Zika Virus and Neuropathogenesis: The Unanswered Question of Which Strain Is More Prone to Causing Microcephaly and Other Neurological Defects.

Despite being perceived to be a relatively innocuous pathogen during its circulation in Africa in the 20th century, consequent outbreaks in French Polynesia and Latin America revealed the Zika virus (ZIKV) to be capable of causing severe neurological defects. Foetuses infected with the virus during pregnancy developed a range of pathologies including microcephaly, cerebral calcifications and macular scarring. These are now collectively known as Congenital Zika syndrome (CZS). It has been established that the neuropathogenesis of ZIKV results from infection of neural progenitor cells in the developing cerebral cortex. Following this, two main hypotheses have emerged: the virus causes either apoptosis or premature differentiation of neural progenitor cells, reducing the final number of mature neurons in the cerebral cortex. This review describes the cellular processes which could potentially cause virus induced apoptosis or premature differentiation, leading to speculation that a combination of the two may be responsible for the pathologies associated with ZIKV. The review also discusses which specific lineages of the ZIKV can employ these mechanisms. It has been unclear in the past whether the virus evolved its neurotropic capability following circulation in Africa, or if the virus has always caused microcephaly but public health surveillance in Africa had failed to detect it. Understanding the true neuropathogenesis of ZIKV is key to being prepared for further outbreaks in the future, and it will also provide insight into how neurotropic viruses can cause profound and life-long neurological defects

Analysis of the assembly and maturation processes of the Infectious Bursal Disease Virus capsid

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 30-06-0

Haur Hezkuntzatik Lehen Hezkuntzara bidea egiten

39, 11 p. -- Bibliogr.: p. 38-39[EUS] Gradu Amaierako Lan honen bidez, haurrek Haur Hezkuntzatik Lehen Hezkuntzara igarotzean bizi duten errealitatera hurbildu nahi dugu, eta trantsizio honi dagokion hezkuntza errealitatea ezagutu. Horretarako, ikerketa lan bat eraman dugu aurrera, non, bi etapetako 55 irakasleren eta 153 familiaren artean dagoen koordinazioa, trantsizio horri aurre egiteko Haur Hezkuntzako azken ikasturtetik haiekin egiten den prestakuntza, familiek ikastetxearekin duten harremana eta aldaketa bizi duten haurrek Lehen Hezkuntzako lehen mailan izan ditzaketen jokabide eta zailtasunak aztertu ditugun. Bertan ikusiko dugu zein garrantzitsua den prozesu hau eskoletan erregulatzea, eta irakasle eta gurasoen arteko elkarlana bultzatzea, trantsizio honetan ikasleei bidea errazteko.[ES] Mediante este Trabajo de Fin de Grado, queremos acercarnos a la realidad que viven los estudiantes en la transición de Educación Infantil a Educación Primaria, y conocer la realidad educativa que corresponde a esta transición. Para ello, hemos llevado a cabo un trabajo de investigación en el que hemos analizado la coordinación entre el profesorado y las familias de ambas etapas, la formación que se realiza con ellas desde el último curso de Educación Infantil para hacer frente a esta transición, la relación de las familias con el centro y las conductas y dificultades que pueden tener los niños y niñas que viven el cambio en el primer curso de Educación Primaria. Aquí veremos la importancia de regular este proceso en las escuelas y de impulsar la colaboración entre el profesorado y los padres y madres para facilitar el camino al alumnado en esta transición.[EN] Through this Final Degree Project, we want to get closer to the reality experienced by students in the transition from Infant to Primary Education, and to know the educational reality that corresponds to this transition. To do this, we have carried out a research project in which we have analysed the coordination between teachers and families in both stages, the training that is carried out with them from the last year of Infant Education to deal with this transition, the relationship between families and the centre and the behaviours and difficulties that children who experience the change in the first year of Primary Education may have. Here we will see the importance of regulating this process in schools and promoting collaboration between teachers and parents in order to facilitate the transition for students

High-Resolution Analysis of Coronavirus Gene Expression by RNA Sequencing and Ribosome Profiling.

