RESUMO
Bats are special in their ability to live long and host many emerging viruses. Our previous studies showed that bats have altered inflammasomes, which are central players in aging and infection. However, the role of inflammasome signaling in combating inflammatory diseases remains poorly understood. Here, we report bat ASC2 as a potent negative regulator of inflammasomes. Bat ASC2 is highly expressed at both the mRNA and protein levels and is highly potent in inhibiting human and mouse inflammasomes. Transgenic expression of bat ASC2 in mice reduced the severity of peritonitis induced by gout crystals and ASC particles. Bat ASC2 also dampened inflammation induced by multiple viruses and reduced mortality of influenza A virus infection. Importantly, it also suppressed SARS-CoV-2-immune-complex-induced inflammasome activation. Four key residues were identified for the gain of function of bat ASC2. Our results demonstrate that bat ASC2 is an important negative regulator of inflammasomes with therapeutic potential in inflammatory diseases.
Assuntos
Proteínas Reguladoras de Apoptose , Quirópteros , Inflamassomos , Ribonucleoproteínas , Viroses , Animais , Humanos , Camundongos , Proteínas Reguladoras de Apoptose/metabolismo , Quirópteros/imunologia , COVID-19 , Inflamassomos/imunologia , Ribonucleoproteínas/metabolismo , SARS-CoV-2 , Viroses/imunologia , Fenômenos Fisiológicos ViraisRESUMO
Memory T cells induced by previous pathogens can shape susceptibility to, and the clinical severity of, subsequent infections1. Little is known about the presence in humans of pre-existing memory T cells that have the potential to recognize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we studied T cell responses against the structural (nucleocapsid (N) protein) and non-structural (NSP7 and NSP13 of ORF1) regions of SARS-CoV-2 in individuals convalescing from coronavirus disease 2019 (COVID-19) (n = 36). In all of these individuals, we found CD4 and CD8 T cells that recognized multiple regions of the N protein. Next, we showed that patients (n = 23) who recovered from SARS (the disease associated with SARS-CoV infection) possess long-lasting memory T cells that are reactive to the N protein of SARS-CoV 17 years after the outbreak of SARS in 2003; these T cells displayed robust cross-reactivity to the N protein of SARS-CoV-2. We also detected SARS-CoV-2-specific T cells in individuals with no history of SARS, COVID-19 or contact with individuals who had SARS and/or COVID-19 (n = 37). SARS-CoV-2-specific T cells in uninfected donors exhibited a different pattern of immunodominance, and frequently targeted NSP7 and NSP13 as well as the N protein. Epitope characterization of NSP7-specific T cells showed the recognition of protein fragments that are conserved among animal betacoronaviruses but have low homology to 'common cold' human-associated coronaviruses. Thus, infection with betacoronaviruses induces multi-specific and long-lasting T cell immunity against the structural N protein. Understanding how pre-existing N- and ORF1-specific T cells that are present in the general population affect the susceptibility to and pathogenesis of SARS-CoV-2 infection is important for the management of the current COVID-19 pandemic.
Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/imunologia , Pneumonia Viral/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Linfócitos T/imunologia , Betacoronavirus/química , COVID-19 , Estudos de Casos e Controles , Infecções por Coronavirus/virologia , Proteínas do Nucleocapsídeo de Coronavírus , Reações Cruzadas/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Proteínas do Nucleocapsídeo/química , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Fosfoproteínas , Pneumonia Viral/virologia , SARS-CoV-2RESUMO
Emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern pose a challenge to the effectiveness of current vaccines. A vaccine that could prevent infection caused by known and future variants of concern as well as infection with pre-emergent sarbecoviruses (i.e., those with potential to cause disease in humans in the future) would be ideal. Here we provide data showing that potent cross-clade pan-sarbecovirus neutralizing antibodies are induced in survivors of severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) infection who have been immunized with the BNT162b2 messenger RNA (mRNA) vaccine. The antibodies are high-level and broad-spectrum, capable of neutralizing not only known variants of concern but also sarbecoviruses that have been identified in bats and pangolins and that have the potential to cause human infection. These findings show the feasibility of a pan-sarbecovirus vaccine strategy. (Funded by the Singapore National Research Foundation and National Medical Research Council.).
