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1.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34479991

RESUMO

COVID-19 induces a robust, extended inflammatory "cytokine storm" that contributes to an increased morbidity and mortality, particularly in patients with type 2 diabetes (T2D). Macrophages are a key innate immune cell population responsible for the cytokine storm that has been shown, in T2D, to promote excess inflammation in response to infection. Using peripheral monocytes and sera from human patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a murine hepatitis coronavirus (MHV-A59) (an established murine model of SARS), we identified that coronavirus induces an increased Mφ-mediated inflammatory response due to a coronavirus-induced decrease in the histone methyltransferase, SETDB2. This decrease in SETDB2 upon coronavirus infection results in a decrease of the repressive trimethylation of histone 3 lysine 9 (H3K9me3) at NFkB binding sites on inflammatory gene promoters, effectively increasing inflammation. Mφs isolated from mice with a myeloid-specific deletion of SETDB2 displayed increased pathologic inflammation following coronavirus infection. Further, IFNß directly regulates SETDB2 in Mφs via JaK1/STAT3 signaling, as blockade of this pathway altered SETDB2 and the inflammatory response to coronavirus infection. Importantly, we also found that loss of SETDB2 mediates an increased inflammatory response in diabetic Mϕs in response to coronavirus infection. Treatment of coronavirus-infected diabetic Mφs with IFNß reversed the inflammatory cytokine production via up-regulation of SETDB2/H3K9me3 on inflammatory gene promoters. Together, these results describe a potential mechanism for the increased Mφ-mediated cytokine storm in patients with T2D in response to COVID-19 and suggest that therapeutic targeting of the IFNß/SETDB2 axis in T2D patients may decrease pathologic inflammation associated with COVID-19.


Assuntos
Coronavirus/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Mediadores da Inflamação/metabolismo , Inflamação/virologia , Macrófagos/metabolismo , Animais , COVID-19/imunologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Síndrome da Liberação de Citocina , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , SARS-CoV-2/metabolismo , Transdução de Sinais
2.
J Am Chem Soc ; 143(36): 14748-14765, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34490778

RESUMO

The COVID-19 pandemic highlights the need for platform technologies enabling rapid development of vaccines for emerging viral diseases. The current vaccines target the SARS-CoV-2 spike (S) protein and thus far have shown tremendous efficacy. However, the need for cold-chain distribution, a prime-boost administration schedule, and the emergence of variants of concern (VOCs) call for diligence in novel SARS-CoV-2 vaccine approaches. We studied 13 peptide epitopes from SARS-CoV-2 and identified three neutralizing epitopes that are highly conserved among the VOCs. Monovalent and trivalent COVID-19 vaccine candidates were formulated by chemical conjugation of the peptide epitopes to cowpea mosaic virus (CPMV) nanoparticles and virus-like particles (VLPs) derived from bacteriophage Qß. Efficacy of this approach was validated first using soluble vaccine candidates as solo or trivalent mixtures and subcutaneous prime-boost injection. The high thermal stability of our vaccine candidates allowed for formulation into single-dose injectable slow-release polymer implants, manufactured by melt extrusion, as well as microneedle (MN) patches, obtained through casting into micromolds, for prime-boost self-administration. Immunization of mice yielded high titers of antibodies against the target epitope and S protein, and data confirms that antibodies block receptor binding and neutralize SARS-CoV and SARS-CoV-2 against infection of human cells. We present a nanotechnology vaccine platform that is stable outside the cold-chain and can be formulated into delivery devices enabling single administration or self-administration. CPMV or Qß VLPs could be stockpiled, and epitopes exchanged to target new mutants or emergent diseases as the need arises.


