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1.
Sci Rep ; 11(1): 18085, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508172

RESUMO

Effective vaccines are slowing the COVID-19 pandemic, but SARS-CoV-2 will likely remain an issue in the future making it important to have therapeutics to treat patients. There are few options for treating patients with COVID-19. We show probenecid potently blocks SARS-CoV-2 replication in mammalian cells and virus replication in a hamster model. Furthermore, we demonstrate that plasma concentrations up to 50-fold higher than the protein binding adjusted IC90 value are achievable for 24 h following a single oral dose. These data support the potential clinical utility of probenecid to control SARS-CoV-2 infection in humans.


Assuntos
Antivirais/farmacologia , Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Probenecid/farmacologia , SARS-CoV-2/fisiologia , Replicação Viral/efeitos dos fármacos , Animais , Chlorocebus aethiops , Células Epiteliais/virologia , Humanos , Pulmão/virologia , Células Vero
2.
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
3.
Nat Commun ; 12(1): 5259, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489452

RESUMO

Magnetoencephalography measures neuromagnetic activity with high temporal, and theoretically, high spatial resolution. We developed an experimental platform combining MEG-compatible optogenetic techniques in nonhuman primates for use as a functional brain-mapping platform. Here we show localization of optogenetically evoked signals to known sources in the superficial arcuate sulcus of cortex and in CA3 of hippocampus at a resolution of 750 µm3. We detect activation in subcortical, thalamic, and extended temporal structures, conforming to known anatomical and functional brain networks associated with the respective sites of stimulation. This demonstrates that high-resolution localization of experimentally produced deep sources is possible within an intact brain. This approach is suitable for exploring causal relationships between discrete brain regions through precise optogenetic control and simultaneous whole brain MEG recording with high-resolution magnetic source imaging (MSI).


Assuntos
Encéfalo/diagnóstico por imagem , Neuroimagem Funcional/métodos , Magnetoencefalografia/métodos , Animais , Proteínas de Bactérias/genética , Encéfalo/fisiologia , Chlorocebus aethiops , Potenciais Evocados/fisiologia , Feminino , Proteínas Luminescentes/genética , Microscopia Confocal , Modelos Neurológicos , Rede Nervosa , Optogenética/métodos , Processamento de Sinais Assistido por Computador
4.
Nat Commun ; 12(1): 5271, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489470

RESUMO

Chimeric antigen receptor (CAR) T cells have emerged as a promising class of therapeutic agents, generating remarkable responses in the clinic for a subset of human cancers. One major challenge precluding the wider implementation of CAR therapy is the paucity of tumor-specific antigens. Here, we describe the development of a CAR targeting the tumor-specific isocitrate dehydrogenase 2 (IDH2) with R140Q mutation presented on the cell surface in complex with a common human leukocyte antigen allele, HLA-B*07:02. Engineering of the hinge domain of the CAR, as well as crystal structure-guided optimization of the IDH2R140Q-HLA-B*07:02-targeting moiety, enhances the sensitivity and specificity of CARs to enable targeting of this HLA-restricted neoantigen. This approach thus holds promise for the development and optimization of immunotherapies specific to other cancer driver mutations that are difficult to target by conventional means.


Assuntos
Antígeno HLA-B7/química , Isocitrato Desidrogenase/metabolismo , Engenharia de Proteínas/métodos , Receptores de Antígenos Quiméricos/química , Animais , Antígenos de Neoplasias/metabolismo , Células COS , Linhagem Celular , Chlorocebus aethiops , Epitopos , Antígeno HLA-B7/metabolismo , Humanos , Fragmentos Fab das Imunoglobulinas/química , Isocitrato Desidrogenase/química , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/imunologia , Mutação , Biblioteca de Peptídeos , Conformação Proteica , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T/fisiologia
5.
Signal Transduct Target Ther ; 6(1): 340, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504054

