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1.
Virology ; 597: 110142, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38959723

RESUMO

OBJECTIVES: The specific humoral immune response resulting from inactivated vaccination following by BA.5 infection, and predictors of XBB variants re-infection in BA.5 infection-recovered nasopharyngeal carcinoma (BA.5-RNPC) patients, were explored. METHODS: Serum SARS-CoV-2 specific antibody levels were assessed using enzyme-linked-immunosorbent-assay. Univariate and multivariate binary logistic regression analyses were conducted to identify factors associated with the magnitude of specific humoral immunity and susceptibility to re-infection by XBB variants. RESULTS: Our data demonstrates that SARS-CoV-2 specific antibody levels were comparable between BA.5-RNPC patients and BA.5 infection-recovered-non-cancerous (BA.5-RNC) individuals. Specifically, serum levels of anti-ancestral-S1-IgG, anti-ancestral-nucleocapsid-protein (NP)-IgG, anti-BA.5-receptor binding domain (RBD)-IgG and anti-XBB.1.1.6-RBD-IgG were higher in BA.5-RNPC patients compared to those without a prior infection. Compared to BA.5-RNPC patients without vaccination, individuals who received inactivated vaccination exhibited significantly higher levels of anti-ancestral-S1-IgG and anti-XBB.1.16-RBD-IgG. Multivariate logistic regression analysis revealed that inactivated vaccination was the most significant predictor of all tested SARS-CoV-2 specific antibodies response. Subsequent analysis indicated that a low globulin level is an independent risk factor for XBB re-infection in BA.5-RNPC patients. CONCLUSIONS: The SARS-CoV-2 specific antibodies have been improved in vaccinated BA.5-RNPC patients. However, the baseline immunity status biomarker IgG is an indicators of XBB variant re-infection risk in BA.5-RNPC patients.


Assuntos
Anticorpos Antivirais , COVID-19 , Imunoglobulina G , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Reinfecção , SARS-CoV-2 , Humanos , Masculino , Feminino , Anticorpos Antivirais/sangue , COVID-19/imunologia , COVID-19/virologia , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/imunologia , Carcinoma Nasofaríngeo/virologia , Carcinoma Nasofaríngeo/genética , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Fatores de Risco , Neoplasias Nasofaríngeas/imunologia , Neoplasias Nasofaríngeas/virologia , Reinfecção/imunologia , Reinfecção/virologia , Adulto , Imunoglobulina G/sangue , Idoso , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Imunidade Humoral , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem
2.
Proc Natl Acad Sci U S A ; 121(28): e2403581121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38968108

RESUMO

Adverse cardiac outcomes in COVID-19 patients, particularly those with preexisting cardiac disease, motivate the development of human cell-based organ-on-a-chip models to recapitulate cardiac injury and dysfunction and for screening of cardioprotective therapeutics. Here, we developed a heart-on-a-chip model to study the pathogenesis of SARS-CoV-2 in healthy myocardium established from human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and a cardiac dysfunction model, mimicking aspects of preexisting hypertensive disease induced by angiotensin II (Ang II). We recapitulated cytopathic features of SARS-CoV-2-induced cardiac damage, including progressively impaired contractile function and calcium handling, apoptosis, and sarcomere disarray. SARS-CoV-2 presence in Ang II-treated hearts-on-a-chip decreased contractile force with earlier onset of contractile dysfunction and profoundly enhanced inflammatory cytokines compared to SARS-CoV-2 alone. Toward the development of potential therapeutics, we evaluated the cardioprotective effects of extracellular vesicles (EVs) from human iPSC which alleviated the impairment of contractile force, decreased apoptosis, reduced the disruption of sarcomeric proteins, and enhanced beta-oxidation gene expression. Viral load was not affected by either Ang II or EV treatment. We identified MicroRNAs miR-20a-5p and miR-19a-3p as potential mediators of cardioprotective effects of these EVs.