Assuntos
Anticorpos Antivirais/sangue , Anticorpos Amplamente Neutralizantes/sangue , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Linfócitos B , Vacina BNT162 , Humanos , Imunogenicidade da Vacina , Filogenia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , SARS-CoV-2/genética , SobreviventesRESUMO
OBJECTIVES: To evaluate the humoral immunogenicity for 6 months after the two-dose coronavirus disease 2019 (COVID-19) mRNA vaccination in adolescents and young adults (AYAs) with childhood-onset rheumatic diseases (cRDs). METHODS: This monocentric observational study was conducted between August 2020 and March 2022. Humoral immunogenicity was assessed at 2-3 weeks after first vaccine dose and 1, 3 and 6 months after the second dose by the cPass™ severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralization antibody (nAb) assay. An inhibition signal of ≥30% defined the seroconversion threshold and the readings were calibrated against the World Health Organization International Standard for SARS-CoV-2 antibodies. RESULTS. ONE HUNDRED AND SIXTY-NINE: AYAs with cRDs were recruited [median age 16.8 years (interquartile range, IQR 14.7-19.5), 52% female, 72% Chinese]. JIA (58%) and SLE (18%) comprised the major diagnoses. After second vaccine dose, 99% seroconverted with a median nAb titre of 1779.8 IU/ml (IQR 882.8-2541.9), declining to 935.6 IU/ml (IQR 261.0-1514.9) and 683.2 IU/ml (IQR 163.5-1400.5) at the 3- and 6-month timepoints, respectively. The diagnosis of JIA [odds ratio (OR) 10.1, 95% CI 1.8-58.4, P = 0.010] and treatment with anti-TNF-α (aTNF) (OR 10.1, 95% CI 1.5-70.0, P = 0.019) were independently associated with a >50% drop of nAb titres at 6 months. Withholding MTX or MMF did not affect the vaccine response or decay rate. The COVID-19 breakthrough infection was estimated at 18.2 cases/1000 patient-months with no clinical risk factors identified. CONCLUSION: Over half of AYAs with cRDs had a significant drop in SARS-CoV-2 nAb at 6-month despite an initial robust humoral response. JIA and aTNF usage are predictors of a faster decay rate.
Assuntos
COVID-19 , Doenças Reumáticas , Criança , Adolescente , Feminino , Humanos , Adulto Jovem , Masculino , Vacinas contra COVID-19 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Inibidores do Fator de Necrose Tumoral , SARS-CoV-2 , Anticorpos Antivirais , Doenças Reumáticas/tratamento farmacológicoRESUMO
OBJECTIVES: Immunogenicity to the SARS-CoV-2 mRNA vaccines in adolescents and young adults (AYA) with childhood-onset rheumatic diseases (cRD) is unknown. We aimed to evaluate the humoral immunogenicity and safety of the vaccines in our AYA with cRD. METHODS: A monocentric observational study with 159 AYA (50.3% female and 70.4% Chinese). Humoral immunogenicity was assessed at 2-3 and 4-6 weeks following first and second vaccination by cPass™ SARS-CoV-2 Neutralization Antibody Assay. Inhibition signal of ≥30% defined the cut-off for positive detection of the SARS-CoV-2 neutralizing antibodies. Vaccine safety and disease activity were assessed within 6 weeks after second vaccination. RESULTS: A total of 64.9% and 99.1% of 159 patients (median age: 16.9, IQR: 14.7-19.5) mounted positive SARS-CoV-2 neutralizing responses after first and second vaccination, respectively. Most patients (89.8%) had ≥90% inhibition signal after second vaccination. Methotrexate and mycophenolate mofetil increased the risk associated with negative cPass neutralization responses following the first vaccination. Holding both medications after each vaccination did not affect immunogenicity. There was no symptomatic COVID-19 infection. Local reaction remained the most common (23.3-25.2%) adverse event, without serious complication. Two and seven patients flared following the first and second vaccination, respectively. Subgroup analyses of the 12-18-year-old cohort did not show any differences in vaccine efficacy, predictors of poor response and general safety, but higher proportion of disease flares. CONCLUSIONS: SARS-CoV-2 mRNA vaccines were efficacious after the two-dose regimen in almost all AYA with cRD without serious adverse event. The rate of disease flare observed is 4.4% after the second mRNA vaccine dose.
