomic profiles in human foreskin fibroblast cells (HFF-1) following ORFV infection. ORFV specifically upregulated and downregulated a variety of genes, including genes involved in antiviral immune response, apoptosis, cell cycle and a series of signaling pathways, such as the IFN and p53-signaling pathways. A range of genes were downregulated at early stage. In contrast, the virus up-regulates a number of cellular genes at late stage.
Project description:Coronaviruses express a repertoire of accessory proteins for evading host immune responses. A small internal (I) accessory gene overlaps with the nucleocapsid (N) gene in an alternative reading frame of viruses that belong to the genus Betacoronavirus. Previous studies reported that I proteins of SARS-CoV (9b), MERS-CoV (8b) and SARS-CoV-2 (9b) inhibit type I interferon (IFN-I) expression through distinct mechanisms and have different roles in pathogenesis. In contrast, the functions of the I proteins of human coronaviruses HCoV-HKU1 (7b) and HCoV-OC43 (8b) have not been previously reported. Although HCoV-HKU1 and HCoV-OC43 predominantly cause common cold in healthy adults (common cold CoVs, CCCoVs), susceptible individuals infected with these viruses can develop severe disease. The lack of robust reverse genetic systems, tissue culture and animal models limit the study of HCoV-HKU1 and HCoV-OC43 pathogenesis. Here, we examined how the heterologous expression of the HCoV-HKU1 and HCoV-OC43 I proteins impact pathogenesis in a mouse model of infection using a prototypic betacoronavirus. We inserted the I gene of HCoV-HKU1 (ORF 7b) and HCoV-OC43 (ORF 8b) independently into the genome of a neurotropic strain of mouse hepatitis virus (J2.2). J2.2 infection is well characterized with clearly defined immune responses which allows the study of these genes in the context of authentic coronavirus infection. We showed that ORF 7b of HCoV-HKU1, but not ORF 8b of HCoV-OC43, ameliorated MHV-J2.2 pathogenesis while ORF 8b of MERS-CoV exacerbated disease. The presence of HCoV-HKU1 ORF 7b decreased virus titers and cytokine expression while ORF 8b of MERS-CoV led to increased immune cell infiltration and virus titers in mice after J2.2 infection. Moreover, proteins expressed by ORF 7b of HCoV-HKU1 and ORF 8b of HCoV-OC43 showed different patterns of subcellular localization. Overall, our findings suggest that the I genes of different betacoronaviruses play unique roles in pathogenesis.