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1.
Nature ; 603(7902): 706-714, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35104837

RESUMO

The SARS-CoV-2 Omicron BA.1 variant emerged in 20211 and has multiple mutations in its spike protein2. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron's evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses. mRNA vaccination as a third vaccine dose rescues and broadens neutralization. Importantly, the antiviral drugs remdesivir and molnupiravir retain efficacy against Omicron BA.1. Replication was similar for Omicron and Delta virus isolates in human nasal epithelial cultures. However, in lung cells and gut cells, Omicron demonstrated lower replication. Omicron spike protein was less efficiently cleaved compared with Delta. The differences in replication were mapped to the entry efficiency of the virus on the basis of spike-pseudotyped virus assays. The defect in entry of Omicron pseudotyped virus to specific cell types effectively correlated with higher cellular RNA expression of TMPRSS2, and deletion of TMPRSS2 affected Delta entry to a greater extent than Omicron. Furthermore, drug inhibitors targeting specific entry pathways3 demonstrated that the Omicron spike inefficiently uses the cellular protease TMPRSS2, which promotes cell entry through plasma membrane fusion, with greater dependency on cell entry through the endocytic pathway. Consistent with suboptimal S1/S2 cleavage and inability to use TMPRSS2, syncytium formation by the Omicron spike was substantially impaired compared with the Delta spike. The less efficient spike cleavage of Omicron at S1/S2 is associated with a shift in cellular tropism away from TMPRSS2-expressing cells, with implications for altered pathogenesis.


Assuntos
COVID-19/patologia , COVID-19/virologia , Fusão de Membrana , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Serina Endopeptidases/metabolismo , Internalização do Vírus , Adulto , Idoso , Idoso de 80 Anos ou mais , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/virologia , Chlorocebus aethiops , Convalescença , Feminino , Humanos , Soros Imunes/imunologia , Intestinos/patologia , Intestinos/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Mutação , Mucosa Nasal/patologia , Mucosa Nasal/virologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Técnicas de Cultura de Tecidos , Virulência , Replicação Viral
2.
J Gen Virol ; 103(1)2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35077345

RESUMO

Norovirus is the leading cause of epidemic and endemic acute gastroenteritis worldwide and the most frequent cause of foodborne illness in the United States. There is no specific treatment for norovirus infections and therapeutic interventions are based on alleviating symptoms and limiting viral transmission. The immune response to norovirus is not completely understood and mechanistic studies have been hindered by lack of a robust cell culture system. In recent years, the human intestinal enteroid/human intestinal organoid system (HIE/HIO) has enabled successful human norovirus replication. Cells derived from HIE have also successfully been subjected to genetic manipulation using viral vectors as well as CRISPR/Cas9 technology, thereby allowing studies to identify antiviral signaling pathways important in controlling norovirus infection. RNA sequencing using HIE cells has been used to investigate the transcriptional landscape during norovirus infection and to identify antiviral genes important in infection. Other cell culture platforms such as the microfluidics-based gut-on-chip technology in combination with the HIE/HIO system also have the potential to address fundamental questions on innate immunity to human norovirus. In this review, we highlight the recent advances in understanding the innate immune response to human norovirus infections in the HIE system, including the application of advanced molecular technologies that have become available in recent years such as the CRISPR/Cas9 and RNA sequencing, as well as the potential application of single cell transcriptomics, viral proteomics, and gut-on-a-chip technology to further elucidate innate immunity to norovirus.


Assuntos
Infecções por Caliciviridae/imunologia , Gastroenterite/imunologia , Intestinos/virologia , Organoides/imunologia , Gastroenterite/virologia , Humanos , Imunidade Inata , Intestinos/imunologia , Modelos Biológicos , Norovirus/patogenicidade , Norovirus/fisiologia , Organoides/virologia , Análise de Sequência de RNA , Replicação Viral
3.
Nat Commun ; 13(1): 17, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013162

