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1.
PLoS Pathog ; 18(6): e1010553, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35653397

RESUMO

Nelson Bay orthoreovirus (NBV), a member of the family Reoviridae, genus Orthoreovirus, is a bat-borne virus that causes respiratory diseases in humans. NBV encodes two unique nonstructural proteins, fusion-associated small transmembrane (FAST) protein and p17 protein, in the S1 gene segment. FAST induces cell-cell fusion between infected cells and neighboring cells and the fusogenic activity is required for efficient viral replication. However, the function of p17 in the virus cycle is not fully understood. Here, various p17 mutant viruses including p17-deficient viruses were generated by a reverse genetics system for NBV. The results demonstrated that p17 is not essential for viral replication and does not play an important role in viral pathogenesis. On the other hand, NBV p17 regulated viral replication in a bat cell line but not in other human and animal cell lines. Nuclear localization of p17 is associated with the regulation of NBV replication in bat cells. We also found that p17 dramatically enhances the cell-cell fusion activity of NBV FAST protein for efficient replication in bat cells. Furthermore, we found that a protein homologue of NBV p17 from another bat-borne orthoreovirus, but not those of avian orthoreovirus or baboon orthoreovirus, also supported efficient viral replication in bat cells using a p17-deficient virus-based complementation approach. These results provide critical insights into the functioning of the unique replication machinery of bat-borne viruses in their natural hosts.


Assuntos
Quirópteros , Orthoreovirus , Reoviridae , Animais , Anticorpos Antivirais , Vírus de DNA , Orthoreovirus/genética , Replicação Viral
2.
Pol J Vet Sci ; 25(1): 109-118, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35575862

RESUMO

A novel avian orthoreovirus (N-ARV) variant characterized with obvious arthritis and synovial inflammation, was isolated from Shandong, China in May 2016. It caused chicken poor growth and enormous economic losses to the poultry industry of China. However, there are few effective methods for detecting the antibody levels of N-ARV. In this study, a viral structural protein σC was expressed using the prokaryotic expression vector pET32a (+). The target protein was obtained by inducing for 6 hours at an IPTG concentration of 0.6mM. The optimal dilution of the coating antigen and serum antibody were determined to be 1000 fold and 10 fold respectively. A specificity test showed that there was no positive reactivity between N-ARV and other pathogens, and when the positive serum was diluted 100 times detection results were still checkable. The repeatability of this method was determined by the inter assay and intra assay tests with variability ranging from 4.85% to 7.93%. In conclusion, this indirect enzyme linked immunosorbent assay (ELISA) will be useful for large-scale serological surveys and monitoring antibody levels in N-ARV infection.


Assuntos
Orthoreovirus Aviário , Orthoreovirus , Doenças das Aves Domésticas , Infecções por Reoviridae , Animais , Anticorpos Antivirais , Galinhas , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças das Aves Domésticas/diagnóstico , Infecções por Reoviridae/diagnóstico , Infecções por Reoviridae/veterinária , Sensibilidade e Especificidade , Proteínas Virais
3.
Viruses ; 14(5)2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35632773

RESUMO

Aquareovirus, which is a member of the Reoviridae family, was isolated from aquatic animals. A close molecular evolutionary relationship between aquareoviruses and mammalian orthoreoviruses was revealed. However, the functions of the aquareovirus genome-encoded proteins are poorly understood. We investigated the molecular characteristics of the outer capsid proteins, namely, VP5 and VP7, of grass carp reovirus (GCRV). The peptides VP5 and VP7 were determined using in-gel tryptic digestion and mass spectrometry. Recovered peptides represented 76% and 66% of the full-length VP5 and VP7 sequences, respectively. Significantly, two-lysine acetylation, as well as two-serine and two-threonine phosphorylation modifications, were first revealed in VP5. We found that the initial amino acid in VP5 was Pro43, suggesting that a lower amount of VP5 remained uncleaved in virions at the autocleavage site (Asn42-Pro43). Further biochemical evidence showed that the cleaved VP5N/VP5C conformation was the major constituent of the particles. Moreover, early cleavage fragments of VP7 and enhanced infectivity were detected after limited tryptic digestion of GCRV, indicating that stepwise VP7 cleavage is essential for VP5 conformational rearrangement. Our results provide insights into the roles of posttranslational modifications in VP5 and its association with VP7 in the viral life cycle.