Assuntos
COVID-19 , Doenças Reumáticas , Vacinas Virais , Criança , Humanos , Adulto Jovem , Adolescente , Feminino , Masculino , Anticorpos Neutralizantes , Testes de Neutralização , SARS-CoV-2 , Vacinas Virais/efeitos adversos , Vacinas de Produtos Inativados , Anticorpos Antivirais , Vacinação , Doenças Reumáticas/induzido quimicamente , RNA Mensageiro , Imunogenicidade da Vacina , Vacinas de mRNARESUMO
BACKGROUND: Key knowledge gaps remain in the understanding of viral dynamics and immune response of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. METHODS: We evaluated these characteristics and established their association with clinical severity in a prospective observational cohort study of 100 patients with PCR-confirmed SARS-CoV-2 infection (mean age, 46 years; 56% male; 38% with comorbidities). Respiratory samples (n = 74) were collected for viral culture, serum samples for measurement of IgM/IgG levels (n = 30), and plasma samples for levels of inflammatory cytokines and chemokines (n = 81). Disease severity was correlated with results from viral culture, serologic testing, and immune markers. RESULTS: Fifty-seven (57%) patients developed viral pneumonia, of whom 20 (20%) required supplemental oxygen, including 12 (12%) with invasive mechanical ventilation. Viral culture from respiratory samples was positive for 19 of 74 patients (26%). No virus was isolated when the PCR cycle threshold (Ct) value was >30 or >14 days after symptom onset. Seroconversion occurred at a median (IQR) of 12.5 (9-18) days for IgM and 15.0 (12-20) days for IgG; 54/62 patients (87.1%) sampled at day 14 or later seroconverted. Severe infections were associated with earlier seroconversion and higher peak IgM and IgG levels. Levels of IP-10, HGF, IL-6, MCP-1, MIP-1α, IL-12p70, IL-18, VEGF-A, PDGF-BB, and IL-1RA significantly correlated with disease severity. CONCLUSIONS: We found virus viability was associated with lower PCR Ct value in early illness. A stronger antibody response was associated with disease severity. The overactive proinflammatory immune signatures offer targets for host-directed immunotherapy, which should be evaluated in randomized controlled trials.
Assuntos
COVID-19 , Pneumonia Viral , Anticorpos Antivirais , Feminino , Humanos , Imunoglobulina M , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , SARS-CoV-2 , SoroconversãoRESUMO
Natural reservoir hosts can sustain infection of pathogens without succumbing to overt disease. Multiple bat species host a plethora of viruses, pathogenic to other mammals, without clinical symptoms. Here, we detail infection of bat primary cells, immune cells, and cell lines with Dengue virus. While antibodies and viral RNA were previously detected in wild bats, their ability to sustain infection is not conclusive. Old-world fruitbat cells can be infected, producing high titres of virus with limited cellular responses. In addition, there is minimal interferon (IFN) response in cells infected with MOIs leading to dengue production. The ability to support in vitro replication/production raises the possibility of bats as a transient host in the life cycle of dengue or similar flaviviruses. New antibody serology evidence from Asia/Pacific highlights the previous exposure and raises awareness that bats may be involved in flavivirus dynamics and infection of other hosts.