Members of the family Coronaviridae have the largest genomes of all RNA viruses, typically in the region of 30 kilobases. Several coronaviruses, such as Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and Middle East respiratory syndrome-related coronavirus (MERS-CoV), are of medical importance, with high mortality rates and, in the case of SARS-CoV, significant pandemic potential. Other coronaviruses, such as Porcine epidemic diarrhea virus and Avian coronavirus, are important livestock pathogens. Ribosome profiling is a technique which exploits the capacity of the translating ribosome to protect around 30 nucleotides of mRNA from ribonuclease digestion. Ribosome-protected mRNA fragments are purified, subjected to deep sequencing and mapped back to the transcriptome to give a global "snap-shot" of translation. Parallel RNA sequencing allows normalization by transcript abundance. Here we apply ribosome profiling to cells infected with Murine coronavirus, mouse hepatitis virus, strain A59 (MHV-A59), a model coronavirus in the same genus as SARS-CoV and MERS-CoV. The data obtained allowed us to study the kinetics of virus transcription and translation with exquisite precision. We studied the timecourse of positive and negative-sense genomic and subgenomic viral RNA production and the relative translation efficiencies of the different virus ORFs. Virus mRNAs were not found to be translated more efficiently than host mRNAs; rather, virus translation dominates host translation at later time points due to high levels of virus transcripts. Triplet phasing of the profiling data allowed precise determination of translated reading frames and revealed several translated short open reading frames upstream of, or embedded within, known virus protein-coding regions. Ribosome pause sites were identified in the virus replicase polyprotein pp1a ORF and investigated experimentally. Contrary to expectations, ribosomes were not found to pause at the ribosomal frameshift site. To our knowledge this is the first application of ribosome profiling to an RNA virus.NI was supported by a Sir Henry Wellcome Postdoctoral Fellowship (Wellcome Trust, 092334/Z/10/Z). Work in the AEF lab was funded by grants from the Wellcome Trust (088789 and 106207), the U.K. Biotechnology and Biological Research Council (BBSRC) (BB/J007072/1 and BB/J015652/1), and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No [646891]). Work in the IB laboratory was supported by the Medical Research Council (MRC) (MR/M011747/1) and the Biotechnology and Biological Sciences Research Council (BBSRC) (BB/L000334/1).This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.ppat.100547

The use of duplex-specific nuclease in ribosome profiling and a user-friendly software package for Ribo-seq data analysis.

Ribosome profiling is a technique that permits genome-wide, quantitative analysis of translation and has found broad application in recent years. Here we describe a modified profiling protocol and software package designed to benefit more broadly the translation community in terms of simplicity and utility. The protocol, applicable to diverse organisms, including organelles, is based largely on previously published profiling methodologies, but uses duplex-specific nuclease (DSN) as a convenient, species-independent way to reduce rRNA contamination. We show that DSN-based depletion compares favorably with other commonly used rRNA depletion strategies and introduces little bias. The profiling protocol typically produces high levels of triplet periodicity, facilitating the detection of coding sequences, including upstream, downstream, and overlapping open reading frames (ORFs) and an alternative ribosome conformation evident during termination of protein synthesis. In addition, we provide a software package that presents a set of methods for parsing ribosomal profiling data from multiple samples, aligning reads to coding sequences, inferring alternative ORFs, and plotting average and transcript-specific aspects of the data. Methods are also provided for extracting the data in a form suitable for differential analysis of translation and translational efficiency.This work was supported by an EMBL long-term postdoctoral fellowship to B.Y.C., Sir Henry Wellcome Fellowships to B.Y.C. and N.I., a Wellcome Trust PhD scholarship to J.D.J., a Wellcome Trust Fellowship to A.E.F. (088789), and UK Biotechnology and Biological Sciences Research Council grants to I.B. (BB/L000334/ 1) and A.E.F. (BB/J007072/1). Work in the Baulcombe laboratory is supported by The Gatsby Charitable Foundation and the European Research Council Advanced Investigator grant TRIBE. D.C.B. is the Royal Society Edward Penley Abraham Research Professor. We wish to thank Professor Stuart G. Siddell, University of Bristol, for providing the murine 17 clone 1 cellsThis is the final version of the article. It was first available from Cold Springs Harbor Press via http://dx.doi.org/10.1261/rna.052548.11

An upstream protein-coding region in enteroviruses modulates virus infection in gut epithelial cells.

