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1.
Clin Infect Dis ; 73(6): e1329-e1336, 2021 09 15.
Article in English | MEDLINE | ID: covidwho-1411883

ABSTRACT

BACKGROUND: Healthcare personnel (HCP) are at increased risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We posit that current infection control guidelines generally protect HCP from SARS-CoV-2 infection in a healthcare setting. METHODS: In this retrospective case series, we used viral genomics to investigate the likely source of SARS-CoV-2 infection in HCP at a major academic medical institution in the Upper Midwest of the United States between 25 March and 27 December 2020. We obtained limited epidemiological data through informal interviews and review of the electronic health record and combined this information with healthcare-associated viral sequences and viral sequences collected in the broader community to infer the most likely source of infection in HCP. RESULTS: We investigated SARS-CoV-2 infection clusters involving 95 HCP and 137 possible patient contact sequences. The majority of HCP infections could not be linked to a patient or coworker (55 of 95 [57.9%]) and were genetically similar to viruses circulating concurrently in the community. We found that 10.5% of HCP infections (10 of 95) could be traced to a coworker. Strikingly, only 4.2% (4 of 95) could be traced to a patient source. CONCLUSIONS: Infections among HCP add further strain to the healthcare system and put patients, HCP, and communities at risk. We found no evidence for healthcare-associated transmission in the majority of HCP infections evaluated. Although we cannot rule out the possibility of cryptic healthcare-associated transmission, it appears that HCP most commonly become infected with SARS-CoV-2 via community exposure. This emphasizes the ongoing importance of mask wearing, physical distancing, robust testing programs, and rapid distribution of vaccines.


Subject(s)
COVID-19 , SARS-CoV-2 , Delivery of Health Care , Health Personnel , Humans , Retrospective Studies , United States/epidemiology
2.
BMC Complement Med Ther ; 21(1): 141, 2021 May 12.
Article in English | MEDLINE | ID: covidwho-1388756

ABSTRACT

BACKGROUND: Herbal remedies of Echinacea purpurea tinctures are widely used today to reduce common cold respiratory tract infections. METHODS: Transcriptome, epigenome and kinome profiling allowed a systems biology level characterisation of genomewide immunomodulatory effects of a standardized Echinacea purpurea (L.) Moench extract in THP1 monocytes. RESULTS: Gene expression and DNA methylation analysis revealed that Echinaforce® treatment triggers antiviral innate immunity pathways, involving tonic IFN signaling, activation of pattern recognition receptors, chemotaxis and immunometabolism. Furthermore, phosphopeptide based kinome activity profiling and pharmacological inhibitor experiments with filgotinib confirm a key role for Janus Kinase (JAK)-1 dependent gene expression changes in innate immune signaling. Finally, Echinaforce® treatment induces DNA hypermethylation at intergenic CpG, long/short interspersed nuclear DNA repeat elements (LINE, SINE) or long termininal DNA repeats (LTR). This changes transcription of flanking endogenous retroviral sequences (HERVs), involved in an evolutionary conserved (epi) genomic protective response against viral infections. CONCLUSIONS: Altogether, our results suggest that Echinaforce® phytochemicals strengthen antiviral innate immunity through tonic IFN regulation of pattern recognition and chemokine gene expression and DNA repeat hypermethylated silencing of HERVs in monocytes. These results suggest that immunomodulation by Echinaforce® treatment holds promise to reduce symptoms and duration of infection episodes of common cold corona viruses (CoV), Severe Acute Respiratory Syndrome (SARS)-CoV, and new occurring strains such as SARS-CoV-2, with strongly impaired interferon (IFN) response and weak innate antiviral defense.


