RESUMO
BACKGROUND: The factors contributing to the accelerated convergent evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are not fully understood. Unraveling the contribution of viral replication in immunocompromised patients is important for the early detection of novel mutations and developing approaches to limit COVID-19. METHODS: We deep sequenced SARS-CoV-2 RNA from 192 patients (64% hospitalized, 39% immunosuppressed) and compared the viral genetic diversity within the patient groups of different immunity and hospitalization status. Serial sampling of 14 patients was evaluated for viral evolution in response to antiviral treatments. RESULTS: We identified hospitalized and immunosuppressed patients with significantly higher levels of viral genetic diversity and variability. Further evaluation of serial samples revealed accumulated mutations associated with escape from neutralizing antibodies in a subset of the immunosuppressed patients treated with antiviral therapies. Interestingly, the accumulated viral mutations that arose in this early Omicron wave, which were not common in the patient viral lineages, represent convergent mutations that are prevalent in the later Omicron sublineages, including the XBB, BA.2.86.1 and its descendent JN sublineages. CONCLUSIONS: Our results illustrate the importance of identifying convergent mutations generated during antiviral therapy in immunosuppressed patients, as they may contribute to the future evolutionary landscape of SARS-CoV-2. Our study also provides evidence of a correlation between SARS-CoV-2 convergent mutations and specific antiviral treatments. Evaluating high-confidence genomes from distinct waves in the pandemic with detailed patient metadata allows for discerning of convergent mutations that contribute to the ongoing evolution of SARS-CoV-2.
Assuntos
Antivirais , COVID-19 , Evolução Molecular , Hospedeiro Imunocomprometido , Mutação , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Antivirais/uso terapêutico , COVID-19/virologia , COVID-19/imunologia , Masculino , Feminino , Pessoa de Meia-Idade , Anticorpos Neutralizantes/imunologia , Idoso , Adulto , RNA Viral/genética , Tratamento Farmacológico da COVID-19 , Variação Genética , FilogeniaRESUMO
We recently reported that mutations in both the spike glycoprotein and nonstructural protein 6 (nsp6) were associated with attenuation of the SARS-CoV-2 Omicron BA.1 variant. While mutations in spike allow evasion of neutralizing antibodies and promote specific modes of viral entry, the role of nsp6 mutations in pathogenesis is less clear. Nsp6 is essential for modifying the endoplasmic reticulum and generating double-membrane vesicles, the site of viral RNA replication. To investigate the evolution of nsp6, we evaluated 91,596 high-confidence human SARS-CoV-2 whole-genome sequences across 19 variants and lineages. While nsp6 of early variants of concern, such as Alpha, Beta, and Gamma, carried a triple amino acid deletion (106-108, termed ΔSGF), the Delta, Epsilon, and Mu lineages retained the ancestral nsp6 sequence. For nsp6 in the emerging Omicron variants, we report a transition from an amino acid 105-107 ΔLSG deletion in BA.1 to increased dominance of the ΔSGF in BA.2 and subsequent lineages. Our findings indicate that deletion within nsp6 was independently selected in multiple lineages of SARS-CoV-2, both early and late in the pandemic. Analysis of SARS-CoV-2-related coronaviruses in bats and pangolins revealed nsp6 sequences similar to the ancestral SARS-CoV-2 virus, indicating that the deletion in nsp6 may be an adaptation to replication in humans. Analysis of nsp6 sequences from multiple coronaviruses predicts a multipass transmembrane protein with a conserved C-terminal domain. Monitoring and evaluating changes in nsp6 and other nonstructural proteins will contribute to our understanding of factors associated with the attenuation of pandemic coronaviruses. IMPORTANCE There is an ongoing need to evaluate genetic changes in SARS-CoV-2 for effects on transmission and pathogenesis. We recently reported an unexpected role for replicase component nsp6, in addition to changes in spike, in the attenuation of Omicron BA.1. In this commentary, we document a triple-amino-acid deletion in a predicted lumenal domain of nsp6 that was found in multiple, independent variants of SARS-CoV-2, including all recent Omicron lineages. Furthermore, we modeled the predicted structure of nsp6, implicating a multipass transmembrane architecture as conserved in members of the Coronaviridae family. This information can guide future studies investigating the role of nsp6 in the pathogenesis of existing and emerging coronaviruses.