Assuntos
Quirópteros/virologia , Vírus da Dengue/fisiologia , Dengue/veterinária , Animais , Australásia/epidemiologia , Linhagem Celular , Quirópteros/imunologia , Dengue/epidemiologia , Dengue/imunologia , Vírus da Dengue/imunologia , Interações Hospedeiro-Patógeno , Imunidade Inata , Malásia/epidemiologia , Internalização do VírusRESUMO
Malaria, despite being one of the world's oldest infectious diseases, remains difficult to eradicate because the parasite is rapidly developing resistance to frontline chemotherapies. Previous studies have shown that the parasite exhibits features resembling programmed cell death upon treatment with drugs that disrupt its digestive vacuole (DV), providing a phenotypic readout that can be detected using the imaging flow cytometer. Large compound collections can thus be screened to identify drugs that are able to disrupt the DV of the malaria parasite using this high-content high-throughput screening platform. As a proof-of-concept, 4440 compounds were screened using this platform in 4months and 254 hits (5.7% hit rate) were obtained. Additionally, 25 compounds (0.6% top hit rate) were observed to retain potent DV disruption activity that was comparable to the canonical DV disruptive drug chloroquine when tested at a ten-fold lower concentration from the original screen. This pilot study demonstrates the robustness and high-throughput capability of the imaging flow cytometer and we report herein the methodology of this screening assay.
Assuntos
Eritrócitos/parasitologia , Citometria de Fluxo/métodos , Citometria por Imagem/métodos , Estágios do Ciclo de Vida/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Vacúolos/efeitos dos fármacos , Compostos de Anilina/química , Antimaláricos/química , Antimaláricos/farmacologia , Benzimidazóis/química , Carbocianinas/química , Células Cultivadas , Eritrócitos/efeitos dos fármacos , Eritrócitos/ultraestrutura , Corantes Fluorescentes/química , Ensaios de Triagem em Larga Escala , Humanos , Estágios do Ciclo de Vida/fisiologia , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/ultraestrutura , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Coloração e Rotulagem/métodos , Vacúolos/ultraestrutura , Xantenos/químicaRESUMO
The development of an effective malaria vaccine has remained elusive even until today. This is because of our incomplete understanding of the immune mechanisms that confer and/or correlate with protection. Human volunteers have been protected experimentally from a subsequent challenge by immunization with Plasmodium falciparum sporozoites under drug cover. Here, we demonstrate that sera from the protected individuals contain neutralizing antibodies against the pre-erythrocytic stage. To identify the antigen(s) recognized by these antibodies, a newly developed library of P. falciparum antigens was screened with the neutralizing sera. Antibodies from protected individuals recognized a broad antigenic repertoire of which three antigens, PfMAEBL, PfTRAP and PfSEA1 were recognized by most protected individuals. As a proof of principle, we demonstrated that anti-PfMAEBL antibodies block liver stage development in human hepatocytes. Thus, these antigens identified are promising targets for vaccine development against malaria.
Assuntos
Anticorpos Antiprotozoários/biossíntese , Antígenos de Protozoários/imunologia , Imunidade Humoral , Malária Falciparum/prevenção & controle , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Receptores de Superfície Celular/imunologia , Animais , Anticorpos Neutralizantes/biossíntese , Antígenos de Protozoários/genética , Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Reações Cruzadas , Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/imunologia , Hepatócitos/parasitologia , Humanos , Soros Imunes/química , Vacinas Antimaláricas/administração & dosagem , Malária Falciparum/imunologia , Malária Falciparum/parasitologia , Biblioteca de Peptídeos , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Receptores de Superfície Celular/genética , Esporozoítos/imunologia , VacinaçãoRESUMO
Resistance to antimalarial therapies, including artemisinin, has emerged as a significant challenge. Reversal of acquired resistance can be achieved using agents that resensitize resistant parasites to a previously efficacious therapy. Building on our initial work describing novel chemoreversal agents (CRAs) that resensitize resistant parasites to chloroquine (CQ), we herein report new hybrid single agents as an innovative strategy in the battle against resistant malaria. Synthetically linking a CRA scaffold to chloroquine produces hybrid compounds with restored potency toward a range of resistant malaria parasites. A preferred compound, compound 35, showed broad activity and good potency against seven strains resistant to chloroquine and artemisinin. Assessment of aqueous solubility, membrane permeability, and in vitro toxicity in a hepatocyte line and a cardiomyocyte line indicates that compound 35 has a good therapeutic window and favorable drug-like properties. This study provides initial support for CQ-CRA hybrid compounds as a potential treatment for resistant malaria.
