Scientific projects
GENERAL CONTEXT
Group B Enteroviruses (Picornaviridae) are non-enveloped, single-stranded RNA viruses of positive polarity. These common and ubiquitous pathogens are responsible for common acute or persistent infections in various human target tissues including the cardiovascular system. Their (+) RNA genome of 7.5 kpb is composed of a non-coding region at the 5' end that is crucial for the initiation of viral replication and translation mechanisms.
Natural viral forms with terminal deletions of variable length in the 5' non-coding region (5'NC) have been characterized using molecular approaches (NGS) in murine or human EV-B induced infections by our team.
The CardioVir team studies the viral and immunological mechanisms involved in acute and persistent EV-B viral infections and their role in the development of unexplained cardiac pathologies.
Theme 1
Impact of deleted RNA forms of the enterovirus genome on the type 1 interferon response during myocarditis
Funding: French Federation of Cardiology
The incidence of myocarditis is approximately 1.5 million cases per year worldwide. In the United States and Europe, this cardiomyopathy results mainly from infection of cardiac tissue by human group B enteroviruses, and is considered one of the major causes of sudden cardiac death or dilated cardiomyopathy (DCM) in children and young adults. Currently, the virological and immunological mechanisms that regulate the progression of acute viral myocarditis to the severe or fulminant form or to the chronic phase that leads to DCM remain unknown and limit the development of new targeted therapeutic strategies.
Our viro-clinical investigations (human sample banks already constituted) and experimental investigations (in vitro in cultured human heart cells and in vivo in DBA2/J mice) will allow us to (I) to identify in group B Enteroviruses (CVB3) the immunogenic sequences and RNA structures of the 5'NC region capable of activating the type I interferon pathway in humans; (II) to determine the main RLR-type receptors (RIG-1, MDA5, LGP2) in human cardiac cells capable of binding the viral RNA structures identified previously (objective I); (III) to study the modulation of type 1 IFN pathways by specific agonists of innate immunity receptors (identified in objective II) and the impact of this activation on cardiac injury scores and mortality of DBA2/J mice with acute or chronic CVB3/28 myocarditis.
The immunovirological results obtained during the study of the acute phase of enterovirus myocarditis will allow the identification of new virological or immunological biomarkers that will allow the detection of patients at risk of severe or chronic clinical forms in clinical practice. Moreover, our experimental data obtained in the mouse model of CVB3 myocarditis could eventually allow to propose new immunomodulatory treatments (immunotherapies) adapted to the stage of evolution and the clinical severity of viral myocarditis.
Key words: myocarditis, innate immune response, Enterovirus, type 1 interferon, 5'NC.
Theme 2
Impact of the viral RNA epitranscriptome during infection (ViroMOD)
Funding: Fonds régional de coopération pour la recherche-APP 2021-2023, PI: Louri Motorin (Université de Lorraine); Co-PI: Laurent Andreoletti.
Collaborations:
- IMoPA (Ingénierie Moléculaire et Physiopathologie Articulaire) - UMR 7365 CNRS – Université de Lorraine
- M3i Modèles insectes d’immunité innée – UPR 9022 – Université de Strasbourg
RNA modifications, commonly referred to as epitranscriptome, are observed on specific residues of cellular RNAs and play a key role for their maturation and functionality. Among more than one hundred and fifty described chemical modifications, methylation of nucleotides at different positions is the most abundant. In the last decade, the development of new detection approaches by high-throughput genome-wide sequencing has led to the identification of mRNA methylation providing a new level of regulation of gene expression.
However, very few studies have been devoted so far to viral RNA modifications and, despite the identification of some RNA modifications present in viruses, little is known about their roles in virus infection and propagation. Some modifications of viral RNAs appear today fundamental for the regulation of arboviruses (ZIKA and Dengue) and other viruses. This ambitious project has an integrative dimension, since it combines the mapping of the epitranscriptome of viral RNAs with genetic and molecular virology approaches.
