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1.
J Virol Methods ; 305: 114538, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35513136

RESUMO

Tamdy virus (TAMV) is an emerging zoonotic tick-borne arbovirus in the genus Orthonairovirus. Reports of human infections with TAMV have been increasing and development of a rapid detection assay is thus urgently required. In the present study, singleplex and dual-target real-time reverse transcription PCR (qRT-PCR) assays were established for the detection of TAMV. Sensitivity and specificity were evaluated, which demonstrated high sensitivity for both the singleplex and dual-target qRT-PCR assays with no cross-reaction with common bunyaviruses and tick-borne viruses. The TaqMan-based qRT-PCR methodology established in this study can be employed for epidemiological surveillance and pathogenesis studies of TAMV.


Assuntos
Orthobunyavirus , Thogotovirus , Carrapatos , Animais , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa , Sensibilidade e Especificidade
2.
Viruses ; 14(4)2022 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-35458390

RESUMO

Antibodies to influenza D virus (IDV) have been detected in horses, but no evidence of disease in the field has been reported. To determine whether IDV is infectious, immunogenic, and pathogenic in horses, four 2-year-old horses seronegative for both influenza A (H3N8) and D viruses were intranasally inoculated with 6.25 × 107 TCID50/animal of D/bovine/California/0363/2019 (D/CA2019) virus, using a portable equine nebulizer system. Horses were observed daily for clinical signs including rectal temperature, nasal discharge, coughing, lung sounds, tachycardia, and tachypnea. No horses exhibited clinical signs of disease. Nasopharyngeal swabs collected from 1-8 days post-infection demonstrated virus shedding by qRT-PCR. The horses showed evidence of seroconversion as early as 13 days post-infection (dpi) and the geometric mean of the antibody titers (GMT) of all four horses ranged from 16.82-160 as demonstrated by the microneutralization assay. Further, deep RNA sequencing of the virus isolated in embryonated chicken eggs revealed no adaptive mutations indicating that IDV can replicate in horses, suggesting the possibility of interspecies transmission of IDV with bovine reservoir into equids in nature.


Assuntos
Doenças dos Cavalos , Vírus da Influenza A Subtipo H3N8 , Infecções por Orthomyxoviridae , Orthomyxoviridae , Thogotovirus , Animais , Anticorpos Antivirais , Bovinos , Cavalos
3.
Arch Virol ; 167(4): 1181-1184, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35301569

RESUMO

Influenza D virus (IDV) is endemic in cattle on several continents and can also infect a wide range of hosts. IDV was first detected in a bovine respiratory disease outbreak associated with bovine alphaherpesvirus 1 in Brazil. Sequence analysis of partial segments showed that the virus is phylogenetically divergent from previously described IDVs from other continents. As the first molecular description of IDV in South America, this can be a first step toward investigating IDV infections in cattle in Brazil and surrounding countries in which the beef industry is economically important.


Assuntos
Doenças dos Bovinos , Infecções por Orthomyxoviridae , Orthomyxoviridae , Thogotovirus , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Thogotovirus/genética
4.
Antiviral Res ; 200: 105291, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35296419

RESUMO

Bourbon virus (BRBV) is an emerging tick-borne orthomyxovirus that causes severe febrile illness in humans. There are no specific treatments for BRBV disease currently available. Here, we developed a highly accessible and robust, quantitative fluorescence-based BRBV minigenome (MG) system and applied it to high-throughput antiviral drug screening. We demonstrated that human dihydroorotate dehydrogenase (DHODH) inhibitors, hDHODH-IN-4 and brequinar, efficiently reduced BRBV RNA synthesis, and validated these findings using infectious BRBV in vitro. The DHODH inhibitors also exhibited high potency in inhibiting MG activities of other orthomyxoviruses with emerging zoonotic potential, including bat influenza A virus, swine influenza D virus, and Thogoto virus. Our newly developed MG system is a powerful platform for antiviral drug screening across the Orthomyxoviridae family, enabling rapid development and deployment of antivirals against future emerging orthomyxoviruses.


