Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 727
Filtrar
1.
J Hepatol ; 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33845058

RESUMO

BACKGROUND & AIMS: Rat hepatitis E virus (Orthohepevirus species C; HEV-C1) is an emerging cause of viral hepatitis in humans. HEV-C1 is divergent from other HEV variants infecting humans that belong to Orthohepevirus species A (HEV-A). This study assessed HEV-C1 antigenic divergence from HEV-A and investigated the impact of this divergence on infection susceptibility, serological test sensitivity, and vaccine efficacy. METHODS: Immunodominant E2s peptide sequences of HEV-A and HEV-C1 were aligned. Interactions of HEV-C1 E2s and anti-HEV-A monoclonal antibodies (mAbs) were modeled. Recombinant peptides incorporating E2s of HEV-A (HEV-A4 p239) and HEV-C1 (HEV-C1 p241) were expressed. HEV-A and HEV-C1 patient sera were tested using antibody enzymatic immunoassays (EIA), antigen EIAs, and HEV-A4 p239/HEV-C1 p241 immunoblots. Rats immunized with HEV-A1 p239 vaccine (Hecolin), HEV-A4 p239 or HEV-C1 p241 peptides were challenged with a HEV-C1 strain. RESULTS: E2s sequence identity between HEV-A and HEV-C1 was only 48%. There was low conservation at E2s residues (23/53; 43.4%) involved in mAb binding. Anti-HEV-A mAbs bound HEV-C1 poorly in homology modeling and antigen EIAs. Divergence resulted in low sensitivity of commercial antigen (0%) and antibody EIAs (10 - 70%) for HEV-C1 diagnosis. Species-specific HEV-A4 p239/HEV-C1 p241 immunoblots accurately differentiated HEV-A and HEV-C1 serological profiles in immunized rats (18/18; 100%) and infected-patient sera (32/36; 88.9%). Immunization with Hecolin and HEV-A4 p239 was partially protective while HEV-C1 p241 was fully protective against HEV-C1 infection in rats. CONCLUSIONS: Antigenic divergence significantly decreases sensitivity of hepatitis E serodiagnostic assays for HEV-C1 infection. Species-specific immunoblots are useful for diagnosing HEV-C1 and differentiating HEV-A & HEV-C1 serological profiles. Prior HEV-A exposure is not protective against HEV-C1. HEV-C1 p241 is an immunogenic vaccine candidate against HEV-C1.

2.
Clin Infect Dis ; 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33851214

RESUMO

BACKGROUND: Nosocomial outbreaks with superspreading of COVID-19 due to a possible airborne transmission has not been reported. METHODS: Epidemiological analysis, environmental samplings, and whole genome sequencing (WGS) were performed for a hospital outbreak. RESULTS: A superspreading event involving 12 patients and 9 healthcare workers (HCWs) occurred within 4 days in 3 of 6 cubicles at an old-fashioned general ward with no air exhaust built within the cubicles. The environmental contamination by SARS-CoV-2 RNA was significantly higher in air grilles (>2m from patients' head and not reachable by hands) than high-touch clinical surfaces (36.4%, 8/22 vs 3.4%, 1/29, p=0.003). Six (66.7%) of 9 contaminated air exhaust grilles were located outside patient cubicle. The clinical attack rate of patients was significantly higher than HCWs (15.4%, 12/78 exposed-patients vs 4.6%, 9/195 exposed-HCWs, p=0.005). Moreover, clinical attack rate of ward-based HCWs was significantly higher than non-ward-based HCWs (8.1%, 7/68 vs 1.8%, 2/109, p=0.045). The episodes (mean ± S.D) of patient-care duty assignment in the cubicles was significantly higher among infected ward-based HCWs than non-infected ward-based HCWs (6.0±2.4 vs 3.0±2.9, p=0.012) during the outbreak period. The outbreak strains belong to SARS-CoV-2 lineage, B.1.36.27 (GISAID Clade GH) with the unique S-T470N mutation on WGS. CONCLUSION: This nosocomial point source superspreading due to possible airborne transmission demonstrated the need for stringent SARS-CoV-2 screening at admission to healthcare facilities and better architectural design of the ventilation system to prevent such outbreaks. Portable high-efficiency particulate filters were installed in each cubicle to improve ventilation before resumption of clinical service.

