20 research outputs found
A randomized open label phase-II clinical trial with or without infusion of plasma from subjects after convalescence of SARS-CoV-2 infection in high-risk patients with confirmed severe SARS-CoV-2 disease (RECOVER): a structured summary of a study protocol for a randomised controlled trial
OBJECTIVES: Primary objectives • To assess the time from randomisation until an improvement within 84 days defined as two points on a seven point ordinal scale or live discharge from the hospital in high-risk patients (group 1 to group 4) with SARS-CoV-2 infection requiring hospital admission by infusion of plasma from subjects after convalescence of SARS-CoV-2 infection or standard of care. Secondary objectives • To assess overall survival, and the overall survival rate at 28 56 and 84 days. • To assess SARS-CoV-2 viral clearance and load as well as antibody titres. • To assess the percentage of patients that required mechanical ventilation. • To assess time from randomisation until discharge. TRIAL DESIGN: Randomised, open-label, multicenter phase II trial, designed to assess the clinical outcome of SARS-CoV-2 disease in high-risk patients (group 1 to group 4) following treatment with anti-SARS-CoV-2 convalescent plasma or standard of care. PARTICIPANTS: High-risk patients >18 years of age hospitalized with SARS-CoV-2 infection in 10-15 university medical centres will be included. High-risk is defined as SARS-CoV-2 positive infection with Oxygen saturation at ≤ 94% at ambient air with additional risk features as categorised in 4 groups: • Group 1, pre-existing or concurrent hematological malignancy and/or active cancer therapy (incl. chemotherapy, radiotherapy, surgery) within the last 24 months or less. • Group 2, chronic immunosuppression not meeting the criteria of group 1. • Group 3, age ≥ 50 - 75 years meeting neither the criteria of group 1 nor group 2 and at least one of these criteria: Lymphopenia 1μg/mL. • Group 4, age ≥ 75 years meeting neither the criteria of group 1 nor group 2. Observation time for all patients is expected to be at least 3 months after entry into the study. Patients receive convalescent plasma for two days (day 1 and day 2) or standard of care. For patients in the standard arm, cross over is allowed from day 10 in case of not improving or worsening clinical condition. Nose/throat swabs for determination of viral load are collected at day 0 and day 1 (before first CP administration) and subsequently at day 2, 3, 5, 7, 10, 14, 28 or until discharge. Serum for SARS-Cov-2 diagnostic is collected at baseline and subsequently at day 3, 7, 14 and once during the follow-up period (between day 35 and day 84). There is a regular follow-up of 3 months. All discharged patients are followed by regular phone calls. All visits, time points and study assessments are summarized in the Trial Schedule (see full protocol Table 1). All participating trial sites will be supplied with study specific visit worksheets that list all assessments and procedures to be completed at each visit. All findings including clinical and laboratory data are documented by the investigator or an authorized member of the study team in the patient's medical record and in the electronic case report forms (eCRFs). INTERVENTION AND COMPARATOR: This trial will analyze the effects of convalescent plasma from recovered subjects with SARS-CoV-2 antibodies in high-risk patients with SARS-CoV-2 infection. Patients at high risk for a poor outcome due to underlying disease, age or condition as listed above are eligible for enrollment. In addition, eligible patients have a confirmed SARS-CoV-2 infection and O2 saturation ≤ 94% while breathing ambient air. Patients are randomised to receive (experimental arm) or not receive (standard arm) convalescent plasma in two bags (238 - 337 ml plasma each) from different donors (day 1, day 2). A cross over from the standard arm into the experimental arm is possible after day 10 in case of not improving or worsening clinical condition. MAIN OUTCOMES: Primary endpoints: The main purpose of the study is to assess the time from randomisation until an improvement within 84 days defined as two points on a seven-point ordinal scale or live discharge from the hospital in high-risk patients (group 1 to group 4) with SARS-CoV-2 infection requiring hospital admission by infusion of plasma from subjects after convalescence of a SARS-CoV-2 infection or standard of care. Secondary endpoints: • Overall survival, defined as the time from randomisation until death from any cause 28-day, 56-day and 84-day overall survival rates. • SARS-CoV-2 viral clearance and load as well as antibody titres. • Requirement mechanical ventilation at any time during hospital stay (yes/no). • Time until discharge from randomisation. • Viral load, changes in antibody titers and cytokine profiles are analysed in an exploratory manner using paired non-parametric tests (before - after treatment). RANDOMISATION: Upon confirmation of eligibility (patients must meet all inclusion criteria and must not meet exclusion criteria described in section 5.3 and 5.4 of the full protocol), the clinical site must contact a centralized internet randomization system ( https://randomizer.at/ ). Patients are randomized using block randomisation to one of the two arms, experimental arm or standard arm, in a 1:1 ratio considering a stratification according to the 4 risk groups (see Participants). BLINDING (MASKING): The study is open-label, no blinding will be performed. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A total number of 174 patients is required for the entire trial, n=87 per group. TRIAL STATUS: Protocol version 1.2 dated 09/07/2020. A recruitment period of approximately 9 months and an overall study duration of approximately 12 months is anticipated. Recruitment of patients starts in the third quarter of 2020. The study duration of an individual patient is planned to be 3 months. After finishing all study-relevant procedures, therapy, and follow-up period, the patient is followed in terms of routine care and treated if necessary. Total trial duration: 18 months Duration of the clinical phase: 12 months First patient first visit (FPFV): 3rd Quarter 2020 Last patient first visit (LPFV): 2nd Quarter 2021 Last patient last visit (LPLV): 3rd Quarter 2021 Trial Report completed: 4th Quarter 2021 TRIAL REGISTRATION: EudraCT Number: 2020-001632-10, https://www.clinicaltrialsregister.eu/ctr-search/trial/2020-001632-10/DE , registered on 04/04/2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2). The eCRF is attached (Additional file 3)
Lysigenous Aerenchyma Formation in Arabidopsis Is Controlled by LESION SIMULATING DISEASE1[W][OA]
Aerenchyma tissues form gas-conducting tubes that provide roots with oxygen under hypoxic conditions. Although aerenchyma have received considerable attention in Zea mays, the signaling events and genes controlling aerenchyma induction remain elusive. Here, we show that Arabidopsis thaliana hypocotyls form lysigenous aerenchyma in response to hypoxia and that this process involves H2O2 and ethylene signaling. By studying Arabidopsis mutants that are deregulated for excess light acclimation, cell death, and defense responses, we find that the formation of lysigenous aerenchyma depends on the plant defense regulators LESION SIMULATING DISEASE1 (LSD1), ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1), and PHYTOALEXIN DEFICIENT4 (PAD4) that operate upstream of ethylene and reactive oxygen species production. The obtained results indicate that programmed cell death of lysigenous aerenchyma in hypocotyls occurs in a similar but independent manner from the foliar programmed cell death. Thus, the induction of aerenchyma is subject to a genetic and tissue-specific program. The data lead us to conclude that the balanced activities of LSD1, EDS1, and PAD4 regulate lysigenous aerenchyma formation in response to hypoxia
Comparison of the Nodule vs. Root Transcriptome of the Actinorhizal Plant Datisca glomerata : Actinorhizal Nodules Contain a Specific Class of Defensins
Actinorhizal root nodule symbioses are very diverse, and the symbiosis of Datisca glomerata has previously been shown to have many unusual aspects. In order to gain molecular information on the infection mechanism, nodule development and nodule metabolism, we compared the transcriptomes of D. glomerata roots and nodules. Root and nodule libraries representing the 3'-ends of cDNAs were subjected to high-throughput parallel 454 sequencing. To identify the corresponding genes and to improve the assembly, Illumina sequencing of the nodule transcriptome was performed as well. The evaluation revealed 406 differentially regulated genes, 295 of which (72.7%) could be assigned a function based on homology. Analysis of the nodule transcriptome showed that genes encoding components of the common symbiosis signaling pathway were present in nodules of D. glomerata, which in combination with the previously established function of SymRK in D. glomerata nodulation suggests that this pathway is also active in actinorhizal Cucurbitales. Furthermore, comparison of the D. glomerata nodule transcriptome with nodule transcriptomes from actinorhizal Fagales revealed a new subgroup of nodule-specific defensins that might play a role specific to actinorhizal symbioses. The D. glomerata members of this defensin subgroup contain an acidic C-terminal domain that was never found in plant defensins before.AuthorCount:5;Fundin Agency:Forskningsradet Formas (Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning) 2005-2773-3234-80; Vetenskapsradet (Swedish Research Council) 2007-17840-52674-16; Fundacao para a Ciencia e Tecnologia (FCT) SFRH/BPD/43228/2008</p
A reverse genetics system for Zika virus based on a simple molecular cloning strategy