Assuntos
Thogotovirus , Carrapatos , Animais , Antivirais/farmacologia , Avaliação Pré-Clínica de Medicamentos , Ensaios de Triagem em Larga Escala , Thogotovirus/genética
5.
Viruses ; 14(2)2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-35215819

RESUMO

Both influenza A virus (IAV) and influenza D virus (IDV) are enzootic in pigs. IAV causes approximately 100% morbidity with low mortality, whereas IDV leads to only mild respiratory diseases in pigs. In this study, we performed a series of coinfection experiments in vitro and in vivo to understand how IAV and IDV interact and cause pathogenesis during coinfection. The results showed that IAV inhibited IDV replication when infecting swine tracheal epithelial cells (STECs) with IAV 24 or 48 h prior to IDV inoculation and that IDV suppressed IAV replication when IDV preceded IAV inoculation by 48 h. Virus interference was not identified during simultaneous IAV/IDV infections or with 6 h between the two viral infections, regardless of their order. The interference pattern at 24 and 48 h correlated with proinflammatory responses induced by the first infection, which, for IDV, was slower than for IAV by about 24 h. The viruses did not interfere with each other if both infected the cells before proinflammatory responses were induced. Coinfection in pigs further demonstrated that IAV interfered with both viral shedding and virus replication of IDV, especially in the upper respiratory tract. Clinically, coinfection of IDV and IAV did not show significant enhancement of disease pathogenesis, compared with the pigs infected with IAV alone. In summary, this study suggests that interference during coinfection of IAV and IDV is primarily due to the proinflammatory response; therefore, it is dependent on the time between infections and the order of infection. This study facilitates our understanding of virus epidemiology and pathogenesis associated with IAV and IDV coinfection.


Assuntos
Coinfecção/virologia , Vírus da Influenza A/fisiologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Thogotovirus/fisiologia , Interferência Viral , Animais , Coinfecção/imunologia , Vírus da Influenza A/genética , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/imunologia , Thogotovirus/genética , Fatores de Tempo , Replicação Viral
6.
Viruses ; 14(2)2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-35216016

RESUMO

Influenza D virus (IDV) was first described in 2011 and has been found to mainly circulate among cattle and swine populations worldwide. Nasal swab samples were collected from 100 Danish calf herds (83 dairy and 17 veal herds) from 2018-2020. Influenza D virus was detected in 12 of the herds. Samples with the lowest cycle quantification value were selected for full genome sequencing. A hemagglutinin-esterase fusion (HEF) gene sequence from a Danish IDV collected in 2015 was also included in this study. Phylogenetic analysis showed that viruses from seven of the IDV-positive herds belonged to the D/OK lineage and clustered together in the HEF tree with the IDV collected in 2015. Viruses from the four other herds belonged to the D/660 lineage, where three of the viruses clustered closely together, while the fourth virus was more phylogenetically distant in all gene segments. The high level of genetic similarity between viruses from two different herds involved in calf trading suggests that transmission occurred through the movement of calves. This study is, to our knowledge, the first to describe the characterization of IDV in calves in Denmark.


Assuntos
Doenças dos Bovinos/virologia , Infecções por Orthomyxoviridae/veterinária , Thogotovirus/genética , Animais , Bovinos , Dinamarca , Hemaglutininas Virais/genética , Filogenia , Reação em Cadeia da Polimerase , Proteínas Virais de Fusão/genética , Sequenciamento Completo do Genoma
7.
J Virol ; 96(5): e0155621, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35019718

