Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe.

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%).

Destabilization of the human RED-SMU1 splicing complex as a basis for host-directed antiinfluenza strategy.

New therapeutic strategies targeting influenza are actively sought due to limitations in current drugs available. Host-directed therapy is an emerging concept to target host functions involved in pathogen life cycles and/or pathogenesis, rather than pathogen components themselves. From this perspective, we focused on an essential host partner of influenza viruses, the RED-SMU1 splicing complex.

Metal-Tagging Transmission Electron Microscopy and Immunogold Labeling on Tokuyasu Cryosections to Image Influenza A Virus Ribonucleoprotein Transport and Packaging.

Transmission electron microscopy (TEM) has been instrumental for studying viral infections. In particular, methods for labeling macromolecules at the ultrastructural level, by integrating biochemistry, molecular biology, and morphology, have allowed to study the functions of viral macromolecular complexes within the cellular context. Here, we describe a strategy for imaging influenza virus ribonucleoproteins in infected cells with two complementary labeling methods, metal-tagging transmission electron microscopy or METTEM, a highly sensitive technique based on the use of a metal-binding protein as a clonable tag, and immunogold labeling on thawed cryosections, a very specific labeling method that allows to study the distribution of different proteins simultaneously.

Influenza virus genome reaches the plasma membrane via a modified endoplasmic reticulum and Rab11-dependent vesicles.

Transport of neo-synthesized influenza A virus (IAV) viral ribonucleoproteins (vRNPs) from the nucleus to the plasma membrane involves Rab 11 but the precise mechanism remains poorly understood. We used metal-tagging and immunolabeling to visualize viral proteins and cellular endomembrane markers by electron microscopy of IAV-infected cells. Unexpectedly, we provide evidence that the vRNP components and the Rab11 protein are present at the membrane of a modified, tubulated endoplasmic reticulum (ER) that extends all throughout the cell, and on irregularly coated vesicles (ICVs).

Influenza A Virus Polymerase Recruits the RNA Helicase DDX19 to Promote the Nuclear Export of Viral mRNAs.

Enhancing the knowledge of host factors that are required for efficient influenza A virus (IAV) replication is essential to address questions related to pathogenicity and to identify targets for antiviral drug development. Here we focused on the interplay between IAV and DExD-box RNA helicases (DDX), which play a key role in cellular RNA metabolism by remodeling RNA-RNA or RNA-protein complexes. We performed a targeted RNAi screen on 35 human DDX proteins to identify those involved in IAV life cycle.

Rational development of an attenuated recombinant cyprinid herpesvirus 3 vaccine using prokaryotic mutagenesis and in vivo bioluminescent imaging.

Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57.

Recruitment of RED-SMU1 complex by Influenza A Virus RNA polymerase to control Viral mRNA splicing.

Influenza A viruses are major pathogens in humans and in animals, whose genome consists of eight single-stranded RNA segments of negative polarity. Viral mRNAs are synthesized by the viral RNA-dependent RNA polymerase in the nucleus of infected cells, in close association with the cellular transcriptional machinery. Two proteins essential for viral multiplication, the exportin NS2/NEP and the ion channel protein M2, are produced by splicing of the NS1 and M1 mRNAs, respectively.

Feeding Cyprinus carpio with infectious materials mediates cyprinid herpesvirus 3 entry through infection of pharyngeal periodontal mucosa.

Cyprinid herpesvirus 3 (CyHV-3), also known as Koi herpesvirus, is the etiological agent of a mortal disease in common and koi carp. Recently, we investigated the entry of CyHV-3 in carp using bioluminescence imaging and a CyHV-3 recombinant strain expressing luciferase (LUC). We demonstrated that the skin is the major portal of entry after inoculation of carp by immersion in water containing CyHV-3.

Cyprinid herpesvirus 3.

The recently designated cyprinid herpesvirus 3 (CyHV-3) is an emerging agent that causes fatal disease in common and koi carp. Since its emergence in the late 1990s, this highly contagious pathogen has caused severe financial losses in common and koi carp culture industries worldwide. In addition to its economic role, recent studies suggest that CyHV-3 may have a role in fundamental research.