Enteroviruses comprise a large group of mammalian pathogens that includes poliovirus. Pathology in humans ranges from sub-clinical to acute flaccid paralysis, myocarditis and meningitis. Until now, all of the enteroviral proteins were thought to derive from the proteolytic processing of a polyprotein encoded in a single open reading frame. Here we report that many enterovirus genomes also harbour an upstream open reading frame (uORF) that is subject to strong purifying selection. Using echovirus 7 and poliovirus 1, we confirmed the expression of uORF protein in infected cells. Through ribosome profiling (a technique for the global footprinting of translating ribosomes), we also demonstrated translation of the uORF in representative members of the predominant human enterovirus species, namely Enterovirus A, B and C. In differentiated human intestinal organoids, uORF protein-knockout echoviruses are attenuated compared to the wild-type at late stages of infection where membrane-associated uORF protein facilitates virus release. Thus, we have identified a previously unknown enterovirus protein that facilitates virus growth in gut epithelial cells-the site of initial viral invasion into susceptible hosts. These findings overturn the 50-year-old dogma that enteroviruses use a single-polyprotein gene expression strategy and have important implications for the understanding of enterovirus pathogenesis.This work was supported by Wellcome Trust grant [106207] and European Research Council grant [646891] to A.E.F; and Wellcome Trust grants 097997/Z/11/Z and 207498/Z/17/Z to I.G

Manipulation of the unfolded protein response: A pharmacological strategy against coronavirus infection.

Coronavirus infection induces the unfolded protein response (UPR), a cellular signalling pathway composed of three branches, triggered by unfolded proteins in the endoplasmic reticulum (ER) due to high ER load. We have used RNA sequencing and ribosome profiling to investigate holistically the transcriptional and translational response to cellular infection by murine hepatitis virus (MHV), often used as a model for the Betacoronavirus genus to which the recently emerged SARS-CoV-2 also belongs. We found the UPR to be amongst the most significantly up-regulated pathways in response to MHV infection. To confirm and extend these observations, we show experimentally the induction of all three branches of the UPR in both MHV- and SARS-CoV-2-infected cells. Over-expression of the SARS-CoV-2 ORF8 or S proteins alone is itself sufficient to induce the UPR. Remarkably, pharmacological inhibition of the UPR greatly reduced the replication of both MHV and SARS-CoV-2, revealing the importance of this pathway for successful coronavirus replication. This was particularly striking when both IRE1α and ATF6 branches of the UPR were inhibited, reducing SARS-CoV-2 virion release (~1,000-fold). Together, these data highlight the UPR as a promising antiviral target to combat coronavirus infection

Small-molecule inhibition of METTL3 as a strategy against myeloid leukaemia.

N6-methyladenosine (m6A) is an abundant internal RNA modification1,2 that is catalysed predominantly by the METTL3-METTL14 methyltransferase complex3,4. The m6A methyltransferase METTL3 has been linked to the initiation and maintenance of acute myeloid leukaemia (AML), but the potential of therapeutic applications targeting this enzyme remains unknown5-7. Here we present the identification and characterization of STM2457, a highly potent and selective first-in-class catalytic inhibitor of METTL3, and a crystal structure of STM2457 in complex with METTL3-METTL14. Treatment of tumours with STM2457 leads to reduced AML growth and an increase in differentiation and apoptosis. These cellular effects are accompanied by selective reduction of m6A levels on known leukaemogenic mRNAs and a decrease in their expression consistent with a translational defect. We demonstrate that pharmacological inhibition of METTL3 in vivo leads to impaired engraftment and prolonged survival in various mouse models of AML, specifically targeting key stem cell subpopulations of AML. Collectively, these results reveal the inhibition of METTL3 as a potential therapeutic strategy against AML, and provide proof of concept that the targeting of RNA-modifying enzymes represents a promising avenue for anticancer therapy