3.
Nat Commun ; 12(1): 1914, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772013

RESUMO

Innate immunity is important for host defense by eliciting rapid anti-viral responses and bridging adaptive immunity. Here, we show that endogenous lipids released from virus-infected host cells activate lung γδ T cells to produce interleukin 17 A (IL-17A) for early protection against H1N1 influenza infection. During infection, the lung γδ T cell pool is constantly supplemented by thymic output, with recent emigrants infiltrating into the lung parenchyma and airway to acquire tissue-resident feature. Single-cell studies identify IL-17A-producing γδ T (Tγδ17) cells with a phenotype of TCRγδhiCD3hiAQP3hiCXCR6hi in both infected mice and patients with pneumonia. Mechanistically, host cell-released lipids during viral infection are presented by lung infiltrating CD1d+ B-1a cells to activate IL-17A production in γδ T cells via γδTCR-mediated IRF4-dependent transcription. Reduced IL-17A production in γδ T cells is detected in mice either lacking B-1a cells or with ablated CD1d in B cells. Our findings identify a local host-immune crosstalk and define important cellular and molecular mediators for early innate defense against lung viral infection.


Assuntos
Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/imunologia , Lipídeos/imunologia , Infecções por Orthomyxoviridae/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Animais , Antígenos CD1d/imunologia , Antígenos CD1d/metabolismo , Feminino , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/metabolismo , Influenza Humana/virologia , Fatores Reguladores de Interferon/imunologia , Fatores Reguladores de Interferon/metabolismo , Interleucina-17/imunologia , Interleucina-17/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/virologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/virologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo
4.
Cell ; 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33713620

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause acute respiratory disease and multiorgan failure. Finding human host factors that are essential for SARS-CoV-2 infection could facilitate the formulation of treatment strategies. Using a human kidney cell line-HK-2-that is highly susceptible to SARS-CoV-2, we performed a genome-wide RNAi screen and identified virus dependency factors (VDFs), which play regulatory roles in biological pathways linked to clinical manifestations of SARS-CoV-2 infection. We found a role for a secretory form of SARS-CoV-2 receptor, soluble angiotensin converting enzyme 2 (sACE2), in SARS-CoV-2 infection. Further investigation revealed that SARS-CoV-2 exploits receptor-mediated endocytosis through interaction between its spike with sACE2 or sACE2-vasopressin via AT1 or AVPR1B, respectively. Our identification of VDFs and the regulatory effect of sACE2 on SARS-CoV-2 infection shed insight into pathogenesis and cell entry mechanisms of SARS-CoV-2 as well as potential treatment strategies for COVID-19.

5.
Nature ; 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727703

RESUMO

The COVID-19 pandemic is the third outbreak this century of a zoonotic disease caused by a coronavirus, following the emergence of severe acute respiratory syndrome (SARS) in 20031 and Middle East respiratory syndrome (MERS) in 20122. Treatment options for coronaviruses are limited. Here we show that clofazimine-an anti-leprosy drug with a favourable safety profile3-possesses inhibitory activity against several coronaviruses, and can antagonize the replication of SARS-CoV-2 and MERS-CoV in a range of in vitro systems. We found that this molecule, which has been approved by the US Food and Drug Administration, inhibits cell fusion mediated by the viral spike glycoprotein, as well as activity of the viral helicase. Prophylactic or therapeutic administration of clofazimine in a hamster model of SARS-CoV-2 pathogenesis led to reduced viral loads in the lung and viral shedding in faeces, and also alleviated the inflammation associated with viral infection. Combinations of clofazimine and remdesivir exhibited antiviral synergy in vitro and in vivo, and restricted viral shedding from the upper respiratory tract. Clofazimine, which is orally bioavailable and comparatively cheap to manufacture, is an attractive clinical candidate for the treatment of outpatients and-when combined with remdesivir-in therapy for hospitalized patients with COVID-19, particularly in contexts in which costs are an important factor or specialized medical facilities are limited. Our data provide evidence that clofazimine may have a role in the control of the current pandemic of COVID-19 and-possibly more importantly-in dealing with coronavirus diseases that may emerge in the future.