Subject(s)
COVID-19/drug therapy , Echinacea , Immunologic Factors/pharmacology , Monocytes/drug effects , Plant Extracts/pharmacology , SARS-CoV-2/drug effects , Gene Expression , Humans , Immunity, Innate/drug effects , Immunologic Factors/therapeutic use , Interferons/drug effects , Phytotherapy , Plant Extracts/therapeutic use
3.
Brief Bioinform ; 22(2): 1150-1160, 2021 03 22.
Article in English | MEDLINE | ID: covidwho-1352102

ABSTRACT

The outbreak caused by the novel coronavirus SARS-CoV-2 has been declared a global health emergency. G-quadruplex structures in genomes have long been considered essential for regulating a number of biological processes in a plethora of organisms. We have analyzed and identified 25 four contiguous GG runs (G2NxG2NyG2NzG2) in the SARS-CoV-2 RNA genome, suggesting putative G-quadruplex-forming sequences (PQSs). Detailed analysis of SARS-CoV-2 PQSs revealed their locations in the open reading frames of ORF1 ab, spike (S), ORF3a, membrane (M) and nucleocapsid (N) genes. Identical PQSs were also found in the other members of the Coronaviridae family. The top-ranked PQSs at positions 13385 and 24268 were confirmed to form RNA G-quadruplex structures in vitro by multiple spectroscopic assays. Furthermore, their direct interactions with viral helicase (nsp13) were determined by microscale thermophoresis. Molecular docking model suggests that nsp13 distorts the G-quadruplex structure by allowing the guanine bases to be flipped away from the guanine quartet planes. Targeting viral helicase and G-quadruplex structure represents an attractive approach for potentially inhibiting the SARS-CoV-2 virus.


Subject(s)
COVID-19/virology , G-Quadruplexes , SARS-CoV-2/chemistry , Humans , Molecular Docking Simulation , Open Reading Frames
4.
Int J Mol Sci ; 22(7)2021 Mar 26.
Article in English | MEDLINE | ID: covidwho-1299435

ABSTRACT

The importance of gene expression regulation in viruses based upon G-quadruplex may point to its potential utilization in therapeutic targeting. Here, we present analyses as to the occurrence of putative G-quadruplex-forming sequences (PQS) in all reference viral dsDNA genomes and evaluate their dependence on PQS occurrence in host organisms using the G4Hunter tool. PQS frequencies differ across host taxa without regard to GC content. The overlay of PQS with annotated regions reveals the localization of PQS in specific regions. While abundance in some, such as repeat regions, is shared by all groups, others are unique. There is abundance within introns of Eukaryota-infecting viruses, but depletion of PQS in introns of bacteria-infecting viruses. We reveal a significant positive correlation between PQS frequencies in dsDNA viruses and corresponding hosts from archaea, bacteria, and eukaryotes. A strong relationship between PQS in a virus and its host indicates their close coevolution and evolutionarily reciprocal mimicking of genome organization.


Subject(s)
Computational Biology/methods , DNA/genetics , G-Quadruplexes , Genome, Viral , Viral Proteins/genetics , Archaea/virology , Bacteria/virology , Gene Expression Regulation , Genome , Humans , Viruses/genetics
5.
Emerg Infect Dis ; 27(8): 2052-2063, 2021 08.
Article in English | MEDLINE | ID: covidwho-1278367

ABSTRACT

Coronavirus disease has disproportionately affected persons in congregate settings and high-density workplaces. To determine more about the transmission patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in these settings, we performed whole-genome sequencing and phylogenetic analysis on 319 (14.4%) samples from 2,222 SARS-CoV-2-positive persons associated with 8 outbreaks in Minnesota, USA, during March-June 2020. Sequencing indicated that virus spread in 3 long-term care facilities and 2 correctional facilities was associated with a single genetic sequence and that in a fourth long-term care facility, outbreak cases were associated with 2 distinct sequences. In contrast, cases associated with outbreaks in 2 meat-processing plants were associated with multiple SARS-CoV-2 sequences. These results suggest that a single introduction of SARS-CoV-2 into a facility can result in a widespread outbreak. Early identification and cohorting (segregating) of virus-positive persons in these settings, along with continued vigilance with infection prevention and control measures, is imperative.