Assuntos
Angiotensina II , COVID-19 , Vesículas Extracelulares , Células-Tronco Pluripotentes Induzidas , Miócitos Cardíacos , SARS-CoV-2 , Humanos , Angiotensina II/farmacologia , COVID-19/virologia , COVID-19/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/virologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Vesículas Extracelulares/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Apoptose/efeitos dos fármacos , Dispositivos Lab-On-A-Chip , MicroRNAs/metabolismo , MicroRNAs/genética , Citocinas/metabolismo
3.
ACS Chem Biol ; 19(7): 1593-1603, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-38980755

RESUMO

The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) highlighted a critical need to discover more effective antivirals. While therapeutics for SARS-CoV-2 exist, its nonstructural protein 13 (Nsp13) remains a clinically untapped target. Nsp13 is a helicase responsible for unwinding double-stranded RNA during viral replication and is essential for propagation. Like other helicases, Nsp13 has two active sites: a nucleotide binding site that hydrolyzes nucleoside triphosphates (NTPs) and a nucleic acid binding channel that unwinds double-stranded RNA or DNA. Targeting viral helicases with small molecules, as well as the identification of ligand binding pockets, have been ongoing challenges, partly due to the flexible nature of these proteins. Here, we use a virtual screen to identify ligands of Nsp13 from a collection of clinically used drugs. We find that a known ion channel inhibitor, IOWH-032, inhibits the dual ATPase and helicase activities of SARS-CoV-2 Nsp13 at low micromolar concentrations. Kinetic and binding assays, along with computational and mutational analyses, indicate that IOWH-032 interacts with the RNA binding interface, leading to displacement of nucleic acid substrate, but not bound ATP. Evaluation of IOWH-032 with microbial helicases from other superfamilies reveals that it is selective for coronavirus Nsp13. Furthermore, it remains active against mutants representative of observed SARS-CoV-2 variants. Overall, this work provides a new inhibitor for Nsp13 and provides a rationale for a recent observation that IOWH-032 lowers SARS-CoV-2 viral loads in human cells, setting the stage for the discovery of other potent viral helicase modulators.


Assuntos
Antivirais , Reposicionamento de Medicamentos , SARS-CoV-2 , Proteínas não Estruturais Virais , SARS-CoV-2/efeitos dos fármacos , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/farmacologia , Antivirais/química , Humanos , RNA Helicases/metabolismo , RNA Helicases/antagonistas & inibidores , COVID-19/virologia , Ácidos Nucleicos/metabolismo , Ácidos Nucleicos/química , Betacoronavirus/efeitos dos fármacos , Tratamento Farmacológico da COVID-19 , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/antagonistas & inibidores , Metiltransferases
4.
Sci Transl Med ; 16(756): eadn0136, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39018367

RESUMO

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) represent an urgent public health challenge and are estimated to affect more than 60 million individuals globally. Although a growing body of evidence suggests that dysregulated immune reactions may be linked with PASC symptoms, most investigations have primarily centered around blood-based studies, with few focusing on samples derived from affected tissues. Furthermore, clinical studies alone often provide correlative insights rather than causal mechanisms. Thus, it is essential to compare clinical samples with relevant animal models and conduct functional experiments to understand the etiology of PASC. In this study, we comprehensively compared bronchoalveolar lavage fluid single-cell RNA sequencing data derived from clinical PASC samples and a mouse model of PASC. This revealed a pro-fibrotic monocyte-derived macrophage response in respiratory PASC, as well as abnormal interactions between pulmonary macrophages and respiratory resident T cells, in both humans and mice. Interferon-γ (IFN-γ) emerged as a key node mediating the immune anomalies in respiratory PASC. Neutralizing IFN-γ after the resolution of acute SARS-CoV-2 infection reduced lung inflammation and tissue fibrosis in mice. Together, our study underscores the importance of performing comparative analysis to understand the cause of PASC and suggests that the IFN-γ signaling axis might represent a therapeutic target.