Assuntos
Vacinas contra COVID-19/metabolismo , COVID-19/epidemiologia , COVID-19/prevenção & controle , Preparações de Ação Retardada/química , SARS-CoV-2/metabolismo , Vacinas de Subunidades/metabolismo , Animais , Comovirus , Simulação por Computador , Composição de Medicamentos , Epitopos/química , Temperatura Alta , Humanos , Masculino , Camundongos Endogâmicos BALB C , Nanopartículas/química , Peptídeos/química , Vacinação , Vacinas de Partículas Semelhantes a Vírus/química
3.
Front Endocrinol (Lausanne) ; 12: 726967, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34484128

RESUMO

In March 2020, the WHO declared coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a global pandemic. Obesity was soon identified as a risk factor for poor prognosis, with an increased risk of intensive care admissions and mechanical ventilation, but also of adverse cardiovascular events. Obesity is associated with adipose tissue, chronic low-grade inflammation, and immune dysregulation with hypertrophy and hyperplasia of adipocytes and overexpression of pro-inflammatory cytokines. However, to implement appropriate therapeutic strategies, exact mechanisms must be clarified. The role of white visceral adipose tissue, increased in individuals with obesity, seems important, as a viral reservoir for SARS-CoV-2 via angiotensin-converting enzyme 2 (ACE2) receptors. After infection of host cells, the activation of pro-inflammatory cytokines creates a setting conducive to the "cytokine storm" and macrophage activation syndrome associated with progression to acute respiratory distress syndrome. In obesity, systemic viral spread, entry, and prolonged viral shedding in already inflamed adipose tissue may spur immune responses and subsequent amplification of a cytokine cascade, causing worse outcomes. More precisely, visceral adipose tissue, more than subcutaneous fat, could predict intensive care admission; and lower density of epicardial adipose tissue (EAT) could be associated with worse outcome. EAT, an ectopic adipose tissue that surrounds the myocardium, could fuel COVID-19-induced cardiac injury and myocarditis, and extensive pneumopathy, by strong expression of inflammatory mediators that could diffuse paracrinally through the vascular wall. The purpose of this review is to ascertain what mechanisms may be involved in unfavorable prognosis among COVID-19 patients with obesity, especially cardiovascular events, emphasizing the harmful role of excess ectopic adipose tissue, particularly EAT.


Assuntos
COVID-19/metabolismo , Cardiomiopatias/metabolismo , Gordura Intra-Abdominal/metabolismo , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/complicações , COVID-19/imunologia , Cardiomiopatias/imunologia , Cardiomiopatias/patologia , Cardiopatias/imunologia , Cardiopatias/metabolismo , Cardiopatias/patologia , Humanos , Inflamação , Gordura Intra-Abdominal/patologia , Obesidade/complicações , Obesidade/imunologia , Obesidade/patologia , Pericárdio , Prognóstico , SARS-CoV-2/metabolismo , Serina Endopeptidases/metabolismo
4.
Int J Mol Sci ; 22(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502335

RESUMO

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the pathogen responsible for the outbreak of a severe, rapidly developing pneumonia (Coronavirus disease 2019, COVID-19). The virus enzyme, called 3CLpro or main protease (Mpro), is essential for viral replication, making it a most promising target for antiviral drug development. Recently, we adopted the drug repurposing as appropriate strategy to give fast response to global COVID-19 epidemic, by demonstrating that the zonulin octapeptide inhibitor AT1001 (Larazotide acetate) binds Mpro catalytic domain. Thus, in the present study we tried to investigate the antiviral activity of AT1001, along with five derivatives, by cell-based assays. Our results provide with the identification of AT1001 peptide molecular framework for lead optimization step to develop new generations of antiviral agents of SARS-CoV-2 with an improved biological activity, expanding the chance for success in clinical trials.


Assuntos
Antivirais/farmacologia , Simulação de Acoplamento Molecular , Oligopeptídeos/química , Peptídeos/metabolismo , SARS-CoV-2/efeitos dos fármacos , Antivirais/química , Antivirais/metabolismo , Antivirais/uso terapêutico , Sítios de Ligação , COVID-19/tratamento farmacológico , COVID-19/virologia , Domínio Catalítico , Linhagem Celular , Citomegalovirus/efeitos dos fármacos , Reposicionamento de Medicamentos , Herpesvirus Humano 3/efeitos dos fármacos , Humanos , Simulação de Dinâmica Molecular , Peptídeos/síntese química , Peptídeos/farmacologia , Peptídeos/uso terapêutico , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/metabolismo , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/metabolismo
5.
Signal Transduct Target Ther ; 6(1): 337, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489403