RESUMO

As COVID-19 continues to spread rapidly worldwide and variants continue to emerge, the development and deployment of safe and effective vaccines are urgently needed. Here, we developed an mRNA vaccine based on the trimeric receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) protein fused to ferritin-formed nanoparticles (TF-RBD). Compared to the trimeric form of the RBD mRNA vaccine (T-RBD), TF-RBD delivered intramuscularly elicited robust and durable humoral immunity as well as a Th1-biased cellular response. After further challenge with live SARS-CoV-2, immunization with a two-shot low-dose regimen of TF-RBD provided adequate protection in hACE2-transduced mice. In addition, the mRNA template of TF-RBD was easily and quickly engineered into a variant vaccine to address SARS-CoV-2 mutations. The TF-RBD multivalent vaccine produced broad-spectrum neutralizing antibodies against Alpha (B.1.1.7) and Beta (B.1.351) variants. This mRNA vaccine based on the encoded self-assembled nanoparticle-based trimer RBD provides a reference for the design of mRNA vaccines targeting SARS-CoV-2.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , Nanopartículas , SARS-CoV-2/imunologia , Vacinas Sintéticas , Animais , COVID-19/imunologia , COVID-19/patologia , Vacinas contra COVID-19/química , Vacinas contra COVID-19/farmacologia , Chlorocebus aethiops , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Transgênicos , Nanopartículas/química , Nanopartículas/uso terapêutico , Células Th1/imunologia , Células Th1/patologia , Vacinas Sintéticas/química , Vacinas Sintéticas/imunologia , Células Vero
6.
Artigo em Inglês | MEDLINE | ID: mdl-34501610

RESUMO

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is mainly transmitted through respiratory droplets from positive subjects to susceptible hosts or by direct contact with an infected individual. Our study focuses on the in vitro minimal time of viral absorption as well as the minimal quantity of virus able to establish a persistent infection in Vero E6 cells. We observed that 1 min of in vitro virus exposure is sufficient to generate a cytopathic effect in cells after 7 days of infection, even at a multiplicity of infection (MOI) value of 0.01. Being aware that our findings have been obtained using an in vitro cellular model, we demonstrated that short-time exposures and low viral concentrations are able to cause infection, thus opening questions about the risk of SARS-CoV-2 transmissibility even following short contact times.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Chlorocebus aethiops , Efeito Citopatogênico Viral , Humanos , Células Vero
7.
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
8.
Transl Vis Sci Technol ; 10(9): 7, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34351367

RESUMO

Purpose: To assess whether ozonated-oil in liposome eyedrop gel (OED) could be used to prevent the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection in an in vitro infection model. Methods: First, we tested the efficacy of OED on in vitro cell regeneration and dry eye resolution in human corneal epithelial cells (hCE-2). Second, we assessed the in vitro anti-SARS-CoV-2 infection efficacy of OED using Vero E6 cells. Tissues were examined to assess different parameters: morphology, histology, and mRNA expression at 24 hours after treatment. Results: OED could restore 50% of the scratch in the monolayer of hCE-2 cells in vitro compared with the 25% obtained with phosphate-buffered saline solution (PBS). At 24 hours after treatment with OED, the number of microvilli and the mucin network were restored, as observed using scanning electron microscopy. In Vero E6 cells infected with a primary SARS-CoV-2 strain and treated with OED two times/day, viral replication was found to be inhibited, with a 70-fold reduction observed at 72 hours after infection compared with that under the untreated and PBS-treated conditions. Conclusions: SARS-CoV-2 transmission through the ocular surface should not be ignored. Although the prevalence of coronavirus disease 2019 conjunctivitis infection is low, the need for a barrier to prevent possible viral infection is warranted. OED treatment may prevent the risk of SARS-CoV-2 infection after 72 hours of twice-daily applications. Translational Relevance: Dry eye condition might be a risk factor for SARS-CoV-2 infection and OED treatment may have a preventive role.