RESUMO

Defense against intracellular infection has been extensively studied in vertebrate hosts, but less is known about invertebrate hosts; specifically, the transcription factors that induce defense against intracellular intestinal infection in the model nematode Caenorhabditis elegans remain understudied. Two different types of intracellular pathogens that naturally infect the C. elegans intestine are the Orsay virus, which is an RNA virus, and microsporidia, which comprise a phylum of fungal pathogens. Despite their molecular differences, these pathogens induce a common host transcriptional response called the intracellular pathogen response (IPR). Here we show that zip-1 is an IPR regulator that functions downstream of all known IPR-activating and regulatory pathways. zip-1 encodes a putative bZIP transcription factor, and we show that zip-1 controls induction of a subset of genes upon IPR activation. ZIP-1 protein is expressed in the nuclei of intestinal cells, and is at least partially required in the intestine to upregulate IPR gene expression. Importantly, zip-1 promotes resistance to infection by the Orsay virus and by microsporidia in intestinal cells. Altogether, our results indicate that zip-1 represents a central hub for triggers of the IPR, and that this transcription factor has a protective function against intracellular pathogen infection in C. elegans.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica , Caenorhabditis elegans , Enterócitos , Interações Hospedeiro-Patógeno/fisiologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/microbiologia , Caenorhabditis elegans/virologia , Proteínas de Caenorhabditis elegans/imunologia , Proteínas de Caenorhabditis elegans/metabolismo , Enterócitos/imunologia , Enterócitos/microbiologia , Enterócitos/virologia , Imunidade Inata/fisiologia , Intestinos/microbiologia , Intestinos/virologia , Invertebrados/imunologia , Microsporídios/patogenicidade , Vírus de RNA/patogenicidade
4.
Commun Biol ; 5(1): 48, 2022 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-35027665

RESUMO

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a severe global health challenge. We isolate and characterize two previously unidentified lytic phages, P24 and P39, with large burst sizes active against ST11 KL64, a major CRKP lineage. P24 and P39 represent species of the genera Przondovirus (Studiervirinae subfamily) and Webervirus (Drexlerviridae family), respectively. P24 and P39 together restrain CRKP growth to nearly 8 h. Phage-resistant mutants exhibit reduced capsule production and decreased virulence. Modifications in mshA and wcaJ encoding capsule polysaccharide synthesis mediate P24 resistance whilst mutations in epsJ encoding exopolysaccharide synthesis cause P39 resistance. We test P24 alone and together with P39 for decolonizing CRKP using mouse intestinal colonization models. Bacterial load shed decrease significantly in mice treated with P24 and P39. In conclusion, we report the characterization of two previously unidentified lytic phages against CRKP, revealing phage resistance mechanisms and demonstrating the potential of lytic phages for intestinal decolonization.


Assuntos
Antibacterianos/farmacologia , Bacteriófagos/fisiologia , Enterobacteriáceas Resistentes a Carbapenêmicos/virologia , Carbapenêmicos/farmacologia , Intestinos/virologia , Klebsiella pneumoniae/virologia , Viroma , Animais , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Camundongos
5.
Virology ; 567: 47-56, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34998225

RESUMO

Huanglongbing is caused by Candidatus Liberibacter asiaticus (CLas) and transmitted by Diaphorina citri. D. citri harbors various insect-specific viruses, including the Diaphorina citri flavi-like virus (DcFLV). The distribution and biological role of DcFLV in its host and the relationship with CLas are unknown. DcFLV was found in various organs of D. citri, including the midgut and salivary glands, where it co-localized with CLas. CLas-infected nymphs had the highest DcFLV titers compared to the infected adults and CLas-free adults and nymphs. DcFLV was vertically transmitted to offspring from female D. citri and was temporarily detected in Citrus macrophylla and grapefruit leaves from greenhouse and field. The incidences of DcFLV and CLas were positively correlated in field-collected D. citri samples, suggesting that DcFLV might be associated with CLas in the vector. These results provide new insights on the interactions between DcFLV, the D. citri, and CLas.


Assuntos
Citrus/microbiologia , Flavivirus/genética , Hemípteros/virologia , Insetos Vetores/virologia , Liberibacter/genética , Ninfa/virologia , Animais , DNA Bacteriano/genética , Feminino , Hemípteros/microbiologia , Insetos Vetores/microbiologia , Intestinos/microbiologia , Intestinos/virologia , Liberibacter/patogenicidade , Ninfa/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , RNA Viral/genética , Glândulas Salivares/microbiologia , Glândulas Salivares/virologia , Simbiose/fisiologia
6.
J Pediatr ; 243: 214-218.e5, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34843710

RESUMO

A previously healthy 12-year-old boy had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related multisystem inflammatory syndrome (MIS-C) that was rapidly fatal. Autopsy revealed the presence of a large intracardiac thrombus. SARS-CoV-2 spike protein was detected in intestinal cells, supporting the hypothesis that viral presence in the gut may be related to the immunologic response of MIS-C.