RESUMO

SARS-CoV-2 has been reported to show a capacity for invading the brains of humans and model animals. However, it remains unclear whether and how SARS-CoV-2 crosses the blood-brain barrier (BBB). Herein, SARS-CoV-2 RNA was occasionally detected in the vascular wall and perivascular space, as well as in brain microvascular endothelial cells (BMECs) in the infected K18-hACE2 transgenic mice. Moreover, the permeability of the infected vessel was increased. Furthermore, disintegrity of BBB was discovered in the infected hamsters by administration of Evans blue. Interestingly, the expression of claudin5, ZO-1, occludin and the ultrastructure of tight junctions (TJs) showed unchanged, whereas, the basement membrane was disrupted in the infected animals. Using an in vitro BBB model that comprises primary BMECs with astrocytes, SARS-CoV-2 was found to infect and cross through the BMECs. Consistent with in vivo experiments, the expression of MMP9 was increased and collagen IV was decreased while the markers for TJs were not altered in the SARS-CoV-2-infected BMECs. Besides, inflammatory responses including vasculitis, glial activation, and upregulated inflammatory factors occurred after SARS-CoV-2 infection. Overall, our results provide evidence supporting that SARS-CoV-2 can cross the BBB in a transcellular pathway accompanied with basement membrane disrupted without obvious alteration of TJs.


Assuntos
Membrana Basal/metabolismo , Barreira Hematoencefálica/metabolismo , COVID-19/metabolismo , SARS-CoV-2/metabolismo , Junções Íntimas/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Membrana Basal/patologia , Membrana Basal/virologia , Barreira Hematoencefálica/patologia , Barreira Hematoencefálica/virologia , COVID-19/genética , COVID-19/patologia , Chlorocebus aethiops , Modelos Animais de Doenças , Humanos , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Transgênicos , SARS-CoV-2/genética , Junções Íntimas/genética , Junções Íntimas/patologia , Junções Íntimas/virologia , Células Vero
6.
PLoS One ; 16(9): e0252849, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34499652

RESUMO

Reverse vaccinology is an evolving approach for improving vaccine effectiveness and minimizing adverse responses by limiting immunizations to critical epitopes. Towards this goal, we sought to identify immunogenic amino acid motifs and linear epitopes of the SARS-CoV-2 spike protein that elicit IgG in COVID-19 mRNA vaccine recipients. Paired pre/post vaccination samples from N = 20 healthy adults, and post-vaccine samples from an additional N = 13 individuals were used to immunoprecipitate IgG targets expressed by a bacterial display random peptide library, and preferentially recognized peptides were mapped to the spike primary sequence. The data identify several distinct amino acid motifs recognized by vaccine-induced IgG, a subset of those targeted by IgG from natural infection, which may mimic 3-dimensional conformation (mimotopes). Dominant linear epitopes were identified in the C-terminal domains of the S1 and S2 subunits (aa 558-569, 627-638, and 1148-1159) which have been previously associated with SARS-CoV-2 neutralization in vitro and demonstrate identity to bat coronavirus and SARS-CoV, but limited homology to non-pathogenic human coronavirus. The identified COVID-19 mRNA vaccine epitopes should be considered in the context of variants, immune escape and vaccine and therapy design moving forward.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Mapeamento de Epitopos , Motivos de Aminoácidos , Sequência de Aminoácidos , Infecções por Coronavirus/imunologia , Humanos , Imunoglobulina G/sangue , SARS-CoV-2/química , SARS-CoV-2/metabolismo , Alinhamento de Sequência , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo
7.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34470866

RESUMO

Emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the need for next-generation vaccines able to elicit broad and durable immunity. Here we report the evaluation of a ferritin nanoparticle vaccine displaying the receptor-binding domain of the SARS-CoV-2 spike protein (RFN) adjuvanted with Army Liposomal Formulation QS-21 (ALFQ). RFN vaccination of macaques using a two-dose regimen resulted in robust, predominantly Th1 CD4+ T cell responses and reciprocal peak mean serum neutralizing antibody titers of 14,000 to 21,000. Rapid control of viral replication was achieved in the upper and lower airways of animals after high-dose SARS-CoV-2 respiratory challenge, with undetectable replication within 4 d in seven of eight animals receiving 50 µg of RFN. Cross-neutralization activity against SARS-CoV-2 variant B.1.351 decreased only approximately twofold relative to WA1/2020. In addition, neutralizing, effector antibody and cellular responses targeted the heterotypic SARS-CoV-1, highlighting the broad immunogenicity of RFN-ALFQ for SARS-CoV-like Sarbecovirus vaccine development.