Assuntos
Líquido da Lavagem Broncoalveolar , COVID-19 , Interferon gama , SARS-CoV-2 , Análise de Célula Única , COVID-19/imunologia , COVID-19/patologia , COVID-19/virologia , COVID-19/complicações , Animais , Interferon gama/metabolismo , Humanos , Camundongos , Líquido da Lavagem Broncoalveolar/virologia , Modelos Animais de Doenças , Pulmão/patologia , Pulmão/virologia , Camundongos Endogâmicos C57BL , Macrófagos Alveolares/imunologia , Masculino , Feminino , Linfócitos T/imunologia
5.
ACS Appl Mater Interfaces ; 16(28): 37275-37287, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38959130

RESUMO

Titanium dioxide (TiO2) shows significant potential as a self-cleaning material to inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and prevent virus transmission. This study provides insights into the impact of UV-A light on the photocatalytic inactivation of adsorbed SARS-CoV-2 virus-like particles (VLPs) on a TiO2 surface at the molecular and atomic levels. X-ray photoelectron spectroscopy, combined with density functional theory calculations, reveals that spike proteins can adsorb on TiO2 predominantly via their amine and amide functional groups in their amino acids blocks. We employ atomic force microscopy and grazing-incidence small-angle X-ray scattering (GISAXS) to investigate the molecular-scale morphological changes during the inactivation of VLPs on TiO2 under light irradiation. Notably, in situ measurements reveal photoinduced morphological changes of VLPs, resulting in increased particle diameters. These results suggest that the denaturation of structural proteins induced by UV irradiation and oxidation of the virus structure through photocatalytic reactions can take place on the TiO2 surface. The in situ GISAXS measurements under an N2 atmosphere reveal that the virus morphology remains intact under UV light. This provides evidence that the presence of both oxygen and UV light is necessary to initiate photocatalytic reactions on the surface and subsequently inactivate the adsorbed viruses. The chemical insights into the virus inactivation process obtained in this study contribute significantly to the development of solid materials for the inactivation of enveloped viruses.


Assuntos
SARS-CoV-2 , Titânio , Raios Ultravioleta , Titânio/química , Titânio/efeitos da radiação , SARS-CoV-2/efeitos da radiação , SARS-CoV-2/química , Inativação de Vírus/efeitos da radiação , Inativação de Vírus/efeitos dos fármacos , Humanos , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , COVID-19/virologia , COVID-19/prevenção & controle , Adsorção , Propriedades de Superfície
6.
Cell Rep Med ; 5(7): 101642, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38981485

RESUMO

In order to assess homeostatic mechanisms in the lung after COVID-19, changes in the protein signature of bronchoalveolar lavage from 45 patients with mild to moderate disease at three phases (acute, recovery, and convalescent) are evaluated over a year. During the acute phase, inflamed and uninflamed phenotypes are characterized by the expression of tissue repair and host defense response molecules. With recovery, inflammatory and fibrogenic mediators decline and clinical symptoms abate. However, at 9 months, quantified radiographic abnormalities resolve in the majority of patients, and yet compared to healthy persons, all showed ongoing activation of cellular repair processes and depression of the renin-kallikrein-kinin, coagulation, and complement systems. This dissociation of prolonged reparative processes from symptom and radiographic resolution suggests that occult ongoing disruption of the lung proteome is underrecognized and may be relevant to recovery from other serious viral pneumonias.


Assuntos
COVID-19 , Pulmão , Proteoma , SARS-CoV-2 , Humanos , COVID-19/metabolismo , COVID-19/patologia , COVID-19/virologia , Proteoma/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Pulmão/diagnóstico por imagem , Feminino , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/isolamento & purificação , Estudos Longitudinais , Adulto , Líquido da Lavagem Broncoalveolar/química , Idoso
7.
Influenza Other Respir Viruses ; 18(7): e13339, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39012045

RESUMO

We describe humoral immune responses in 105 ambulatory patients with laboratory-confirmed SARS-CoV-2 Omicron variant infection. In dried blood spot (DBS) collected within 5 days of illness onset and during convalescence, we measured binding antibody (bAb) against ancestral spike protein receptor binding domain (RBD) and nucleocapsid (N) protein using a commercial multiplex bead assay. Geometric mean bAb concentrations against RBD increased by a factor of 2.5 from 1258 to 3189 units/mL and by a factor of 47 against N protein from 5.5 to 259 units/mL between acute illness and convalescence; lower concentrations were associated with greater geometric mean ratios. Paired DBS specimens may be used to evaluate humoral response to SARS-CoV-2 infection.


