Search results for "RNA virus"
showing 10 items of 149 documents
Beyond malaria: The inhibition of viruses by artemisinin-type compounds
2018
Abstract Natural products represent valuable chemical scaffolds for drug development. A recent success story in this context was artemisinin, which is not only active against malaria but also to other diseases. This raised the interest of artemisinin's potential for drug repurposing. On the present review, we give an overview on artemisinin's antiviral activity. There is good in vitro and in vivo evidence for the activity of artemisinin and its derivatives against DNA viruses of the Herpesviridae and Hepadnaviridae families such as cytomegaloviruses, human herpesvirus 6, herpes simplex viruses 1 and 2, Epstein-Barr virus and Hepatitis B virus. The evidence is weaker for Polyomaviruses and p…
STABILITY OF A STOCHASTICALLY PERTURBED MODEL OF INTRACELLULAR SINGLE-STRANDED RNA VIRUS REPLICATION
2019
Compared to the replication of double-stranded RNA and DNA viruses, the replication of single-stranded viruses requires the production of a number of intermediate strands that serve as templates for the synthesis of genomic-sense strands. Two theoretical extreme mechanisms for replication for such single-stranded viruses have been proposed; one extreme being represented by the so-called linear stamping machine and the opposite extreme by the exponential growth. Of course, real systems are more complex and examples have been described in which a combination of such extreme mechanisms can also occur: a fraction of the produced progeny resulting from a stamping-machine type of replication that…
Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal
2020
The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients. Resumen: La pandemia por coronavirus SARS-CoV-2 (Covid-19) está evolucionando de manera muy rápida y representa un riesgo especial en pacientes inmunodeprimidos y con comorbilidades añadidas. El conocimiento sobre esta in…
Modelling temperature-dependent dynamics of single and mixed infections in a plant virus
2022
Multiple viral infection is an important issue in health and agriculture with strong impacts on society and the economy. Several investigations have dealt with the population dynamics of viruses with different dynamic properties, focusing on strain competition during multiple infections and the effects on viruses’ hosts. Recent interest has been on how multiple infections respond to abiotic factors such as temperature (T). This is especially important in the case of plant pathogens, whose dynamics could be affected significantly by global warming. However, few mathematical models incorporate the effect of T on parasite fitness, especially in mixed infections. Here, we investigate simple mat…
RNA2-encoded VP37 protein of Broad bean wilt virus 1 is a determinant of pathogenicity, host susceptibility, and a suppressor of post-transcriptional…
2020
Abstract Broad bean wilt virus 1 (BBWV‐1, genus Fabavirus, family Secoviridae) is a bipartite, single‐stranded positive‐sense RNA virus infecting many horticultural and ornamental crops worldwide. RNA1 encodes proteins involved in viral replication whereas RNA2 encodes two coat proteins (the large and small coat proteins) and two putative movement proteins (MPs) of different sizes with overlapping C‐terminal regions. In this work, we determined the role played by the small putative BBWV‐1 MP (VP37) on virus pathogenicity, host specificity, and suppression of post‐transcriptional gene silencing (PTGS). We engineered a BBWV‐1 35S‐driven full‐length cDNA infectious clone corresponding to BBWV‐…
Performance of QuantiFERON-TB Gold Plus for detection of latent tuberculosis infection in pregnant women living in a tuberculosis- and HIV-endemic se…
2017
We evaluated the performance of QuantiFERON-TB Gold Plus (QFT-Plus), which includes two Mycobacterium tuberculosis antigen formulations (TB1 and TB2), for detection of latent tuberculosis infection during pregnancy. Eight-hundred-twenty-nine Ethiopian pregnant women (5.9% HIV-positive) were tested with QFT-Plus, with bacteriological sputum analysis performed for women with clinically suspected tuberculosis and HIV-positive women irrespective of clinical presentation. QFT-Plus read-out was categorized according to the conventional cut-off (0.35 IU/ml) for both antigen formulations. In addition, we analysed the distribution of QFT-Plus results within a borderline zone (0.20–0.70 IU/ml), and i…
Single-Cell Analysis of RNA Virus Infection Identifies Multiple Genetically Diverse Viral Genomes within Single Infectious Units
2015
Summary Genetic diversity enables a virus to colonize novel hosts, evade immunity, and evolve drug resistance. However, viral diversity is typically assessed at the population level. Given the existence of cell-to-cell variation, it is critical to understand viral genetic structure at the single-cell level. By combining single-cell isolation with ultra-deep sequencing, we characterized the genetic structure and diversity of a RNA virus shortly after single-cell bottlenecks. Full-length sequences from 881 viral plaques derived from 90 individual cells reveal that sequence variants pre-existing in different viral genomes can be co-transmitted within the same infectious unit to individual cell…
Experimental evolution of an oncolytic vesicular stomatitis virus with increased selectivity for p53-deficient cells
2014
Experimental evolution has been used for various biotechnological applications including protein and microbial cell engineering, but less commonly in the field of oncolytic virotherapy. Here, we sought to adapt a rapidly evolving RNA virus to cells deficient for the tumor suppressor gene p53, a hallmark of cancer cells. To achieve this goal, we established four independent evolution lines of the vesicular stomatitis virus (VSV) in p53-knockout mouse embryonic fibroblasts (p53-/- MEFs) under conditions favoring the action of natural selection. We found that some evolved viruses showed increased fitness and cytotoxicity in p53-/- cells but not in isogenic p53+/+ cells, indicating gene-specifi…
Evolution of RNA virus in spatially structured heterogeneous environments
2003
A hallmark of the infectious cycle for many RNA viruses parasitizing multicellular hosts is the need to invade and successfully replicate in tissues that comprise a variety of cell types. Thus, multicellular hosts represent a heterogeneous environment to evolving viral populations. To understand viral adaptation to multicellular hosts, we took a double approach. First, we developed a mathematical model that served to make predictions concerning the dynamics of viral populations evolving in heterogeneous environments. Second, the predictions were tested by evolving vesicular stomatitis virus in vitro on a spatially structured environment formed by three different cell types. In the absence o…
Replication of the hepatitis C virus
2000
Infection with the hepatitis C virus (HCV) is a major cause of chronic liver disease. HCV is an enveloped plus-strand RNA virus closely related to flavi- and pestiviruses. The first cloning of the HCV genome, about 10 years ago, initiated research efforts leading to the elucidation of the genomic organization and the definition of the functions of most viral proteins. Despite this progress the lack of convenient animal models and appropriate in vitro propagation systems have hampered a full understanding of the way the virus multiplies. This review summarizes our current knowledge about HCV replication and describes attempts pursued in the last few years to establish efficient and reliable …