scholarly journals Advancing Marburg virus antiviral screening: Optimization of a novel T7 polymerase-independent minigenome system

2021 ◽  
Vol 185 ◽  
pp. 104977
Author(s):  
Bert Vanmechelen ◽  
Joren Stroobants ◽  
Kurt Vermeire ◽  
Piet Maes
Keyword(s):  
Marburg Virus ◽  
Minigenome System ◽  
T7 Polymerase

scholarly journals Development of a T7-Independent MARV Minigenome System

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 27
Author(s):  
Bert Vanmechelen ◽  
Joren Stroobants ◽  
Kurt Vermeire ◽  
Piet Maes
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Virus Disease ◽  
Ectopic Expression ◽  
Cell Types ◽  
Marburg Virus ◽  
Antiviral Compound ◽  
Wide Range ◽  
Compound Screening ◽  
Minigenome System

Marburg virus (MARV) is the only known pathogenic filovirus that does not belong to the genus Ebolavirus. It causes a severe hemorrhagic fever that is associated with a high mortality rate (>80%). The potential for filoviruses to cause devastating outbreaks, in combination with the lack of licensed therapeutics and vaccines for Marburg virus disease, illustrates the need for more MARV research. However, research involving MARV is hindered by its dependency on access to high-containment laboratories. Virus alternatives such as minigenomes have proven to be a useful tool to study virus replication and transcription at lower biosafety levels, and can be used for antiviral compound screening. All currently available MARV minigenomes are dependent on the addition of an ectopic T7 RNA polymerase that can drive minigenome expression. While this allows for high expression levels, the ectopic expression of a T7 polymerase is not feasible in all cell types, and acts as a confounding factor in compound screening assays. We have developed an alternative MARV minigenome system that is controlled by an RNA polymerase II promoter, which is natively expressed in most mammalian cell types. We show here that this novel minigenome can be used in a wide range of cell types, and can be easily amended to a 96-well format to be used for high-throughput compound screening, thereby providing a valuable alternative to previously developed MARV minigenomes.

scholarly journals Development and optimization of a novel T7 polymerase-independent Marburg virus minigenome system

2020 ◽  
Author(s):  
Bert Vanmechelen ◽  
Joren Stroobants ◽  
Kurt Vermeire ◽  
Piet Maes
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Cell Types ◽  
Marburg Virus ◽  
Attractive Alternative ◽  
Wide Range ◽  
Compound Screening ◽  
Exogenous Expression ◽  
Screening Assays ◽  
T7 Polymerase

AbstractMarburg virus (MARV) is the only known pathogenic filovirus not belonging to the genus Ebolavirus. Minigenomes have proven a useful tool to study MARV, but all existing MARV minigenomes are dependent on the addition of an exogenous T7 RNA polymerase to drive minigenome expression. However, exogenous expression of a T7 polymerase is not always feasible and acts as a confounding factor in compound screening assays. We have developed an alternative minigenome that is controlled by the natively expressed RNA polymerase II. We demonstrate here the characteristics of this new system and its applicability in a wide range of cell types. Our system shows a clear concentration-dependent activity and outperforms the existing T7 polymerase-based system at higher concentrations, especially in difficult-to-transfect cell lines. In addition, we show that our system can be used for high-throughput compound screening in a 96-well format, thereby providing an attractive alternative to previously developed MARV minigenomes.

scholarly journals Determining the Patchwork Lattice of Ebola and Marburg Virus Matrix Layers Using Cryo-Electron Tomography

2021 ◽  
Vol 27 (S1) ◽  
pp. 1884-1884
Author(s):  
William Wan ◽  
Mairi Clarke ◽  
Michael Norris ◽  
Larissa Kolesnikova ◽  
Alexander Koehler ◽  
...  
Keyword(s):  
Electron Tomography ◽  
Marburg Virus ◽  
Cryo Electron Tomography

scholarly journals Combination therapy protects macaques against advanced Marburg virus disease

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Robert W. Cross ◽  
Zachary A. Bornholdt ◽  
Abhishek N. Prasad ◽  
Viktoriya Borisevich ◽  
Krystle N. Agans ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Rhesus Monkeys ◽  
Viral Infections ◽  
Virus Disease ◽  
Marburg Virus ◽  
Therapeutic Window ◽  
Post Inoculation ◽  
Primate Model ◽  
Lethal Infection ◽  
Human Primate