The Zika virus (ZIKV) has recently attracted major research interest as infection was unexpectedly associated with neurological manifestations in developing foetuses and with Guillain-Barré syndrome in infected adults. Understanding the underlying molecular mechanisms requires reverse genetic systems, which allow manipulation of infectious cDNA clones at will. In the case of flaviviruses, to which ZIKV belongs, several reports have indicated that the construction of full-length cDNA clones is difficult due to toxicity during plasmid amplification in Escherichia coli. Toxicity of flaviviral cDNAs has been linked to the activity of cryptic prokaryotic promoters within the region encoding the structural proteins leading to spurious transcription and expression of toxic viral proteins. Here, we employ an approach based on in silico prediction and mutational silencing of putative promoters to generate full-length cDNA clones of the historical MR766 strain and the contemporary French Polynesian strain H/PF/2013 of ZIKV. While for both strains construction of full-length cDNA clones has failed in the past, we show that our approach generates cDNA clones that are stable on single bacterial plasmids and give rise to infectious viruses with properties similar to those generated by other more complex assembly strategies. Further, we generate luciferase and fluorescent reporter viruses as well as sub-genomic replicons that are fully functional and suitable for various research and drug screening applications. Taken together, this study confirms that in silico prediction and silencing of cryptic prokaryotic promoters is an efficient strategy to generate full-length cDNA clones of flaviviruses and reports novel tools that will facilitate research on ZIKV biology and development of antiviral strategies
Validation of SAGE-type library comparison results and analysis of expression levels of genes encoding proteins involved in infection thread formation by quantitative real-time polymerase chain reaction (qPCR).
<p>Values for qPCR results represent means of three biological replicates.</p>*<p>Contigs were originally classified based on 454 sequencing results. The tendency (nodule-enhanced or root-enhanced expression with R>10 based on the evaluation of the SAGE-type libraries) is considered to be confirmed when the fold change ≥2 (for nodule-enhanced genes) and ≤−2 (for root-enhanced genes) and the difference is significant, p<0.05. Bold indicates p<0.05; bold underline indicates p<0.0019 (Bonferroni correction).</p>†<p>Due to R<10.</p
<i>D. glomerata</i> homologs of genes encoding components of the common symbiosis pathway or proteins involved in infection thread growth in legumes (legume data from [34], [36], [39], [40], [42], [43], [44], [77], [78], [79], [80], [81], [82], [83], [84], [85], [86], [87], [88]).
<p>qPCRs were performed based on RNA from nodules and roots of non-inoculated plants. The last column refers to the expression in uninfected legume roots <i>vs</i>. mature legume nodules. If expression levels in roots and nodules differed by a factor of 2 or more, expression is described as nodule-enhanced or root-enhanced, respectively. If expression levels in both organs differed by a factor of 100 or more, expression is described as root- or nodule-specific, respectively. When more than one <i>D. glomerata</i> homolog of a legume gene is listed, the <i>D. glomerata</i> contig with the strongest homology between its implicated protein and the legume protein(s) is listed first. Homologies between the legume proteins and the <i>D. glomerata</i> proteins are given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072442#pone.0072442.s005" target="_blank">Table S2</a>.</p><p>n.d. – not determined.</p
An orthogonal proteomic survey uncovers novel Zika virus host factors
Zika virus (ZIKV) has recently emerged as a global health concern owing to its widespread diffusion and its association with severe neurological symptoms and microcephaly in newborns1. However, the molecular mechanisms that are responsible for the pathogenicity of ZIKV remain largely unknown. Here we use human neural progenitor cells and the neuronal cell line SK-N-BE2 in an integrated proteomics approach to characterize the cellular responses to viral infection at the proteome and phosphoproteome level, and use affinity proteomics to identify cellular targets of ZIKV proteins. Using this approach, we identify 386 ZIKV-interacting proteins, ZIKV-specific and pan-flaviviral activities as well as host factors with known functions in neuronal development, retinal defects and infertility. Moreover, our analysis identified 1,216 phosphorylation sites that are specifically up- or downregulated after ZIKV infection, indicating profound modulation of fundamental signalling pathways such as AKT, MAPK–ERK and ATM–ATR and thereby providing mechanistic insights into the proliferation arrest elicited by ZIKV infection. Functionally, our integrative study identifies ZIKV host-dependency factors and provides a comprehensive framework for a system-level understanding of ZIKV-induced perturbations at the levels of proteins and cellular pathways
Defensin amino acid sequence alignment.
