Newellknudsen5697

Human adenovirus (HAdV) is used extensively as a vector for gene delivery for a variety of purposes, including gene therapy and vaccine development. Most adenoviral vectors used for these approaches have a deletion of early region 1 (E1), which is complemented by the cell line. Most commonly, these are 293 cells for HAdV serotype 2 or 5. The 293 cells have the left end of HAdV5 integrated into chromosome 19 and express the E1 genes and protein IX. We observed that viruses with the E1 region deleted often grow less well on 293 cells than E1 wild-type viruses. Therefore, we investigated whether this poor growth is caused by splicing differences between the E1A RNA provided by the cell line (in trans) and the E1A RNA provided by the infecting viral genome (in cis). We observed that E1A RNA that was expressed from the genomes of 293 cells was spliced differently during infection with an E1A-deleted dl312 virus than E1A RNA from the same cells infected with dl309 or wt300. Importantly, 293 cells were not able to frious viral genes. Deletions in essential genes, such as E1, are often complemented by the cell line that is used for virus propagation in trans Here, we show that even complete genetic complementation of a viral gene does not result in full protein complementation, a defect that compromises virus growth. This is particularly important when high viral yields are crucial, as in virus production for vaccine development or gene therapy.DNA damage-inducible transcript 3 (DDIT3) plays important roles in endoplasmic reticulum (ER) stress-induced apoptosis and autophagy, but its role in innate immunity is not clear. Here, we report that DDIT3 inhibits the antiviral immune response during bovine viral diarrhea virus (BVDV) infection by targeting mitochondrial antiviral signaling (MAVS) in Madin-Darby bovine kidney (MDBK) cells and in mice. BVDV infection induced high DDIT3 mRNA and protein expression. DDIT3 overexpression inhibited type I interferon (IFN-I) and IFN-stimulated gene production, thereby promoting BVDV replication, while DDIT3 knockdown promoted the antiviral innate immune response to suppress viral replication. DDIT3 promoted NF-κB-dependent ovarian tumor (OTU) deubiquitinase 1 (OTUD1) expression. Furthermore, OTUD1 induced upregulation of the E3 ubiquitin ligase Smurf1 by deubiquitinating Smurf1, and Smurf1 degraded MAVS in MDBK cells in a ubiquitination-dependent manner, ultimately inhibiting IFN-I production. Moreover, knocking out DDIT3 promoted the antiviral innate immune response to reduce BVDV replication and pathological changes in mice. These findings provide direct insights into the molecular mechanisms by which DDIT3 inhibits IFN-I production by regulating MAVS degradation.IMPORTANCE Extensive studies have demonstrated roles of DDIT3 in apoptosis and autophagy during viral infection. However, the role of DDIT3 in innate immunity remains largely unknown. Here, we show that DDIT3 is positively regulated in bovine viral diarrhea virus (BVDV)-infected Madin-Darby bovine kidney (MDBK) cells and could significantly enhance BVDV replication. Importantly, DDIT3 induced OTU deubiquitinase 1 (OTUD1) expression by activating the NF-κB signaling pathway, thus increasing intracellular Smurf1 protein levels to degrade MAVS and inhibit IFN-I production during BVDV infection. Together, these results indicate that DDIT3 plays critical roles in host innate immunity repression and viral infection facilitation.Kaposi's sarcoma-associated herpesvirus (KSHV) is a human oncogenic virus and the causative agent of Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. During lytic reactivation, there is a temporal cascade of viral gene expression that results in the production of new virions. One of the viral factors that is expressed during reactivation is open reading frame 59 (ORF59), the viral DNA polymerase processivity factor. ORF59 plays an essential role for DNA synthesis and is required for the nuclear localization of the viral DNA polymerase (ORF9) to the origin of lytic replication (oriLyt). In addition to its functions in viral DNA synthesis, ORF59 has been shown to interact with chromatin complexes, including histones and cellular methyltransferases. In this study, a series of KSHV BACmids containing 50-amino acid (aa) deletions within ORF59 were generated to determine the interaction domains between ORF59 and histones, as well as to assess the effects on replication fitness as as. One of the proteins that is vital to this process is open reading frame 59 (ORF59), the viral encoded polymerase processivity factor. Selleck Veliparib Previous work has demonstrated that the function of ORF59 is closely connected to its association with other viral and cellular factors. The studies presented here extend that work to include the interaction between ORF59 and histones. This interaction offers an additional level of regulation of the chromatinized viral genome, ultimately influencing DNA synthesis and transcription dynamics.Fowl adenovirus serotype 4 (FAdV-4) is a hepatotropic virus that causes severe hepatic damage characterized by basophilic intranuclear inclusion bodies, vacuolar degeneration, and multifocal necrosis in hepatocytes. Many aspects of FAdV-4 infection and pathogenesis, however, remain unknown. Here, we found that FAdV-4-induced hepatic injury is accompanied by the accumulation of oil droplets (triglycerides) in the cytoplasm of hepatocytes, a typical indicator of steatosis, in FAdV-4-infected chickens. Significant upregulation of adipose synthesis-related genes, such as liver X receptor-α (LXR-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding protein-1c (SREBP-1c), and significant downregulation of low-density lipoprotein secretion-related genes and lipid oxidation- and lipid decomposition-related genes were observed in the infected chickens. FAdV-4 infection in cultured leghorn male hepatoma (LMH) cells caused similar signs of steatosis, with alterations in vartivating the LXR-α signaling pathway and highlighting the therapeutic potential of strategies targeting the LXR-α pathway for the treatment of FAdV-4 infection.