Assuntos
Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Humanos , COVID-19/imunologia , COVID-19/virologia , SARS-CoV-2/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Feminino , Adulto , Masculino , Pessoa de Meia-Idade , Glicoproteína da Espícula de Coronavírus/imunologia , Idoso , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Adulto Jovem , Imunidade Humoral , Formação de Anticorpos
8.
Artigo em Inglês | MEDLINE | ID: mdl-39021123

RESUMO

Abstract: There were 108 norovirus-positive outbreaks in 2022, with 45 (41.7%) occurring during the first quarter (Q1), January-March. Aged care facilities accounted for 44.4% of norovirus-positive outbreaks; 43.5% were in childcare settings. Overall, the GII.P31/GII.4 genotype was the most common, involved in 39.4% of outbreaks; however, there were shifts in the most common genotype across the year. In Q1, the GII.P31/GII.4 genotype accounted for 73.3% of typed outbreaks, but by Q3 (July-September) the GII.P7/GII.6 was the most prominent genotype at 45.0%. In Q4 (October-December), the dominant genotype had changed again to GII.P16/GII.4 (52.6%). While the incidence of norovirus outbreaks in 2022 was average regarding overall prevalence and genotype diversity, there are still ongoing effects from the coronavirus disease 2019 (COVID-19) pandemic in relation to seasonality, outbreak demographics and specimen referral.


Assuntos
COVID-19 , Infecções por Caliciviridae , Surtos de Doenças , Genótipo , Norovirus , SARS-CoV-2 , Humanos , Norovirus/genética , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Incidência , COVID-19/epidemiologia , COVID-19/virologia , Vitória/epidemiologia , SARS-CoV-2/genética , Estações do Ano , Gastroenterite/epidemiologia , Gastroenterite/virologia , Criança , Idoso
9.
Mikrochim Acta ; 191(8): 466, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39017814

RESUMO

The CRISPR/Cas13 nucleases have been widely documented for nucleic acid detection. Understanding the intricacies of CRISPR/Cas13's reaction components is pivotal for harnessing its full potential for biosensing applications. Herein, we report on the influence of CRISPR/Cas13a reaction components on its trans-cleavage activity and the development of an on-chip total internal reflection fluorescence microscopy (TIRFM)-powered RNA sensing system. We used SARS-CoV-2 synthetic RNA and pseudovirus as a model system. Our results show that optimizing Mg2+ concentration, reporter length, and crRNA combination significantly improves the detection sensitivity. Under optimized conditions, we detected 100 fM unamplified SARS-CoV-2 synthetic RNA using a microtiter plate reader. To further improve sensitivity and provide a new amplification-free RNA sensing toolbox, we developed a TIRFM-based amplification-free RNA sensing system. We were able to detect RNA down to 100 aM. Furthermore, the TIRM-based detection system developed in this study is 1000-fold more sensitive than the off-coverslip assay. The possible clinical applicability of the system was demonstrated by detecting SARS-CoV-2 pseudovirus RNA. Our proposed sensing system has the potential to detect any target RNA with slight modifications to the existing setup, providing a universal RNA detection platform.


Assuntos
Sistemas CRISPR-Cas , RNA Viral , SARS-CoV-2 , SARS-CoV-2/genética , RNA Viral/análise , RNA Viral/genética , Humanos , COVID-19/diagnóstico , COVID-19/virologia , Técnicas Biossensoriais/métodos , Proteínas Associadas a CRISPR , Microscopia de Fluorescência , Dispositivos Lab-On-A-Chip , Limite de Detecção , Magnésio/química , Teste de Ácido Nucleico para COVID-19/métodos
10.
Influenza Other Respir Viruses ; 18(7): e13348, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38949103

