Control of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic requires accurate laboratory testing to identify infected individuals, while also clearing essential staff to continue work. At the current time a number of qRT-PCR assays have been developed to identify SARS-CoV-2, targeting multiple positions in the viral genome. While the mutation rate of SARS-CoV-2 is moderate, given the large number of transmission chains it is prudent to monitor circulating viruses for variants that might compromise these assays. Here we report the identification of a C-to-U transition at position 26,340 of the SARS-CoV-2 genome which is associated with failure of the cobas® SARS-CoV-2 E-gene qRT-PCR in eight patients. As the cobas® SARS-CoV-2 assay targets two positions in the genome, the individuals carrying this variant were still called as SARS-CoV-2 positive. Whole genome sequencing of SARS-CoV-2 showed all to carry closely related viruses. Examination of viral genomes deposited on GISAID showed this mutation has arisen independently at least four times. This work highlights the necessity of monitoring SARS-CoV-2 for the emergence of SNPs which might adversely affect RT-PCRs used in diagnostics. Additionally, it argues that two regions in SARS-CoV-2 should be targeted to avoid false negatives.
Since the start of the COVID-19 pandemic, an unprecedented number of genomic sequences of SARS-CoV-2 have been generated and shared with the scientific community. The unparalleled volume of available genetic data presents a unique opportunity to gain real-time insights into the virus transmission during the pandemic, but also a daunting computational hurdle if analysed with gold-standard phylogeographic approaches. To tackle this practical limitation, we here describe and apply a rapid analytical pipeline to analyse the spatio-temporal dispersal history and dynamics of SARS-CoV-2 lineages. As a proof of concept, we focus on the Belgian epidemic, which has had one of the highest spatial densities of available SARS-CoV-2 genomes. Our pipeline has the potential to be quickly applied to other countries or regions, with key benefits in complementing epidemiological analyses in assessing the impact of intervention measures or their progressive easement.
To cite this version:Isabelle Coupienne Isabelle Coupienne, Sébastien Bontems, Michael Dewaele, Noemi Rubio, Yvette Habraken, et al.. NF-kappaB inhibition improves the sensitivity of human glioblastoma cells to 5-aminolevulinic acid-based photodynamic therapy. Biochemical Pharmacology, Elsevier, 2011, 81 (5) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A c c e p t e d M a n u s c r i p t 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 AbstractGlioblastoma constitute the most frequent and deadliest brain tumors of astrocytic origin.They are very resistant to all current therapies and are associated with a huge rate of recurrence. In most cases, this type of tumor is characterized by a constitutive activation of the nuclear factor-kappaB (NF-B). This factor is known to be a key regulator of various physiological processes such as inflammation, immune response, cell growth or apoptosis. In the present study, we explored the role of NF-B activation in the sensitivity of human glioblastoma cells to a treatment by 5-aminolevulinic acid (5-ALA)-based photodynamic therapy (PDT). 5-ALA is a physiological compound widely used in PDT as well as in tumor photodetection (PDD). Our results show that inhibition of NF-κB improves glioblastoma cell death in response to 5-ALA-PDT. We then studied the molecular mechanisms underlying the cell death induced by PDT combined or not with NF-B inhibition. We found that apoptosis was induced by PDT but in an incomplete manner and that, unexpectedly, NF-B inhibition reduced its level. Oppositely PDT mainly induces necrosis in glioblastoma cells and NF-B is found to have anti-necrotic functions in this context. The autophagic flux was also enhanced as a result of 5-ALA-PDT and we demonstrate that stimulation of autophagy acts as a prosurvival mechanism confering protection against PDT-mediated necrosis. These data point out that 5-ALA-PDT has an interesting potential as a mean to treat glioblastoma and that inhibition of NF-B renders glioblastoma cells more sensitive to the treatment.
During the early phase of varicella-zoster virus (VZV) infection, Immediate Early protein 63 (IE63) is expressed rapidly and abundantly in the nucleus, while during latency, this protein is confined mostly to the cytoplasm. Because phosphorylation is known to regulate many cellular events, we investigated the importance of this modification on the cellular localization of IE63 and on its regulatory properties. We demonstrate here that cellular casein kinases I and II are implicated in the in vitro and in vivo phosphorylation of IE63. A mutational approach also indicated that phosphorylation of the protein is important for its correct cellular localization in a cell type-dependent fashion. Using an activity test, we demonstrated that IE63 was able to repress the gene expression driven by two VZV promoters and that phosphorylation of the protein was required for its full repressive properties. Finally, we showed that IE63 was capable of exerting its repressive activity in the cytoplasm, as well as in the nucleus, suggesting a regulation at the transcriptional and/or posttranscriptional level.
Latent infection of human ganglia with Varicella-Zoster virus (VZV) is characterized by a highly restricted pattern of viral gene expression. To enhance understanding of this process we used in situ hybridization (ISH) in a rat model of VZV latency to examine expression of RNA corresponding to eight different VZV genes in rat dorsal root ganglia (DRG) at various times after footpad inoculation with wild-type VZV. PCR in situ amplification was also used to determine the cell specificity of latent VZV DNA. It was found that the pattern of viral gene expression at 1 week after infection was different from that observed at the later times of 1 and 18 months after infection. Whereas multiple genes were expressed at 1 week after infection, gene expression was restricted at the later time points when latency had been established. At the later time points after infection the RNA transcripts expressed most frequently were those for VZV genes 21, 62, and 63. Gene 63 was expressed more than any other gene studied. While VZV DNA was detected almost exclusively in 5-10% of neurons, VZV RNA was detected in both neurons and nonneuronal cells at an approximate ratio of 3:1. A newly described monoclonal antibody to VZV gene 63-encoded protein was used to detect this protein in neuronal nuclei and cytoplasm in almost half of the DRG studied. These results demonstrate that (1) this rat model of latency has close similarities in terms of viral gene expression to human VZV latency which makes it a useful tool for studying this process and its experimental modulation and (2) expression of VZV gene 63 appears to be the single most consistent feature of VZV latency.
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