Subject(s)
COVID-19 , SARS-CoV-2 , Disease Outbreaks , Humans , Minnesota/epidemiology , Phylogeny
6.
J Antimicrob Chemother ; 76(9): 2230-2233, 2021 08 12.
Article in English | MEDLINE | ID: covidwho-1276183

ABSTRACT

This article provides a brief overview of drug resistance to antiviral therapy as well as known and emergent variability in key SARS-CoV-2 viral sequences. The purpose is to stimulate deliberation about the need to consider drug resistance prior to widespread roll-out of antivirals for SARS-CoV-2. Many existing candidate agents have mechanisms of action involving drug targets likely to be critical for future drug development. Resistance emerged quickly with monotherapies deployed for other pulmonary viruses such as influenza virus, and in HIV mutations in key drug targets compromised efficacy of multiple drugs within a class. The potential for drug resistance in SARS-CoV-2 has not yet been rigorously debated or assessed, and we call for more academic and industry research on this potentially important future threat prior to widespread roll-out of monotherapies for COVID-19 treatment and prevention.


Subject(s)
COVID-19 , Coronavirus Infections , Animals , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Coronavirus Infections/drug therapy , Drug Resistance, Viral , Humans , SARS-CoV-2
7.
Brief Bioinform ; 22(6)2021 11 05.
Article in English | MEDLINE | ID: covidwho-1263649

ABSTRACT

Single-cell sequencing is a biotechnology to sequence one layer of genomic information for individual cells in a tissue sample. For example, single-cell DNA sequencing is to sequence the DNA from every single cell. Increasing in complexity, single-cell multi-omics sequencing, or single-cell multimodal omics sequencing, is to profile in parallel multiple layers of omics information from a single cell. In practice, single-cell multi-omics sequencing actually detects multiple traits such as DNA, RNA, methylation information and/or protein profiles from the same cell for many individuals in a tissue sample. Multi-omics sequencing has been widely applied to systematically unravel interplay mechanisms of key components and pathways in cell. This survey overviews recent developments in single-cell multi-omics sequencing, and their applications to understand complex diseases in particular the COVID-19 pandemic. We also summarize machine learning and bioinformatics techniques used in the analysis of the intercorrelated multilayer heterogeneous data. We observed that variational inference and graph-based learning are popular approaches, and Seurat V3 is a commonly used tool to transfer the missing variables and labels. We also discussed two intensively studied issues relating to data consistency and diversity and commented on currently cared issues surrounding the error correction of data pairs and data imputation methods. The survey is concluded with some open questions and opportunities for this extraordinary field.


Subject(s)
COVID-19/genetics , Pandemics , Proteomics , SARS-CoV-2/genetics , Algorithms , COVID-19/virology , Computational Biology , Data Analysis , Genomics , Humans , Machine Learning , SARS-CoV-2/pathogenicity , Single-Cell Analysis
8.
J Virol Methods ; 295: 114197, 2021 09.
Article in English | MEDLINE | ID: covidwho-1240483

ABSTRACT

OBJECTIVES: The SARS-CoV-2 pandemic has created an unprecedented need for rapid large-scale diagnostic testing to prompt clinical and public health interventions. Currently, several quantitative reverse-transcription polymerase chain reaction (RT-qPCR) assays recommended by the World Health Organization are being used by clinical and public health laboratories and typically target regions of the RNA-dependent RNA polymerase (RdRp), envelope (E) and nucleocapsid (N) coding region. However, it is currently unclear if results from different tests are comparable. This study aimed to clarify the clinical performances of the primer/probe sets designed by US CDC and Charité/Berlin to help clinical laboratories in assay selection for SARS-CoV-2 routine detection. METHODS: We compared the clinical performances of the recommended primer/probe sets using one hundred nasopharyngeal swab specimens from patients who were clinically diagnosed with COVID-19. An additional 30 "pre-intervention screening" samples from patients who were not suspected of COVID-19 were also included in this study. We also performed sequence alignment between 31064 European SARS-CoV-2 and variants of concern genomes and the recommended primer/probe sets. RESULTS: The present study demonstrates substantial differences in SARS-CoV-2 RNA detection sensitivity among the primer/probe sets recommended by the World Health Organization especially for low-level viral loads. The alignment of thousands of SARS-CoV-2 sequences reveals that the genetic diversity remains relatively low at the primer/probe binding sites. However, multiple nucleotide mismatches might contribute to false negatives. CONCLUSION: An understanding of the limitations depending on the targeted genes and primer/probe sets may influence the selection of molecular detection assays by clinical laboratories.