RESUMO

Understanding the clinical spectrum of SARS-CoV-2 infection, including the asymptomatic fraction, is important as asymptomatic individuals are still able to infect other individuals and contribute to ongoing transmission. The WHO Unity Household transmission investigation (HHTI) protocol provides a platform for the prospective and systematic collection of high-quality clinical, epidemiological, serological and virological data from SARS-CoV-2 confirmed cases and their household contacts. These data can be used to understand key severity and transmissibility parameters-including the asymptomatic proportion-in relation to local epidemic context and help inform public health response. We aimed to estimate the asymptomatic proportion of SARS-CoV-2 Omicron variant infections in Unity-aligned HHTIs. We conducted a systematic review and meta-analysis in alignment with the PRISMA 2020 guidelines and registered our systematic review on PROSPERO (CRD42022378648). We searched EMBASE, Web of Science, MEDLINE and bioRxiv and medRxiv from 1 November 2021 to 22 August 2023. We identified 8368 records, of which 98 underwent full text review. We identified only three studies for data extraction, with substantial variation in study design and corresponding estimates of the asymptomatic proportion. As a result, we did not generate a pooled estimate or I2 metric. The limited number of quality studies that we identified highlights the need for improved preparedness and response capabilities to facilitate robust HHTI implementation, analysis and reporting, to better inform national, regional and global risk assessments and policymaking.


Assuntos
Infecções Assintomáticas , COVID-19 , Características da Família , SARS-CoV-2 , Humanos , Infecções Assintomáticas/epidemiologia , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/virologia , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação
11.
J Med Microbiol ; 73(7)2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38963412

RESUMO

Introduction. In India, the SARS-CoV-2 Delta wave (2020-2021) faded away with the advent of the Omicron variants (2021-present). Dengue incidences were observed to be less in Southeast Asia during the active years of the pandemic (2020-2021). However, dengue virus type 3 (DV3) cases were increasingly reported in this region (including India) concurrent with the progression of the Omicron waves since 2022.Hypothesis. What could be the reason(s) behind this unusual DV3 surge after an overall dip in dengue incidences in many parts of Southeast Asia?Aim. We, therefore, investigated the current state of cross-reactivity of prevalent (Omicron era) SARS-CoV-2 serums with different DV serotypes and evaluated the impact of such serums on DV neutralization in cell culture.Methodology. Fifty-five COVID-19 serum samples (January-September 2022) and three pre-pandemic archived serum samples from apparently healthy individuals were tested for DV or SARS-CoV-2 IgM/IgG using the lateral flow immunoassays. DV1-4 virus neutralization tests (VNTs) were done with the SARS-CoV-2 antibody (Ab)-positive serums in Huh7 cells. DV3 envelope (env) gene was PCR amplified and sequenced for three archived DV isolates, one from 2017 and two from 2021.Results. SARS-CoV-2 Ab-positive samples constituted 74.5 % of the serums. Of these, 41.5 % were DV cross-reactive and 58.5 % were not. The DV cross-reactive serums neutralized all DV serotypes (DV1-4), as per previous results and this study. The DV non-cross-reactive serums (58.5 %) also cross-neutralized DV1, 2 and 4 but increased DV3 infectivity by means of antibody-dependent enhancement of infection as evident from significantly higher DV3 titres in VNT compared to control serums. The DV3 envelope was identical among the three isolates, including isolate 1 used in VNTs. Our results suggest that DV cross-reactivity of SARS-CoV-2 serums diminished with the shift from Delta to Omicron prevalence. Such COVID-19 serums (DV non-cross-reactive) might have played a major role in causing DV3 surge during the Omicron waves.Conclusion. Patients suspected of dengue or COVID-19 should be subjected to virus/antigen tests and serological tests for both the diseases for definitive diagnosis, prognosis and disease management.