Assuntos
Antimaláricos/química , Antimaláricos/farmacologia , Cloroquina/química , Cloroquina/farmacologia , Artemisininas/química , Artemisininas/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Malaria remains a world-threatening disease largely because of the lack of a long-lasting and fully effective vaccine. MAEBL is a type 1 transmembrane molecule with a chimeric cysteine-rich ectodomain homologous to regions of the Duffy binding-like erythrocyte binding protein and apical membrane antigen 1 (AMA1) antigens. Although MAEBL does not appear to be essential for the survival of blood-stage forms, ectodomains M1 and M2, homologous to AMA1, seem to be involved in parasite attachment to erythrocytes, especially M2. MAEBL is necessary for sporozoite infection of mosquito salivary glands and is expressed in liver stages. Here, the Plasmodium yoelii MAEBL-M2 domain was expressed in a prokaryotic vector. C57BL/6J mice were immunized with doses of P. yoelii recombinant protein rPyM2-MAEBL. High levels of antibodies, with balanced IgG1 and IgG2c subclasses, were achieved. rPyM2-MAEBL antisera were capable of recognizing the native antigen. Anti-MAEBL antibodies recognized different MAEBL fragments expressed in CHO cells, showing stronger IgM and IgG responses to the M2 domain and repeat region, respectively. After a challenge with P. yoelii YM (lethal strain)-infected erythrocytes (IE), up to 90% of the immunized animals survived and a reduction of parasitemia was observed. Moreover, splenocytes harvested from immunized animals proliferated in a dose-dependent manner in the presence of rPyM2-MAEBL. Protection was highly dependent on CD4(+), but not CD8(+), T cells toward Th1. rPyM2-MAEBL antisera were also able to significantly inhibit parasite development, as observed in ex vivo P. yoelii erythrocyte invasion assays. Collectively, these findings support the use of MAEBL as a vaccine candidate and open perspectives to understand the mechanisms involved in protection.
Assuntos
Vacinas Antimaláricas/imunologia , Malária/prevenção & controle , Plasmodium yoelii/imunologia , Proteínas de Protozoários/química , Proteínas de Protozoários/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , Eritrócitos/parasitologia , Feminino , Humanos , Imunização , Malária/imunologia , Malária/mortalidade , Malária/parasitologia , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/química , Vacinas Antimaláricas/genética , Masculino , Merozoítos/química , Merozoítos/crescimento & desenvolvimento , Merozoítos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Plasmodium yoelii/química , Plasmodium yoelii/genética , Plasmodium yoelii/crescimento & desenvolvimento , Estrutura Terciária de Proteína , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/genética , Esporozoítos/química , Esporozoítos/crescimento & desenvolvimento , Esporozoítos/imunologiaRESUMO
PURPOSE: The identification of infectious etiologies is important in the management of uveitis. Ocular fluid testing is required, but multiplex testing faces challenges due to the limited volume sampled. The determination of antibody repertoire of aqueous humor (AH) is not possible with conventional assays. We investigated the use of a highly multiplexable serological assay VirScan, a Phage ImmunoPrecipitation Sequencing (PhIP-Seq) library derived from the sequences of more than 200 viruses to determine the antibody composition of AH in patients with uveitis. DESIGN: Prospective, case control study. METHODS: We analyzed the paired AH and plasma samples of 11 immunocompetent patients with active polymerase chain reaction-positive cytomegalovirus (CMV) anterior uveitis and the AH of 34 control patients undergoing cataract surgery with no known uveitis in an institutional practice. The samples were tested using VirScan PhIP-Seq, and the entire pan-viral antibody repertoire was determined using peptide tile ranking by normalized counts to identify significant antibodies enrichment against all viruses with human tropism. RESULTS: Significant enrichment of antibodies to Herpesviridae, Picornavirdae, and Paramyxoviridae was detectable in 20 µL of AH samples from patients with CMV uveitis and controls. Patients with CMV uveitis had relative enrichment of anti-CMV antibodies in AH compared with their plasma. Epitope-level mapping identified significant enrichment of antibodies against CMV tegument protein pp150 (P = 1.5e-06) and envelope glycoprotein B (P = .0045) in the AH compared with controls. CONCLUSIONS: Our proof-of-concept study not only sheds light on the antibody repertoire of AH but also expands the utility of PhIP-Seq to future studies to detect antibodies in AH in the study of inflammatory eye diseases.