<p>The amino acid sequences of the mature peptides of DgDEF1 and DgDEF2 are compared with the sequences of four mature defensin peptides of the A3 class, a defensin from <i>Arabidopsis halleri</i> (AhPDF1.4; GenBank accession no. AY961379.1), the Antifungal Protein 1 from <i>Raphanus sativus</i> seeds (RsAFP1) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072442#pone.0072442-Terras1" target="_blank">[55]</a>, a defensin from <i>D. merckii</i> (AMP1) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072442#pone.0072442-Osborn1" target="_blank">[53]</a> and the aluminum-induced tobacco protein (NtPit1) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072442#pone.0072442-Ezaki1" target="_blank">[52]</a>. Gaps to optimize the alignment were introduced using the program ClustalW (EMBL), and the editor GeneDoc was used to present the alignment <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0072442#pone.0072442-Nicholas1" target="_blank">[89]</a>. Identical amino acids at conserved positions are labeled by inverse print, whereas positions without full amino acid conservation are shaded in gray. Asterisks mark the cysteine residues conserved in the defensins from plants other than <i>D. glomerata</i>. All negatively charged amino acids in the unique C-terminal domains of DgDEF1 and DgDEF1 are marked by bold print and underlined.</p
A novel interaction between dengue virus nonstructural protein 1 and the NS4A-2K-4B precursor is required for viral RNA replication but not for formation of the membranous replication organelle
Dengue virus (DENV) has emerged as major human pathogen. Despite the serious socioeconomic impact of DENV-associated diseases, antiviral therapy is missing. DENV replicates in the cytoplasm of infected cells and induces a membranous replication organelle, formed by invaginations of the endoplasmic reticulum membrane and designated vesicle packets (VPs). Nonstructural protein 1 (NS1) of DENV is a multifunctional protein. It is secreted from cells to counteract antiviral immune responses, but also critically contributes to the severe clinical manifestations of dengue. In addition, NS1 is indispensable for viral RNA replication, but the underlying molecular mechanism remains elusive. In this study, we employed a combination of genetic, biochemical and imaging approaches to dissect the determinants in NS1 contributing to its various functions in the viral replication cycle. Several important observations were made. First, we identified a cluster of amino acid residues in the exposed region of the β-ladder domain of NS1 that are essential for NS1 secretion. Second, we revealed a novel interaction of NS1 with the NS4A-2K-4B cleavage intermediate, but not with mature NS4A or NS4B. This interaction is required for RNA replication, with two residues within the connector region of the NS1 “Wing” domain being crucial for binding of the NS4A-2K-4B precursor. By using a polyprotein expression system allowing the formation of VPs in the absence of viral RNA replication, we show that the NS1 –NS4A-2K-4B interaction is not required for VP formation, arguing that the association between these two proteins plays a more direct role in the RNA amplification process. Third, through analysis of polyproteins containing deletions in NS1, and employing a trans-complementation assay, we show that both cis and trans acting elements within NS1 contribute to VP formation, with the capability of NS1 mutants to form VPs correlating with their capability to support RNA replication. In conclusion, these results reveal a direct role of NS1 in VP formation that is independent from RNA replication, and argue for a critical function of a previously unrecognized NS4A-2K-NS4B precursor specifically interacting with NS1 and promoting viral RNA replication