Subject(s)
DNA Primers/genetics , Genome, Viral/genetics , SARS-CoV-2/isolation & purification , COVID-19/diagnosis , COVID-19/virology , COVID-19 Nucleic Acid Testing , Coronavirus/genetics , Humans , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Sensitivity and Specificity , Sequence Alignment , Viral Load , Viral Proteins/genetics
9.
Comput Biol Med ; 134: 104451, 2021 07.
Article in English | MEDLINE | ID: covidwho-1237662

ABSTRACT

COVID-19, a global pandemic caused by an RNA virus named SARS-CoV-2 has brought the world to a standstill in terms of infectivity, casualty, and commercial plummet. RNA viruses can encode microRNAs (miRNAs) capable of modulating host gene expression, and with that notion, we aimed to predict viral miRNA like sequences of MERS-CoV, SARS-CoV and SARS-CoV-2, analyze sequence reciprocity and investigate SARS-CoV-2 encoded potential miRNA-human genes interaction using bioinformatics tools. In this study, we retrieved 206 SARS-CoV-2 genomes, executed phylogenetic analysis, and the selected reference genome (MT434792.1) exhibited about 99% similarities among the retrieved genomes. We predicted 402, 137, and 85 putative miRNAs of MERS-CoV (NC_019843.3), SARS-CoV (NC_004718.3), and SARS-CoV-2 (MT434792.1) genome, respectively. Sequence similarity was analyzed among 624 miRNAs which revealed that the predicted miRNAs of SARS-CoV-2 share a cluster with the clad of miRNAs from MERS-CoV and SARS-CoV. Only SARS-CoV-2 derived 85 miRNAs were encountered for target prediction and 29 viral miRNAs seemed to target 119 human genes. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis suggested the involvement of respective genes in various pathways and biological processes. Finally, we focused on eight putative miRNAs influencing 14 genes that are involved in the adaptive hypoxic response, neuroinvasion and hormonal regulation, and tumorigenic progression in patients with COVID-19. SARS-CoV-2 encoded miRNAs may cause misexpression of some critical regulators and facilitate viral neuroinvasion, altered hormonal axis, and tumorigenic events in the human host. However, these propositions need validation from future studies.


Subject(s)
COVID-19 , MicroRNAs , Computer Simulation , Humans , MicroRNAs/genetics , Phylogeny , SARS-CoV-2
10.
Proc Natl Acad Sci U S A ; 118(21)2021 05 25.
Article in English | MEDLINE | ID: covidwho-1220249

ABSTRACT

Prolonged detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and recurrence of PCR-positive tests have been widely reported in patients after recovery from COVID-19, but some of these patients do not appear to shed infectious virus. We investigated the possibility that SARS-CoV-2 RNAs can be reverse-transcribed and integrated into the DNA of human cells in culture and that transcription of the integrated sequences might account for some of the positive PCR tests seen in patients. In support of this hypothesis, we found that DNA copies of SARS-CoV-2 sequences can be integrated into the genome of infected human cells. We found target site duplications flanking the viral sequences and consensus LINE1 endonuclease recognition sequences at the integration sites, consistent with a LINE1 retrotransposon-mediated, target-primed reverse transcription and retroposition mechanism. We also found, in some patient-derived tissues, evidence suggesting that a large fraction of the viral sequences is transcribed from integrated DNA copies of viral sequences, generating viral-host chimeric transcripts. The integration and transcription of viral sequences may thus contribute to the detection of viral RNA by PCR in patients after infection and clinical recovery. Because we have detected only subgenomic sequences derived mainly from the 3' end of the viral genome integrated into the DNA of the host cell, infectious virus cannot be produced from the integrated subgenomic SARS-CoV-2 sequences.