Assuntos
COVID-19 , Chlorocebus aethiops , Humanos , Lipossomos , Óleos , Soluções Oftálmicas , SARS-CoV-2
9.
Vaccine ; 39(36): 5214-5223, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34334254

RESUMO

Smallpox, a disease caused by the variola virus, is one of the most dangerous diseases and had killed numerous people before it was eradicated in 1980. However, smallpox has emerged as the most threatening bio-terrorism agent; as the first- and second-generation smallpox vaccines have been controversial and have caused severe adverse reactions, new demands for safe smallpox vaccines have been raised and some attenuated smallpox vaccines have been developed. We have developed a cell culture-based highly attenuated third-generation smallpox vaccine candidate KVAC103 strain by 103 serial passages of the Lancy-Vaxina strain derived from the Lister in Vero cells. Several clones were selected, taking into consideration their shape, size, and growth rate in mammalian cells. The clones were then inoculated intracerebrally in suckling mice to test for neurovirulence by observing survival. Protective immune responses in adult mice were examined by measuring the levels of neutralization antibodies and IFN-γ expression. Among several clones, clone 7 was considered the best alternative candidate because there was no mortality in suckling mice against a lethal challenge. In addition, enhanced neutralizing antibodies and T-cell mediated IFN-γ production were observed in clone 7-immunized mice. Clone 7 was named "KVAC103" and was used for the skin toxicity test and full-genome analysis. KVAC103-inoculated rabbits showed reduced skin lesions compared to those inoculated with the Lister strain, Lancy-Vaxina. A whole genome analysis of KVAC103 revealed two major deleted regions that might contribute to the reduced virulence of KVAC103 compared to the Lister strain. Phylogenetic inference supported the close relationship with the Lister strain. Collectively, our data demonstrate that KVAC103 holds promise for use as a third-generation smallpox vaccine strain due to its enhanced safety and efficacy.


Assuntos
Vacina Antivariólica , Varíola , Vírus da Varíola , Animais , Anticorpos Antivirais , Chlorocebus aethiops , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Coelhos , Varíola/prevenção & controle , Vacinas Atenuadas , Vírus Vaccinia/genética , Células Vero
10.
J Gen Virol ; 102(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34382930

RESUMO

Since the successful use of vaccinia virus (VACV) in the immunization strategies to eliminate smallpox, research has been focused on the development of recombinant VACV strains expressing proteins from various pathogens. Attempts at decreasing the side effects associated with exposure to recombinant, wild-type viral strains have led to the development of attenuated viruses. Yet while these attenuated VACV's have improved safety profiles compared to unmodified strains, their clinical use has been hindered due to efficacy issues in stimulating a host immune response. This deficiency has largely been attributed to decreased production of the target protein for immunization. Efforts to increase protein production from attenuated VACV strains has largely centered around modulation of viral factors, while manipulation of the translation of viral mRNAs has been largely unexplored. In this study we evaluate the use of translation enhancing element hTEE-658 to increase recombinant protein production in an attenuated VACV system. Optimization of the use of this motif is also attempted by combining it with strategies that have demonstrated effectiveness in previous research. We show that extension of the 5' leader sequence containing hTEE-658 does not improve motif function, nor does the combination with other known translation enhancing elements. However, the sole use of hTEE-658 in an attenuated VACV system is shown to increase protein expression levels beyond those of a standard viral promoter when used with a wild-type virus. Taken together these results highlight the potential for hTEE-658 to improve the effectiveness of attenuated VACV vaccine candidates and give insights into the optimal sequence context for its use in vaccine design.


Assuntos
Vacina Antivariólica/biossíntese , Varíola/prevenção & controle , Vírus Vaccinia , Animais , Linhagem Celular , Chlorocebus aethiops , Humanos , Vacinas Atenuadas/biossíntese , Vacinas Sintéticas/biossíntese , Vírus Vaccinia/genética , Vírus Vaccinia/imunologia
11.
Cells ; 10(8)2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34440816

RESUMO

The mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) egress, similar to those of other coronaviruses, remain poorly understood. The virus buds in intracellular compartments and is therefore thought to be released by the biosynthetic secretory pathway. However, several studies have recently challenged this hypothesis. It has been suggested that coronaviruses, including SARS-CoV-2, use lysosomes for egress. In addition, a focused ion-beam scanning electron microscope (FIB/SEM) study suggested the existence of exit tunnels linking cellular compartments rich in viral particles to the extracellular space resembling those observed for the human immunodeficiency (HIV) in macrophages. Here, we analysed serial sections of Vero cells infected with SARS-CoV-2 by transmission electron microscopy (TEM). We found that SARS-CoV-2 was more likely to exit the cell in small secretory vesicles. Virus trafficking within the cells involves small vesicles, with each generally containing a single virus particle. These vesicles then fuse with the plasma membrane to release the virus into the extracellular space. This work sheds new light on the late stages of the SARS-CoV-2 infectious cycle of potential value for guiding the development of new antiviral strategies.