RESUMO

Thogotoviruses are tick-borne arboviruses that comprise a unique genus within the Orthomyxoviridae family. Infections with thogotoviruses primarily cause disease in livestock with occasional reports of human infections suggesting a zoonotic potential. In the past, multiple genetically distinct thogotoviruses were isolated mostly from collected ticks. However, many aspects regarding their phylogenetic relationships, morphological characteristics, and virulence in mammals remain unclear. For the present comparative study, we used a collection of 10 different thogotovirus isolates from different geographic areas. Next-generation sequencing and subsequent phylogenetic analyses revealed a distinct separation of these viruses into two major clades, the Thogoto-like and Dhori-like viruses. Electron microscopy demonstrated a heterogeneous morphology with spherical and filamentous particles being present in virus preparations. To study their pathogenicity, we analyzed the viruses in a small animal model system. In intraperitoneally infected C57BL/6 mice, all isolates showed a tropism for liver, lung, and spleen. Importantly, we did not observe horizontal transmission to uninfected, highly susceptible contact mice. The isolates enormously differed in their capacity to induce disease, ranging from subclinical to fatal outcomes. In vivo multistep passaging experiments of two low-pathogenic isolates showed no increased virulence and sequence analyses of the passaged viruses indicated a high stability of the viral genomes after 10 mouse passages. In summary, our analysis demonstrates the broad genetic and phenotypic variability within the thogotovirus genus. Moreover, thogotoviruses are well adapted to mammals but their horizontal transmission seems to depend on ticks as their vectors. IMPORTANCE Since their discovery over 60 years ago, 15 genetically distinct members of the thogotovirus genus have been isolated. These arboviruses belong to the Orthomyxovirus family and share many features with influenza viruses. However, numerous of these isolates have not been characterized in depth. In the present study, we comparatively analyzed a collection of 10 different thogotovirus isolates to answer basic questions about their phylogenetic relationships, morphology, and pathogenicity in mice. Our results highlight shared and unique characteristics of this diverse genus. Taken together, these observations provide a framework for the phylogenic classification and phenotypic characterization of newly identified thogotovirus isolates that could potentially cause severe human infections as exemplified by the recently reported, fatal Bourbon virus cases in the United States.


Assuntos
Thogotovirus , Carrapatos , Animais , Genoma Viral , Mamíferos/genética , Camundongos , Camundongos Endogâmicos C57BL , Filogenia
8.
Virology ; 568: 1-11, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35063656

RESUMO

Influenza D virus (IDV) is an emerged virus that was first isolated in 2011 in the United States. Evidence suggests that IDV has broad host tropism and zoonotic potential. However, the immune evasion mechanism of IDV has not been explored. In the present study, we identified that the Matrix protein 1 (M1) of IDV is a negative regulator of virus- or RIG-IN-triggered type I interferon induction. Co-immunoprecipitation experiments revealed that M1 specifically interacts with tumor necrosis factor receptor associated factor 6 (TRAF6) and potentiates its proteasomal degradation by promoting K48-linked polyubiquitination. Moreover, we discovered that E3 ubiquitin ligase KEAP1 is recruited by M1 to catalyze K48-linked polyubiquitination of TRAF6, and promotes TRAF6 destabilization. Consequently, the degradation cascade mediated by M1 blocks RIG-I-TRAF6 mediated interferon signaling. Taken together, our findings reveal a negative regulatory role for the IDV M1 in the type І interferon pathway.


Assuntos
Interações Hospedeiro-Patógeno , Influenza Humana/metabolismo , Influenza Humana/virologia , Interferon Tipo I/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Thogotovirus/fisiologia , Proteínas da Matriz Viral/metabolismo , Linhagem Celular , Genes Reporter , Humanos , Imunidade Inata , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Transdução de Sinais
9.
Emerg Infect Dis ; 28(2): 436-439, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35075999

RESUMO

Oz virus is a novel thogotovirus isolated from ticks that causes lethal infection in mice. We conducted serosurveillance of Oz virus infection among humans and wild mammals in Japan using virus-neutralization tests and ELISAs. Results showed that Oz virus may be naturally infecting humans and other mammalian hosts.


Assuntos
Thogotovirus , Carrapatos , Animais , Japão/epidemiologia , Mamíferos , Camundongos , Zoonoses
10.
J Med Virol ; 94(6): 2855-2859, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34811769

RESUMO

Influenza D virus (IDV) was first isolated from a swine with respiratory disease symptoms in 2011 in the United States. Epidemiological and serological studies support the hypothesis that cattle represent the natural reservoir of IDV with periodical spillover events to other animal hosts. Little is known about the seroprevalence in humans and in specific target groups such as veterinarians in Italy. This study was designed to assess the prevalence of antibodies against two influenza D lineages (D/660 and D/OK) in Italy in archived serum samples from veterinarians working with swine collected in 2004. Serum samples were tested by haemagglutination inhibition (HI) and virus neutralization (VN) assays. Results showed that 4.88% (4/82) of tested samples were positive for D/660 and 2.44% (2/82) for D/OK by HI assay. Three out of four samples showed positivity when tested by VN assay. Our data suggest undetected IDVs might have circulated and/or been introduced in Italy as early as 2004 at least in some animal species such as swine. In addition, it seems that the virus was circulating among veterinarians before the first isolation in 2011. This finding highlights the importance to continue monitoring the IDV spread in animals and humans for more detailed surveillance.