Assuntos
Anticorpos Antivirais , COVID-19 , Reações Cruzadas , Vírus da Dengue , SARS-CoV-2 , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/virologia , COVID-19/epidemiologia , COVID-19/sangue , COVID-19/imunologia , Anticorpos Antivirais/sangue , Vírus da Dengue/genética , Vírus da Dengue/imunologia , Vírus da Dengue/classificação , Índia/epidemiologia , Dengue/virologia , Dengue/sangue , Dengue/epidemiologia , Dengue/imunologia , Testes de Neutralização , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue
12.
World J Gastroenterol ; 30(22): 2866-2880, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38947288

RESUMO

Coronavirus disease 2019 (COVID-19), caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome, multiple organ failure, and death. Despite extensive studies on the pathogenicity of SARS-CoV-2, its impact on the hepatobiliary system remains unclear. While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels, the exact source of this damage is not fully understood. Proposed mechanisms for injury include direct cytotoxicity, collateral damage from inflammation, drug-induced liver injury, and ischemia/hypoxia. However, evidence often relies on blood tests with liver enzyme abnormalities. In this comprehensive review, we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients, drawing from liver biopsies, complete autopsies, and in vitro liver analyses. We present evidence of the direct impact of SARS-CoV-2 on the liver, substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes, including mitochondrial swelling, endoplasmic reticulum dilatation, and hepatocyte apoptosis. Additionally, we describe the diverse liver pathology observed during COVID-19 infection, encompassing necrosis, steatosis, cholestasis, and lobular inflammation. We also discuss the emergence of long-term complications, notably COVID-19-related secondary sclerosing cholangitis. Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.


Assuntos
COVID-19 , Fígado , SARS-CoV-2 , Humanos , COVID-19/complicações , COVID-19/patologia , COVID-19/virologia , Fígado/patologia , Fígado/virologia , SARS-CoV-2/patogenicidade , Hepatopatias/patologia , Hepatopatias/virologia , Hepatopatias/etiologia , Hepatócitos/patologia , Hepatócitos/virologia
14.
Nat Commun ; 15(1): 5503, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951531

RESUMO

Proline is widely known as the only proteogenic amino acid with a secondary amine. In addition to its crucial role in protein structure, the secondary amino acid modulates neurotransmission and regulates the kinetics of signaling proteins. To understand the structural basis of proline import, we solved the structure of the proline transporter SIT1 in complex with the COVID-19 viral receptor ACE2 by cryo-electron microscopy. The structure of pipecolate-bound SIT1 reveals the specific sequence requirements for proline transport in the SLC6 family and how this protein excludes amino acids with extended side chains. By comparing apo and substrate-bound SIT1 states, we also identify the structural changes that link substrate release and opening of the cytoplasmic gate and provide an explanation for how a missense mutation in the transporter causes iminoglycinuria.


Assuntos
Enzima de Conversão de Angiotensina 2 , Microscopia Crioeletrônica , Prolina , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/genética , Prolina/metabolismo , Humanos , SARS-CoV-2/metabolismo , SARS-CoV-2/genética , COVID-19/virologia , COVID-19/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/química , Modelos Moleculares
15.
BMC Infect Dis ; 24(1): 654, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951848

RESUMO

Vaccination against COVID-19 was integral to controlling the pandemic that persisted with the continuous emergence of SARS-CoV-2 variants. Using a mathematical model describing SARS-CoV-2 within-host infection dynamics, we estimate differences in virus and immunity due to factors of infecting variant, age, and vaccination history (vaccination brand, number of doses and time since vaccination). We fit our model in a Bayesian framework to upper respiratory tract viral load measurements obtained from cases of Delta and Omicron infections in Singapore, of whom the majority only had one nasopharyngeal swab measurement. With this dataset, we are able to recreate similar trends in URT virus dynamics observed in past within-host modelling studies fitted to longitudinal patient data.We found that Omicron had higher R0,within values than Delta, indicating greater initial cell-to-cell spread of infection within the host. Moreover, heterogeneities in infection dynamics across patient subgroups could be recreated by fitting immunity-related parameters as vaccination history-specific, with or without age modification. Our model results are consistent with the notion of immunosenescence in SARS-CoV-2 infection in elderly individuals, and the issue of waning immunity with increased time since last vaccination. Lastly, vaccination was not found to subdue virus dynamics in Omicron infections as well as it had for Delta infections.This study provides insight into the influence of vaccine-elicited immunity on SARS-CoV-2 within-host dynamics, and the interplay between age and vaccination history. Furthermore, it demonstrates the need to disentangle host factors and changes in pathogen to discern factors influencing virus dynamics. Finally, this work demonstrates a way forward in the study of within-host virus dynamics, by use of viral load datasets including a large number of patients without repeated measurements.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Vacinação , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , COVID-19/epidemiologia , SARS-CoV-2/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Pessoa de Meia-Idade , Idoso , Adulto , Singapura/epidemiologia , Fatores Etários , Carga Viral , Adulto Jovem , Teorema de Bayes , Modelos Teóricos , Masculino , Idoso de 80 Anos ou mais , Feminino , Adolescente
17.
Rev Med Virol ; 34(4): e2569, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38986606