Assuntos
COVID-19 , Intestinos , Glicoproteína da Espícula de Coronavírus , COVID-19/complicações , COVID-19/patologia , Criança , Evolução Fatal , Humanos , Intestinos/virologia , Masculino , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica
7.
Am J Surg Pathol ; 46(1): 89-96, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34081038

RESUMO

Approximately 20% of patients with symptomatic syndrome-associated coronavirus-2 (SARS-CoV-2) infection have gastrointestinal bleeding and/or diarrhea. Most are managed without endoscopic evaluation because the risk of practitioner infection outweighs the value of biopsy analysis unless symptoms are life-threatening. As a result, much of what is known about the gastrointestinal manifestations of coronavirus disease-2019 (COVID-19) has been gleaned from surgical and autopsy cases that suffer from extensive ischemic injury and/or poor preservation. There are no detailed reports describing any other gastrointestinal effects of SARS-CoV-2 even though >3,000,000 people have died from COVID-19 worldwide. The purpose of this study is to report the intestinal findings related to SARS-CoV-2 infection by way of a small case series including one with evidence of direct viral cytopathic effect and 2 with secondary injury attributed to viral infection. Infection can be confirmed by immunohistochemical stains directed against SARS-CoV-2 spike protein, in situ hybridization for spike protein-encoding RNA, and ultrastructural visualization of viruses within the epithelium. It induces cytoplasmic blebs and tufted epithelial cells without inflammation and may not cause symptoms. In contrast, SARS-CoV-2 infection can cause gastrointestinal symptoms after the virus is no longer detected, reflecting systemic activation of cytokine and complement cascades rather than direct viral injury. Reversible mucosal ischemia features microvascular injury with hemorrhage, small vessel thrombosis, and platelet-rich thrombi. Systemic cytokine elaboration and dysbiosis likely explain epithelial cell injury that accompanies diarrheal symptoms. These observations are consistent with clinical and in vitro data and contribute to our understanding of the protean manifestations of COVID-19.


Assuntos
COVID-19/patologia , Enteropatias/patologia , Enteropatias/virologia , Intestinos/patologia , Intestinos/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Biópsia , COVID-19/diagnóstico , COVID-19/imunologia , Citocinas/metabolismo , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/imunologia , Hemorragia Gastrointestinal/patologia , Hemorragia Gastrointestinal/virologia , Humanos , Enteropatias/diagnóstico , Enteropatias/imunologia , Intestinos/imunologia , Isquemia/diagnóstico , Isquemia/imunologia , Isquemia/patologia , Isquemia/virologia , Masculino , Trombose/diagnóstico , Trombose/imunologia , Trombose/patologia , Trombose/virologia
8.
Viruses ; 13(12)2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34960711

RESUMO

Porcine deltacoronavirus (PDCoV) is a novel coronavirus that causes diarrhea in nursing piglets. Studies showed that PDCoV uses porcine aminopeptidase N (pAPN) as an entry receptor, but the infection of pAPN-knockout cells or pigs with PDCoV revealed that pAPN might be not a critical functional receptor, implying there exists an unidentified receptor involved in PDCoV infection. Herein, we report that sialic acid (SA) can act as an attachment receptor for PDCoV invasion and facilitate its infection. We first demonstrated that the carbohydrates destroyed on the cell membrane using NaIO4 can alleviate the susceptibility of cells to PDCoV. Further study showed that the removal of SA, a typical cell-surface carbohydrate, could influence the PDCoV infectivity to the cells significantly, suggesting that SA was involved in the infection. The results of plaque assay and Western blotting revealed that SA promoted PDCoV infection by increasing the number of viruses binding to SA on the cell surface during the adsorption phase, which was also confirmed by atomic force microscopy at the microscopic level. In in vivo experiments, we found that the distribution levels of PDCoV and SA were closely relevant in the swine intestine, which contains huge amount of trypsin. We further confirmed that SA-binding capacity to PDCoV is related to the pre-treatment of PDCoV with trypsin. In conclusion, SA is a novel attachment receptor for PDCoV infection to enhance its attachment to cells, which is dependent on the pre-treatment of trypsin on PDCoV. This study paves the way for dissecting the mechanisms of PDCoV-host interactions and provides new strategies to control PDCoV infection.