6.
Nat Commun ; 12(1): 1517, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750821

RESUMO

Up to date, effective antivirals have not been widely available for treating COVID-19. In this study, we identify a dual-functional cross-linking peptide 8P9R which can inhibit the two entry pathways (endocytic pathway and TMPRSS2-mediated surface pathway) of SARS-CoV-2 in cells. The endosomal acidification inhibitors (8P9R and chloroquine) can synergistically enhance the activity of arbidol, a spike-ACE2 fusion inhibitor, against SARS-CoV-2 and SARS-CoV in cells. In vivo studies indicate that 8P9R or the combination of repurposed drugs (umifenovir also known as arbidol, chloroquine and camostat which is a TMPRSS2 inhibitor), simultaneously interfering with the two entry pathways of coronaviruses, can significantly suppress SARS-CoV-2 replication in hamsters and SARS-CoV in mice. Here, we use drug combination (arbidol, chloroquine, and camostat) and a dual-functional 8P9R to demonstrate that blocking the two entry pathways of coronavirus can be a promising and achievable approach for inhibiting SARS-CoV-2 replication in vivo. Cocktail therapy of these drug combinations should be considered in treatment trials for COVID-19.


Assuntos
Antivirais/farmacologia , Reposicionamento de Medicamentos , Peptídeos/farmacologia , Internalização do Vírus/efeitos dos fármacos , Animais , Chlorocebus aethiops , Cloroquina/farmacologia , Descoberta de Drogas , Feminino , Células HEK293 , Humanos , Indóis/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Serina Endopeptidases/metabolismo , Células Vero
8.
Emerg Microbes Infect ; 10(1): 507-535, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33666147

RESUMO

Without modern medical management and vaccines, the severity of the Coronavirus Disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) might approach the magnitude of 1894-plague (12 million deaths) and 1918-A(H1N1) influenza (50 million deaths) pandemics. The COVID-19 pandemic was heralded by the 2003 SARS epidemic which led to the discovery of human and civet SARS-CoV-1, bat SARS-related-CoVs, Middle East respiratory syndrome (MERS)-related bat CoV HKU4 and HKU5, and other novel animal coronaviruses. The suspected animal-to-human jumping of 4 betacoronaviruses including the human coronaviruses OC43(1890), SARS-CoV-1(2003), MERS-CoV(2012), and SARS-CoV-2(2019) indicates their significant pandemic potential. The presence of a large reservoir of coronaviruses in bats and other wild mammals, culture of mixing and selling them in urban markets with suboptimal hygiene, habit of eating exotic mammals in highly populated areas, and the rapid and frequent air travels from these areas are perfect ingredients for brewing rapidly exploding epidemics. The possibility of emergence of a hypothetical SARS-CoV-3 or other novel viruses from animals or laboratories, and therefore needs for global preparedness should not be ignored. We reviewed representative publications on the epidemiology, virology, clinical manifestations, pathology, laboratory diagnostics, treatment, vaccination, and infection control of COVID-19 as of 20 January 2021, which is 1 year after person-to-person transmission of SARS-CoV-2 was announced. The difficulties of mass testing, labour-intensive contact tracing, importance of compliance to universal masking, low efficacy of antiviral treatment for severe disease, possibilities of vaccine or antiviral-resistant virus variants and SARS-CoV-2 becoming another common cold coronavirus are discussed.