Assuntos
Infecções por Orthomyxoviridae , Orthomyxoviridae , Doenças dos Suínos , Thogotovirus , Médicos Veterinários , Animais , Anticorpos Antivirais , Bovinos , Humanos , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/epidemiologia , Thogotovirus/fisiologia
11.
Vet Microbiol ; 264: 109298, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34906835

RESUMO

The influenza D virus (IDV) uses a trimeric hemagglutinin-esterase fusion protein (HEF) for attachment to 9-O-acetylated sialic acid receptors on the cell surface of host species. So far research has revealed that farm animals such as cattle, domestic pigs, goats, sheep and horses contain the necessary receptors on the epithelial surface of the respiratory tract to accommodate binding of the IDV HEF protein of both worldwide clades D/Oklahoma (D/OK) and D/Oklahoma/660 (D/660). More recently, seroprevalence studies have identified IDV-seropositive wildlife such as wild boar, deer, dromedaries, and small ruminants. However, no research has thus far been conducted in wildlife to reveal the distribution of acetylated sialic acid receptors that accommodate binding of IDV. Using our previously developed tissue microarray (TMA) system, we developed TMAs containing respiratory tissues of various wild and domestic species including wild boar, deer, dromedary, springbok, water buffalo, tiger, hedgehog, and Asian elephant. Protein histochemical staining of these TMAs with HEF proteins showed no receptor binding for wild Suidae, Cervidae and tiger. However, receptors were present in dromedary, springbok, water buffalo, Asian elephant, and hedgehog. In contrast to previously tested farm animals, a difference in host tropism was observed between the D/OK and D/660 clade HEF proteins in Asian elephant, and water buffalo. These results show that IDV can attach to the respiratory tract of wildlife which might facilitate transmission of IDV between wildlife and domestic animals.


Assuntos
Infecções por Orthomyxoviridae , Receptores de Superfície Celular , Thogotovirus , Animais , Animais Domésticos/virologia , Animais Selvagens/virologia , Bovinos , Cervos , Cavalos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Receptores de Superfície Celular/imunologia , Estudos Soroepidemiológicos , Ovinos , Thogotovirus/classificação , Thogotovirus/genética , Thogotovirus/metabolismo
12.
Viruses ; 13(12)2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34960680

RESUMO

We conducted a systematic review and meta-analysis to investigate the prevalence and current knowledge of influenza A virus (IAV) and influenza D virus (IDV) in non-human mammalian hosts in Africa. PubMed, Google Scholar, Wiley Online Library and World Organisation for Animal Health (OIE-WAHIS) were searched for studies on IAV and IDV from 2000 to 2020. Pooled prevalence and seroprevalences were estimated using the quality effects meta-analysis model. The estimated pooled prevalence and seroprevalence of IAV in pigs in Africa was 1.6% (95% CI: 0-5%) and 14.9% (95% CI: 5-28%), respectively. The seroprevalence of IDV was 87.2% (95% CI: 24-100%) in camels, 9.3% (95% CI: 0-24%) in cattle, 2.2% (95% CI: 0-4%) in small ruminants and 0.0% (95% CI: 0-2%) in pigs. In pigs, H1N1 and H1N1pdm09 IAVs were commonly detected. Notably, the highly pathogenic H5N1 virus was also detected in pigs. Other subtypes detected serologically and/or virologically included H3N8 and H7N7 in equids, H1N1, and H3N8 and H5N1 in dogs and cats. Furthermore, various wildlife animals were exposed to different IAV subtypes. For prudent mitigation of influenza epizootics and possible human infections, influenza surveillance efforts in Africa should not neglect non-human mammalian hosts. The impact of IAV and IDV in non-human mammalian hosts in Africa deserves further investigation.