Assuntos
Deltacoronavirus/fisiologia , Ácido N-Acetilneuramínico/metabolismo , Receptores Virais/metabolismo , Tripsina/metabolismo , Ligação Viral , Animais , Carboidratos , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/virologia , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Deltacoronavirus/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Intestinos/metabolismo , Intestinos/virologia , Ácido Periódico/farmacologia , Suínos , Doenças dos Suínos/virologia , Tripsina/farmacologia
9.
Viruses ; 13(12)2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34960667

RESUMO

The HIV reservoir size in target CD4+ T cells during primary infection remains unknown. Here, we sorted peripheral and intestinal CD4+ T cells and quantified the levels of cell-associated SIV RNA and DNA in rhesus macaques within days of SIVmac251 inoculation. As a major target cell of HIV/SIV, CD4+ T cells in both tissues contained a large amount of SIV RNA and DNA at day 8-13 post-SIV infection, in which productive SIV RNA highly correlated with the levels of cell-associated SIV DNA. Memory CD4+ T cells had much higher viral RNA and DNA than naïve subsets, yet memory CD4+ T cells co-expressing CCR5 had no significant reservoir size compared with those that were CCR5-negative in blood and intestine. Collectively, memory CD4+ T cells appear to be the major targets for primary infection, and viral reservoirs are equally distributed in systemic and lymphoid compartments in acutely SIV-infected macaques.


Assuntos
Linfócitos T CD4-Positivos/virologia , Intestinos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Linfócitos T CD4-Positivos/imunologia , Intestinos/imunologia , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/virologia , Carga Viral
10.
mBio ; 12(6): e0320821, 2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34903043

RESUMO

Rotavirus (RV)-encoded nonstructural protein 1 (NSP1), the product of gene segment 5, effectively antagonizes host interferon (IFN) signaling via multiple mechanisms. Recent studies with the newly established RV reverse genetics system indicate that NSP1 is not essential for the replication of the simian RV SA11 strain in cell culture. However, the role of NSP1 in RV infection in vivo remains poorly characterized due to the limited replication of heterologous simian RVs in the suckling mouse model. Here, we used an optimized reverse genetics system and successfully recovered recombinant murine RVs with or without NSP1 expression. While the NSP1-null virus replicated comparably with the parental murine RV in IFN-deficient and IFN-competent cell lines in vitro, it was highly attenuated in 5-day-old wild-type suckling pups in both the 129sv and C57BL/6 backgrounds. In the absence of NSP1 expression, murine RV had significantly reduced replication in the ileum, systemic spread to mesenteric lymph nodes, fecal shedding, diarrhea occurrence, and transmission to uninoculated littermates. The defective replication of the NSP1-null RV in small intestinal tissues occurred as early as 1 day postinfection. Of interest, the replication and pathogenesis defects of NSP1-null RV were only minimally rescued in Stat1 knockout pups, suggesting that NSP1 facilitates RV replication in an IFN-independent manner. Our findings highlight a pivotal function of NSP1 during homologous RV infections in vivo and identify NSP1 as an ideal viral protein for targeted attenuation for future vaccine development. IMPORTANCE Rotavirus remains one of the most important causes of severe diarrhea and dehydration in young children worldwide. Although NSP1 is dispensable for rotavirus replication in cell culture, its exact role in virus infection in vivo remains unclear. In this study, we demonstrate, for the first time in a pathologically valid homologous small animal model, that in the context of a fully replication-competent, pathogenic, and transmissible murine rotavirus, loss of NSP1 expression substantially attenuated virus replication in the gastrointestinal tract, diarrheal disease, and virus transmission. Notably, the NSP1-deficient murine rotavirus also replicated poorly in mice lacking host interferon or inflammasome signaling. Our data provide the first piece of evidence that NSP1 is essential for murine rotavirus replication in vivo, making it an attractive target for developing improved next-generation rotavirus vaccines better suited for socioeconomically disadvantaged and immunocompromised individuals.