Assuntos
Vacinas contra COVID-19/administração & dosagem , COVID-19/virologia , Macaca mulatta/imunologia , Nanopartículas/química , Receptores Virais/metabolismo , SARS-CoV-2/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/imunologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Ferritinas/química , SARS-CoV-2/metabolismo , Linfócitos T/imunologia
8.
Oxid Med Cell Longev ; 2021: 7866992, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34497683

RESUMO

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is posing a great threat to the global economy and public health security. Together with the acknowledged angiotensin-converting enzyme 2, glucose-regulated protein 78, transferrin receptor, AXL, kidney injury molecule-1, and neuropilin 1 are also identified as potential receptors to mediate SARS-CoV-2 infection. Therefore, how to inhibit or delay the binding of SARS-CoV-2 with the abovementioned receptors is a key step for the prevention and treatment of COVID-19. As the third gasotransmitter, hydrogen sulfide (H2S) plays an important role in many physiological and pathophysiological processes. Recently, survivors were reported to have significantly higher H2S levels in COVID-19 patients, and mortality was significantly greater among patients with decreased H2S levels. Considering that the beneficial role of H2S against COVID-19 and COVID-19-induced comorbidities and multiorgan damage has been well-examined and reported in some excellent reviews, this review will discuss the recent findings on the potential receptors of SARS-CoV-2 and how H2S modulates the above receptors, in turn blocking SARS-CoV-2 entry into host cells.


Assuntos
Antivirais/farmacologia , Sulfeto de Hidrogênio/farmacologia , Receptores de Superfície Celular/metabolismo , SARS-CoV-2/metabolismo , Animais , Humanos , Especificidade de Órgãos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , SARS-CoV-2/efeitos dos fármacos
9.
Int J Mol Sci ; 22(17)2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34502086

RESUMO

In recent years, enzymes have risen as promising therapeutic tools for different pathologies, from metabolic deficiencies, such as fibrosis conditions, ocular pathologies or joint problems, to cancer or cardiovascular diseases. Treatments based on the catalytic activity of enzymes are able to convert a wide range of target molecules to restore the correct physiological metabolism. These treatments present several advantages compared to established therapeutic approaches thanks to their affinity and specificity properties. However, enzymes present some challenges, such as short in vivo half-life, lack of targeted action and, in particular, patient immune system reaction against the enzyme. For this reason, it is important to monitor serum immune response during treatment. This can be achieved by conventional techniques (ELISA) but also by new promising tools such as microarrays. These assays have gained popularity due to their high-throughput analysis capacity, their simplicity, and their potential to monitor the immune response of patients during enzyme therapies. In this growing field, research is still ongoing to solve current health problems such as COVID-19. Currently, promising therapeutic alternatives using the angiotensin-converting enzyme 2 (ACE2) are being studied to treat COVID-19.


Assuntos
Enzima de Conversão de Angiotensina 2/uso terapêutico , COVID-19/tratamento farmacológico , Terapia Enzimática/métodos , Proteínas Recombinantes/uso terapêutico , Enzima de Conversão de Angiotensina 2/farmacologia , Ensaios Clínicos Fase II como Assunto , Composição de Medicamentos/métodos , Estabilidade Enzimática , Terapia Enzimática/história , Terapia Enzimática/tendências , Meia-Vida , História do Século XX , História do Século XXI , Humanos , Proteínas Recombinantes/farmacologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/metabolismo , Resultado do Tratamento , Internalização do Vírus/efeitos dos fármacos
10.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502139