RESUMO

We aimed to assess the performance of Ag-RDT and RT-qPCR with regard to detecting infectious SARS-CoV-2 in cell cultures, as their diagnostic test accuracy (DTA) compared to virus isolation remains largely unknown. We searched three databases up to 15 December 2021 for DTA studies. The bivariate model was used to synthesise the estimates. Risk of bias was assessed using QUADAS-2/C. Twenty studies (2605 respiratory samples) using cell culture and at least one molecular test were identified. All studies were at high or unclear risk of bias in at least one domain. Three comparative DTA studies reported results on Ag-RDT and RT-qPCR against cell culture. Two studies evaluated RT-qPCR against cell culture only. Fifteen studies evaluated Ag-RDT against cell culture as reference standard in RT-qPCR-positive samples. For Ag-RDT, summary sensitivity was 93% (95% CI 78; 98%) and specificity 87% (95% CI 70; 95%). For RT-qPCR, summary sensitivity (continuity-corrected) was 98% (95% CI 95; 99%) and specificity 45% (95% CI 28; 63%). In studies relying on RT-qPCR-positive subsamples (n = 15), the summary sensitivity of Ag-RDT was 93% (95% CI 92; 93%) and specificity 63% (95% CI 63; 63%). Ag-RDT show moderately high sensitivity, detecting most but not all samples demonstrated to be infectious based on virus isolation. Although RT-qPCR exhibits high sensitivity across studies, its low specificity to indicate infectivity raises the question of its general superiority in all clinical settings. Study findings should be interpreted with caution due to the risk of bias, heterogeneity and the imperfect reference standard for infectivity.


Assuntos
COVID-19 , SARS-CoV-2 , Sensibilidade e Especificidade , Humanos , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , COVID-19/diagnóstico , COVID-19/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Técnicas de Cultura de Células/métodos , Teste para COVID-19/métodos , Teste de Ácido Nucleico para COVID-19/métodos , Testes de Diagnóstico Rápido
18.
Biomed Environ Sci ; 37(6): 639-646, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38988114

RESUMO

Objective: To develop a highly sensitive and rapid nucleic acid detection method for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We designed, developed, and manufactured an integrated disposable device for SARS-CoV-2 nucleic acid extraction and detection. The precision of the liquid transfer and temperature control was tested. A comparison between our device and a commercial kit for SARS-Cov-2 nucleic acid extraction was performed using real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR). The entire process, from SARS-CoV-2 nucleic acid extraction to amplification, was evaluated. Results: The precision of the syringe transfer volume was 19.2 ± 1.9 µL (set value was 20), 32.2 ± 1.6 (set value was 30), and 57.2 ± 3.5 (set value was 60). Temperature control in the amplification tube was measured at 60.0 ± 0.0 °C (set value was 60) and 95.1 ± 0.2 °C (set value was 95) respectively. SARS-Cov-2 nucleic acid extraction yield through the device was 7.10 × 10 6 copies/mL, while a commercial kit yielded 2.98 × 10 6 copies/mL. The mean time to complete the entire assay, from SARS-CoV-2 nucleic acid extraction to amplification detection, was 36 min and 45 s. The detection limit for SARS-CoV-2 nucleic acid was 250 copies/mL. Conclusion: The integrated disposable devices may be used for SARS-CoV-2 Point-of-Care test (POCT).