Subject(s)
COVID-19/genetics , COVID-19/virology , SARS-CoV-2/genetics , Virus Integration/genetics , Animals , COVID-19/metabolism , Chlorocebus aethiops , Genome, Viral , HEK293 Cells , Humans , RNA, Viral/genetics , SARS-CoV-2/metabolism , Vero Cells , Virus Integration/physiology , Virus Replication/genetics , Virus Replication/physiology
11.
Hum Genomics ; 15(1): 26, 2021 05 07.
Article in English | MEDLINE | ID: covidwho-1220117

ABSTRACT

BACKGROUND: Mathematical approaches have been for decades used to probe the structure of DNA sequences. This has led to the development of Bioinformatics. In this exploratory work, a novel mathematical method is applied to probe the DNA structure of two related viral families: those of coronaviruses and those of influenza viruses. The coronaviruses are SARS-CoV-2, SARS-CoV-1, and MERS. The influenza viruses include H1N1-1918, H1N1-2009, H2N2-1957, and H3N2-1968. METHODS: The mathematical method used is the slow feature analysis (SFA), a rather new but promising method to delineate complex structure in DNA sequences. RESULTS: The analysis indicates that the DNA sequences exhibit an elaborate and convoluted structure akin to complex networks. We define a measure of complexity and show that each DNA sequence exhibits a certain degree of complexity within itself, while at the same time there exists complex inter-relationships between the sequences within a family and between the two families. From these relationships, we find evidence, especially for the coronavirus family, that increasing complexity in a sequence is associated with higher transmission rate but with lower mortality. CONCLUSIONS: The complexity measure defined here may hold a promise and could become a useful tool in the prediction of transmission and mortality rates in future new viral strains.


Subject(s)
Betacoronavirus/classification , Betacoronavirus/genetics , Influenza A virus/classification , Influenza A virus/genetics , Models, Genetic , Betacoronavirus/physiology , Coronavirus Infections/mortality , Coronavirus Infections/transmission , Coronavirus Infections/virology , Evolution, Molecular , Humans , Influenza A virus/physiology , Influenza, Human/mortality , Influenza, Human/transmission , Influenza, Human/virology , Sequence Analysis, DNA , Species Specificity , Time Factors
12.
Nat Microbiol ; 6(7): 899-909, 2021 07.
Article in English | MEDLINE | ID: covidwho-1205445

ABSTRACT

SARS-CoV-2 entry requires sequential cleavage of the spike glycoprotein at the S1/S2 and the S2' cleavage sites to mediate membrane fusion. SARS-CoV-2 has a polybasic insertion (PRRAR) at the S1/S2 cleavage site that can be cleaved by furin. Using lentiviral pseudotypes and a cell-culture-adapted SARS-CoV-2 virus with an S1/S2 deletion, we show that the polybasic insertion endows SARS-CoV-2 with a selective advantage in lung cells and primary human airway epithelial cells, but impairs replication in Vero E6, a cell line used for passaging SARS-CoV-2. Using engineered spike variants and live virus competition assays and by measuring growth kinetics, we find that the selective advantage in lung and primary human airway epithelial cells depends on the expression of the cell surface protease TMPRSS2, which enables endosome-independent virus entry by a route that avoids antiviral IFITM proteins. SARS-CoV-2 virus lacking the S1/S2 furin cleavage site was shed to lower titres from infected ferrets and was not transmitted to cohoused sentinel animals, unlike wild-type virus. Analysis of 100,000 SARS-CoV-2 sequences derived from patients and 24 human postmortem tissues showed low frequencies of naturally occurring mutants that harbour deletions at the polybasic site. Taken together, our findings reveal that the furin cleavage site is an important determinant of SARS-CoV-2 transmission.


Subject(s)
COVID-19/transmission , Furin/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Animals , COVID-19/virology , Cathepsins/metabolism , Chlorocebus aethiops , Endosomes/metabolism , Epithelial Cells , Ferrets , Humans , Immune Evasion , Membrane Proteins/metabolism , RNA-Binding Proteins/metabolism , Respiratory System/cytology , Respiratory System/virology , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Vero Cells , Viral Genome Packaging , Virus Internalization , Virus Replication , Virus Shedding
13.
J Leukoc Biol ; 111(1): 283-289, 2022 01.
Article in English | MEDLINE | ID: covidwho-1178997