Assuntos
COVID-19 , Quirópteros , Humanos , Animais , SARS-CoV-2/genética , Proteínas de Membrana , Aminoácidos , Glicoproteína da Espícula de CoronavírusRESUMO
A simple and robust cell culture system is essential for generating authentic SARS-CoV-2 stocks for evaluation of viral pathogenicity, screening of antiviral compounds, and preparation of inactivated vaccines. Evidence suggests that Vero E6, a cell line commonly used in the field to grow SARS-CoV-2, does not support efficient propagation of new viral variants and triggers rapid cell culture adaptation of the virus. We generated a panel of 17 human cell lines overexpressing SARS-CoV-2 entry factors and tested their ability to support viral infection. Two cell lines, Caco-2/AT and HuH-6/AT, demonstrated exceptional susceptibility, yielding highly concentrated virus stocks. Notably, these cell lines were more sensitive than Vero E6 cells in recovering SARS-CoV-2 from clinical specimens. Further, Caco-2/AT cells provided a robust platform for producing genetically reliable recombinant SARS-CoV-2 through a reverse genetics system. These cellular models are a valuable tool for the study of SARS-CoV-2 and its continuously emerging variants.
RESUMO
Human society is dependent on nature1,2, but whether our ecological foundations are at risk remains unknown in the absence of systematic monitoring of species' populations3. Knowledge of species fluctuations is particularly inadequate in the marine realm4. Here we assess the population trends of 1,057 common shallow reef species from multiple phyla at 1,636 sites around Australia over the past decade. Most populations decreased over this period, including many tropical fishes, temperate invertebrates (particularly echinoderms) and southwestern Australian macroalgae, whereas coral populations remained relatively stable. Population declines typically followed heatwave years, when local water temperatures were more than 0.5 °C above temperatures in 2008. Following heatwaves5,6, species abundances generally tended to decline near warm range edges, and increase near cool range edges. More than 30% of shallow invertebrate species in cool latitudes exhibited high extinction risk, with rapidly declining populations trapped by deep ocean barriers, preventing poleward retreat as temperatures rise. Greater conservation effort is needed to safeguard temperate marine ecosystems, which are disproportionately threatened and include species with deep evolutionary roots. Fundamental among such efforts, and broader societal needs to efficiently adapt to interacting anthropogenic and natural pressures, is greatly expanded monitoring of species' population trends7,8.
Assuntos
Antozoários , Recifes de Corais , Calor Extremo , Peixes , Aquecimento Global , Invertebrados , Oceanos e Mares , Água do Mar , Alga Marinha , Animais , Austrália , Peixes/classificação , Invertebrados/classificação , Aquecimento Global/estatística & dados numéricos , Alga Marinha/classificação , Dinâmica Populacional , Densidade Demográfica , Água do Mar/análise , Extinção Biológica , Conservação dos Recursos Naturais/tendências , Equinodermos/classificaçãoRESUMO
BACKGROUND: Kawasaki disease (KD) is a febrile illness of young childhood that can result in coronary artery aneurysms and death. Coronavirus disease 2019 (COVID-19) mitigation strategies resulted in a marked decrease in KD cases worldwide, supporting a transmissible respiratory agent as the cause. We previously reported a peptide epitope recognized by monoclonal antibodies (MAbs) derived from clonally expanded peripheral blood plasmablasts from 3 of 11 KD children, suggesting a common disease trigger in a subset of patients with KD. METHODS: We performed amino acid substitution scans to develop modified peptides with improved recognition by KD MAbs. We prepared additional MAbs from KD peripheral blood plasmablasts and assessed MAb characteristics that were associated with binding to the modified peptides. RESULTS: We report a modified peptide epitope that is recognized by 20 MAbs from 11 of 12 KD patients. These MAbs predominantly use heavy chain VH3-74; two-thirds of VH3-74 plasmablasts from these patients recognize the epitope. The MAbs were nonidentical between patients but share a common complementarity-determining region 3 (CDR3) motif. CONCLUSIONS: These results demonstrate a convergent VH3-74 plasmablast response to a specific protein antigen in children with KD, supporting one predominant causative agent in the etiopathogenesis of the illness.