Assuntos
Carpas , Orthoreovirus , Reoviridae , Animais , Anticorpos Antivirais/metabolismo , Proteínas do Capsídeo/metabolismo , Carpas/metabolismo , Mamíferos , Vírion/metabolismo
4.
Front Immunol ; 13: 914010, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35634331

RESUMO

Grass carp haemorrhagic disease caused by grass carp reovirus II is a serious disease of the aquaculture industry and vaccination is the only effective method of GCRV protection. In this study, Lactococcus lactis was used as oral vaccine delivery to express the GCRV II VP6 protein. We evaluated the protective efficacy of the live vaccine strain to induce mucosal immune protection. After oral administration, the recombinant strains remained in the hindgut for antigen presentation and increased the survival rate 46.7% and the relative percent survival 42.9%, respectively versus control vaccination. Though L. lactis alone can induce the inflammatory response by stimulating the mucosal immune system, the recombinant L. lactis expressing VP6 greatly enhanced nonspecific immune responses via expression of immune related genes of the fish. Furthermore, both systemic and mucosal immunity was elicited following oral immunization with the recombinant strain and this strain also elicited an inflammatory response and cellular immunity to enhance the protective effect. L. lactis can therefore be utilized as a mucosal immune vector to trigger high levels of immune protection in fish at both the systemic and mucosal levels. L. lactis is a promising candidate for oral vaccine delivery.


Assuntos
Carpas , Doenças dos Peixes , Lactococcus lactis , Orthoreovirus , Infecções por Reoviridae , Reoviridae , Vacinas , Animais , Anticorpos Antivirais , Imunidade nas Mucosas , Infecções por Reoviridae/prevenção & controle , Infecções por Reoviridae/veterinária , Vacinas/metabolismo
5.
PLoS Pathog ; 18(5): e1010506, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35533206

RESUMO

Viruses can hijack autophagosomes as the nonlytic release vehicles in cultured host cells. However, how autophagosome-mediated viral spread occurs in infected host tissues or organs in vivo remains poorly understood. Here, we report that an important rice reovirus, rice gall dwarf virus (RGDV) hijacks autophagosomes to traverse multiple insect membrane barriers in the midgut and salivary gland of leafhopper vector to enhance viral spread. Such virus-containing double-membraned autophagosomes are prevented from degradation, resulting in increased viral propagation. Mechanistically, viral nonstructural protein Pns11 induces autophagy and embeds itself in the autophagosome membranes. The autophagy-related protein 5 (ATG5)-ATG12 conjugation is essential for initial autophagosome membrane biogenesis. RGDV Pns11 specifically interacts with ATG5, both in vitro and in vivo. Silencing of ATG5 or Pns11 expression suppresses ATG8 lipidation, autophagosome formation, and efficient viral propagation. Thus, Pns11 could directly recruit ATG5-ATG12 conjugation to induce the formation of autophagosomes, facilitating viral spread within the insect bodies. Furthermore, Pns11 potentially blocks autophagosome degradation by directly targeting and mediating the reduced expression of N-glycosylated Lamp1 on lysosomal membranes. Taken together, these results highlight how RGDV remodels autophagosomes to benefit viral propagation in its insect vector.


Assuntos
Orthoreovirus , Oryza , Reoviridae , Animais , Autofagossomos/metabolismo , Autofagia , Insetos Vetores , Insetos/metabolismo , Oryza/metabolismo , Reoviridae/metabolismo , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral
6.
Front Immunol ; 13: 768621, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464421