Assuntos
Intestinos/virologia , Infecções por Rotavirus/virologia , Rotavirus/fisiologia , Rotavirus/patogenicidade , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Animais , Humanos , Interferons/genética , Interferons/metabolismo , Intestinos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Rotavirus/genética , Infecções por Rotavirus/genética , Infecções por Rotavirus/metabolismo , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo , Proteínas não Estruturais Virais/genética
11.
Viruses ; 13(12)2021 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-34960807

RESUMO

A commercial pig farm with no history of porcine circovirus 2 (PCV2) or porcine reproductive and respiratory syndrome virus (PRRSV) repeatedly reported a significant reduction in body weight gain and wasting symptoms in approximately 20-30% of the pigs in the period between three and six weeks after weaning. As standard clinical interventions failed to tackle symptomatology, viral metagenomics were used to describe and monitor the enteric virome at birth, 3 weeks, 4 weeks, 6 weeks, and 9 weeks of age. The latter four sampling points were 7 days, 3 weeks, and 6 weeks post weaning, respectively. Fourteen distinct enteric viruses were identified within the herd, which all have previously been linked to enteric diseases. Here we show that wasting is associated with alterations in the enteric virome of the pigs, characterized by: (1) the presence of enterovirus G at 3 weeks of age, followed by a higher prevalence of the virus in wasting pigs at 6 weeks after weaning; (2) rotaviruses at 3 weeks of age; and (3) porcine sapovirus one week after weaning. However, the data do not provide a causal link between specific viral infections and the postweaning clinical problems on the farm. Together, our results offer evidence that disturbances in the enteric virome at the preweaning stage and early after weaning have a determining role in the development of intestinal barrier dysfunctions and nutrient uptake in the postweaning growth phase. Moreover, we show that the enteric viral load sharply increases in the week after weaning in both healthy and wasting pigs. This study is also the first to report the dynamics and co-infection of porcine rotavirus species and porcine astrovirus genetic lineages during the first 9 weeks of the life of domestic pigs.


Assuntos
Enterovirus Suínos/isolamento & purificação , Intestinos/virologia , Rotavirus/isolamento & purificação , Sapovirus/isolamento & purificação , Doenças dos Suínos/virologia , Viroma/fisiologia , Síndrome de Emaciação/veterinária , Animais , Astroviridae/isolamento & purificação , Feminino , Masculino , Metagenômica , Suínos , Síndrome de Emaciação/virologia , Desmame
12.
Curr Opin Virol ; 51: 164-171, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34742036

RESUMO

Not all viruses associated with humans cause disease. Non-pathogenic human-infecting viruses are predicted as important for immune system induction and preparation. Phages that infect bacteria are the most abundant predators of the human microbial ecosystem, promoting and maintaining bacterial diversity. Metagenomic analyses of the human gut virome and microbiome are unravelling the intricate predator-prey dynamics of phage-bacteria co-existence, co-evolution, and their interplay with the human host. While most adults harbour a distinctly individualistic and persistent community of virulent phages, new-borns are dominated by temperate phages heavily influenced by environmental exposures. The future development of microbiome-based interventions, therapeutics, and manipulation, will require a greater understanding of the human microbiome and the virome.


Assuntos
Saúde , Intestinos/virologia , Viroma , Vírus/isolamento & purificação , Humanos , Metagenômica , Viroma/genética , Vírus/genética
13.
mSphere ; 6(6): e0062321, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34730374

RESUMO

Human noroviruses (HuNoVs) are acute viral gastroenteritis pathogens that affect all age groups, yet no approved vaccines and drugs to treat HuNoV infection are available. In this study, we screened an antiviral compound library to identify compound(s) showing anti-HuNoV activity using a human intestinal enteroid (HIE) culture system in which HuNoVs are able to replicate reproducibly. Dasabuvir (DSB), which has been developed as an anti-hepatitis C virus agent, was found to inhibit HuNoV infection in HIEs at micromolar concentrations. Dasabuvir also inhibited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human rotavirus A (RVA) infection in HIEs. To our knowledge, this is the first study to screen an antiviral compound library for HuNoV using HIEs, and we successfully identified dasabuvir as a novel anti-HuNoV inhibitor that warrants further investigation. IMPORTANCE Although there is an urgent need to develop effective antiviral therapy directed against HuNoV infection, compound screening to identify anti-HuNoV drug candidates has not been reported so far. Using a human HIE culture system, our compound screening successfully identified dasabuvir as a novel anti-HuNoV inhibitor. Dasabuvir's inhibitory effect was also demonstrated in the cases of SARS-CoV-2 and RVA infection, highlighting the usefulness of the HIE platform for screening antiviral agents against various viruses that target the intestines.