The ViroMOD project brings together partners in Lorraine, Alsace and Champagne-Ardenne who are scientists with international visibility and diverse backgrounds including RNA biologists (IMoPA, Nancy), experts in molecular virology and insect genetics (UPR9022, Strasbourg) and in medical virology (EA-4684, Reims). The ViroMOD project will generate complementary expertises by integrating different technological approaches and biological models.
The project has three scientific objectives: to map post-transcriptional modifications of genomic RNAs (gRNAs) of positive polarity for CVB3 and SARS-Cov-2 viruses; to study the impact of gRNA modifications on viral genome replication and maturation; and to study the detection of modified viral RNAs by the host innate immune system
In the field of molecular virology, the comprehensive characterization of the epitranscriptome of viral RNAs will be crucial for a better understanding of the defense mechanisms against these infections. Modulation of viral RNA modifications may help to restore the efficiency of recognition mechanisms as well as the elimination of the virus, or, at least, limit its spread to a very large extent.
Key words: Infection, molecular virology, epitranscriptomics, RNA modification
Sudden cardiac death and myocarditis expertise skills
CardioVir department team have developed and used molecular biology tests (RT-qPCR TaqMan, multiplex chips…) to detect common cardiotropic viruses in human heart biopsies samples, either endomyocardial biopsies or autopsy heart tissues samples (Ref: https://www.intechopen.com/chapters/21880). These virological analyses are completed by histology and immunohistochemistry when paraffin-embedded cardiac tissues are available, to detect inflammatory cells markers (CD3, CD68, HLA-DR…). Our fields of expertise encompass fulminant myocarditis in the young and children (endomyocardial biopsies), and SCD in the young (autopsy cardiac samples) for a better understanding of the role of common viruses and to assess the incidence of viral myocarditis in Europe.
This original CardioVir unit expertise is generally a specific request for specific cases such as sudden death sine materia, immunotherapies and myocarditis, etc, for which an aetiological viral or infectious diagnosis can be a medico legal mandatory. These viral analyses are generally free and requested for diagnostic and research purposes. National (Paris, Lyon…) and international (Sheffield, UK; Madrid, Spain) collaborations, including publications, have resulted from these investigations. Results are sent to the physician who in turn informed the patient or its family, resulting in further preventive strategies for sudden death or myocarditis cases.
Regional and national expertise’s and skills in the detection and typing of SARS-CoV-2
Written by Marie Glenet
Faced with the health crisis related to SARS-CoV-2 pandemic and within the framework of the low daily capacities levels of SARS-CoV-2 detection within the Champagne Ardenne general population in June 2020, the University of Reims Champagne-Ardenne (URCA) signed with the University Hospital of Reims and subsequently with two groups of medical analysis laboratories (“Unilabs” and “”Bioxa”), under prefectural exemption, agreements allowing the establishment of a clinical laboratory approved by the regional health agency (ARS) and the Marne prefecture. This structure was headed by Prof. Laurent ANDREOLETTI within the EA-4684 structure at the Reims Medicine Faculty. This original diagnostic laboratory has been operating in high throughput screening (500 to 2500 molecular detection tests for SARS-CoV-2) from Monday to Saturday thanks to the mobilization of CardioVir staff and URCA volunteers (19-25 peoples) and was able to daily perform 2500 RT-PCR SARS-CoV-2 assays in human respiratory samples.
As of March 15, 2021, the laboratory performed COVID-19 variant typing tests on positive specimens, distinguishing Beta (South African/Brazilian) and Delta (UK or UK mutated) variants from the original Wuhan strain. Since June 2021, the laboratory has had a highly performance NGS platform for whole genome or Spike gene sequencing of SARS-CoV-2. Our laboratory has usefully submitted 41 full-length SARS-CoV- 2 genome sequences on EMERGEN-DB platform in order to contribute to the genomic surveillance of SARS-CoV-2 in France through NGS sequencing. Currently, this structural laboratory organization remains on health alert to continue the SARS-CoV-2 screening or genotyping assays.