RESUMO

Piscine orthoreovirus (PRV) is a virus in the genus Orthoreovirus of the Reoviridae family, first described in 2010 associated with Heart and Skeletal Muscle Inflammation (HSMI) in Atlantic salmon (Salmo salar). Three phases of PRV infection have been described, the early entry and dissemination, the acute dissemination phase, and the persistence phase. Depending on the PRV genotype and the host, infection can last for life. Mechanisms of immune response to PRV infection have been just beginning to be studied and the knowledge in this matter is here revised. PRV induces a classical antiviral immune response in experimental infection of salmonid erythrocytes, including transcriptional upregulation of ifn-α, rig-i, mx, and pkr. In addition, transcript upregulation of tcra, tcrb, cd2, il-2, cd4-1, ifn-γ, il-12, and il-18 has been observed in Atlantic salmon infected with PRV, indicating that PRV elicited a Th1 type response probably as a host defense strategy. The high expression levels of cd8a, cd8b, and granzyme-A in PRV-infected fish suggest a positive modulatory effect on the CTL-mediated immune response. This is consistent with PRV-dependent upregulation of the genes involved in antigen presentation, including MHC class I, transporters, and proteasome components. We also review the potential immune mechanisms associated with the persistence phenotype of PRV-infected fish and its consequence for the development of a secondary infection. In this scenario, the application of a vaccination strategy is an urgent and challenging task due to the emergence of this viral infection that threatens salmon farming.


Assuntos
Doenças dos Peixes , Orthoreovirus , Infecções por Reoviridae , Animais , Imunidade , Orthoreovirus/fisiologia
7.
J Virol ; 96(9): e0051522, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35416720

RESUMO

Viral antagonism of innate immune pathways is a common mechanism by which viruses evade immune surveillance. Infection of host cells with reovirus leads to the blockade of NF-κB, a key transcriptional regulator of the hosts' innate immune response. One mechanism by which reovirus infection results in inhibition of NF-κB is through a diminishment in levels of upstream activators, IKKß and NEMO. Here, we demonstrate a second, distinct mechanism by which reovirus blocks NF-κB. We report that expression of a single viral protein, σ3, is sufficient to inhibit expression of NF-κB target genes. Further, σ3-mediated blockade of NF-κB occurs without changes to IκB kinase (IKK) levels or activity. Among NF-κB targets, the expression of type I interferon is significantly diminished by σ3 expression. Expression of NF-κB target genes varies following infection with closely related reovirus strains. Our genetic analysis identifies that these differences are controlled by polymorphisms in the amino acid sequence of σ3. This work identifies a new role for reovirus σ3 as a viral antagonist of NF-κB-dependent antiviral pathways. IMPORTANCE Host cells mount a response to curb virus replication in infected cells and prevent spread of virus to neighboring, as yet uninfected, cells. The NF-κB family of proteins is important for the cell to mediate this response. In this study, we show that a single protein, σ3, produced by mammalian reovirus, impairs the function of NF-κB. We demonstrate that by blocking NF-κB, σ3 diminishes the hosts' response to infection to promote viral replication. This work identifies a second, previously unknown, mechanism by which reovirus blocks this aspect of the host cell response.


Assuntos
Orthoreovirus , Infecções por Reoviridae , Reoviridae , Animais , Antivirais , Mamíferos , NF-kappa B/metabolismo , Orthoreovirus/metabolismo , Reoviridae/fisiologia , Infecções por Reoviridae/metabolismo , Transdução de Sinais
8.
Virology ; 570: 117-122, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35398775

RESUMO

The small brown planthopper, Laodelphax striatellus (Hemiptera: Delphacidae), is an efficient vector of several economically important plant viruses. In this study, a novel reovirus-like virus was identified in L. striatellus, named Laodelphax striatellus reovirus (LSRV). The complete genome of LSRV was 28,207 nt, comprising of ten segments encoded 11 deduced proteins. All genome segments were conserved with AGUAA at the 5'-terminal and GUUGUC at 3'-terminal and segment-specific inverted terminal repeats. In addition, genomic characteristics and phylogenetic analysis suggested that LSRV was a new member of genus Fijivirus. Importantly, LSRV was widely distributed in various tissues and highest expressed in adult heads. However, LSRV was unable to horizontal replication in rice plants. Moreover, typical profiles of LSRV-derived small interfering RNAs indicated host antiviral RNA interference pathway was involved in LSRV infection. In conclusion, LSRV may be considered as a new species of the genus Fijivirus in the order Reovirales.