Assuntos
/epidemiologia , Animais , /prevenção & controle , /imunologia , Modelos Animais de Doenças , Humanos , Mutação , /genética , Replicação Viral
9.
Clin Infect Dis ; 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33675655

RESUMO

Throughout the COVID-19 pandemic, divergent SARS-CoV-2 lineages have emerged continuously, mostly through the genomic accumulation of substitutions. We report the discovery of a SARS-CoV-2 variant with a novel genomic architecture characterized by absent ORF7a, ORF7b and ORF8, and a C-terminally modified ORF6 product resulting from partial 5'-UTR duplication and transposition.

10.
Cell Host Microbe ; 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33657424

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by a burst in the upper respiratory portal for high transmissibility. To determine human neutralizing antibodies (HuNAbs) for entry protection, we tested three potent HuNAbs (IC50 range, 0.0007-0.35 µg/mL) against live SARS-CoV-2 infection in the golden Syrian hamster model. These HuNAbs inhibit SARS-CoV-2 infection by competing with human angiotensin converting enzyme-2 for binding to the viral receptor binding domain (RBD). Prophylactic intraperitoneal or intranasal injection of individual HuNAb or DNA vaccination significantly reduces infection in the lungs but not in the nasal turbinates of hamsters intranasally challenged with SARS-CoV-2. Although postchallenge HuNAb therapy suppresses viral loads and lung damage, robust infection is observed in nasal turbinates treated within 1-3 days. Our findings demonstrate that systemic HuNAb suppresses SARS-CoV-2 replication and injury in lungs; however, robust viral infection in nasal turbinate may outcompete the antibody with significant implications to subprotection, reinfection, and vaccine.

11.
Artigo em Inglês | MEDLINE | ID: mdl-33666789

RESUMO

A multi-pronged carbapenemase-producing Enterobacteriaceae (CPE) screening strategy was implemented in Hong Kong West healthcare network. Of 199,192 fecal specimens from 77,194 patients screening from 1 July 2011 to 30 June 2019, the incidence of CPE per 1000 patient admission significantly increased from 0.01 (2012) to 1.9 (2018) (p<0.01). With appropriate infection control measures, the incidence of nosocomial CPE per 1000 CPE colonization day decreased from 22.34 (2014) to 10.65 (2018) (p=0.0094). Exposure to wet market for purchasing raw pork (p=0.007), beef (p=0.017), chicken (p=0.026), and vegetable (p=0.034) for >3 times per week significantly associated with community acquisition of CPE. Strategic CPE control measures should be implemented in both the hospital and the community.

12.
Infect Control Hosp Epidemiol ; : 1-39, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33736729

RESUMO

BACKGROUND: Nosocomial outbreaks leading to healthcare workers (HCWs) infection and death have been increasingly reported during the coronavirus disease 2019 (COVID-19) pandemic. An effective intervention is urgently needed to reduce nosocomial acquisition. METHODS: We summarized our experience of multi-pronged infection control (IC) strategy in the first 300 days (December 31, 2019 to October 25, 2020) of COVID-19 era under the governance of Hospital Authority in Hong Kong. RESULTS: Of 5,296 COVID-19 patients, 4,808 (90.8%) were diagnosed in the first (142 cases), second (896 cases), and third wave (3,770 cases) of COVID-19 in Hong Kong. Except for one patient who died before admission, all COVID-19 patients were admitted to public healthcare system which culminated to 78,834 COVID-19 patient-days. The median length of stay was 13 days (ranged, 1-128). Of 81,955 HCWs, thirty-eight (0.05%) HCWs [13 professional (2 doctors, 11 nurses) and 25 non-professional staff], had COVID-19. Except for 5 of 38 (13.2%) infected by HCW-to-HCW transmission in the non-clinical settings, no HCW had documented transmission from COVID-19 patients in the hospitals. The incidence of COVID-19 among HCWs was significantly lower than that of our general population (0.46 per 1,000 HCWs vs 0.71 per 1,000 population, p=0.008). The incidence of COVID-19 among professional staff was significantly lower than that of non-professional staff (0.30 vs 0.66 per 1,000 FTE, p=0.022). CONCLUSION: Hospital-based approach spared our healthcare service from being overloaded. No nosocomial COVID-19 in HCWs was found in the first 300 days of COVID-19 era in Hong Kong with our multi-pronged IC strategy.