Assuntos
Vírus da Influenza A , Mamíferos/virologia , Infecções por Orthomyxoviridae/veterinária , Thogotovirus , África/epidemiologia , Animais , Animais Selvagens/virologia , Anticorpos Antivirais/sangue , Vírus da Influenza A/imunologia , Mamíferos/imunologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia , Prevalência , Estudos Soroepidemiológicos , Thogotovirus/imunologia
13.
Microbiol Spectr ; 9(3): e0169021, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34937196

RESUMO

Bovine respiratory disease (BRD) is a major disease of young cattle whose etiology lies in complex interactions between pathogens and environmental and host factors. Despite a high frequency of codetection of respiratory pathogens in BRD, data on the molecular mechanisms and pathogenesis associated with viral and bacterial interactions are still limited. In this study, we investigated the effects of a coinfection with influenza D virus (IDV) and Mycoplasma bovis in cattle. Naive calves were infected by aerosol with a French IDV strain and an M. bovis strain. The combined infection shortened the incubation period, worsened the disease, and led to more severe macroscopic and microscopic lesions compared to these parameters in calves infected with only one pathogen. In addition, IDV promoted colonization of the lower respiratory tract (LRT) by M. bovis and increased white cell recruitment to the airway lumen. The transcriptomic analysis highlighted an upregulation of immune genes in the lungs of coinfected calves. The gamma interferon (IFN-γ) gene was shown to be the gene most statistically overexpressed after coinfection at 2 days postinfection (dpi) and at least until 7 dpi, which correlated with the high level of lymphocytes in the LRT. Downregulation of the PACE4 and TMPRSS2 endoprotease genes was also highlighted, being a possible reason for the faster clearance of IDV in the lungs of coinfected animals. Taken together, our coinfection model with two respiratory pathogens that when present alone induce moderate clinical signs of disease was shown to increase the severity of the disease in young cattle and a strong transcriptomic innate immune response in the LRT, especially for IFN-γ. IMPORTANCE Bovine respiratory disease (BRD) is among the most prevalent diseases in young cattle. BRD is due to complex interactions between viruses and/or bacteria, most of which have a moderate individual pathogenicity. In this study, we showed that coinfection with influenza D virus (IDV) and Mycoplasma bovis increased the severity of the respiratory disease in calves in comparison with IDV or M. bovis infection. IDV promoted M. bovis colonization of the lower respiratory tract and increased white cell recruitment to the airway lumen. The transcriptomic analysis highlighted an upregulation of immune genes in the lungs of coinfected calves. The IFN-γ gene in particular was highly overexpressed after coinfection, correlated with the disease severity, immune response, and white cell recruitment in the lungs. In conclusion, we showed that IDV facilitates coinfections within the BRD complex by modulating the local innate immune response, providing new insights into the mechanisms involved in severe respiratory diseases.


Assuntos
Complexo Respiratório Bovino/patologia , Coinfecção/patologia , Imunidade Inata/imunologia , Infecções por Mycoplasma/veterinária , Infecções por Orthomyxoviridae/veterinária , Animais , Complexo Respiratório Bovino/microbiologia , Bovinos , Coinfecção/imunologia , Coinfecção/microbiologia , Interferon gama/imunologia , Infecções por Mycoplasma/patologia , Mycoplasma bovis/imunologia , Infecções por Orthomyxoviridae/patologia , Índice de Gravidade de Doença , Thogotovirus/imunologia
14.
Viruses ; 13(11)2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34834971

RESUMO

Influenza D virus (IDV) may cause the bovine respiratory disease complex, which is the most common and costly disease affecting the cattle industry. Previously, we revealed that eight segments could be actively packaged in its single virion, suggesting that IDV with the seven-segmented genome shows an agnostic genome packaging mechanism. Herein, we engineered an eight-segmented recombinant IDV in which the NS1 or NS2 genes were separated from NS segment into independent segments (NS1 or NS2 segments, respectively), leading to monocistronic translation of each NS protein. We constructed two plasmids: one for the viral RNA (vRNA)-synthesis of the NS1 segment with a silent mutation at the splicing acceptor site, which controls NS2 transcription in the NS segment; and another for the RNA synthesis of the NS2 segment, with deletion of the intron in the NS segment. These plasmids and six other vRNA-synthesis plasmids were used to fabricate an infectious eight-segmented IDV via reverse genetics. This system enables analysis of the functions of NS1 or NS2. We tested the requirement of the N-terminal overlapping region (NOR) in these proteins for viral infectivity. We rescued a virus with NOR-deleted NS2 protein, which displayed a growth rate equivalent to that of the eight-segmented virus with intact NS2. Thus, the NOR may not influence viral growth. In contrast, a virus with NOR-deleted NS1 protein could not be rescued. These results indicate that the eight-segmented rescue system of IDV may provide an alternative method to analyze viral proteins at the molecular level.