Assuntos
Hemípteros , Orthoreovirus , Vírus de Plantas , Reoviridae , Animais , Insetos , Orthoreovirus/genética , Filogenia , Reoviridae/genética
9.
Front Biosci (Landmark Ed) ; 27(4): 138, 2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35468697

RESUMO

BACKGROUND: Oncolytic properties had been demonstrated in Mammalian Orthoreovirus (MRV) and Avian Orthorevirus (ARV). Besides MRV and ARV, Pteropine Orthoreovirus (PRV) is also categorized under the genus Orthoreovirus. PRV7S (Sikamat virus) is an orthoreovirus isolated in Malaysia. Present study aims to investigate the oncolytic effects of PRV7S on ranges of nasopharyngeal carcinoma (NPC) cells through apoptosis in comparison to MRV3. METHODS: Non-cancerous nasopharyngeal (NCNP) and NPC cells were infected by PRV7S and MRV3. The effects of PRV7S on the proliferation inhibition and apoptotic activity of NPC cells was examined using MTT assay and flow cytometry. Additionally, western blot assay was performed to analyze the expression of RAS and apoptotic protein. Lastly, qPCR assay was performed to demonstrate that PRV7S and MRV3 replicated in infected-NPC and infected-NCNP cells. RESULTS: The proliferation of NPC cells were significantly inhibited after PRV7S infection in a time dependent manner in comparison to infected-NCPC cells. Flow cytometry analysis showed that PRV7S infection was able to induce apoptosis on NPC cells at 48 hpi. Western blot results showed that upon PRV7S infection, N/H/K RAS protein expression was reduced, whereas caspase-3 protein expression increased in NPC cells. qPCR assay showed higher viral load of PRV7S found in infected-NPC compared to infected-NCNP cells. CONCLUSIONS: PRV7S inhibits the proliferation and induces apoptosis of NPC cells similar to MRV3. Therefore, PRV7S is a potential oncolytic virus.


Assuntos
Neoplasias Nasofaríngeas , Orthoreovirus , Animais , Linhagem Celular Tumoral , Proliferação de Células , Mamíferos , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/terapia
10.
Fish Shellfish Immunol ; 123: 142-151, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35219830

RESUMO

Grass carp reovirus genotype Ⅱ (GCRV II) causes severe hemorrhagic disease in grass carp and affects the aquaculture industry in China. GCRV Ⅱ isolates have been collected from different epidemic areas in China, and these isolates can lead to different degrees of hemorrhagic symptoms in grass carp. Rare minnow (Gobiocypris rarus) is widely used as a model fish to study the mechanism of hemorrhagic disease because of its high sensitivity to GCRV. In this study, the protein levels in the spleen of rare minnow after infection with GCRV virulent isolate JZ809 and attenuated isolate XT422 were investigated using isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomics. 109 and 50 differentially expressed proteins (DEPs) in the virulent and attenuated infection groups were obtained, respectively, among which 40 DEPs were identified in both groups. Combining protein expression profiling with gene ontology (GO) annotation, the responses of rare minnow to the two genotypes GCRV Ⅱ in terms of upregulated proteins were similar, focusing on ATP synthesis, in which ATP can serve as a "danger" signal to activate an immunoreaction in eukaryotes. Meanwhile, the virulent genotype JZ809 induced more immunoproteins and increased the levels of ubiquitin-proteasome system members to adapt to virus infection. However, together with a persistent and excessive inflammatory response and declining carbon metabolism, rare minnow presented more severe hemorrhagic disease and mortality after infection with virulent JZ809 than with attenuated XT422. The results provide a valuable information that will increase our understanding of the pathogenesis of viruses with different levels of virulence and the mechanism of interaction between the virus and host. Furthermore, the 6 proteins that were only significantly upregulated in the XT422 infection group all belonged to cluster 2, and 28 of 30 proteins that were only upregulated in JZ809 infection group were clustered into cluster 1. For the downregulated proteins, all DEPs in the XT422 infection group were clustered into cluster 4, and 25 of 39 proteins that were only significantly downregulated in the JZ809 infection group belonged to cluster 3. The results indicated that the DEPs in the attenuated XT422 infection group might be sensitive and their abundance changed more quickly when fish experienced virus infection.