13.
Eur J Med Chem ; 215: 113267, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33639344

RESUMO

Inhibitors of the proteasome have been extensively studied for their applications in the treatment of human diseases such as hematologic malignancies, autoimmune disorders, and viral infections. Many of the proteasome inhibitors reported in the literature target the non-primed site of proteasome's substrate binding pocket. In this study, we designed, synthesized and characterized a series of novel α-keto phenylamide derivatives aimed at both the primed and non-primed sites of the proteasome. In these derivatives, different substituted phenyl groups at the head group targeting the primed site were incorporated in order to investigate their structure-activity relationship and optimize the potency of α-keto phenylamides. In addition, the biological effects of modifications at the cap moiety, P1, P2 and P3 side chain positions were explored. Many derivatives displayed highly potent biological activities in proteasome inhibition and anticancer activity against a panel of six cancer cell lines, which were further rationalized by molecular modeling analyses. Furthermore, a representative α-ketoamide derivative was tested and found to be active in inhibiting the cellular infection of SARS-CoV-2 which causes the COVID-19 pandemic. These results demonstrate that this new class of α-ketoamide derivatives are potent anticancer agents and provide experimental evidence of the anti-SARS-CoV-2 effect by one of them, thus suggesting a possible new lead to develop antiviral therapeutics for COVID-19.


Assuntos
Amidas/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Cetonas/farmacologia , Inibidores de Proteassoma/farmacologia , /efeitos dos fármacos , Amidas/síntese química , Amidas/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antivirais/síntese química , Antivirais/metabolismo , Sítios de Ligação , Calpaína/química , Calpaína/metabolismo , Linhagem Celular Tumoral , /metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Cetonas/síntese química , Cetonas/metabolismo , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/síntese química , Inibidores de Proteassoma/metabolismo , Ligação Proteica , Relação Estrutura-Atividade
14.
J Virol ; 95(9)2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33627391

RESUMO

Influenza A viruses (IAVs) continue to pose an imminent threat to humans due to annual influenza epidemic outbreaks and episodic pandemics with high mortality rates. In this context, the suboptimal vaccine coverage and efficacy, coupled with recurrent events of viral resistance against a very limited antiviral portfolio, emphasize an urgent need for new additional prophylactic and therapeutic options, including new antiviral targets and drugs with new mechanisms of action to prevent and treat influenza virus infection. Here, we characterized a novel influenza A virus nucleoprotein (NP) inhibitor, FA-6005, that inhibited a broad spectrum of human pandemic and seasonal influenza A and B viruses in vitro and protects mice against lethal influenza A virus challenge. The small molecule FA-6005 targeted a conserved NP I41 domain and acted as a potentially broad, multimechanistic anti-influenza virus therapeutic since FA-6005 suppressed influenza virus replication and perturbed intracellular trafficking of viral ribonucleoproteins (vRNPs) from early to late stages. Cocrystal structures of the NP/FA-6005 complex reconciled well with concurrent mutational studies. This study provides the first line of direct evidence suggesting that the newly identified NP I41 pocket is an attractive target for drug development that inhibits multiple functions of NP. Our results also highlight FA-6005 as a promising candidate for further development as an antiviral drug for the treatment of IAV infection and provide chemical-level details for inhibitor optimization.IMPORTANCE Current influenza antivirals have limitations with regard to their effectiveness and the potential emergence of resistance. Therefore, there is an urgent need for broad-spectrum inhibitors to address the considerable challenges posed by the rapid evolution of influenza viruses that limit the effectiveness of vaccines and lead to the emergence of antiviral drug resistance. Here, we identified a novel influenza A virus NP antagonist, FA-6005, with broad-spectrum efficacy against influenza viruses, and our study presents a comprehensive study of the mode of action of FA-6005 with the crystal structure of the compound in complex with NP. The influenza virus inhibitor holds promise as an urgently sought-after therapeutic option offering a mechanism of action complementary to existing antiviral drugs for the treatment of influenza virus infection and should further aid in the development of universal therapeutics.