ABSTRACT

The potential protective or pathogenic role of the adaptive immune response to SARS-CoV-2 infection has been vigorously debated. While COVID-19 patients consistently generate a T lymphocyte response to SARS-CoV-2 antigens, evidence of significant immune dysregulation in these patients continues to accumulate. In this study, next generation sequencing of the T cell receptor beta chain (TRB) repertoire was conducted in hospitalized COVID-19 patients to determine if immunogenetic differences of the TRB repertoire contribute to disease course severity. Clustering of highly similar TRB CDR3 amino acid sequences across COVID-19 patients yielded 781 shared TRB sequences. The TRB sequences were then filtered for known associations with common diseases such as EBV and CMV. The remaining sequences were cross-referenced to a publicly accessible dataset that mapped COVID-19 specific TCRs to the SARS-CoV-2 genome. We identified 158 SARS-CoV-2 specific TRB sequences belonging to 134 clusters in our COVID-19 patients. Next, we investigated 113 SARS-CoV-2 specific clusters binding only one peptide target in relation to disease course. Distinct skewing of SARS-CoV-2 specific TRB sequences toward the nonstructural proteins (NSPs) encoded within ORF1a/b of the SARS-CoV-2 genome was observed in clusters associated with critical disease course when compared to COVID-19 clusters associated with a severe disease course. These data imply that T-lymphocyte reactivity towards peptides from NSPs of SARS-CoV-2 may not constitute an effective adaptive immune response and thus may negatively affect disease severity.


Subject(s)
COVID-19/immunology , COVID-19/pathology , Hospitalization , Receptors, Antigen, T-Cell, alpha-beta/immunology , Severity of Illness Index , Viral Proteins/immunology , Aged , Amino Acid Sequence , COVID-19/virology , Complementarity Determining Regions/immunology , Genome, Viral , Humans , Polyproteins/chemistry , Polyproteins/immunology , Polyproteins/metabolism , SARS-CoV-2/genetics , Time Factors , Viral Proteins/chemistry , Viral Proteins/metabolism
14.
Biomedicines ; 9(4)2021 Apr 11.
Article in English | MEDLINE | ID: covidwho-1178106

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a global pandemic of coronavirus disease in 2019 (COVID-19). Genome surveillance is a key method to track the spread of SARS-CoV-2 variants. Genetic diversity and evolution of SARS-CoV-2 were analyzed based on 260,673 whole-genome sequences, which were sampled from 62 countries between 24 December 2019 and 12 January 2021. We found that amino acid (AA) substitutions were observed in all SARS-CoV-2 proteins, and the top six proteins with the highest substitution rates were ORF10, nucleocapsid, ORF3a, spike glycoprotein, RNA-dependent RNA polymerase, and ORF8. Among 25,629 amino acid substitutions at 8484 polymorphic sites across the coding region of the SARS-CoV-2 genome, the D614G (93.88%) variant in spike and the P323L (93.74%) variant in RNA-dependent RNA polymerase were the dominant variants on six continents. As of January 2021, the genomic sequences of SARS-CoV-2 could be divided into at least 12 different clades. Distributions of SARS-CoV-2 clades were featured with temporal and geographical dynamics on six continents. Overall, this large-scale analysis provides a detailed mapping of SARS-CoV-2 variants in different geographic areas at different time points, highlighting the importance of evaluating highly prevalent variants in the development of SARS-CoV-2 antiviral drugs and vaccines.

15.
J Clin Invest ; 131(1)2021 01 04.
Article in English | MEDLINE | ID: covidwho-1169921

ABSTRACT

A considerable fraction of B cells recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with germline-encoded elements of their B cell receptor, resulting in the production of neutralizing and nonneutralizing antibodies. We found that antibody sequences from different discovery cohorts shared biochemical properties and could be retrieved across validation cohorts, confirming the stereotyped character of this naive response in coronavirus disease 2019 (COVID-19). While neutralizing antibody sequences were found independently of disease severity, in line with serological data, individual nonneutralizing antibody sequences were associated with fatal clinical courses, suggesting detrimental effects of these antibodies. We mined 200 immune repertoires from healthy individuals and 500 repertoires from patients with blood or solid cancers - all acquired prior to the pandemic - for SARS-CoV-2 antibody sequences. While the largely unmutated B cell rearrangements occurred in a substantial fraction of immune repertoires from young and healthy individuals, these sequences were less likely to be found in individuals over 60 years of age and in those with cancer. This reflects B cell repertoire restriction in aging and cancer, and may to a certain extent explain the different clinical courses of COVID-19 observed in these risk groups. Future studies will have to address if this stereotyped B cell response to SARS-CoV-2 emerging from unmutated antibody rearrangements will create long-lived memory.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Gene Rearrangement, B-Lymphocyte , Immunologic Memory , SARS-CoV-2/immunology , Adult , Aged , COVID-19/epidemiology , Cohort Studies , Female , Humans , Male , Middle Aged
16.
J AOAC Int ; 104(4): 948-958, 2021 Aug 20.
Article in English | MEDLINE | ID: covidwho-1169681