Assuntos
Carpas , Cyprinidae , Doenças dos Peixes , Orthoreovirus , Infecções por Reoviridae , Reoviridae , Trifosfato de Adenosina , Animais , Anticorpos Antivirais , Genótipo , Proteômica , Infecções por Reoviridae/veterinária
11.
Transbound Emerg Dis ; 69(2): 623-631, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33559313

RESUMO

Mammalian orthoreoviruses (MRVs) can infect many mammals including human, and numerous higher virulent MRVs have been reported in recent years. The first mink orthoreovirus was reported in China in 2011. In the present study, three new strains of mammalian orthoreoviruses were isolated from mink and found to be most closely related to human strain MRV2Tou05 and other human strains. Mink experiments demonstrated that the isolated mink reoviruses did not lead to severe pathogenicity. Viruses were eliminated within 2 weeks after infection, but they may cause viral enteritis disease in puppies.


Assuntos
Orthoreovirus de Mamíferos , Orthoreovirus , Animais , Cães , Vison , Orthoreovirus/genética , Orthoreovirus de Mamíferos/genética , Filogenia , Virulência
12.
J Med Virol ; 94(2): 771-775, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34708881

RESUMO

Pteropine orthoreovirus (PRV) is an emerging zoonotic respiratory virus that can be transmitted from bats to humans. In Malaysia, aside from PRV2P (Pulau virus) being isolated from Pteropus hypomelanus sampled in Tioman Island, PRV3M (Melaka virus), PRV4K (Kampar virus), and PRV7S (Sikamat virus) were all isolated from samples of patients who reported having a disease spectrum from acute respiratory distress to influenza-like illness and sometimes even with enteric symptoms such as diarrhea and abdominal pain. Screening of sera collected from human volunteers on Tioman Island in 2001-2002 demonstrated that 12.8% (14/109) were positive for PRV2P and PRV3M. Taking all these together, we aim to investigate the serological prevalence of PRV (including PRV4K and PRV7S) among Tioman Island inhabitants again with the assumption that the seroprevalence rate will remain nearly similar to the above reported if human exposure to bats is still happening in the island. Using sera collected from human volunteers on the same island in 2017, we demonstrated seroprevalence of 17.8% (28/157) against PRV2P and PRV3M, respectively. Seropositivity of 11.4% among Tioman Island inhabitants against PRV4K and PRV7S, respectively, was described in this study. In addition, the seroprevalence of 89.5% (17/19), 73.6% (14/19), 63.0% (12/19), and 73.6% (14/19) against PRV2P, PRV3M, PRV4K, and PRV7S, respectively, were observed among pteropid bats in the island. We revealed that the seroprevalence of PRV among island inhabitants remains nearly similar after nearly two decades, suggesting that potential spill-over events in bat-human interface areas in the Tioman Island. We are unclear whether such spillover was directly from bats to humans, as suspected for the PRV3M human cases, or from an intermediate host(s) yet to be identified. There is a high possibility of the viruses circulating among the bats as demonstrated by high seroprevalence against PRV in the bats.


Assuntos
Quirópteros/virologia , Orthoreovirus/genética , Orthoreovirus/fisiologia , Infecções por Reoviridae/veterinária , Zoonoses/transmissão , Adolescente , Adulto , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Quirópteros/sangue , Feminino , Voluntários Saudáveis , Humanos , Malásia , Masculino , Pessoa de Meia-Idade , Infecções por Reoviridae/virologia , Estudos Soroepidemiológicos , Adulto Jovem , Zoonoses/sangue , Zoonoses/virologia
13.
Front Immunol ; 12: 729017, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603301