15.
Stem Cell Reports ; 16(3): 493-504, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33626333

RESUMO

Enteroviruses, such as EV-A71 and CVA16, mainly infect the human gastrointestinal tract. Human coronaviruses, including SARS-CoV and SARS-CoV-2, have been variably associated with gastrointestinal symptoms. We aimed to optimize the human intestinal organoids and hypothesize that these optimized intestinal organoids can recapitulate enteric infections of enterovirus and coronavirus. We demonstrate that the optimized human intestinal organoids enable better simulation of the native human intestinal epithelium, and that they are significantly more susceptible to EV-A71 than CVA16. Higher replication of EV-A71 than CVA16 in the intestinal organoids triggers a more vigorous cellular response. However, SARS-CoV and SARS-CoV-2 exhibit distinct dynamics of virus-host interaction; more robust propagation of SARS-CoV triggers minimal cellular response, whereas, SARS-CoV-2 exhibits lower replication capacity but elicits a moderate cellular response. Taken together, the disparate profile of the virus-host interaction of enteroviruses and coronaviruses in human intestinal organoids may unravel the cellular basis of the distinct pathogenicity of these viral pathogens.


Assuntos
/virologia , Enterovirus Humano A/patogenicidade , Infecções por Enterovirus/virologia , Intestinos/virologia , Organoides/virologia , /patogenicidade , Animais , Linhagem Celular , Chlorocebus aethiops , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Mucosa Intestinal/virologia , Células Vero , Replicação Viral/fisiologia
16.
mSphere ; 6(1)2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568452

RESUMO

Compared to other human coronaviruses, the genetic diversity and evolution of human coronavirus 229E (HCoV-229E) are relatively understudied. We report a fatal case of COVID-19 pneumonia coinfected with HCoV-229E in Hong Kong. Genome sequencing of SARS-CoV-2 and HCoV-229E from a nasopharyngeal sample of the patient showed that the SARS-CoV-2 strain HK13 was most closely related to SARS-CoV-2 type strain Wuhan-Hu-1 (99.99% nucleotide identity), compatible with his recent history of travel to Wuhan. The HCoV-229E strain HK20-42 was most closely related to HCoV-229E strain SC0865 from the United States (99.86% nucleotide identity). To investigate if it may represent a newly emerged HCoV-229E genotype in Hong Kong, we retrieved 41 archived respiratory samples that tested positive for HCoV-229E from 2004 to 2019. Pneumonia and exacerbations of chronic airway diseases were common among infected patients. Complete RdRp, S, and N gene sequencing of the 41 HCoV-229E strains revealed that our contemporary HCoV-229E strains have undergone significant genetic drift with clustering of strains in chronological order. Two novel genogroups were identified, in addition to previously described genogroups 1 to 4, with recent circulating strains including strain HK20-42 belonging to novel genogroup 6. Positive selection was detected in the spike protein and receptor-binding domain, which may be important for viral evolution at the receptor-binding interphase. Molecular dating analysis showed that HCoV-229E shared the most recent common ancestor with bat and camel/alpaca 229E-related viruses at ∼1884, while camel/alpaca viruses had a relatively recent common ancestor at ∼1999. Further studies are required to ascertain the evolutionary origin and path of HCoV-229E.IMPORTANCE Since its first appearance in the 1960s, the genetic diversity and evolution of human coronavirus 229E (HCoV-229E) have been relatively understudied. In this study, we report a fatal case of COVID-19 coinfected with HCoV-229E in Hong Kong. Genome sequencing revealed that our SARS-CoV-2 strain is highly identical to the SARS-CoV-2 strain from Wuhan, compatible with the patient's recent travel history, whereas our HCoV-229E strain in this study is highly identical to a recent strain in the United States. We also retrieved 41 archived HCoV-229E strains from 2004 to 2019 in Hong Kong for sequence analysis. Pneumonia and exacerbations of chronic airway diseases were common diagnoses among the 41 patients. The results showed that HCoV-229E was evolving in chronological order. Two novel genogroups were identified in addition to the four preexisting HCoV-229E genogroups, with recent circulating strains belonging to novel genogroup 6. Molecular clock analysis dated bat-to-human and bat-to-camelid transmission to as early as 1884.