ABSTRACT

BACKGROUND: The COVID-19 Indoor Test™ by Phylagen uses a real-time PCR Assay to detect nucleic acid from SARS-CoV-2, the causative agent of COVID-19, which is extracted from swabs sampled from environmental surfaces. This information can be used to detect the presence of the virus in indoor environments. OBJECTIVE: To validate the COVID-19 Indoor TestTM by Phylagen as part of the AOAC Research Institute's Emergency Response Validation Performance Tested Method(s)SM program. METHOD: The COVID-19 Indoor Test by Phylagen assay was evaluated for specificity using in silico analysis of 15 764 SARS-CoV-2 sequences and 65 exclusivity organisms. The candidate method was also evaluated in an unpaired matrix study design for one environmental surface (stainless steel) and compared to the U.S. Centers for Disease Control and Prevention 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel (Revision 4, Effective 6/12/2020). RESULTS: Results of the in silico analysis demonstrated the specificity of the method in being able to detect SARS-CoV-2 target sequences and discriminate them from near-neighbors. In the matrix study, the candidate method demonstrated statistically significant better recovery of the target analyte than the reference method (2 × 103 GU/2 × 2" test surface). CONCLUSIONS: The COVID-19 Indoor Test by Phylagen is a rapid and accurate method that can be utilized to monitor the presence of SARS-CoV-2, the causative agent of COVID-19, on stainless-steel surfaces in built environments. HIGHLIGHTS: The COVID-19 Indoor Test by Phylagen assay performed significantly better than the reference method when used to detect SARS-CoV-2 from environmental surfaces.


Subject(s)
COVID-19 , COVID-19 Nucleic Acid Testing , Humans , Real-Time Polymerase Chain Reaction , SARS-CoV-2 , Sensitivity and Specificity , Stainless Steel
17.
Arch Virol ; 166(6): 1735-1739, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1147594

ABSTRACT

We developed a next-generation SARS-CoV-2 sequencing platform and obtained the first SARS-CoV-2 sequences from patients in Croatia at the beginning of the COVID-19 outbreak in the spring of 2020. Integrating the sequencing and the epidemiological data, we show that patients were infected with different SARS-CoV-2 variants belonging to different clades (mostly G and GH). This result confirms that there was widespread virus transmission early in 2020. Interestingly, we identified a unique mutation resulting in a V13I substitution in Nsp5A, the main viral protease, in a patient who had not received antiviral therapy.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , Genetic Variation , SARS-CoV-2/genetics , Coronavirus 3C Proteases/chemistry , Croatia/epidemiology , Genome, Viral , Humans , Models, Molecular , Phylogeny , Protein Conformation , Whole Genome Sequencing
18.
BioData Min ; 14(1): 20, 2021 Mar 20.
Article in English | MEDLINE | ID: covidwho-1143238