RESUMO

Piscine orthoreovirus (PRV-1) infection causes heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). The virus is also associated with focal melanized changes in white skeletal muscle where PRV-1 infection of macrophages appears to be important. In this study, we studied the macrophage polarization into M1 (pro-inflammatory) and M2 (anti-inflammatory) phenotypes during experimentally induced HSMI. The immune response in heart with HSMI lesions was characterized by CD8+ and MHC-I expressing cells and not by polarized macrophages. Fluorescent in situ hybridization (FISH) assays revealed localization of PRV-1 in a few M1 macrophages in both heart and skeletal muscle. M2 type macrophages were widely scattered in the heart and were more abundant in heart compared to the skeletal muscle. However, the M2 macrophages did not co-stain for PRV-1. There was a strong cellular immune response to the infection in the heart compared to that of the skeletal muscle, seen as increased MHC-I expression, partly in cells also containing PRV-1 RNA, and a high number of cytotoxic CD8+ granzyme producing cells that targeted PRV-1. In skeletal muscle, MHC-I expressing cells and CD8+ cells were dispersed between myocytes, but these cells did not stain for PRV-1. Gene expression analysis by RT-qPCR complied with the FISH results and confirmed a drop in level of PRV-1 following the cell mediated immune response. Overall, the results indicated that M1 macrophages do not contribute to the initial development of HSMI. However, large numbers of M2 macrophages reside in the heart and may contribute to the subsequent fast recovery following clearance of PRV-1 infection.


Assuntos
Linfócitos T CD8-Positivos/virologia , Doenças dos Peixes/virologia , Coração/virologia , Macrófagos/virologia , Orthoreovirus/patogenicidade , Infecções por Retroviridae/virologia , Salmo salar/virologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Doenças dos Peixes/imunologia , Doenças dos Peixes/metabolismo , Interações Hospedeiro-Patógeno , Imunidade Celular , Macrófagos/imunologia , Macrófagos/metabolismo , Músculo Esquelético/imunologia , Músculo Esquelético/metabolismo , Músculo Esquelético/virologia , Miocárdio/imunologia , Miocárdio/metabolismo , Orthoreovirus/imunologia , Fenótipo , Infecções por Retroviridae/imunologia , Infecções por Retroviridae/metabolismo , Salmo salar/imunologia , Salmo salar/metabolismo , Fatores de Tempo , Carga Viral
14.
Vet Res ; 52(1): 131, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34649601

RESUMO

Piscine orthoreovirus-1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar). However, it has been shown that PRV-1 variants differ in their ability to induce HSMI. The objective of this work was to identify the PRV-1 variants in Norwegian aquaculture and their geographical distribution. Sequencing and subsequent analysis of the five genomic segments (S1, S4, M2, L1 and L2) putatively linked to virulence, made out the basis of the study. Thirty-seven Norwegian PRV-1 isolates were sequenced, and they grouped into eight genogroups based on combinations of the five analyzed genomic segments. Two groups were defined as high-virulent and two low-virulent, based on comparison with PRV-1 reference isolates with known virulence. The remaining four groups were of unknown virulence. The geographic distribution indicated a higher frequency of the high-virulent isolates in the mid- and northern regions. The present study confirms circulation of both high- and low-virulent isolates of PRV-1 in farmed Atlantic salmon in Norway. To reduce the impact of PRV-1 related disease, detection and differentiation between high- and low-virulent genogroups of PRV-1 could be a targeted approach for reduction of high-virulent variants.


Assuntos
Doenças dos Peixes/virologia , Genótipo , Orthoreovirus/genética , Orthoreovirus/patogenicidade , Infecções por Reoviridae/veterinária , Salmo salar , Animais , Aquicultura , Noruega , Orthoreovirus/classificação , Infecções por Reoviridae/virologia , Virulência/genética
15.
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
16.
PLoS Negl Trop Dis ; 15(9): e0009768, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34492038