Assuntos
COVID-19 , Síndrome de Linfonodos Mucocutâneos , Humanos , Criança , Epitopos , Formação de Anticorpos , Anticorpos Monoclonais , PeptídeosRESUMO
The SARS-CoV-2 Omicron variant is more immune evasive and less virulent than other major viral variants that have so far been recognized1-12. The Omicron spike (S) protein, which has an unusually large number of mutations, is considered to be the main driver of these phenotypes. Here we generated chimeric recombinant SARS-CoV-2 encoding the S gene of Omicron (BA.1 lineage) in the backbone of an ancestral SARS-CoV-2 isolate, and compared this virus with the naturally circulating Omicron variant. The Omicron S-bearing virus robustly escaped vaccine-induced humoral immunity, mainly owing to mutations in the receptor-binding motif; however, unlike naturally occurring Omicron, it efficiently replicated in cell lines and primary-like distal lung cells. Similarly, in K18-hACE2 mice, although virus bearing Omicron S caused less severe disease than the ancestral virus, its virulence was not attenuated to the level of Omicron. Further investigation showed that mutating non-structural protein 6 (nsp6) in addition to the S protein was sufficient to recapitulate the attenuated phenotype of Omicron. This indicates that although the vaccine escape of Omicron is driven by mutations in S, the pathogenicity of Omicron is determined by mutations both in and outside of the S protein.
Assuntos
COVID-19 , Proteínas do Nucleocapsídeo de Coronavírus , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Fatores de Virulência , Virulência , Animais , Camundongos , Linhagem Celular , Evasão da Resposta Imune , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Proteínas do Nucleocapsídeo de Coronavírus/genética , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Humanos , Vacinas contra COVID-19/imunologia , Pulmão/citologia , Pulmão/virologia , Replicação Viral , MutaçãoRESUMO
The recently identified, globally predominant SARS-CoV-2 Omicron variant (BA.1) is highly transmissible, even in fully vaccinated individuals, and causes attenuated disease compared with other major viral variants recognized to date. The Omicron spike (S) protein, with an unusually large number of mutations, is considered the major driver of these phenotypes. We generated chimeric recombinant SARS-CoV-2 encoding the S gene of Omicron in the backbone of an ancestral SARS-CoV-2 isolate and compared this virus with the naturally circulating Omicron variant. The Omicron S-bearing virus robustly escapes vaccine-induced humoral immunity, mainly due to mutations in the receptor binding motif (RBM), yet unlike naturally occurring Omicron, efficiently replicates in cell lines and primary-like distal lung cells. In K18-hACE2 mice, while Omicron causes mild, non-fatal infection, the Omicron S-carrying virus inflicts severe disease with a mortality rate of 80%. This indicates that while the vaccine escape of Omicron is defined by mutations in S, major determinants of viral pathogenicity reside outside of S.
RESUMO
The pandemic of SARS-CoV-2 is characterized by the emergence of new variants of concern (VOCs) that supplant previous waves of infection. Here, we describe our investigation of the lineages and host-specific mutations identified in a particularly vulnerable population of predominantly older and immunosuppressed SARS-CoV-2-infected patients seen at our medical center in Chicago during the transition from the Delta to Omicron wave. We compare two primer schemes, ArticV4.1 and VarSkip2, used for short read amplicon sequencing, and describe our strategy for bioinformatics analysis that facilitates identifying lineage-associated mutations and host-specific mutations that arise during infection. This study illustrates the ongoing evolution of SARS-CoV-2 VOCs in our community and documents novel constellations of mutations that arise in individual patients. The ongoing evaluation of the evolution of SARS-CoV-2 during this pandemic is important for informing our public health strategies.
Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Humanos , Mutação , SARS-CoV-2/genética , Análise de SequênciaRESUMO
Understanding the magnitude of responses to vaccination during the ongoing SARS-CoV-2 pandemic is essential for ultimate mitigation of the disease. Here, we describe a cohort of 102 subjects (70 COVID-19-naïve, 32 COVID-19-experienced) who received two doses of one of the mRNA vaccines (BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)). We document that a single exposure to antigen via infection or vaccination induces a variable antibody response which is affected by age, gender, race, and co-morbidities. In response to a second antigen dose, both COVID-19-naïve and experienced subjects exhibited elevated levels of anti-spike and SARS-CoV-2 neutralizing activity; however, COVID-19-experienced individuals achieved higher antibody levels and neutralization activity as a group. The COVID-19-experienced subjects exhibited no significant increase in antibody or neutralization titer in response to the second vaccine dose (i.e., third antigen exposure). Finally, we found that COVID-19-naïve individuals who received the Moderna vaccine exhibited a more robust boost response to the second vaccine dose (p = 0.004) as compared to the response to Pfizer-BioNTech. Ongoing studies with this cohort will continue to contribute to our understanding of the range and durability of responses to SARS-CoV-2 mRNA vaccines.
Assuntos
Vacina de mRNA-1273 contra 2019-nCoV/imunologia , Anticorpos Antivirais/sangue , Vacina BNT162/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , SARS-CoV-2/imunologia , Vacinação/estatística & dados numéricos , Vacina de mRNA-1273 contra 2019-nCoV/administração & dosagem , Adulto , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Vacina BNT162/administração & dosagem , COVID-19/imunologia , Estudos de Coortes , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-IdadeRESUMO
The pandemic of COVID-19 caused by SARS-CoV-2 infection continues to spread around the world. Vaccines that elicit protective immunity have reduced infection and mortality, however new viral variants are arising that may evade vaccine-induced immunity or cause disease in individuals who are unable to develop robust vaccine-induced responses. Investigating the role of viral variants in causing severe disease, evading vaccine-elicited immunity, and infecting vulnerable individuals is important for developing strategies to control the pandemic. Here, we report fourteen breakthrough infections of SARS-CoV-2 in vaccinated individuals with symptoms ranging from asymptomatic/mild (6/14) to severe disease (8/14). High viral loads with a median Ct value of 19.6 were detected in the nasopharyngeal specimens from subjects regardless of disease severity. Sequence analysis revealed four distinct virus lineages, including alpha and gamma variants of concern. Immunosuppressed individuals were more likely to be hospitalized after infection (p = 0.047), however no specific variant was associated with severe disease. Our results highlight the high viral load that can occur in asymptomatic breakthrough infections and the vulnerability of immunosuppressed individuals to post-vaccination infections by diverse variants of SARS-CoV-2.
Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Hospedeiro Imunocomprometido , SARS-CoV-2 , Idoso , COVID-19/diagnóstico , COVID-19/imunologia , Feminino , Genoma Viral , Genômica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , SARS-CoV-2/imunologia , Índice de Gravidade de Doença , Vacinas/imunologia , Carga ViralRESUMO
There is an urgent need for antiviral agents that treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We screened a library of 1900 clinically safe drugs against OC43, a human beta coronavirus that causes the common cold, and evaluated the top hits against SARS-CoV-2. Twenty drugs significantly inhibited replication of both viruses in cultured human cells. Eight of these drugs inhibited the activity of the SARS-CoV-2 main protease, 3CLpro, with the most potent being masitinib, an orally bioavailable tyrosine kinase inhibitor. X-ray crystallography and biochemistry show that masitinib acts as a competitive inhibitor of 3CLpro. Mice infected with SARS-CoV-2 and then treated with masitinib showed >200-fold reduction in viral titers in the lungs and nose, as well as reduced lung inflammation. Masitinib was also effective in vitro against all tested variants of concern (B.1.1.7, B.1.351, and P.1).