RESUMO

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is the causative agent of the COVID19 pandemic. The SARS-CoV-2 genome encodes for a small accessory protein termed Orf9b, which targets the mitochondrial outer membrane protein TOM70 in infected cells. TOM70 is involved in a signaling cascade that ultimately leads to the induction of type I interferons (IFN-I). This cascade depends on the recruitment of Hsp90-bound proteins to the N-terminal domain of TOM70. Binding of Orf9b to TOM70 decreases the expression of IFN-I; however, the underlying mechanism remains elusive. We show that the binding of Orf9b to TOM70 inhibits the recruitment of Hsp90 and chaperone-associated proteins. We characterized the binding site of Orf9b within the C-terminal domain of TOM70 and found that a serine in position 53 of Orf9b and a glutamate in position 477 of TOM70 are crucial for the association of both proteins. A phosphomimetic variant Orf9bS53E showed drastically reduced binding to TOM70 and did not inhibit Hsp90 recruitment, suggesting that Orf9b-TOM70 complex formation is regulated by phosphorylation. Eventually, we identified the N-terminal TPR domain of TOM70 as a second binding site for Orf9b, which indicates a so far unobserved contribution of chaperones in the mitochondrial targeting of the viral protein.


Assuntos
COVID-19/transmissão , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , SARS-CoV-2/patogenicidade , Animais , Sítios de Ligação/genética , COVID-19/imunologia , COVID-19/virologia , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/genética , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/isolamento & purificação , Humanos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/isolamento & purificação , Mutação , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Fosfoproteínas/isolamento & purificação , Fosfoproteínas/metabolismo , Fosforilação , Ligação Proteica/genética , Ligação Proteica/imunologia , Domínios Proteicos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Células Vero
11.
PLoS One ; 16(9): e0256566, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34469472

RESUMO

BACKGROUND: Adequate testing is critically important for control of the SARS-CoV-2 pandemic. Antibody testing is an option for case management and epidemiologic studies, with high specificity and variable sensitivity. However, characteristics of local populations may affect performance of these tests. For this reason, the National Institute of Health (INS) and regulatory agencies in Colombia require verification of diagnostic accuracy of tests introduced to the Colombian market. METHODS: We conducted a validation study of the Abbott SARS-CoV-2 test for qualitative detection of IgG using the Abbott Architect i2000SR. Participants and retrospective samples were included from patients with suspected SARS-CoV-2 infection, age ≥18 years, and ≥8 days elapsed since initiation of symptoms. Pre-pandemic plasma samples (taken before October 2019) were used as controls. We estimated the sensitivity, specificity and agreement (kappa) of the Abbott IgG test compared to the gold standard (RT-PCR). RESULTS: The overall sensitivity was 83.1% (95% CI: 75.4-100). Sensitivity among patients with ≥14 days since the start of symptoms was 85.7%, reaching 88% in samples collected from patients with COVID-19 symptoms onset >60 days. Specificity was 100% and the kappa index of agreement was 0.804 (95% CI: 0.642-0.965). CONCLUSIONS: Our findings show high sensitivity and specificity of the Abbott IgG test in a Colombian population, which meet the criteria set by the Colombian INS to aid in the diagnosis of COVID-19. Data from our patient groups also suggest that IgG response is detectable in a high proportion of individuals (88.1%) during the first two months following onset of symptoms.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/instrumentação , COVID-19/sangue , Imunoglobulina G/sangue , Pandemias , SARS-CoV-2/metabolismo , Adulto , Idoso , COVID-19/epidemiologia , Colômbia/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e Especificidade
12.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34493582

RESUMO

Global containment of COVID-19 still requires accessible and affordable vaccines for low- and middle-income countries (LMICs). Recently approved vaccines provide needed interventions, albeit at prices that may limit their global access. Subunit vaccines based on recombinant proteins are suited for large-volume microbial manufacturing to yield billions of doses annually, minimizing their manufacturing cost. These types of vaccines are well-established, proven interventions with multiple safe and efficacious commercial examples. Many vaccine candidates of this type for SARS-CoV-2 rely on sequences containing the receptor-binding domain (RBD), which mediates viral entry to cells via ACE2. Here we report an engineered sequence variant of RBD that exhibits high-yield manufacturability, high-affinity binding to ACE2, and enhanced immunogenicity after a single dose in mice compared to the Wuhan-Hu-1 variant used in current vaccines. Antibodies raised against the engineered protein exhibited heterotypic binding to the RBD from two recently reported SARS-CoV-2 variants of concern (501Y.V1/V2). Presentation of the engineered RBD on a designed virus-like particle (VLP) also reduced weight loss in hamsters upon viral challenge.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Engenharia de Proteínas/métodos , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Animais , Anticorpos Antivirais/imunologia , Antígenos Virais , Sítios de Ligação , COVID-19/virologia , Vacinas contra COVID-19/economia , Humanos , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Saccharomycetales/metabolismo , Vacinas de Subunidades
13.
Sci Rep ; 11(1): 17534, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475438