Assuntos
COVID-19/fisiopatologia , SARS-CoV-2/fisiologia , Vesículas Secretórias/ultraestrutura , Replicação Viral , Animais , Chlorocebus aethiops , Microscopia Eletrônica de Transmissão , Células Vero , Vírion/fisiologia
12.
Molecules ; 26(16)2021 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-34443390

RESUMO

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is producing a large number of infections and deaths globally, the development of supportive and auxiliary treatments is attracting increasing attention. Here, we evaluated SARS-CoV-2-inactivation activity of the polyphenol-rich tea leaf extract TY-1 containing concentrated theaflavins and other virucidal catechins. The TY-1 was mixed with SARS-CoV-2 solution, and its virucidal activity was evaluated. To evaluate the inhibition activity of TY-1 in SARS-CoV-2 infection, TY-1 was co-added with SARS-CoV-2 into cell culture media. After 1 h of incubation, the cell culture medium was replaced, and the cells were further incubated in the absence of TY-1. The viral titers were then evaluated. To evaluate the impacts of TY-1 on viral proteins and genome, TY-1-treated SARS-CoV-2 structural proteins and viral RNA were analyzed using western blotting and real-time RT-PCR, respectively. TY-1 showed time- and concentration-dependent virucidal activity. TY-1 inhibited SARS-CoV-2 infection of cells. The results of western blotting and real-time RT-PCR suggested that TY-1 induced structural change in the S2 subunit of the S protein and viral genome destruction, respectively. Our findings provided basic insights in vitro into the possible value of TY-1 as a virucidal agent, which could enhance the current SARS-CoV-2 control measures.


Assuntos
COVID-19/virologia , Polifenóis/farmacologia , SARS-CoV-2/efeitos dos fármacos , Chá/química , Animais , Antivirais/metabolismo , Antivirais/farmacologia , Biflavonoides/química , Biflavonoides/farmacologia , COVID-19/tratamento farmacológico , COVID-19/metabolismo , Camellia sinensis/metabolismo , Catequina/química , Catequina/farmacologia , Linhagem Celular , Chlorocebus aethiops , Genoma Viral/efeitos dos fármacos , Humanos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Polifenóis/isolamento & purificação , SARS-CoV-2/metabolismo , Células Vero , Carga Viral/efeitos dos fármacos
13.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445605

RESUMO

Coronavirus disease (COVID-19) is a contagious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This case report presents a patient who had difficulty eradicating the corona virus due to being treated with Rituximab, which depletes B lymphocyte cells and therefore disables the production of neutralizing antibodies. The combined use of external anti-viral agents like convalescent plasma, IVIG and Remdesivir successfully helped the patient's immune system to eradicate the virus without B-cell population recovery. In vitro studies showed that convalescent plasma is the main agent that helped in eradicating the virus.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , COVID-19/tratamento farmacológico , COVID-19/imunologia , COVID-19/terapia , SARS-CoV-2/imunologia , Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Animais , Anticorpos Neutralizantes/uso terapêutico , Antivirais/uso terapêutico , COVID-19/diagnóstico por imagem , Chlorocebus aethiops , Humanos , Imunização Passiva , Hospedeiro Imunocomprometido , Rituximab/uso terapêutico , Linfócitos T/imunologia , Células Vero
14.
Nat Genet ; 53(8): 1177-1186, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34341563

RESUMO

Hereditary persistence of fetal hemoglobin (HPFH) ameliorates ß-hemoglobinopathies by inhibiting the developmental switch from γ-globin (HBG1/HBG2) to ß-globin (HBB) gene expression. Some forms of HPFH are associated with γ-globin promoter variants that either disrupt binding motifs for transcriptional repressors or create new motifs for transcriptional activators. How these variants sustain γ-globin gene expression postnatally remains undefined. We mapped γ-globin promoter sequences functionally in erythroid cells harboring different HPFH variants. Those that disrupt a BCL11A repressor binding element induce γ-globin expression by facilitating the recruitment of nuclear transcription factor Y (NF-Y) to a nearby proximal CCAAT box and GATA1 to an upstream motif. The proximal CCAAT element becomes dispensable for HPFH variants that generate new binding motifs for activators NF-Y or KLF1, but GATA1 recruitment remains essential. Our findings define distinct mechanisms through which transcription factors and their cis-regulatory elements activate γ-globin expression in different forms of HPFH, some of which are being recreated by therapeutic genome editing.