Assuntos
Antivirais/farmacologia , Tratamento Farmacológico da COVID-19 , Proteases 3C de Coronavírus/antagonistas & inibidores , Coronavirus Humano OC43/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , SARS-CoV-2/efeitos dos fármacos , Tiazóis/farmacologia , Células A549 , Animais , Antivirais/química , Antivirais/metabolismo , Antivirais/uso terapêutico , Benzamidas , COVID-19/virologia , Domínio Catalítico , Proteases 3C de Coronavírus/química , Proteases 3C de Coronavírus/metabolismo , Coronavirus Humano OC43/fisiologia , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/metabolismo , Células HEK293 , Humanos , Concentração Inibidora 50 , Camundongos , Camundongos Transgênicos , Testes de Sensibilidade Microbiana , Piperidinas , Piridinas , SARS-CoV-2/enzimologia , SARS-CoV-2/fisiologia , Tiazóis/química , Tiazóis/metabolismo , Tiazóis/uso terapêutico , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacosRESUMO
SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we generated a panel of phenotypically diverse, SARS-CoV-2-infectible human cell lines representing different body organs and performed longitudinal survey of cellular proteins and pathways broadly affected by the virus. This revealed universal inhibition of interferon signaling across cell types following SARS-CoV-2 infection. We performed systematic analyses of the JAK-STAT pathway in a broad range of cellular systems, including immortalized cells and primary-like cardiomyocytes, and found that SARS-CoV-2 targeted the proximal pathway components, including Janus kinase 1 (JAK1), tyrosine kinase 2 (Tyk2), and the interferon receptor subunit 1 (IFNAR1), resulting in cellular desensitization to type I IFN. Detailed mechanistic investigation of IFNAR1 showed that the protein underwent ubiquitination upon SARS-CoV-2 infection. Furthermore, chemical inhibition of JAK kinases enhanced infection of stem cell-derived cultures, indicating that the virus benefits from inhibiting the JAK-STAT pathway. These findings suggest that the suppression of interferon signaling is a mechanism widely used by the virus to evade antiviral innate immunity, and that targeting the viral mediators of immune evasion may help block virus replication in patients with COVID-19. IMPORTANCE SARS-CoV-2 can infect various organs in the human body, but the molecular interface between the virus and these organs remains unexplored. In this study, we generated a panel of highly infectible human cell lines originating from various body organs and employed these cells to identify cellular processes commonly or distinctly disrupted by SARS-CoV-2 in different cell types. One among the universally impaired processes was interferon signaling. Systematic analysis of this pathway in diverse culture systems showed that SARS-CoV-2 targets the proximal JAK-STAT pathway components, destabilizes the type I interferon receptor though ubiquitination, and consequently renders the infected cells resistant to type I interferon. These findings illuminate how SARS-CoV-2 can continue to propagate in different tissues even in the presence of a disseminated innate immune response.
Assuntos
COVID-19/metabolismo , Interações entre Hospedeiro e Microrganismos/fisiologia , Janus Quinases/metabolismo , SARS-CoV-2/metabolismo , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Evasão da Resposta Imune , Imunidade Inata , Interferon Tipo I/metabolismo , Janus Quinase 1/metabolismo , Miócitos Cardíacos , Receptor de Interferon alfa e beta/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , TYK2 Quinase/metabolismo , Replicação ViralRESUMO
Understanding the effects of logging and fire on forest soil communities is integral to our knowledge of forest ecology and effective resource management. The resulting changes in soil biota have substantial impacts on forest succession and associated ecosystem processes. We quantified bacterial and fungal abundance, diversity and community composition across a logging and burn severity gradient, approximately one month after fire, in temperate wet eucalypt forests in Tasmania, Australia. Using amplicon sequencing and real-time quantitative PCR of the bacterial 16S rRNA gene and fungal ITS1 region, we demonstrate that (i) burn severity is a strong driver of soil microbial community composition, (ii) logging and high severity burning substantially reduce the biomass and diversity of soil bacteria and fungi, and (iii) the impacts of logging and burning on soil microbial communities are largely restricted to the top 10 cm of soil, with weak impacts on the subsoil. The impacts of disturbance on microbial community composition are greater than the effects of site-to-site edaphic differences. Fire also drives more divergence in community composition than logging alone. Key microbial taxa driving differences in severely burnt soils include bacterial genera implicated in plant-growth promotion and producing antifungal compounds as well as saprotrophic fungi that are also capable of forming ectomycorrhizal associations. Our research suggests that low-moderate severity burns are important for maintaining diversity and biomass in soil microbial communities but having a range of burn severities across a site contributes to the overall diversity of habitat conditions providing for both microbial and plant diversity.