RESUMO
Arthropod-borne viruses represent a crucial public health threat. Current arboviral serology assays are either labor intensive or incapable of distinguishing closely related viruses, and many zoonotic arboviruses that may transition to humans lack any serologic assays. In this study, we present a programmable phage display platform, ArboScan, that evaluates antibody binding to overlapping peptides that represent the proteomes of 691 human and zoonotic arboviruses. We confirm that ArboScan provides detailed antibody binding information from animal sera, human sera, and an arthropod blood meal. ArboScan identifies distinguishing features of antibody responses based on exposure history in a Colombian cohort of Zika patients. Finally, ArboScan details epitope level information that rapidly identifies candidate epitopes with potential protective significance. ArboScan thus represents a resource for characterizing human and animal arbovirus antibody responses at cohort scale.
Assuntos
Anticorpos Antivirais , Arbovírus , Humanos , Arbovírus/imunologia , Arbovírus/isolamento & purificação , Animais , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Peptídeos/imunologia , Peptídeos/química , Infecção por Zika virus/virologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/sangue , Zika virus/imunologia , Epitopos/imunologia , Testes Sorológicos/métodos , Infecções por Arbovirus/virologia , Infecções por Arbovirus/imunologia , Proteoma , Colômbia , Feminino , Biblioteca de Peptídeos , Técnicas de Visualização da Superfície Celular , MasculinoRESUMO
Detection of cytosolic nucleic acids by pattern recognition receptors, including STING and RIG-I, leads to the activation of multiple signalling pathways that culminate in the production of type I interferons (IFNs) which are vital for host survival during virus infection. In addition to protective immune modulatory functions, type I IFNs are also associated with autoimmune diseases. Hence, it is important to elucidate the mechanisms that govern their expression. In this study, we identified a critical regulatory function of the DUSP4 phosphatase in innate immune signalling. We found that DUSP4 regulates the activation of TBK1 and ERK1/2 in a signalling complex containing DUSP4, TBK1, ERK1/2 and IRF3 to regulate the production of type I IFNs. Mice deficient in DUSP4 were more resistant to infections by both RNA and DNA viruses but more susceptible to malaria parasites. Therefore, our study establishes DUSP4 as a regulator of nucleic acid sensor signalling and sheds light on an important facet of the type I IFN regulatory system.
Assuntos
Interferon Tipo I , Proteínas de Membrana , Proteínas Tirosina Fosfatases , Receptores de Superfície Celular , Proteínas Roundabout , Viroses , Animais , Camundongos , Imunidade Inata , Interferon Tipo I/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Viroses/imunologia , Viroses/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Roundabout/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Receptores de Superfície Celular/metabolismoRESUMO
Introduction: Bats are important providers of ecosystem services such as pollination, seed dispersal, and insect control but also act as natural reservoirs for virulent zoonotic viruses. Bats host multiple viruses that cause life-threatening pathology in other animals and humans but, themselves, experience limited pathological disease from infection. Despite bats' importance as reservoirs for several zoonotic viruses, we know little about the broader viral diversity that they host. Bat virus surveillance efforts are challenged by difficulties of field capture and the limited scope of targeted PCR- or ELISA-based molecular and serological detection. Additionally, virus shedding is often transient, thus also limiting insights gained from nucleic acid testing of field specimens. Phage ImmunoPrecipitation Sequencing (PhIP-Seq), a broad serological tool used previously to comprehensively profile viral exposure history in humans, offers an exciting prospect for viral surveillance efforts in wildlife, including bats. Methods: Here, for the first time, we apply PhIP-Seq technology to bat serum, using a viral peptide library originally designed to simultaneously assay exposures to the entire human virome. Results: Using VirScan, we identified past exposures to 57 viral genera-including betacoronaviruses, henipaviruses, lyssaviruses, and filoviruses-in semi-captive Pteropus alecto and to nine viral genera in captive Eonycteris spelaea. Consistent with results from humans, we find that both total peptide hits (the number of enriched viral peptides in our library) and the corresponding number of inferred past virus exposures in bat hosts were correlated with poor bat body condition scores and increased with age. High and low body condition scores were associated with either seropositive or seronegative status for different viruses, though in general, virus-specific age-seroprevalence curves defied assumptions of lifelong immunizing infection, suggesting that many bat viruses may circulate via complex transmission dynamics. Discussion: Overall, our work emphasizes the utility of applying biomedical tools, like PhIP-Seq, first developed for humans to viral surveillance efforts in wildlife, while highlighting opportunities for taxon-specific improvements.