Assuntos
2-Naftilamina/farmacologia , Antivirais/farmacologia , Intestinos/virologia , Organoides/virologia , Bibliotecas de Moléculas Pequenas/farmacologia , Sulfonamidas/farmacologia , Uracila/análogos & derivados , Biópsia , COVID-19/tratamento farmacológico , Infecções por Caliciviridae/tratamento farmacológico , Linhagem Celular , Humanos , Intestinos/efeitos dos fármacos , Intestinos/patologia , Organoides/efeitos dos fármacos , Rotavirus/efeitos dos fármacos , Infecções por Rotavirus/tratamento farmacológico , SARS-CoV-2/efeitos dos fármacos , Uracila/farmacologia
14.
Physiol Rep ; 9(21): e15061, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34755492

RESUMO

Angiotensin-converting enzyme 2 (ACE2) and transmembrane proteases (TMPRSS) are multifunctional proteins required for SARS-CoV-2 infection or for amino acid (AA) transport, and are abundantly expressed in mammalian small intestine, but the identity of the intestinal cell type(s) and sites of expression are unclear. Here we determined expression of SARS-CoV-2 entry factors in different cell types and then compared it to that of representative AA, electrolyte, and mineral transporters. We tested the hypothesis that SARS-CoV-2, AA, electrolyte, and mineral transporters are expressed heterogeneously in different intestinal cell types by making mouse enteroids enriched in enterocytes (ENT), goblet (GOB), Paneth (PAN), or stem (ISC) cells. Interestingly, the expression of ACE2 was apical and modestly greater in ENT, the same pattern observed for its associated AA transporters B0 AT1 and SIT1. TMPRSS2 and TMPRSS4 were more highly expressed in crypt-residing ISC. Expression of electrolyte transporters was dramatically heterogeneous. DRA, NBCe1, and NHE3 were greatest in ENT, while those of CFTR and NKCC1 that play important roles in secretory diarrhea, were mainly expressed in ISC and PAN that also displayed immunohistochemically abundant basolateral NKCC1. Intestinal iron transporters were generally expressed higher in ENT and GOB, while calcium transporters were expressed mainly in PAN. Heterogeneous expression of its entry factors suggests that the ability of SARS-CoV-2 to infect the intestine may vary with cell type. Parallel cell-type expression patterns of ACE2 with B0 AT1 and SIT1 provides further evidence of ACE2's multifunctional properties and importance in AA absorption.


Assuntos
COVID-19/virologia , Eletrólitos/metabolismo , Células Epiteliais/metabolismo , Intestinos/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Minerais/metabolismo , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/metabolismo , COVID-19/patologia , COVID-19/transmissão , Células Epiteliais/citologia , Células Epiteliais/virologia , Imuno-Histoquímica , Intestinos/citologia , Intestinos/virologia , Masculino , Proteínas de Membrana/metabolismo , Camundongos , SARS-CoV-2/isolamento & purificação , Serina Endopeptidases/metabolismo
15.
BMC Microbiol ; 21(1): 300, 2021 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-34717555

RESUMO

BACKGROUND: Zika fever has been a global health security threat, especially in the tropical and subtropical regions where most of the cases occur. The disease is caused by Zika virus (ZIKV), which belongs to the family Flaviviridae, genus Flavivirus. The virus is transmitted by Aedes mosquitoes, mostly by Aedes aegypti, during its blood meal. In this study we present a descriptive analysis, by transmission electron microscopy (TEM), of ZIKV infection in A. aegypti elected tissues at the 3rd day of infection. ZIKV vertical transmission experiments by oral infection were conducted to explore an offspring of natural infection. RESULTS: Gut and ovary tissues harbored a higher number of viral particles. The ZIKV genome was also detected, by RT-qPCR technique, in the organism of orally infected female mosquitoes and in their eggs laid. CONCLUSIONS: The data obtained suggest that the ovary is an organ susceptible to be infected with ZIKV and that virus can be transmitted from mother to a fraction of the progeny.