RESUMO

The COVID-19 pandemic threatens indigenous peoples living in suburban areas of large Brazilian cities and has thus far intensified their pre-existing socio-economic inequalities. We evaluated the epidemiological situation of SARS-CoV-2 infection among residents of the biggest urban multiethnic indigenous community of the Amazonas state, Brazil. Blood samples of 280 indigenous people living in the surrounding area of Manaus were tested for the presence of anti-SARS-CoV-2 IgA or IgG antibodies. The risk factors and sociodemographic information were assessed through an epidemiological questionnaire. We found a total positivity rate of 64.64% (95% CI 59.01-70.28) for SARS-CoV-2 infection. IgA and IgG were detected in 55.71% (95% CI 49.89-61.54) and 60.71% (95% CI 54.98-66.45) of the individuals, respectively. Over 80% of positive individuals were positive for both IgA and IgG.No significant difference in positivity rates between genders or age groups was observed. Moreover, the age group ≥ 60 years old showed the highest antibody ratios (IgA mean ratio = 3.080 ± 1.623; IgG mean ratio = 4.221 ± 1.832), while the age groups 13-19 and 20-29 showed the lowest IgA (mean ratio = 2.268 ± 0.919) and IgG ratios (mean ratio = 2.207 ± 1.246), respectively. Individuals leaving the home more frequently were at higher risk of infection (Odds ratio (OD) 2.61; 95% CI 1.00-1.49; p = 0.048). Five or more individuals per household increased fivefold the risk of virus transmission (OR 2.56; 95% CI 1.09-6.01; p = 0.019). The disproportionate dissemination of SARS-CoV-2 infection observed among the study population might be driven by typical cultural behavior and socioeconomic inequalities. Despite the pandemic threat, this population is not being targeted by public policies and appears to be chronically invisible to the Brazilian authorities.


Assuntos
Teste Sorológico para COVID-19 , COVID-19 , Povos Indígenas , Pandemias , SARS-CoV-2/metabolismo , Adolescente , Adulto , Anticorpos Antivirais/sangue , Brasil/epidemiologia , Brasil/etnologia , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/etnologia , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade
14.
Sci Rep ; 11(1): 17594, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475485

RESUMO

Supplemental vitamin D can reduce the risk and mortality of viral pneumonia. The relationship between 25 hydroxyvitamin D [25(OH)D] levels and the severity and mortality of Coronavirus disease 2019 (COVID-19) was evaluated. In this cross-sectional study, the admitted patients with COVID-19 were categorized as mild, moderate, severe, and critical based on clinical and radiologic characteristics. Calcium, phosphorus, albumin, creatinine, and serum 25(OH)D were measured and their correlation with the severity of disease and mortality were analyzed. During 2 months, 508 patients (442 patients in general wards and 66 patients in the intensive care unit (ICU)) were included. The participants were 56 ± 17 years old (52% male, 37% with comorbidity). Concerning severity, 13%, 42%, 36%, and 9% had mild, moderate, severe, and critical diseases, respectively. The mortality rate was 10.8%. Admission to ICU, severity of disease and mortality decreased significantly across quartiles of 25(OH)D. According to multivariate logistic regression analysis, disease mortality had a positive correlation with age and had a negative correlation with the serum level of 25(OH)D, calcium, and albumin. In hospitalized patients with COVID-19, low 25(OH)D was associated with severe disease and increased ICU admission and mortality rate.


Assuntos
COVID-19/sangue , COVID-19/mortalidade , SARS-CoV-2/metabolismo , Índice de Gravidade de Doença , Vitamina D/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vitamina D/sangue
15.
Sci Rep ; 11(1): 17642, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480056

RESUMO

SARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still limited for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RBD IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8-14 and 15-21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RBD in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.


