Positive-strand RNA viruses have been the cause of several recent outbreaks and epidemics, including the Zika virus epidemic in 2015, the SARS outbreak in 2003, and the ongoing SARS-CoV-2 pandemic.... Show morePositive-strand RNA viruses have been the cause of several recent outbreaks and epidemics, including the Zika virus epidemic in 2015, the SARS outbreak in 2003, and the ongoing SARS-CoV-2 pandemic. On June 18-22, 2022, researchers focusing on positive-strand RNA viruses met for the Keystone Symposium "Positive-Strand RNA Viruses" to share the latest research in molecular and cell biology, virology, immunology, vaccinology, and antiviral drug development. This report presents concise summaries of the scientific discussions at the symposium. Show less
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... Show moreIn 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%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >= 2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections. Show less
The development of gene therapies for central nervous system disorders is challenging because it is difficult to translate preclinical data from current in vitro and in vivo models to the clinic.... Show moreThe development of gene therapies for central nervous system disorders is challenging because it is difficult to translate preclinical data from current in vitro and in vivo models to the clinic. Therefore, we developed induced pluripotent stem cell (iPSC)-derived cerebral organoids as a model for recombinant adeno-associated virus (rAAV) capsid selection and for testing efficacy of AAV-based gene therapy in a human context. Cerebral organoids are physiological 3D structures that better recapitulate the human brain compared with 2D cell lines. To validate the model, we compared the transduction efficiency and distribution of two commonly used AAV serotypes (rAAV5 and rAAV9). In cerebral organoids, transduction with rAAV5 led to higher levels of vector DNA, transgenic mRNA, and protein expression as compared with rAAV9. The superior transduction of rAAV5 was replicated in iPSC-derived neuronal cells. Furthermore, rAAV5-mediated delivery of a human sequence-specific engineered microRNA to cerebral organoids led to a lower expression of its target ataxin-3. Our studies provide a new tool for selecting and deselecting AAV serotypes, and for demonstrating therapeutic efficacy of transgenes in a human context. Implementing cerebral organoids during gene therapy development could reduce the usage of animal models and improve translation to the clinic. Show less
Enteroviruses (EVs) and rhinoviruses (RVs) are significant pathogens of humans and are the subject of intensive clinical and epidemiological research and public health measures, notably in the... Show moreEnteroviruses (EVs) and rhinoviruses (RVs) are significant pathogens of humans and are the subject of intensive clinical and epidemiological research and public health measures, notably in the eradication of poliovirus and in the investigation and control of emerging pathogenic EV types worldwide. EVs and RVs are highly diverse in their antigenic properties, tissue tropism, disease associations and evolutionary relationships, but the latter often conflict with previously developed biologically defined terms, such as "coxsackieviruses", "polioviruses" and "echoviruses", which were used before their genetic interrelationships were understood. This has created widespread formatting problems and inconsistencies in the nomenclature for EV and RV types and species in the literature and public databases. As members of the International Committee for Taxonomy of Viruses (ICTV) Picornaviridae Study Group, we describe the correct use of taxon names for these viruses and have produced a series of recommendations for the nomenclature of EV and RV types and their abbreviations. We believe their adoption will promote greater clarity and consistency in the terminology used in the scientific and medical literature. The recommendations will additionally provide a useful reference guide for journals, other publications and public databases seeking to use standardised terms for the growing multitude of enteroviruses and rhinoviruses described worldwide. Show less
Zoest, R.A. van; Law, M.; Sabin, C.A.; Vaartjes, I.; Valk, M. van der; Arends, J.E.; ... ; Elst-Laurijssen, D.H. 2019
Berg-van de Glind, G.J.D. van den; Vries, J.J.C. de; Wolthers, K.C.; Wiggers-de Bruine, F.T.; Peeters-Scholte, C.M.P.C.D.; Hendef, M. van den; Wezel-Meijler, G. van 2012
BACKGROUND: Human enteroviruses (HEVs) can cause severe infections, especially in patients with a deficient humoral immune response, such as X-linked agammaglobulinemia. In this patient group,... Show moreBACKGROUND: Human enteroviruses (HEVs) can cause severe infections, especially in patients with a deficient humoral immune response, such as X-linked agammaglobulinemia. In this patient group, chronic enteroviral meningitis (CEMA) is feared because of extensive morbidity and high fatality rate. Treatment options consist of intravenous immunoglobulin (IVIG), with various outcomes. Pleconaril is an antiviral agent with in vitro activity against HEVs that has been used in the treatment of HEV infections. METHODS: The efficacy of pleconaril and IVIG against HEV isolated from the patients was assessed in vitro in two patients with CEMA. RESULTS: Echovirus 11 was found in the cerebrospinal fluid (CSF) of case 1. Treatment with high-dose IVIG and pleconaril did not provide any clinical improvement and HEV PCR in CSF remained positive. Case 2 (echovirus 13 positive in CSF) was also treated with IVIG and pleconaril. The patient recovered completely and HEV PCR in CSF became negative. Recent IVIG batches contained low titres of neutralizing antibodies against the patient strains. Echovirus 11 (case 1) was resistant to pleconaril in vitro, whereas echovirus 13 (case 2) was susceptible, in accordance with virological response after treatment and subsequent clinical results. CONCLUSIONS: This is the first report that evaluates efficacy of antiviral treatment in CEMA patients in relation to in vitro susceptibility of clinical virus isolates. Since pleconaril is no longer available for compassionate use we strongly propagate that new drugs should be developed against these potential life threatening HEV infections. Show less