Assuntos
Fator de Ligação a CCAAT/genética , Hemoglobina Fetal/genética , Fator de Transcrição GATA1/genética , gama-Globinas/genética , Animais , Sítios de Ligação , Células COS , Sistemas CRISPR-Cas , Linhagem Celular , Chlorocebus aethiops , Células Eritroides , Edição de Genes/métodos , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Regiões Promotoras Genéticas , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
15.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34413211

RESUMO

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the associated disease COVID-19, requires therapeutic interventions that can be rapidly identified and translated to clinical care. Traditional drug discovery methods have a >90% failure rate and can take 10 to 15 y from target identification to clinical use. In contrast, drug repurposing can significantly accelerate translation. We developed a quantitative high-throughput screen to identify efficacious agents against SARS-CoV-2. From a library of 1,425 US Food and Drug Administration (FDA)-approved compounds and clinical candidates, we identified 17 hits that inhibited SARS-CoV-2 infection and analyzed their antiviral activity across multiple cell lines, including lymph node carcinoma of the prostate (LNCaP) cells and a physiologically relevant model of alveolar epithelial type 2 cells (iAEC2s). Additionally, we found that inhibitors of the Ras/Raf/MEK/ERK signaling pathway exacerbate SARS-CoV-2 infection in vitro. Notably, we discovered that lactoferrin, a glycoprotein found in secretory fluids including mammalian milk, inhibits SARS-CoV-2 infection in the nanomolar range in all cell models with multiple modes of action, including blockage of virus attachment to cellular heparan sulfate and enhancement of interferon responses. Given its safety profile, lactoferrin is a readily translatable therapeutic option for the management of COVID-19.


Assuntos
Antivirais/farmacologia , Fatores Imunológicos/farmacologia , Lactoferrina/farmacologia , SARS-CoV-2/efeitos dos fármacos , Internalização do Vírus/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , COVID-19/tratamento farmacológico , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Células CACO-2 , Linhagem Celular Tumoral , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Descoberta de Drogas , Reposicionamento de Medicamentos/métodos , Células Epiteliais , Heparitina Sulfato/antagonistas & inibidores , Heparitina Sulfato/imunologia , Heparitina Sulfato/metabolismo , Hepatócitos , Ensaios de Triagem em Larga Escala , Humanos , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/patogenicidade , Células Vero
16.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34417349

RESUMO

To investigate the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the immune population, we coincupi bated the authentic virus with a highly neutralizing plasma from a COVID-19 convalescent patient. The plasma fully neutralized the virus for seven passages, but, after 45 d, the deletion of F140 in the spike N-terminal domain (NTD) N3 loop led to partial breakthrough. At day 73, an E484K substitution in the receptor-binding domain (RBD) occurred, followed, at day 80, by an insertion in the NTD N5 loop containing a new glycan sequon, which generated a variant completely resistant to plasma neutralization. Computational modeling predicts that the deletion and insertion in loops N3 and N5 prevent binding of neutralizing antibodies. The recent emergence in the United Kingdom, South Africa, Brazil, and Japan of natural variants with similar changes suggests that SARS-CoV-2 has the potential to escape an effective immune response and that vaccines and antibodies able to control emerging variants should be developed.