Assuntos
/patologia , Resfriado Comum/patologia , Coronavirus Humano 229E/genética , Variação Genética/genética , /genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Criança , Pré-Escolar , Coinfecção/virologia , Evolução Molecular , Feminino , Genoma Viral/genética , Hong Kong , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Domínios Proteicos/genética , Análise de Sequência de RNA , Glicoproteína da Espícula de Coronavírus/genética , Adulto Jovem
17.
Emerg Microbes Infect ; 10(1): 291-304, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33538646

RESUMO

Effective treatments for coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Dexamethasone has been shown to confer survival benefits to certain groups of hospitalized patients, but whether glucocorticoids such as dexamethasone and methylprednisolone should be used together with antivirals to prevent a boost of SARS-CoV-2 replication remains to be determined. Here, we show the beneficial effect of methylprednisolone alone and in combination with remdesivir in the hamster model of SARS-CoV-2 infection. Treatment with methylprednisolone boosted RNA replication of SARS-CoV-2 but suppressed viral induction of proinflammatory cytokines in human monocyte-derived macrophages. Although methylprednisolone monotherapy alleviated body weight loss as well as nasal and pulmonary inflammation, viral loads increased and antibody response against the receptor-binding domain of spike protein attenuated. In contrast, a combination of methylprednisolone with remdesivir not only prevented body weight loss and inflammation, but also dampened viral protein expression and viral loads. In addition, the suppressive effect of methylprednisolone on antibody response was alleviated in the presence of remdesivir. Thus, combinational anti-inflammatory and antiviral therapy might be an effective, safer and more versatile treatment option for COVID-19. These data support testing of the efficacy of a combination of methylprednisolone and remdesivir for the treatment of COVID-19 in randomized controlled clinical trials.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/uso terapêutico , Metilprednisolona/uso terapêutico , /efeitos dos fármacos , Monofosfato de Adenosina/farmacologia , Monofosfato de Adenosina/uso terapêutico , Alanina/farmacologia , Alanina/uso terapêutico , Animais , Anticorpos Antivirais/sangue , Antivirais/farmacologia , /virologia , Citocinas/biossíntese , Citocinas/imunologia , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Humanos , Macrófagos/imunologia , Macrófagos/virologia , Masculino , Mesocricetus , Metilprednisolona/farmacologia , RNA Viral , Sistema Respiratório/patologia , Sistema Respiratório/virologia , Glicoproteína da Espícula de Coronavírus/imunologia , Carga Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
18.
Nat Commun ; 12(1): 134, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420022

RESUMO

Understanding the factors that contribute to efficient SARS-CoV-2 infection of human cells may provide insights on SARS-CoV-2 transmissibility and pathogenesis, and reveal targets of intervention. Here, we analyze host and viral determinants essential for efficient SARS-CoV-2 infection in both human lung epithelial cells and ex vivo human lung tissues. We identify heparan sulfate as an important attachment factor for SARS-CoV-2 infection. Next, we show that sialic acids present on ACE2 prevent efficient spike/ACE2-interaction. While SARS-CoV infection is substantially limited by the sialic acid-mediated restriction in both human lung epithelial cells and ex vivo human lung tissues, infection by SARS-CoV-2 is limited to a lesser extent. We further demonstrate that the furin-like cleavage site in SARS-CoV-2 spike is required for efficient virus replication in human lung but not intestinal tissues. These findings provide insights on the efficient SARS-CoV-2 infection of human lungs.


