miR-26b Inhibits Virus Replication Through Positively Regulating Interferon Signaling

Duck Plague Virus Negatively Regulates IFN Signaling to Promote Virus Proliferation via JNK Signaling Pathway

Duck plague virus (DPV), a member of the alphaherpesvirus subfamily, can cause severe damage and immunosuppression in ducks and geese in China. Since lacking an available cell model, the antiviral signal transduction pathways induction and regulation mechanisms related to DPV infection in duck cells are still enigmatic. Our previous study developed a monocyte/macrophages cell model, which has been applied to study innate immunity with DPV. In the present study, we compared and analyzed transcriptome associated with the DPV infection of CHv (virulent strain) and CHa (avirulent strain) at 48hpi based on the duck monocyte/macrophages cell model and RNA-seq technology. Differentially expressed genes (DEGs) analysis showed 2,909 and 2,438 genes altered in CHv and CHa infected cells compared with control cells. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the DEGs were mainly involved in biological processes such as metabolic pathways, viral infectious diseases, immune system, and signal transduction. The CHv and CHa virus differentially regulated MAPK, NF-κB, and IFN signaling pathways based on transcriptome sequencing data and RT-qPCR results. The JNK inhibitor SP600125 enhanced the IFN signaling, but potentially reduced the VSV and DPV titers in the cell culture supernatant, indicating that JNK negatively regulates the IFN pathway and the inflammatory pathway to promote virus proliferation. The research results may provide promising information to understand the pathogenesis of DPV and provide a novel mechanism by which DPV modulates antiviral signaling and facilitate virus proliferation through hijacking the JNK pathway, which provides a new means for the prevention and control of DPV infection.

Transcriptome of miRNA during inhibition of Bombyx mori nuclear polyhedrosis virus by geldanamycin in BmN cells

Bombyx mori nuclear polyhedrosis virus (BmNPV) is one of several viruses that cause great harm to the sericulture industry, and its pathogenic mechanism is still being explored. Geldanamycin (GA), a kind of HSP90 inhibitor, has been verified to suppress BmNPV proliferation. However, the molecular mechanism by which GA inhibits BmNPV is unclear. MicroRNAs (miRNAs) have been shown to play a key role in regulating virus proliferation and host-pathogen interactions. In this study, BmN cells infected with BmNPV were treated by GA and DMSO for 72 h, respectively, then transcriptome analysis of miRNA was performed from the GA group and the control group. As a result, a total of 29 miRNAs were differentially expressed (DE), with 13 upregulated and 16 downregulated. Using bioinformatics analysis, it was found that the target genes of DEmiRNAs were involved in ubiquitin-mediated proteolysis, phagosome, proteasome, endocytosis pathways, and so on. Six DEmiRNAs were verified by quantitative reverse-transcription polymerase chain reaction. DElong noncoding RNA (DElncRNA)-DEmiRNA-messenger RNA (mRNA) regulatory networks involved in apoptosis and immune pathways were constructed in GA-treated BmN cells, which included 12 DEmiRNA, 132 DElncRNA, and 69 mRNAs. This regulatory network enriched the functional role of miRNA in the BmNPV-silkworm interactions and improved our understanding of the molecular mechanism of HSP90 inhibitors on BmNPV proliferation.

Characterization of microRNA expression in B cells derived from Japanese black cattle naturally infected with bovine leukemia virus by deep sequencing

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), a malignant B cell lymphoma. However, the mechanisms of BLV-associated lymphomagenesis remain poorly understood. Here, after deep sequencing, we performed comparative analyses of B cell microRNAs (miRNAs) in cattle infected with BLV and those without BLV. In BLV-infected cattle, BLV-derived miRNAs (blv-miRNAs) accounted for 38% of all miRNAs in B cells. Four of these blv-miRNAs (blv-miR-B1-5p, blv-miR-B2-5p, blv-miR-B4-3p, and blv-miR-B5-5p) had highly significant positive correlations with BLV proviral load (PVL). The read counts of 90 host-derived miRNAs (bta-miRNAs) were significantly down-regulated in BLV-infected cattle compared to those in uninfected cattle. Only bta-miR-375 had a positive correlation with PVL in BLV-infected cattle and was highly expressed in the B cell lymphoma tissue of EBL cattle. There were a few bta-miRNAs that correlated with BLV tax/rex gene expression; however, BLV AS1 expression had a significant negative correlation with many of the down-regulated bta-miRNAs that are important for tumor development and/or tumor suppression. These results suggest that BLV promotes lymphomagenesis via AS1 and blv-miRNAs, rather than tax/rex, by down-regulating the expression of bta-miRNAs that have a tumor-suppressing function, and this downregulation is linked to increased PVL.

Hidden in plain sight: The effects of BCG vaccination in the COVID-19 pandemic

To investigate the relationship between Bacille Calmette‐Guérin (BCG) vaccination and SARS‐CoV‐2 by a bioinformatics approach, two datasets for the SARS‐CoV‐2 infection group and BCG‐vaccinated group were downloaded. Differentially Expressed Genes were identified. Gene ontology and pathways were functionally enriched, and networking was constructed in NetworkAnalyst. Lastly, the correlation between post‐BCG vaccination and COVID‐19 transcriptome signatures was established. A total of 161 DEGs (113 upregulated DEGs and 48 downregulated genes) were identified in the SARS‐CoV‐2 group. In the pathway enrichment analysis, a cross‐reference of upregulated Kyoto Encyclopedia of Genes and Genomes pathways in SARS‐CoV‐2 with downregulated counterparts in the BCG‐vaccinated group, resulted in the intersection of 45 common pathways, accounting for 86.5% of SARS‐CoV‐2 upregulated pathways. Of these intersecting pathways, a vast majority were immune and inflammatory pathways with top significance in interleukin‐17, tumor necrosis factor, NOD‐like receptors, and nuclear factor‐κB signaling pathways. Given the inverse relationship of the specific differentially expressed gene pathways highlighted in our results, the BCG‐vaccine may play a protective role against COVID‐19 by mounting a nonspecific immunological response and further investigation of this relationship is warranted.