Assuntos
Substituição de Aminoácidos , Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/genética , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/química , Anticorpos Antivirais/genética , Anticorpos Antivirais/farmacologia , Sítios de Ligação , COVID-19/genética , COVID-19/virologia , Chlorocebus aethiops , Convalescença , Expressão Gênica , Humanos , Evasão da Resposta Imune , Soros Imunes/química , Modelos Moleculares , Mutação , Testes de Neutralização , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Células Vero
17.
Nat Commun ; 12(1): 5063, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417466

RESUMO

Depression is a common mental disorder. The standard medical treatment is the selective serotonin reuptake inhibitors (SSRIs). All characterized SSRIs are competitive inhibitors of the serotonin transporter (SERT). A non-competitive inhibitor may produce a more favorable therapeutic profile. Vilazodone is an antidepressant with limited information on its molecular interactions with SERT. Here we use molecular pharmacology and cryo-EM structural elucidation to characterize vilazodone binding to SERT. We find that it exhibits non-competitive inhibition of serotonin uptake and impedes dissociation of [3H]imipramine at low nanomolar concentrations. Our SERT structure with bound imipramine and vilazodone reveals a unique binding pocket for vilazodone, expanding the boundaries of the extracellular vestibule. Characterization of the binding site is substantiated with molecular dynamics simulations and systematic mutagenesis of interacting residues resulting in decreased vilazodone binding to the allosteric site. Our findings underline the versatility of SERT allosteric ligands and describe the unique binding characteristics of vilazodone.


Assuntos
Antidepressivos/farmacologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Inibidores de Captação de Serotonina/farmacologia , Cloridrato de Vilazodona/farmacologia , Regulação Alostérica/efeitos dos fármacos , Animais , Sítios de Ligação , Células COS , Chlorocebus aethiops , Humanos , Cinética , Simulação de Dinâmica Molecular , Proteínas Mutantes/metabolismo , Mutação/genética , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/ultraestrutura
18.
PLoS Pathog ; 17(8): e1009800, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34437657

RESUMO

Type I Interferons (IFN-Is) are a family of cytokines which play a major role in inhibiting viral infection. Resultantly, many viruses have evolved mechanisms in which to evade the IFN-I response. Here we tested the impact of expression of 27 different SARS-CoV-2 genes in relation to their effect on IFN production and activity using three independent experimental methods. We identified six gene products; NSP6, ORF6, ORF7b, NSP1, NSP5 and NSP15, which strongly (>10-fold) blocked MAVS-induced (but not TRIF-induced) IFNß production. Expression of the first three of these SARS-CoV-2 genes specifically blocked MAVS-induced IFNß-promoter activity, whereas all six genes induced a collapse in IFNß mRNA levels, corresponding with suppressed IFNß protein secretion. Five of these six genes furthermore suppressed MAVS-induced activation of IFNλs, however with no effect on IFNα or IFNγ production. In sharp contrast, SARS-CoV-2 infected cells remained extremely sensitive to anti-viral activity exerted by added IFN-Is. None of the SARS-CoV-2 genes were able to block IFN-I signaling, as demonstrated by robust activation of Interferon Stimulated Genes (ISGs) by added interferon. This, despite the reduced levels of STAT1 and phospho-STAT1, was likely caused by broad translation inhibition mediated by NSP1. Finally, we found that a truncated ORF7b variant that has arisen from a mutant SARS-CoV-2 strain harboring a 382-nucleotide deletion associating with mild disease (Δ382 strain identified in Singapore & Taiwan in 2020) lost its ability to suppress type I and type III IFN production. In summary, our findings support a multi-gene process in which SARS-CoV-2 blocks IFN-production, with ORF7b as a major player, presumably facilitating evasion of host detection during early infection. However, SARS-CoV-2 fails to suppress IFN-I signaling thus providing an opportunity to exploit IFN-Is as potential therapeutic antiviral drugs.


Assuntos
Interferon beta/metabolismo , SARS-CoV-2/imunologia , Proteínas Virais/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Chlorocebus aethiops , Fator de Iniciação 2 em Eucariotos/metabolismo , Células HEK293 , Humanos , Interferon beta/genética , Interferon beta/farmacologia , SARS-CoV-2/efeitos dos fármacos , Fator de Transcrição STAT1/metabolismo , Células Vero , Proteínas Virais/genética
19.
J Exp Med ; 218(10)2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34357402