Assuntos
COVID-19 , Equipamentos Descartáveis , RNA Viral , SARS-CoV-2 , SARS-CoV-2/isolamento & purificação , COVID-19/diagnóstico , COVID-19/virologia , Humanos , RNA Viral/isolamento & purificação , RNA Viral/análise , Teste de Ácido Nucleico para COVID-19/instrumentação , Teste de Ácido Nucleico para COVID-19/métodos , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase em Tempo Real/instrumentação
19.
J Med Virol ; 96(7): e29801, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988204

RESUMO

SARS-CoV-2 Omicron lineages continue to emerge and evolve into new sublineages, causing infection waves throughout 2022 and 2023, which has been attributed to immune escape. We examined neutralizing antibody responses to the recently emerged SARS-CoV-2 JN.1 variant in comparison to ancestral D614G and Omicron BA.1, BA.2, BA.5, and XBB.1.5 variants. We tested 79 human sera from cohorts with different combinations of vaccinations and infections, including 23 individuals who had been repeatedly exposed to Omicron. Individuals with a monovalent XBB.1.5 vaccine booster or XBB.1.5 breakthrough infection had robust antibody levels against all variants tested; however, JN.1 evaded antibodies in individuals after single Omicron BA.1, BA.2 or BA.5 breakthrough infections. Moreover, in the non-vaccinated cohort, serum antibodies demonstrated almost no cross-neutralization activities against D614G, XBB.1.5 and JN.1. after infections with earlier Omicron variants. These findings show that SARS-CoV-2-immunity is heterogeneous, depending on different combinations of vaccinations and infections, and emphasize the importance of considering different immune-backgrounds when evaluating novel variants.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , SARS-CoV-2 , Humanos , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Anticorpos Antivirais/sangue , SARS-CoV-2/imunologia , SARS-CoV-2/genética , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Vacinação , Testes de Neutralização , Idoso
20.
J Med Virol ; 96(7): e29797, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988215

RESUMO

Temperature and humidity are studied in the context of seasonal infections in temperate and tropical zones, but the relationship between viral trends and climate variables in temperate subtropical zones remains underexplored. Our retrospective study analyzes respiratory pathogen incidence and its correlation with climate data in a subtropical zone. Retrospective observational study at Moinhos de Vento Hospital, South Brazil, aiming to assess seasonal trends in respiratory pathogens, correlating them with climate data. The study included patients of all ages from various healthcare settings, with data collected between April 2022 and July 2023. Biological samples were analyzed for 24 pathogens using polymerase chain reaction and hybridization techniques; demographic variables were also collected. The data was analyzed descriptively and graphically. Spearman tests and Poisson regression were used as correlation tests. Tests were clustered according to all pathogens, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza viruses, rhinovirus, and respiratory syncytial virus (RSV). Between April 2022 and July 2023, 3329 tests showed a 71.6% positivity rate. Rhinovirus and RSV predominated, exhibiting seasonal patterns. Temperature was inversely correlated with the viruses, notably rhinovirus, but SARS-CoV-2 was positively correlated. Air humidity was positively correlated with all pathogens, RSV, rhinovirus, and atmospheric pressure with all pathogens and rhinovirus. Our results showed statistically significant correlations, with modest effect sizes. Our study did not evaluate causation effects. Despite the correlation between climate and respiratory pathogens, our work suggests additional factors influencing transmission dynamics. Our findings underscore the complex interplay between climate and respiratory infections in subtropical climates.


Assuntos
COVID-19 , Umidade , Estações do Ano , Temperatura , Humanos , Estudos Retrospectivos , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/virologia , Brasil/epidemiologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Criança , Adolescente , Pré-Escolar , Idoso , Adulto Jovem , Lactente , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Clima , Infecções Respiratórias/virologia , Infecções Respiratórias/epidemiologia , Clima Tropical , Recém-Nascido , Rhinovirus/genética , Rhinovirus/isolamento & purificação , Incidência , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Idoso de 80 Anos ou mais
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