Assuntos
Microbiota , Solo , Austrália , Ecossistema , Florestas , Fungos/genética , Microbiota/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo , TasmâniaRESUMO
Forest loss and degradation are the greatest threats to biodiversity worldwide. Rising global wood demand threatens further damage to remaining native forests. Contrasting solutions across a continuum of options have been proposed, yet which of these offers most promise remains unresolved. Expansion of high-yielding tree plantations could free up forest land for conservation provided this is implemented in tandem with stronger policies for conserving native forests. Because plantations and other intensively managed forests often support far less biodiversity than native forests, a second approach argues for widespread adoption of extensive management, or 'ecological forestry', which better simulates natural forest structure and disturbance regimes - albeit with compromised wood yields and hence a need to harvest over a larger area. A third, hybrid suggestion involves 'Triad' zoning where the landscape is divided into three sorts of management (reserve, ecological/extensive management, and intensive plantation). Progress towards resolving which of these approaches holds the most promise has been hampered by the absence of a conceptual framework and of sufficient empirical data formally to identify the most appropriate landscape-scale proportions of reserves, extensive, and intensive management to minimize biodiversity impacts while meeting a given level of demand for wood. In this review, we argue that this central challenge for sustainable forestry is analogous to that facing food-production systems, and that the land sharing-sparing framework devised to establish which approach to farming could meet food demand at least cost to wild species can be readily adapted to assess contrasting forest management regimes. We develop this argument in four ways: (i) we set out the relevance of the sharing-sparing framework for forestry and explore the degree to which concepts from agriculture can translate to a forest management context; (ii) we make design recommendations for empirical research on sustainable forestry to enable application of the sharing-sparing framework; (iii) we present overarching hypotheses which such studies could test; and (iv) we discuss potential pitfalls and opportunities in conceptualizing landscape management through a sharing-sparing lens. The framework we propose will enable forest managers worldwide to assess trade-offs directly between conservation and wood production and to determine the mix of management approaches that best balances these (and other) competing objectives. The results will inform ecologically sustainable forest policy and management, reduce risks of local and global extinctions from forestry, and potentially improve a valuable sector's social license to operate.
Assuntos
Conservação dos Recursos Naturais , Madeira , Biodiversidade , Agricultura Florestal , Florestas , ÁrvoresRESUMO
Coronaviruses rearrange endoplasmic reticulum (ER) membranes to form a reticulovesicular network (RVN) comprised predominantly of double membrane vesicles (DMVs) involved in viral replication. While portions of the RVN have been analyzed by electron tomography (ET), the full extent of the RVN is not known, nor how RVN formation affects ER morphology. Additionally the precise mechanism of DMV formation has not been observed. In this work, we examined large volumes of coronavirus-infected cells at multiple timepoints during infection using serial-section ET. We provide a comprehensive 3D analysis of the ER and RVN which gives insight into the formation mechanism of DMVs as well as the first evidence for their lysosomal degradation. We also show that the RVN breaks down late in infection, concurrent with the ER becoming the main budding compartment for new virions. This work provides a broad view of the multifaceted involvement of ER membranes in coronavirus infection.
Assuntos
Infecções por Coronavirus/virologia , Retículo Endoplasmático/metabolismo , Vírus da Hepatite Murina/fisiologia , Compartimentos de Replicação Viral/metabolismo , Animais , Linhagem Celular , Tomografia com Microscopia Eletrônica , Retículo Endoplasmático/ultraestrutura , Retículo Endoplasmático/virologia , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Lisossomos/virologia , Camundongos , Proteínas Virais/metabolismo , Compartimentos de Replicação Viral/ultraestrutura , Vírion/metabolismo , Montagem de Vírus , Replicação ViralRESUMO
The need to stem the current outbreak of SARS-CoV-2 responsible for COVID-19 is driving the search for inhibitors that will block coronavirus replication and pathogenesis. The coronavirus 3C-like protease (3CLpro) encoded in the replicase polyprotein is an attractive target for antiviral drug development because protease activity is required for generating a functional replication complex. Reagents that can be used to screen for protease inhibitors and for identifying the replicase products of SARS-CoV-2 are urgently needed. Here we describe a luminescence-based biosensor assay for evaluating small molecule inhibitors of SARS-CoV-2 3CLpro/main protease. We also document that a polyclonal rabbit antiserum developed against SARS-CoV 3CLpro cross reacts with the highly conserved 3CLpro of SARS-CoV-2. These reagents will facilitate the pre-clinical evaluation of SARS-CoV-2 protease inhibitors.