RESUMO

BACKGROUND: Pteropine orthoreovirus (PRV) is an emerging bat-borne zoonotic virus that causes severe respiratory illness in humans. Although PRVs have been identified in fruit bats and humans in Australia and Asia, little is known about the prevalence of PRV infection in Africa. Therefore, this study performed an PRV surveillance in fruit bats in Zambia. METHODS: Egyptian fruit bats (Rousettus aegyptiacus, n = 47) and straw-colored fruit bats (Eidolon helvum, n = 33) captured in Zambia in 2017-2018 were screened for PRV infection using RT-PCR and serum neutralization tests. The complete genome sequence of an isolated PRV strain was determined by next generation sequencing and subjected to BLAST and phylogenetic analyses. Replication capacity and pathogenicity of the strain were investigated using Vero E6 cell cultures and BALB/c mice, respectively. RESULTS: An PRV strain, tentatively named Nachunsulwe-57, was isolated from one Egyptian fruit bat. Serological assays demonstrated that 98% of sera (69/70) collected from Egyptian fruit bats (n = 37) and straw-colored fruit bats (n = 33) had neutralizing antibodies against PRV. Genetic analyses revealed that all 10 genome segments of Nachunsulwe-57 were closely related to a bat-derived Kasama strain found in Uganda. Nachunsulwe-57 showed less efficiency in viral growth and lower pathogenicity in mice than another PRV strain, Miyazaki-Bali/2007, isolated from a patient. CONCLUSIONS: A high proportion of Egyptian fruit bats and straw-colored fruit bats were found to be seropositive to PRV in Zambia. Importantly, a new PRV strain (Nachunsulwe-57) was isolated from an Egyptian fruit bat in Zambia, which had relatively weak pathogenicity in mice. Taken together, our findings provide new epidemiological insights about PRV infection in bats and indicate the first isolation of an PRV strain that may have low pathogenicity to humans.


Assuntos
Quirópteros/virologia , Orthoreovirus/isolamento & purificação , Infecções por Reoviridae/veterinária , Animais , Chlorocebus aethiops , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/virologia , Células Vero , Zâmbia/epidemiologia
17.
Virus Genes ; 57(6): 510-520, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34432209

RESUMO

Bats serve as natural hosts of Pteropine orthoreovirus (PRV), an emerging group of bat-borne, zoonotic viruses. Bats appear to possess unique innate immune system responses that can inhibit viral replication, thus reducing clinical symptoms. We examined the innate immune response against PRV and assessed viral replication in cell lines derived from four bat species (Miniopterus fuliginosus, Pteropus dasymallus, Rhinolophus ferrumequinum, and Rousettus leschenaultii), one rodent (Mesocricetous auratus), and human (Homo sapiens). The expression levels of pattern recognition receptors (PRRs) (TLR3, RIG-I, and MDA5) and interferons (IFNB1 and IFNL1) were higher and PRV replication was lower in cell lines derived from M. fuliginosus, R. ferrumequinum, and R. leschenaultii. Reduction of IFNB1 expression by the knockdown of PRRs in the cell line derived from R. ferrumequinum was associated with increased PRV replication. The knockdown of RIG-I led to the most significant reduction in viral replication for all cell lines. These results suggest that RIG-I production is important for antiviral response against PRV in R. ferrumequinum.


Assuntos
Antivirais/farmacologia , Quirópteros , Orthoreovirus , Síndrome Respiratória e Reprodutiva Suína , Animais , Linhagem Celular , Interferons , Orthoreovirus/genética , Receptores de Reconhecimento de Padrão/genética , Receptores de Reconhecimento de Padrão/imunologia , Suínos
18.
Nat Commun ; 12(1): 4176, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234134

RESUMO

Mammalian reovirus (MRV) is the prototypical member of genus Orthoreovirus of family Reoviridae. However, lacking high-resolution structures of its RNA polymerase cofactor µ2 and infectious particle, limits understanding of molecular interactions among proteins and RNA, and their contributions to virion assembly and RNA transcription. Here, we report the 3.3 Å-resolution asymmetric reconstruction of transcribing MRV and in situ atomic models of its capsid proteins, the asymmetrically attached RNA-dependent RNA polymerase (RdRp) λ3, and RdRp-bound nucleoside triphosphatase µ2 with a unique RNA-binding domain. We reveal molecular interactions among virion proteins and genomic and messenger RNA. Polymerase complexes in three Spinoreovirinae subfamily members are organized with different pseudo-D3d symmetries to engage their highly diversified genomes. The above interactions and those between symmetry-mismatched receptor-binding σ1 trimers and RNA-capping λ2 pentamers balance competing needs of capsid assembly, external protein removal, and allosteric triggering of endogenous RNA transcription, before, during and after infection, respectively.