Assuntos
Anticorpos Antivirais , Afinidade de Anticorpos , COVID-19 , Imunoglobulina G , SARS-CoV-2 , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Brasil/epidemiologia , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo
16.
J Mol Model ; 27(10): 276, 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34480634

RESUMO

Rimegepant is a new medicine developed for the management of chronic headache due to migraine. This manuscript is an attempt to study the various structural, physical, and chemical properties of the molecules. The molecule was optimized using B3LYP functional with 6-311G + (2d,p) basis set. Excited state properties of the compound were studied using CAM-B3LYP functional with same basis sets using IEFPCM model in methanol for the implicit solvent atmosphere. The various electronic descriptors helped to identify the reactivity behavior and stability. The compound is found to possess good nonlinear optical properties in the gas phase. The various intramolecular electronic delocalizations and non-covalent interactions were analyzed and explained. As the compound contain several heterocyclic nitrogen atoms, they have potential proton abstraction features, which was analyzed energetically. The most important result from this study is from the molecular docking analysis which indicates that rimegepant binds irreversibly with three established SARS-CoV-2 proteins with ID 6LU7, 6M03, and 6W63 with docking scores - 9.2988, - 8.3629, and - 9.5421 kcal/mol respectively. Further assessment of docked complexes with molecular dynamics simulations revealed that hydrophobic interactions, water bridges, and π-π interactions play a significant role in stabilizing the ligand within the binding region of respective proteins. MMGBSA-free energies further demonstrated that rimegepant is more stable when complexed with 6LU7 among the selected PDB models. As the pharmacology and pharmacokinetics of this molecule are already established, rimegepant can be considered as an ideal candidate with potential for use in the treatment of COVID patients after clinical studies.


Assuntos
Simulação de Dinâmica Molecular , Piperidinas/química , Prótons , Piridinas/química , SARS-CoV-2/química , Proteínas Virais/química , SARS-CoV-2/metabolismo , Proteínas Virais/metabolismo
17.
J Am Chem Soc ; 143(33): 13205-13211, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34375093

RESUMO

The receptor binding and proteolysis of Spike of SARS-CoV-2 release its S2 subunit to rearrange and catalyze viral-cell fusion. This deploys the fusion peptide for insertion into the cell membranes targeted. We show that this fusion peptide transforms from intrinsic disorder in solution into a wedge-shaped structure inserted in bilayered micelles, according to chemical shifts, 15N NMR relaxation, and NOEs. The globular fold of three helices contrasts the open, extended forms of this region observed in the electron density of compact prefusion states. In the hydrophobic, narrow end of the wedge, helices 1 and 2 contact the fatty acyl chains of phospholipids, according to NOEs and proximity to a nitroxide spin label deep in the membrane mimic. The polar end of the wedge may engage and displace lipid head groups and bind Ca2+ ions for membrane fusion. Polar helix 3 protrudes from the bilayer where it might be accessible to antibodies.


Assuntos
Micelas , Peptídeos/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , COVID-19/patologia , COVID-19/virologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Peptídeos/química , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/metabolismo
18.
Adv Biol Regul ; 81: 100822, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34454870

RESUMO

Severe COVID-19 is characterized by lung and multiorgan inflammation and coagulation in the presence of overactivation of the complement system. Complement is a double edged-sward in SARS-Cov-2 infection. On one hand, it can control the viral infection in milder cases, on the other hand in cases with severe and prolonged infection massive complement activation occurs, which can intensify lung and systemic inflammation and promote a procoagulant and prothrombotic state. Several uncontrolled studies and controlled clinical trials with different complement inhibitors have been performed and others are ongoing. Results are promising in some but negative in others. Further studies are required to elucidate the benefit to risk profile of complement inhibitors in COVID-19 patients at different stages of the disease and to clarify the best targets in the complement cascade.