Assuntos
Técnicas Biossensoriais/métodos , Proteases 3C de Coronavírus/metabolismo , Soros Imunes/imunologia , Luciferases/metabolismo , SARS-CoV-2/metabolismo , Animais , Antivirais/farmacologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/genética , Proteases 3C de Coronavírus/imunologia , Reações Cruzadas , Luciferases/genética , Inibidores de Proteases/farmacologia , Coelhos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/metabolismo , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Patient satisfaction is important to patient outcomes. Previous attempts to conceptualize satisfaction have often taken an atheoretical approach and focused on doctors' communication skills. Patients are becoming more active health consumers involved in their health care and current definitions of patient satisfaction may not accurately reflect patient expectations about their health consultations. Earlier research found that meeting patients' emotional needs - through empathy and patient-centered communication - is important to patient satisfaction. New research is needed to explore how those needs can be met given the changing trend in patient behaviors and the focus on patient-centredness. This study employed two communication theories - the Willingness to Communicate Model and Communication Accommodation Theory - to consider both patients' communicative decisions, and the intergroup features of the health context that can influence communicative behaviors. Two hundred and fifty-three patients from health clinics in Canada and Australia described what satisfaction meant to them, and identified what aspects of their health consultation were satisfying (or not), and we investigated their perceptions of doctor's emotional expression. Results suggest that patient perceptions of their participation in the consultation predicts their perceptions of doctor emotional expression, and their satisfaction with the consultation. Patients want both emotional and medical needs met in an environment that balances interpersonal and intergroup communication. Our findings suggest the need to expand current definitions of patient satisfaction, patient-centredness and emotional expression. We discuss the implications of these findings for health practitioners and consider future research that addresses the need for more individualized health care.
Assuntos
Satisfação Pessoal , Relações Médico-Paciente , Comunicação , Humanos , Participação do Paciente , Satisfação do Paciente , PercepçãoRESUMO
We report the generation of a full-length infectious cDNA clone for porcine deltacoronavirus strain USA/IL/2014/026. Similar to the parental strain, the infectious clone virus (icPDCoV) replicated efficiently in cell culture and caused mild clinical symptoms in piglets. To investigate putative viral interferon (IFN) antagonists, we generated two mutant viruses: a nonstructural protein 15 mutant virus that encodes a catalytically-inactive endoribonuclease (icEnUmut), and an accessory gene NS6-deletion virus in which the NS6 gene was replaced with the mNeonGreen sequence (icDelNS6/nG). By infecting PK1 cells with these recombinant PDCoVs, we found that icDelNS6/nG elicited similar levels of type I IFN responses as icPDCoV, however icEnUmut stimulated robust type I IFN responses, demonstrating that the deltacoronavirus endoribonuclease, but not NS6, functions as an IFN antagonist in PK1 cells. Collectively, the construction of a full-length infectious clone and the identification of an IFN-antagonistic endoribonuclease will aid in the development of live-attenuated deltacoronavirus vaccines.
Assuntos
DNA Complementar/isolamento & purificação , Deltacoronavirus/genética , Suínos/virologia , Animais , Células Clonais , Infecções por Coronavirus/patologia , Deltacoronavirus/patogenicidade , Deltacoronavirus/fisiologia , Endorribonucleases/fisiologia , Interferons/antagonistas & inibidores , Replicação ViralRESUMO
SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we performed global proteomic analysis of the virus-host interface in a newly established panel of phenotypically diverse, SARS-CoV-2-infectable human cell lines representing different body organs. This revealed universal inhibition of interferon signaling across cell types following SARS-CoV-2 infection. We performed systematic analyses of the JAK-STAT pathway in a broad range of cellular systems, including immortalized cell lines and primary-like cardiomyocytes, and found that several pathway components were targeted by SARS-CoV-2 leading to cellular desensitization to interferon. These findings indicate that the suppression of interferon signaling is a mechanism widely used by SARS-CoV-2 in diverse tissues to evade antiviral innate immunity, and that targeting the viral mediators of immune evasion may help block virus replication in patients with COVID-19.