Biology subjects

Rootes, C.

Publications and source records attributed to Rootes, C..

3 recordsLinked to original sources

bioRxiv2026

Knockdown of fibrillarin reveals cell- and virus- dependent restriction of henipavirus replication and enhanced antiviral immune signalling

The henipavirus genus includes several highly pathogenic zoonotic viruses that lack medical countermeasures. The 2-O-methyltransferase fibrillarin (FBL) has been identified by genome-wide functional genomics studies as a henipavirus pro-viral factor. While FBL is a potential target for host-directed antiviral therapeutics, its impact on henipavirus replication in cell types relevant to henipavirus disease has not been explored. Here we demonstrate that depleting cellular FBL using short interfering RNAs (siRNAs) has varying impacts on henipavirus replication, depending on cell type and virus. FBL depletion in small airway epithelial cells (HSAEC1-KT) significantly impaired viral gene transcription for Hendra virus (HeV) genotypes 1 and 2 (HeV-g1, HeV-g2), and Nipah virus (NiV) Bangladesh strain (NiV-B), but not NiV Malaysia (NiV-M) strain or Cedar virus (CedV). Conversely, reduced FBL expression in bronchial epithelial (NuLi-1) cells, aortic endothelial (Telo HAEC) cells or neuroblastoma (BE(2)-M17) cells did not inhibit HeV-g1 replication. Transcriptomic analyses revealed that impaired virus replication in FBL knockdown cells was associated with enhanced activation of innate immune pathways and robust upregulation of interferon stimulated genes (ISGs). Together, these findings demonstrate a virus- and cell-type dependent impact of FBL on henipavirus replication and support a role for FBL in modulation of the antiviral innate immune response.

microbiology↗

bioRxiv2021

Ribosome-profiling reveals restricted post transcriptional ex-pression of antiviral cytokines and transcription factors during SARS-CoV-2 infection

The global COVID-19 pandemic caused by SARS-CoV-2 has resulted in over 2.2 million deaths. Disease outcomes range from asymptomatic to severe with, so far, minimal genotypic change to the virus so understanding the host response is paramount. Transcriptomics has become incredibly important in understanding host-pathogen interactions; however, post-transcriptional regulation plays an important role in infection and immunity through translation and mRNA stability, allowing tight control over potent host responses by both the host and the invading virus. Here we apply ribosome profiling to assess post-transcriptional regulation of host genes during SARS-CoV-2 infection of a human lung epithelial cell line (Calu-3). We have identified numerous transcription factors (JUN, ZBTB20, ATF3, HIVEP2 and EGR1) as well as select antiviral cytokine genes, namely IFNB1, IFNL1,2 and 3, IL-6 and CCL5, that are restricted at the post-transcriptional level by SARS-CoV-2 infection and discuss the impact this would have on the host response to infection. This early phase restriction of antiviral transcripts in the lungs may allow high viral load and consequent immune dysregulation typically seen in SARS-CoV-2 infection.

microbiology↗

bioRxiv2020

ILRUN downregulates ACE2 expression and blocks infection of human cells by SARS-CoV-2

The human protein-coding gene ILRUN (inflammation and lipid regulator with UBA-like and NBR1-like domain, previously C6orf106) is a recently-characterised inhibitor of the transcription regulators p300 and CREB-binding protein (CBP). Here we have utilised RNA-seq to define cellular pathways regulated by ILRUN in the context of severe acute respiratory syndrome-associated coronavirus-2 (SARS-CoV-2) infection. We find that inhibition of ILRUN expression increases cellular expression of several members of the renin-angiotensin aldosterone system (RAAS), including the SARS-CoV-2 entry receptor angiotensin converting enzyme 2 (ACE2). Furthermore, inhibition of ILRUN results in increased SARS-CoV-2 replication. These data identify ILRUN as a novel inhibitor of SARS-CoV-2 replication and represents, to our knowledge, the first report of ILRUN as a regulator of the RAAS. SIGNIFICANCE STATEMENTThere is no doubt that the current rapid global spread of COVID-19 has had significant and far-reaching impacts on our health and economy and will continue to do so. Research in emerging infectious diseases, such as severe acute respiratory syndrome-associated coronavirus (SARS-CoV-2), is growing rapidly, with new breakthroughs in the understanding of host-virus interactions and the development of innovative and exciting therapeutic strategies and new knowledge and tools to better protect against the impacts of disease. The human protein-coding gene ILRUN is a recently-characterised inhibitor of the transcription regulators p300 and CREB-binding protein (CBP). Here we present the first evidence that ILRUN modulation has implications for SARS-CoV-2 infections. Virus infectivity assays confirmed that gene silencing of ILRUN had a proviral effect and increased SARS-CoV-2 replication, whilst over-expression of ILRUN inhibited SARS-CoV-2 production. Additionally, we observed that ILRUN also regulates the expression of key elements of the RAAS. These data have important implications for the development of antiviral strategies to deal with the current SARS-CoV-2 pandemic.

cell biology↗