Assuntos
Aedes/virologia , Mosquitos Vetores/virologia , Zika virus/fisiologia , Animais , Feminino , Intestinos/virologia , Microscopia Eletrônica de Transmissão , Ovário/virologia , Óvulo/virologia , RNA Viral/genética , Vírion/ultraestrutura , Zika virus/ultraestrutura , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
16.
Curr Opin Virol ; 51: 141-148, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34700287

RESUMO

Mucosal surfaces in contact with the environment host specific microbiota. The intestinal tract harbours the most abundant and diverse bacterial and viral populations interacting with each other as well as with the host. Viruses of the microbiota are important components of this ecosystem, as shown by viral alterations associated with various pathologies. However, practical and ethical constraints limit functional studies of the virome in humans, making animal models invaluable experimental tools to understand its impact on intestinal physiology. In this review, we present the recent advances in the study of virome in animal models. We focus on the strategies used to characterise viral changes in disease models and approaches to modulate the microbiota using viruses. In reviewing the interplay between viruses, bacteria, and the animal host, we highlight the potential and limitations of these models in elucidating the role of the virome in determining human health and disease.


Assuntos
Interações entre Hospedeiro e Microrganismos , Intestinos/virologia , Modelos Animais , Viroma , Animais , Modelos Animais de Doenças , Humanos
17.
J Gen Virol ; 102(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34714225

RESUMO

Calf diarrhoea has been a major cause of economic losses in the global dairy industry. Many factors, including multiple pathogen infections, can directly or indirectly cause calf diarrhoea. This study compared the faecal virome between 15 healthy calves and 15 calves with diarrhoea. Significantly lower diversity of viruses was found in samples from animals with diarrhoea than those in the healthy ones, and this feature may also be related to the age of the calves. Viruses belonging to the families Astroviridae and Caliciviridae that may cause diarrhoea in dairy calves have been characterized, which revealed that reads of caliciviruses and astroviruses in diarrhoea calves were much higher than those in healthy calves. Five complete genomic sequences closely related to Smacoviridae have been identified, which may participate in the regulation of the gut virus community ecology of healthy hosts together with bacteriophages. This research provides a theoretical basis for further understanding of known or potential enteric pathogens related to calf diarrhoea.


Assuntos
Doenças dos Bovinos/virologia , Bovinos/virologia , Diarreia/veterinária , Intestinos/virologia , Viroma , Animais , Caliciviridae/classificação , Caliciviridae/genética , Caliciviridae/isolamento & purificação , Vírus de DNA/classificação , Vírus de DNA/genética , Vírus de DNA/isolamento & purificação , Indústria de Laticínios , Diarreia/virologia , Fezes/virologia , Genoma Viral , Mamastrovirus/classificação , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Metagenômica , Filogenia
18.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639103

RESUMO

Various pathogens, such as Ebola virus, Marburg virus, Nipah virus, Hendra virus, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2, are threatening human health worldwide. The natural hosts of these pathogens are thought to be bats. The rousette bat, a megabat, is thought to be a natural reservoir of filoviruses, including Ebola and Marburg viruses. Additionally, the rousette bat showed a transient infection in the experimental inoculation of SARS-CoV-2. In the current study, we established and characterized intestinal organoids from Leschenault's rousette, Rousettus leschenaultii. The established organoids successfully recapitulated the characteristics of intestinal epithelial structure and morphology, and the appropriate supplements necessary for long-term stable culture were identified. The organoid showed susceptibility to Pteropine orthoreovirus (PRV) but not to SARS-CoV-2 in experimental inoculation. This is the first report of the establishment of an expandable organoid culture system of the rousette bat intestinal organoid and its sensitivity to bat-associated viruses, PRV and SARS-CoV-2. This organoid is a useful tool for the elucidation of tolerance mechanisms of the emerging rousette bat-associated viruses such as Ebola and Marburg virus.