Assuntos
Doenças dos Bovinos/virologia , Genoma Viral , Thogotovirus/genética , Animais , Bovinos , Genes Virais , Células HEK293 , Humanos , Camundongos , Sítios de Splice de RNA , RNA Viral , Proteínas não Estruturais Virais/genética , Vírion/metabolismo , Replicação Viral
15.
Virol J ; 18(1): 230, 2021 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-34809668

RESUMO

BACKGROUND: In 2011, a new influenza virus, named Influenza D Virus (IDV), was isolated from pigs, and then cattle, presenting influenza-like symptoms. IDV is one of the causative agents of Bovine Respiratory Disease (BRD), which causes high morbidity and mortality in feedlot cattle worldwide. To date, the molecular mechanisms of IDV pathogenicity are unknown. Recent IDV outbreaks in cattle, along with serological and genetic evidence of IDV infection in humans, have raised concerns regarding the zoonotic potential of this virus. Influenza virus polymerase is a determining factor of viral pathogenicity to mammals. METHODS: Here we take a prospective approach to this question by creating a random mutation library about PB2 subunit of the IDV viral polymerase to test which amino acid point mutations will increase viral polymerase activity, leading to increased pathogenicity of the virus. RESULTS: Our work shows some exact sites that could affect polymerase activities in influenza D viruses. For example, two single-site mutations, PB2-D533S and PB2-G603Y, can independently increase polymerase activity. The PB2-D533S mutation alone can increase the polymerase activity by 9.92 times, while the PB2-G603Y mutation increments the activity by 8.22 times. CONCLUSION: Taken together, our findings provide important insight into IDV replication fitness mediated by the PB2 protein, increasing our understanding of IDV replication and pathogenicity and facilitating future studies.


Assuntos
Infecções por Orthomyxoviridae , Orthomyxoviridae , Thogotovirus , Aminoácidos/genética , Animais , Bovinos , Mutação , Suínos , Thogotovirus/genética , Replicação Viral
16.
Microb Pathog ; 160: 105193, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34536503

RESUMO

As a novel member of the Orthomyxoviridae, influenza D virus (IDV) was firstly isolated from swine. However, cattle were found to serve as its primary reservoir. The study of IDV emergence can shed light into the dynamics of zoonotic infections and interspecies transmission. Although there is an increasing number of strains and sequenced IDV strains, their origin, epidemiology and evolutionary dynamics remain unclear. In this study, we reconstruct the diversity and evolutionary dynamics of IDVs. Molecular detection of swine tissue samples shows that six IDV positive samples were identified in the Eastern China. Phylogenetic analyses suggest three major IDV lineages designated as D/Japan, D/OK and D/660 as well as intermediate lineages. IDVs show strong association with geographical location indicating a high level of local transmission, which suggests IDVs tend to establish a local lineage of in situ evolution. In addition, the D/OK lineage widely circulates in swine in Eastern China, and all of the Chinese virus isolates form a distinct sub-clade (D/China sub-lineage). Furthermore, we identified important amino acids in the HEF gene under positive selection that might affect its receptor binding cavity relevant for its broader cell tropism. The combined results highlight that more attention should be paid to the potential threat of IDV to livestock and farming in China.


Assuntos
Doenças dos Bovinos , Infecções por Orthomyxoviridae , Orthomyxoviridae , Thogotovirus , Animais , Bovinos , Evolução Molecular , Infecções por Orthomyxoviridae/veterinária , Filogenia , Suínos , Thogotovirus/genética
17.
Viruses ; 13(9)2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34578330

RESUMO

Influenza D virus (IDV) was first isolated in 2011 in Oklahoma, USA from pigs presenting with influenza-like symptoms. IDV is known to mainly circulate in ruminants, especially cattle. In Africa, there is limited information on the epidemiology of IDV, although the virus has likely circulated in the region since 2012. In the present study, we investigated the seropositivity of IDV among domestic ruminants and swine in West and East Africa from 2017 to 2020. Serum samples were analyzed using the hemagglutination inhibition (HI) assay. Our study demonstrated that IDV is still circulating in Africa, with variations in seropositivity among countries and species. The highest seropositivity was detected in cattle (3.9 to 20.9%). Our data highlights a need for extensive surveillance of IDV in Africa in order to better understand the epidemiology of the virus in the region.