Assuntos
Quirópteros , Reservatórios de Doenças , Animais , Humanos , Ecossistema , Estudos Soroepidemiológicos , ZoonosesRESUMO
The importance of genomic surveillance on emerging diseases continues to be highlighted with the ongoing SARS-CoV-2 pandemic. Here, we present an analysis of a new bat-borne mumps virus (MuV) in a captive colony of lesser dawn bats (Eonycteris spelaea). This report describes an investigation of MuV-specific data originally collected as part of a longitudinal virome study of apparently healthy, captive lesser dawn bats in Southeast Asia (BioProject ID PRJNA561193) which was the first report of a MuV-like virus, named dawn bat paramyxovirus (DbPV), in bats outside of Africa. More in-depth analysis of these original RNA sequences in the current report reveals that the new DbPV genome shares only 86% amino acid identity with the RNA-dependent RNA polymerase of its closest relative, the African bat-borne mumps virus (AbMuV). While there is no obvious immediate cause for concern, it is important to continue investigating and monitoring bat-borne MuVs to determine the risk of human infection.
Assuntos
COVID-19 , Quirópteros , Animais , Humanos , Vírus da Caxumba/genética , Filogenia , SARS-CoV-2 , Genômica , Sudeste Asiático/epidemiologia , Paramyxoviridae/genéticaRESUMO
Multiple Omicron sub-lineages have emerged, with Omicron XBB and XBB.1.5 subvariants becoming the dominant variants globally at the time of this study. The key feature of new variants is their ability to escape humoral immunity despite the fact that there are limited genetic changes from their preceding variants. This raises the question of whether Omicron should be regarded as a separate serotype from viruses serologically clustered with the ancestral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Here, we present cross-neutralization data based on a pseudovirus neutralization test using convalescent sera from naïve individuals who had recovered from primary infection by SARS-CoV-1 and SARS-CoV-2 strains/variants including the ancestral virus and variants Beta, Delta, Omicron BA.1, Omicron BA.2 and Omicron BA.5. The results revealed no significant cross-neutralization in any of the three-way testing for SARS-CoV-1, ancestral SARS-CoV-2 and SARS-CoV-2 Omicron subvariants. The data argue for the assignment of three distinct serotypes for the currently known human-infecting SARS-related coronaviruses.
RESUMO
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern such as Omicron hampered efforts in controlling the ongoing coronavirus disease 2019 pandemic due to their ability to escape neutralizing antibodies induced by vaccination or prior infection, highlighting the need to develop broad-spectrum vaccines and therapeutics. Most human monoclonal antibodies (mAbs) reported to date have not demonstrated true pan-sarbecovirus neutralizing breadth especially against animal sarbecoviruses. Here, we report the isolation and characterization of highly potent mAbs targeting the receptor binding domain (RBD) of huACE2-dependent sarbecovirus from a SARS-CoV survivor vaccinated with BNT162b2. Among the six mAbs identified, one (E7) showed better huACE2-dependent sarbecovirus neutralizing potency and breadth than any other mAbs reported to date. Mutagenesis and cryo-electron microscopy studies indicate that these mAbs have a unique RBD contact footprint and that E7 binds to a quaternary structure-dependent epitope.