Assuntos
Proteínas do Capsídeo/metabolismo , Nucleosídeo-Trifosfatase/metabolismo , Orthoreovirus/ultraestrutura , RNA Viral/metabolismo , Fatores de Transcrição/metabolismo , Regulação Alostérica , Animais , Proteínas do Capsídeo/ultraestrutura , Linhagem Celular , Microscopia Crioeletrônica , Regulação Viral da Expressão Gênica , Genoma Viral , Macaca mulatta , Nucleosídeo-Trifosfatase/ultraestrutura , Orthoreovirus/genética , Orthoreovirus/metabolismo , Multimerização Proteica , RNA de Cadeia Dupla/metabolismo , RNA de Cadeia Dupla/ultraestrutura , RNA Mensageiro/metabolismo , RNA Viral/ultraestrutura , RNA Polimerase Dependente de RNA/metabolismo , Fatores de Transcrição/ultraestrutura , Ativação Transcricional , Montagem de Vírus/genética
19.
Arch Virol ; 166(9): 2563-2567, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34117534

RESUMO

Taro reovirus (TaRV) has been reported infecting taro (Colocasia esculenta) in the South Pacific, but information on the virus is limited. Here, we report the genome sequence of a reovirus infecting taro in Papua New Guinea that had 10 genomic segments ranging from 1.1 to 3.9 kilobase pairs (kbp) in length with a total genome length of 26.3 kbp. TaRV was most closely related to rice ragged stunt virus (RRSV) but did not cross-react with RRSV polyclonal antisera. TaRV was not detected in 82 germplasm accessions of taro in Hawaii, or samples collected in American Samoa, Fiji, Guam, Palau, or Vanuatu.


Assuntos
Colocasia/virologia , Orthoreovirus/classificação , Orthoreovirus/genética , Sequência de Aminoácidos , Sequência de Bases , Genoma Viral , Hawaii , Sequenciamento de Nucleotídeos em Larga Escala , Orthoreovirus/isolamento & purificação , Filogenia , Reoviridae/classificação , Reoviridae/genética
20.
Front Immunol ; 12: 664624, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995395

RESUMO

Melanized focal changes in white skeletal muscle of farmed Atlantic salmon, "black spots", is a quality problem affecting on average 20% of slaughtered fish. The spots appear initially as "red spots" characterized by hemorrhages and acute inflammation and progress into black spots characterized by chronic inflammation and abundant pigmented cells. Piscine orthoreovirus 1 (PRV-1) was previously found to be associated with macrophages and melano-macrophages in red and black spots. Here we have addressed the inflammatory microenvironment of red and black spots by studying the polarization status of the macrophages and cell mediated immune responses in spots, in both PRV-1 infected and non-infected fish. Samples that had been collected at regular intervals through the seawater production phase in a commercial farm were analyzed by multiplex fluorescent in situ hybridization (FISH) and RT-qPCR methods. Detection of abundant inducible nitric oxide synthase (iNOS2) expressing M1-polarized macrophages in red spots demonstrated a pro-inflammatory microenvironment. There was an almost perfect co-localization with the iNOS2 expression and PRV-1 infection. Black spots, on the other side, had few iNOS2 expressing cells, but a relatively high number of arginase-2 expressing anti-inflammatory M2-polarized macrophages containing melanin. The numerous M2-polarized melano-macrophages in black spots indicate an ongoing healing phase. Co-localization of PRV-1 and cells expressing CD8+ and MHC-I suggests a targeted immune response taking place in the spots. Altogether, this study indicates that PRV-1 induces a pro-inflammatory environment that is important for the pathogenesis of the spots. We do not have indication that infection of PRV-1 is the initial causative agent of this condition.


Assuntos
Microambiente Celular , Doenças dos Peixes/etiologia , Doenças dos Peixes/metabolismo , Macrófagos/imunologia , Macrófagos/virologia , Orthoreovirus/fisiologia , Infecções por Reoviridae/veterinária , Salmo salar , Animais , Biomarcadores , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Doenças dos Peixes/patologia , Imunofluorescência , Imuno-Histoquímica , Ativação de Macrófagos/genética , Ativação de Macrófagos/imunologia , Macrófagos/patologia , Complexo Principal de Histocompatibilidade/genética , Complexo Principal de Histocompatibilidade/imunologia
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