Assuntos
COVID-19/sangue , COVID-19/tratamento farmacológico , Ativação do Complemento/efeitos dos fármacos , Inativadores do Complemento/uso terapêutico , Proteínas do Sistema Complemento/metabolismo , SARS-CoV-2/metabolismo , Humanos , Pulmão/metabolismo , Pulmão/patologia , Índice de Gravidade de Doença
19.
J Neuroimmunol ; 359: 577696, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34418815

RESUMO

AIM: To determine the influence of high-efficacy disease modifying therapy (DMT) on the development of IgG SARS-CoV-2 antibody response in COVID-19 convalescent people with multiple sclerosis (pwMS). METHODS: Seventy-four pwMS taking high-efficacy DMTs (specifically natalizumab, fingolimod, alemtuzumab, ocrelizumab, cladribine and ublituximab) and diagnosed with COVID-19 and 44 healthy persons (HC) were enrolled. SARS-CoV2 antibodies were tested with Elecsys® Anti-SARSCoV-2 S assay. RESULTS: pwMS taking high-efficacy DMTs had a significantly higher chance of having negative titer of SARS-CoV2 antibodies compared to healthy controls (33 negative pwMS [44.6%] compared to one negative HC [2.3%], p < 0.001). pwMS taking B-cell depleting therapy (ocrelizumab and ublituximab) had a significantly higher chance of having negative titer of SARS-CoV2 antibodies compared to pwMS on all other DMTs (29 negative pwMS on B-cell therapy [64.4%] compared to four negative pwMS on all other DMTs [13.8%], p < 0.001). Out of other DMTs, two (33.3%) pwMS taking fingolimod and two (16.7%) pwMS taking cladribine failed to develop IgG SARS-COV-2 antibodies. B-cell depleting therapy independently predicted negative titer of IgG SARS-CoV-2 antibody (Exp[B] =0.014, 95%CI 0.002-0.110, p < 0.001). CONCLUSIONS: A significant proportion of convalescent COVID-19 pwMS on high-efficacy DMTs will not develop IgG SARS-CoV-2 antibodies. B-cell depleting therapies independently predict negative and low titer of IgG SARS-CoV-2 antibody.


Assuntos
COVID-19/tratamento farmacológico , COVID-19/imunologia , Imunidade Humoral/imunologia , Fatores Imunológicos/uso terapêutico , Imunossupressores/uso terapêutico , SARS-CoV-2/imunologia , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/sangue , Estudos de Casos e Controles , Feminino , Humanos , Imunidade Humoral/efeitos dos fármacos , Fatores Imunológicos/farmacologia , Imunossupressores/farmacologia , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/metabolismo , Resultado do Tratamento
20.
Cells ; 10(8)2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34440612

RESUMO

Assessment of humoral immunity to SARS-CoV-2 and other infectious agents is typically restricted to detecting antigen-specific antibodies in the serum. Rarely does immune monitoring entail assessment of the memory B-cell compartment itself, although it is these cells that engage in secondary antibody responses capable of mediating immune protection when pre-existing antibodies fail to prevent re-infection. There are few techniques that are capable of detecting rare antigen-specific B cells while also providing information regarding their relative abundance, class/subclass usage and functional affinity. In theory, the ELISPOT/FluoroSpot (collectively ImmunoSpot) assay platform is ideally suited for antigen-specific B-cell assessments since it provides this information at single-cell resolution for individual antibody-secreting cells (ASC). Here, we tested the hypothesis that antigen-coating efficiency could be universally improved across a diverse set of viral antigens if the standard direct (non-specific, low affinity) antigen absorption to the membrane was substituted by high-affinity capture. Specifically, we report an enhancement in assay sensitivity and a reduction in required protein concentrations through the capture of recombinant proteins via their encoded hexahistidine (6XHis) affinity tag. Affinity tag antigen coating enabled detection of SARS-CoV-2 Spike receptor binding domain (RBD)-reactive ASC, and also significantly improved assay performance using additional control antigens. Collectively, establishment of a universal antigen-coating approach streamlines characterization of the memory B-cell compartment after SARS-CoV-2 infection or COVID-19 vaccinations, and facilitates high-throughput immune-monitoring efforts of large donor cohorts in general.


Assuntos
Antígenos Virais/análise , Linfócitos B/imunologia , ELISPOT/métodos , Memória Imunológica , SARS-CoV-2/imunologia , Proteínas Virais/imunologia , Animais , COVID-19 , Histidina , Humanos , Camundongos , Oligopeptídeos , SARS-CoV-2/metabolismo
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