Assuntos
/metabolismo , /transmissão , Ácidos Siálicos/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Ligação Viral , Animais , Células CACO-2 , Linhagem Celular Tumoral , Chlorocebus aethiops , Cricetinae , Furina/metabolismo , Células HEK293 , Heparitina Sulfato/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Intestinos/virologia , Pulmão/patologia , Pulmão/virologia , Síndrome Respiratória Aguda Grave/patologia , Células Vero , Internalização do Vírus , Replicação Viral/fisiologia
19.
Nat Commun ; 12(1): 216, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431849

RESUMO

While a number of human coronaviruses are believed to be originated from ancestral viruses in bats, it remains unclear if bat coronaviruses are ready to cause direct bat-to-human transmission. Here, we report the isolation of a MERS-related coronavirus, Tylonycteris-bat-CoV-HKU4, from lesser bamboo bats. Tylonycteris-bat-CoV-HKU4 replicates efficiently in human colorectal adenocarcinoma and hepatocarcinoma cells with cytopathic effects, and can utilize human-dipeptidyl-peptidase-4 and dromedary camel-dipeptidyl-peptidase-4 as the receptors for cell entry. Flow cytometry, co-immunoprecipitation and surface plasmon resonance assays show that Tylonycteris-bat-CoV-HKU4-receptor-binding-domain can bind human-dipeptidyl-peptidase-4, dromedary camel-dipeptidyl-peptidase-4, and Tylonycteris pachypus-dipeptidyl-peptidase-4. Tylonycteris-bat-CoV-HKU4 can infect human-dipeptidyl-peptidase-4-transgenic mice by intranasal inoculation with self-limiting disease. Positive virus and inflammatory changes were detected in lungs and brains of infected mice, associated with suppression of antiviral cytokines and activation of proinflammatory cytokines and chemokines. The results suggest that MERS-related bat coronaviruses may overcome species barrier by utilizing dipeptidyl-peptidase-4 and potentially emerge in humans by direct bat-to-human transmission.


Assuntos
Quirópteros/virologia , Infecções por Coronavirus/virologia , Dipeptidil Peptidase 4/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Animais , Encéfalo/patologia , Células CACO-2 , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Infecções por Coronavirus/transmissão , Citocinas/metabolismo , Dipeptidil Peptidase 4/genética , Células HEK293 , Especificidade de Hospedeiro , Humanos , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Coronavírus da Síndrome Respiratória do Oriente Médio/genética
20.
Clin Infect Dis ; 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33515458

RESUMO

BACKGROUND: Mass vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is ongoing amidst widespread transmission during the Coronavirus Disease 2019 (COVID-19) pandemic. Disease phenotypes of SARS-CoV-2 exposure occurring around the time of vaccine administration have not been described. METHODS: Two-dose (14 days apart) vaccination regimen with a formalin-inactivated whole virion SARS-CoV-2 in golden Syrian hamster model was established. To investigate the disease phenotypes of a one-dose regimen given 3 days prior (D-3), 1 (D1) or 2 (D2) days after, or on the day (D0) of virus challenge, we monitored the serial clinical severity, tissue histopathology, virus burden, and antibody response of the vaccinated hamsters. RESULTS: The one-dose vaccinated hamsters had significantly lower clinical disease severity score, body weight loss, lung histology score, nucleocapsid protein expression in lung, infectious virus titres in the lung and nasal turbinate, inflammatory changes in intestines and a higher serum neutralizing antibody or IgG titre against the spike receptor-binding domain or nucleocapsid protein when compared to unvaccinated controls. These improvements were particularly noticeable in D-3, but also in D0, D1 and even D2 vaccinated hamsters to varying degrees. No increased eosinophilic infiltration was found in the nasal turbinate, lung, and intestine after virus challenge. Significantly higher serum titre of fluorescent foci microneutralization inhibition antibody was detected in D1 and D2 vaccinated hamsters at day 4 post-challenge compared to controls despite undetectable neutralizing antibody titre. CONCLUSIONS: Vaccination just before or soon after exposure to SARS-CoV-2 does not worsen disease phenotypes and may even ameliorate infection.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...