Assuntos
COVID-19/virologia , Quirópteros/virologia , Organoides/virologia , Orthoreovirus/fisiologia , Infecções por Reoviridae/virologia , SARS-CoV-2/fisiologia , Animais , COVID-19/veterinária , Técnicas de Cultura de Células , Células Cultivadas , Quirópteros/fisiologia , Humanos , Intestinos/citologia , Intestinos/virologia , Organoides/citologia , Infecções por Reoviridae/veterinária
19.
Cell ; 184(23): 5759-5774.e20, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34678144

RESUMO

NLRP6 is important in host defense by inducing functional outcomes including inflammasome activation and interferon production. Here, we show that NLRP6 undergoes liquid-liquid phase separation (LLPS) upon interaction with double-stranded RNA (dsRNA) in vitro and in cells, and an intrinsically disordered poly-lysine sequence (K350-354) of NLRP6 is important for multivalent interactions, phase separation, and inflammasome activation. Nlrp6-deficient or Nlrp6K350-354A mutant mice show reduced inflammasome activation upon mouse hepatitis virus or rotavirus infection, and in steady state stimulated by intestinal microbiota, implicating NLRP6 LLPS in anti-microbial immunity. Recruitment of ASC via helical assembly solidifies NLRP6 condensates, and ASC further recruits and activates caspase-1. Lipoteichoic acid, a known NLRP6 ligand, also promotes NLRP6 LLPS, and DHX15, a helicase in NLRP6-induced interferon signaling, co-forms condensates with NLRP6 and dsRNA. Thus, LLPS of NLRP6 is a common response to ligand stimulation, which serves to direct NLRP6 to distinct functional outcomes depending on the cellular context.


Assuntos
Inflamassomos/metabolismo , Vírus de RNA/fisiologia , Receptores de Superfície Celular/metabolismo , Sequência de Aminoácidos , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Hepatócitos/virologia , Intestinos/virologia , Proteínas Intrinsicamente Desordenadas/química , Lipopolissacarídeos/metabolismo , Fígado/virologia , Camundongos , Polilisina/metabolismo , Ligação Proteica , RNA de Cadeia Dupla/metabolismo , Receptores de Superfície Celular/química , Transdução de Sinais , Ácidos Teicoicos/metabolismo
20.
Front Immunol ; 12: 737403, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34489981

RESUMO

The global amphibian declines are compounded by ranavirus infections such as Frog Virus 3 (FV3), and amphibian tadpoles more frequently succumb to these pathogens than adult animals. Amphibian gastrointestinal tracts represent a major route of ranavirus entry, and viral pathogenesis often leads to hemorrhaging and necrosis within this tissue. Alas, the differences between tadpole and adult amphibian immune responses to intestinal ranavirus infections remain poorly defined. As interferon (IFN) cytokine responses represent a cornerstone of vertebrate antiviral immunity, it is pertinent that the tadpoles and adults of the anuran Xenopus laevis frog mount disparate IFN responses to FV3 infections. Presently, we compared the tadpole and adult X. laevis responses to intestinal FV3 infections. Our results indicate that FV3-challenged tadpoles mount more robust intestinal type I and III IFN responses than adult frogs. These tadpole antiviral responses appear to be mediated by myeloid cells, which are recruited into tadpole intestines in response to FV3 infections. Conversely, myeloid cells bearing similar cytology already reside within the intestines of healthy (uninfected) adult frogs, possibly accounting for some of the anti-FV3 resistance of these animals. Further insight into the differences between tadpole and adult frog responses to ranaviral infections is critical to understanding the facets of susceptibility and resistance to these pathogens.


Assuntos
Proteínas de Anfíbios/metabolismo , Infecções por Vírus de DNA/virologia , Interferons/metabolismo , Intestinos/virologia , Células Mieloides/virologia , Ranavirus/patogenicidade , Xenopus laevis/virologia , Fatores Etários , Animais , Infecções por Vírus de DNA/imunologia , Infecções por Vírus de DNA/metabolismo , Suscetibilidade a Doenças , Feminino , Interações Hospedeiro-Patógeno , Intestinos/embriologia , Intestinos/imunologia , Larva/imunologia , Larva/metabolismo , Larva/virologia , Masculino , Células Mieloides/imunologia , Células Mieloides/metabolismo , Ranavirus/imunologia , Carga Viral , Xenopus laevis/embriologia , Xenopus laevis/imunologia , Xenopus laevis/metabolismo
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