Assuntos
COVID-19 , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Animais , Humanos , Anticorpos Antivirais , Testes de Neutralização , Vacina BNT162 , Anticorpos Monoclonais/química , Microscopia Crioeletrônica , COVID-19/prevenção & controle , SARS-CoV-2RESUMO
IMPORTANCE: Since January 2020, Singapore has implemented comprehensive measures to suppress SARS-CoV-2. Despite this, the country has experienced contrasting epidemics, with limited transmission in the community and explosive outbreaks in migrant worker dormitories. OBJECTIVE: To estimate SARS-CoV-2 infection incidence among migrant workers and the general population in Singapore. DESIGN: Prospective serological cohort studies. SETTING: Two cohort studies - in a migrant worker dormitory and in the general population in Singapore. PARTICIPANTS: 478 residents of a SARS-CoV-2-affected migrant worker dormitory were followed up between May and July 2020, with blood samples collected on recruitment and after 2 and 6 weeks. In addition, 937 community-dwelling adult Singapore residents, for whom pre-pandemic sera were available, were recruited. These individuals also provided a serum sample on recruitment in November/December 2020. EXPOSURE: Exposure to SARS-CoV-2 in a densely populated migrant worker dormitory and in the general population. MAIN OUTCOMES AND MEASURES: The main outcome measures were the incidences of SARS-CoV-2 infection in migrant workers and in the general population, as determined by the detection of neutralizing antibodies against SARS-CoV-2, and adjusting for assay sensitivity and specificity using a Bayesian modeling framework. RESULTS: No evidence of community SARS-CoV-2 exposure was found in Singapore prior to September 2019. It was estimated that < 2 per 1000 adult residents in the community were infected with SARS-CoV-2 in 2020 (cumulative seroprevalence: 0.16%; 95% CrI: 0.008-0.72%). Comparison with comprehensive national case notification data suggested that around 1 in 4 infections in the general population were associated with symptoms. In contrast, in the migrant worker cohort, almost two-thirds had been infected by July 2020 (cumulative seroprevalence: 63.8%; 95% CrI: 57.9-70.3%); no symptoms were reported in almost all of these infections. CONCLUSIONS AND RELEVANCE: Our findings demonstrate that SARS-CoV-2 suppression is possible with strict and rapid implementation of border restrictions, case isolation, contact tracing, quarantining, and social-distancing measures. However, the risk of large-scale epidemics in densely populated environments requires specific consideration in preparedness planning. Prioritization of these settings in vaccination strategies should minimize the risk of future resurgences and potential spillover of transmission to the wider community.
Assuntos
COVID-19 , Migrantes , Adulto , Teorema de Bayes , Humanos , Pandemias , Estudos Prospectivos , SARS-CoV-2 , Estudos Soroepidemiológicos , Singapura/epidemiologiaRESUMO
BACKGROUND: Comprehensive characterization of exposures and immune responses to viral infections is critical to a basic understanding of human health and disease. We previously developed the VirScan system, a programmable phage-display technology for profiling antibody binding to a library of peptides designed to span the human virome. Previous VirScan analytical approaches did not carefully account for antibody cross-reactivity among sequences shared by related viruses or for the disproportionate representation of individual viruses in the library. METHODS: Here we present the AntiViral Antibody Response Deconvolution Algorithm (AVARDA), a multi-module software package for analyzing VirScan datasets. AVARDA provides a probabilistic assessment of infection with species-level resolution by considering sequence alignment of all library peptides to each other and to all human viruses. We employed AVARDA to analyze VirScan data from a cohort of encephalitis patients with either known viral infections or undiagnosed etiologies. We further assessed AVARDA's utility in associating viral infection with type 1 diabetes and lupus. FINDINGS: By comparing acute and convalescent sera, AVARDA successfully confirmed or detected encephalitis-associated responses to human herpesviruses 1, 3, 4, 5, and 6, improving the rate of diagnosing viral encephalitis in this cohort by 44%. AVARDA analyses of VirScan data from the type 1 diabetes and lupus cohorts implicated enterovirus and herpesvirus infections, respectively. INTERPRETATION: AVARDA, in combination with VirScan and other pan-pathogen serological techniques, is likely to find broad utility in the epidemiology and diagnosis of infectious diseases. FUNDING: This work was made possible by support from the National Institutes of Health (NIH), the US Army Research Office, the Singapore Infectious Diseases Initiative (SIDI), the Singapore Ministry of Health's National Medical Research Council (NMRC) and the Singapore National Research Foundation (NRF).