RESUMO

IFN-I and IFN-III immunity in the nasal mucosa is poorly characterized during SARS-CoV-2 infection. We analyze the nasal IFN-I/III signature, namely the expression of ISGF-3-dependent IFN-stimulated genes, in mildly symptomatic COVID-19 patients and show its correlation with serum IFN-α2 levels, which peak at symptom onset and return to baseline from day 10 onward. Moreover, the nasal IFN-I/III signature correlates with the nasopharyngeal viral load and is associated with the presence of infectious viruses. By contrast, we observe low nasal IFN-I/III scores despite high nasal viral loads in a subset of critically ill COVID-19 patients, which correlates with the presence of autoantibodies (auto-Abs) against IFN-I in both blood and nasopharyngeal mucosa. In addition, functional assays in a reconstituted human airway epithelium model of SARS-CoV-2 infection confirm the role of such auto-Abs in abrogating the antiviral effects of IFN-I, but not those of IFN-III. Thus, IFN-I auto-Abs may compromise not only systemic but also local antiviral IFN-I immunity at the early stages of SARS-CoV-2 infection.


Assuntos
Autoanticorpos/imunologia , COVID-19/imunologia , Interferon Tipo I/imunologia , SARS-CoV-2/imunologia , Adulto , Idoso , Animais , Antivirais/imunologia , Antivirais/farmacologia , Autoanticorpos/sangue , COVID-19/sangue , COVID-19/virologia , Chlorocebus aethiops , Feminino , Humanos , Interferon Tipo I/farmacologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Cavidade Nasal/imunologia , Cavidade Nasal/virologia , Estudos Prospectivos , SARS-CoV-2/fisiologia , Células Vero , Carga Viral/efeitos dos fármacos , Carga Viral/imunologia , Replicação Viral/efeitos dos fármacos , Replicação Viral/imunologia
20.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361724

RESUMO

Orchids are rich treasure troves of various important phytomolecules. Among the various medicinal orchids, Ansellia africana stands out prominently in the preparing of various herbal medicines due to its high therapeutic importance. The nodal explants of A. africana were sampled from asymbiotically germinated seedlings on basal Murashige and Skoog (MS) medium and were micropropagated in MS medium supplemented with 3% sucrose and 10 µM meta topolin (mT) + 5 µM naphthalene acetic acid (NAA) +15 µM indole butyric acid (IBA) + 30 µM phloroglucinol (PG). In the present study, the essential oil was extracted by hydrodistillation and the oleoresins by the solvent extraction method from the micropropagated A. africana. The essential oil and the oleoresins were analysed by Gas Chromatography (GC) and GC/MS (Mass spectrometry). A total of 84 compounds were identified. The most predominant components among them were linoleic acid (18.42%), l-ascorbyl 2,6-dipalmitate (11.50%), linolenic acid (10.98%) and p-cresol (9.99%) in the essential oil; and eicosane (26.34%), n-butyl acetate (21.13%), heptadecane (16.48%) and 2-pentanone, 4-hydroxy-4-methyl (11.13%) were detected in the acetone extract; heptadecane (9.40%), heneicosane (9.45%), eicosane (6.40%), n-butyl acetate (14.34%) and styrene (22.20%) were identified and quantified in the ethyl acetate extract. The cytotoxic activity of essential oil and oleoresins of micropropagated A. africana was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay on Vero cells compared to the standard drug doxorubicin chloride. The present research contains primary information about the therapeutic utility of the essential oil and oleoresins of A. africana with a promising future research potential of qualitative and quantitative improvement through synchronised use of biotechnological techniques.


Assuntos
Citotoxinas/isolamento & purificação , Óleos Voláteis/isolamento & purificação , Orchidaceae/química , Extratos Vegetais/isolamento & purificação , Plântula/química , Acrilatos/isolamento & purificação , Alcanos/isolamento & purificação , Animais , Ácido Ascórbico/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cresóis/isolamento & purificação , Meios de Cultura/química , Meios de Cultura/farmacologia , Citotoxinas/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Hidroponia/métodos , Ácido Linoleico/isolamento & purificação , Extração Líquido-Líquido/métodos , Óleos Voláteis/farmacologia , Orchidaceae/metabolismo , Palmitatos/isolamento & purificação , Pentanóis/isolamento & purificação , Pentanonas/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais , Plântula/metabolismo , África do Sul , Estireno/isolamento & purificação , Células Vero , Ácido alfa-Linoleico/isolamento & purificação
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