Prevalence of SARS-CoV-2 and co-occurrence/co-infection with malaria during the first wave of the pandemic (the Burkina Faso case)

Africa accounts for 1.5% of the global coronavirus disease 2019 (COVID-19) cases and 2.7% of deaths, but this low incidence has been partly attributed to the limited testing capacity in most countries. In addition, the population in many African countries is at high risk of infection with endemic infectious diseases such as malaria. Our aim is to determine the prevalence and circulation of SARS-CoV-2 variants, and the frequency of co-infection with the malaria parasite. We conducted serological tests and microscopy examinations on 998 volunteers of different ages and sexes in a random and stratified population sample in Burkina-Faso. In addition, nasopharyngeal samples were taken for RT-qPCR of SARS-COV-2 and for whole viral genome sequencing. Our results show a 3.2% and a 2.5% of SARS-CoV-2 seroprevalence and PCR positivity; and 22% of malaria incidence, over the sampling period, with marked differences linked to age. Importantly, we found 2 cases of confirmed co-infection and 8 cases of suspected co-infection mostly in children and teenagers. Finally, we report the genome sequences of 13 SARS-CoV-2 isolates circulating in Burkina Faso at the time of analysis, assigned to lineages: A.19, A.21, B.1.1.404, B.1.1.118, B.1 and grouped into clades; 19B, 20A and 20B. This is the first population-based study about SARS-CoV-2 and malaria in Burkina Faso during the first wave of the pandemic, providing a relevant estimation of the real prevalence of SARS-CoV-2 and variants circulating in this Sub-Saharan African country. Besides, it highlights the low frequency of co-infection with malaria in African communities.This research work received funding from by the European Commission NextGenerationEU (Regulation EU 2020/2094) and grant 202020E159 through CSIC Global Health Platform (PTI Salud Global).N

Circulation of SARS-CoV-2 and co-infection with Plasmodium falciparum in Equatorial Guinea

The impact of COVID-19 in Africa has been a big concern since the beginning of the pandemic. However, low incidence of COVID-19 case severity and mortality has been reported in many African countries, although data are highly heterogeneous and, in some regions, like Sub-Saharan Africa, very scarce. Many of these regions are also the cradle of endemic infectious diseases like malaria. The aim of this study was to determine the prevalence of SARS-CoV-2, the diversity and origin of circulating variants as well as the frequency of co-infections with malaria in Equatorial Guinea. For this purpose, we conducted antigen diagnostic tests for SARS-CoV-2, and microscopy examinations for malaria of 1,556 volunteers at six health centres in Bioko and Bata from June to October 2021. Nasopharyngeal swab samples were also taken for molecular detection of SARS-COV-2 by RT-qPCR and whole genome viral sequencing. We report 3.0% of SARS-CoV-2 and 24.4% of malaria prevalence over the sampling in Equatorial Guinea. SARS-CoV-2 cases were found at a similar frequency in all age groups, whereas the age groups most frequently affected by malaria were children (36.8% [95% CI 30.9-42.7]) and teenagers (34.7% [95% CI 29.5-39.9]). We found six cases of confirmed co-infection of malaria and SARS-CoV-2 distributed among all age groups, representing a 0.4% frequency of co-infection in the whole sampled population. Interestingly, the majority of malaria and SARS-CoV-2 co-infections were mild. We obtained the genome sequences of 43 SARS-CoV-2 isolates, most of which belong to the lineage Delta (AY.43) and that according to our pandemic-scale phylogenies were introduced from Europe in multiple occasions (7 transmission groups and 17 unique introductions). This study is relevant in providing first-time estimates of the actual prevalence of SARS-CoV-2 in this malaria-endemic country, with the identification of circulating variants, their origin, and the occurrence of SARS-CoV-2 and malaria co-infection.We would like to thank all volunteers who participated in this study and the local authorities and communities in Equatorial Guinea for their support. We also thank the IPBLN and IBV core facilities for their support to project activitiesN