AbstractMonoclonal antibodies (mAbs) and remdesivir, a small-molecule antiviral, are promising monotherapies for many viruses, including members of the genera Marburgvirus and Ebolavirus (family Filoviridae), and more recently, SARS-CoV-2. One of the major challenges of acute viral infections is the treatment of advanced disease. Thus, extending the window of therapeutic intervention is critical. Here, we explore the benefit of combination therapy with a mAb and remdesivir in a non-human primate model of Marburg virus (MARV) disease. While rhesus monkeys are protected against lethal infection when treatment with either a human mAb (MR186-YTE; 100%), or remdesivir (80%), is initiated 5 days post-inoculation (dpi) with MARV, no animals survive when either treatment is initiated alone beginning 6 dpi. However, by combining MR186-YTE with remdesivir beginning 6 dpi, significant protection (80%) is achieved, thereby extending the therapeutic window. These results suggest value in exploring combination therapy in patients presenting with advanced filovirus disease.

scholarly journals Deep learning-based recognition of cell structures in fluorescence microscopy sequences with respect to their morphology on cells infected with Marburg virus

2020 ◽  
Vol 6 (3) ◽  
pp. 501-504
Author(s):  
Dennis Schmidt ◽  
Andreas Rausch ◽  
Thomas Schanze
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Infected Cell ◽  
Network Architecture ◽  
Image Sequences ◽  
Marburg Virus ◽  
Microscopic Image ◽  
Cell Structures ◽  
Fast Recognition ◽  
Subviral Particles

AbstractThe Institute of Virology at the Philipps-Universität Marburg is currently researching possible drugs to combat the Marburg virus. This involves classifying cell structures based on fluoroscopic microscopic image sequences. Conventionally, membranes of cells must be marked for better analysis, which is time consuming. In this work, an approach is presented to identify cell structures in images that are marked for subviral particles. It could be shown that there is a correlation between the distribution of subviral particles in an infected cell and the position of the cell’s structures. The segmentation is performed with a "Mask-R-CNN" algorithm, presented in this work. The model (a region-based convolutional neural network) is applied to enable a robust and fast recognition of cell structures. Furthermore, the network architecture is described. The proposed method is tested on data evaluated by experts. The results show a high potential and demonstrate that the method is suitable.

scholarly journals Fractal Dimensions of Subviral Particle Movement

2018 ◽  
Vol 4 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Andreas Rausch ◽  
Thomas Schanze
Keyword(s):  
Virus Disease ◽  
Fractal Dimensions ◽  
Real Data ◽  
Marburg Virus ◽  
Virus Infections ◽  
Fluorescence Image ◽  
Good Potential ◽  
Infected Cells ◽  
Subviral Particle ◽  
Subviral Particles

AbstractThe development of new medicines against virus infections like the Marburg virus disease requires an accurate knowledge of the respective pathogens. Conventionally, this process is very time expensive. In cooperation with the Virology of the Philipps-University in Marburg an automatic tracking algorithm for subviral particles in fluorescence image sequences was developed and programmed. To expand the benefit for the pharmaceutical researchers, also the trackevaluations need to be widely automated. In this work, a new parameterizing-method facing the fractal dimensions of spline interpolated subviral particle tracks is presented and tested with simulated and real data. The results reveal a good potential to classify tracks and, thus, types of subviral particles in infected cells.

scholarly journals Marburg virus survivor immune responses are Th1 skewed with limited neutralizing antibody responses

2017 ◽  
Vol 214 (9) ◽  
pp. 2563-2572 ◽  
Author(s):  
Spencer W. Stonier ◽  
Andrew S. Herbert ◽  
Ana I. Kuehne ◽  
Ariel Sobarzo ◽  
Polina Habibulin ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Ebola Virus ◽  
T Cell Responses ◽  
Neutralizing Antibody ◽  
Cd8 T Cell ◽  
Marburg Virus ◽  
Antibody Responses ◽  
Cd4 T Cell ◽  
Cell Responses

Until recently, immune responses in filovirus survivors remained poorly understood. Early studies revealed IgM and IgG responses to infection with various filoviruses, but recent outbreaks have greatly expanded our understanding of filovirus immune responses. Immune responses in survivors of Ebola virus (EBOV) and Sudan virus (SUDV) infections have provided the most insight, with T cell responses as well as detailed antibody responses having been characterized. Immune responses to Marburg virus (MARV), however, remain almost entirely uncharacterized. We report that immune responses in MARV survivors share characteristics with EBOV and SUDV infections but have some distinct differences. MARV survivors developed multivariate CD4+ T cell responses but limited CD8+ T cell responses, more in keeping with SUDV survivors than EBOV survivors. In stark contrast to SUDV survivors, rare neutralizing antibody responses in MARV survivors diminished rapidly after the outbreak. These results warrant serious consideration for any vaccine or therapeutic that seeks to be broadly protective, as different filoviruses may require different immune responses to achieve immunity.

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