ABSTRACT

The evolutionary dynamics of SARS-CoV-2 have been carefully monitored since the COVID-19 pandemic began in December 2019. However, analysis has focused primarily on single nucleotide polymorphisms and largely ignored the role of insertions and deletions (indels) as well as recombination in SARS-CoV-2 evolution. Using sequences from the GISAID database, we catalogue over 100 insertions and deletions in the SARS-CoV-2 consensus sequences. We hypothesize that these indels are artifacts of recombination events between SARS-CoV-2 replicates whereby RNA-dependent RNA polymerase (RdRp) re-associates with a homologous template at a different loci ("imperfect homologous recombination"). We provide several independent pieces of evidence that suggest this. (1) The indels from the GISAID consensus sequences are clustered at specific regions of the genome. (2) These regions are also enriched for 5' and 3' breakpoints in the transcription regulatory site (TRS) independent transcriptome, presumably sites of RNA-dependent RNA polymerase (RdRp) template-switching. (3) Within raw reads, these indel hotspots have cases of both high intra-host heterogeneity and intra-host homogeneity, suggesting that these indels are both consequences of de novo recombination events within a host and artifacts of previous recombination. We briefly analyze the indels in the context of RNA secondary structure, noting that indels preferentially occur in "arms" and loop structures of the predicted folded RNA, suggesting that secondary structure may be a mechanism for TRS-independent template-switching in SARS-CoV-2 or other coronaviruses. These insights into the relationship between structural variation and recombination in SARS-CoV-2 can improve our reconstructions of the SARS-CoV-2 evolutionary history as well as our understanding of the process of RdRp template-switching in RNA viruses.

19.
iScience ; 24(4): 102295, 2021 Apr 23.
Article in English | MEDLINE | ID: covidwho-1122125

ABSTRACT

Macrophages promote an early host response to infection by releasing pro-inflammatory cytokines such as interleukin-1ß (IL-1ß), TNF, and IL-6. The bioactivity of IL-1ß is classically dependent on NLRP3 inflammasome activation, which culminates in caspase-1 activation and pyroptosis. Recent studies suggest a role for NLRP3 inflammasome activation in lung inflammation and fibrosis in both COVID-19 and SARS, and there is evidence of NLRP3 involvement in HIV-1 disease. Here, we show that GU-rich single-stranded RNA (GU-rich RNA) derived from SARS-CoV-2, SARS-CoV-1, and HIV-1 trigger a TLR8-dependent pro-inflammatory cytokine response from human macrophages in the absence of pyroptosis, with GU-rich RNA from the SARS-CoV-2 spike protein triggering the greatest inflammatory response. Using genetic and pharmacological inhibition, we show that the induction of mature IL-1ß is through a non-classical pathway dependent on caspase-1, caspase-8, the NLRP3 inflammasome, potassium efflux, and autophagy while being independent of TRIF (TICAM1), vitamin D3, and pyroptosis.

20.
Nucleic Acids Res ; 49(D1): D706-D714, 2021 01 08.
Article in English | MEDLINE | ID: covidwho-1117393

ABSTRACT

The COVID-19 outbreak has become a global emergency since December 2019. Analysis of SARS-CoV-2 sequences can uncover single nucleotide variants (SNVs) and corresponding evolution patterns. The Global Evaluation of SARS-CoV-2/hCoV-19 Sequences (GESS, https://wan-bioinfo.shinyapps.io/GESS/) is a resource to provide comprehensive analysis results based on tens of thousands of high-coverage and high-quality SARS-CoV-2 complete genomes. The database allows user to browse, search and download SNVs at any individual or multiple SARS-CoV-2 genomic positions, or within a chosen genomic region or protein, or in certain country/area of interest. GESS reveals geographical distributions of SNVs around the world and across the states of USA, while exhibiting time-dependent patterns for SNV occurrences which reflect development of SARS-CoV-2 genomes. For each month, the top 100 SNVs that were firstly identified world-widely can be retrieved. GESS also explores SNVs occurring simultaneously with specific SNVs of user's interests. Furthermore, the database can be of great help to calibrate mutation rates and identify conserved genome regions. Taken together, GESS is a powerful resource and tool to monitor SARS-CoV-2 migration and evolution according to featured genomic variations. It provides potential directive information for prevalence prediction, related public health policy making, and vaccine designs.


Subject(s)
COVID-19/prevention & control , Computational Biology/methods , Databases, Genetic , Genome, Viral/genetics , Genomics/methods , SARS-CoV-2/genetics , Algorithms , COVID-19/epidemiology , COVID-19/virology , Disease Outbreaks , Global Health , Humans , Internet , Mutation Rate , Polymorphism, Single Nucleotide , Population Dynamics , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Viral Proteins/genetics , Viral Proteins/metabolism
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