Assuntos
Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/imunologia , Ruminantes/imunologia , Ruminantes/virologia , Thogotovirus/imunologia , Thogotovirus/patogenicidade , África Oriental/epidemiologia , África Ocidental/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Feminino , Masculino , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
18.
J Gen Virol ; 102(7)2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34269676

RESUMO

Type I interferons (IFNs) are a first line of defence against viral infections. Upon infection, a first small wave of early type I IFN, mainly IFN-ß and particularly IFN-α4, are induced and bind to the type I IFN receptor (IFNAR) to amplify the IFN response. It was shown for several viruses that robust type I IFN responses require this positive feedback loop via the IFNAR. Recently, we showed that infection of IFNAR knockout mice with the orthomyxovirus Thogoto virus lacking the ML open reading frame (THOV(ML-)) results in the expression of unexpected high amounts of type I IFN. To investigate if IFNAR-independent IFN responses are unique for THOV(ML-), we performed infection experiments with several negative-strand RNA viruses using different routes and dosages for infection. A variety of these viruses induced type I IFN responses IFNAR-independently when using the intraperitoneal (i.p.) route for infection. In vitro studies demonstrated that myeloid dendritic cells (mDC) are capable of producing IFNAR-independent IFN-α responses that are dependent on the expression of the adaptor protein mitochondrial antiviral-signalling protein (MAVS) whereas pDC where entirely depending on the IFNAR feedback loop in vitro. Thus, depending on dose and route of infection, the IFNAR feedback loop is not strictly necessary for robust type I IFN expression and an IFNAR-independent type I IFN production might be the rule rather than the exception for infections with numerous negative-strand RNA viruses.


Assuntos
Interferon-alfa/biossíntese , Vírus de RNA de Sentido Negativo/imunologia , Infecções por Vírus de RNA/imunologia , Receptor de Interferon alfa e beta/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Células Dendríticas/imunologia , Células Dendríticas/virologia , Camundongos , Camundongos Endogâmicos C57BL , Células Mieloides/imunologia , Células Mieloides/virologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Infecções por Vírus de RNA/virologia , Receptor de Interferon alfa e beta/genética , Thogotovirus , Carga Viral
19.
J Virol ; 95(18): e0097121, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34190601

RESUMO

The newly identified influenza D virus (IDV) of the Orthomyxoviridae family has a wide host range with a broad geographical distribution. Despite the first appearance in U.S. pig herds in 2011, subsequent studies demonstrated that IDV is widespread in global cattle populations, supporting a theory that IDV utilizes bovines as a primary reservoir. Our investigation of the two reference influenza D viruses, D/swine/Oklahoma/1334/2011 (OK/11), isolated from swine, and D/Bovine/Oklahoma/660/2013 (660/13), isolated from cattle, revealed that 660/13 replicated to titers approximately 100-fold higher than those for OK/11 in multiple cell lines. By using a recently developed IDV reverse-genetics system derived from low-titer OK/11, we generated recombinant chimeric OK/11 viruses in which one of the seven genome segments was replaced with its counterpart from high-titer 660/13 virus. Further characterization demonstrated that the replication level of the chimeric OK/11 virus was significantly increased only when harboring the 660/13 nucleoprotein (NP) segment. Finally, through both gain-of-function and loss-of-function experiments, we identified that one amino acid residue at position 381, located in the body domain of NP protein, was a key determinant for the replication difference between the low-titer OK/11 virus and the high-titer 660/13 virus. Taken together, our findings provide important insight into IDV replication fitness mediated by the NP protein, which should facilitate future study of the infectious virus particle production mechanism of IDV. IMPORTANCE Little is known about the virus infection and production mechanism for newly discovered influenza D virus (IDV), which utilizes bovines as a primary reservoir, with frequent spillover to new hosts, including swine. In this study, we showed that of two well-characterized IDVs, 660/13 replicated more efficiently (approximately 100-fold higher) than OK/11. Using a recently developed IDV reverse-genetics system, we identified viral nucleoprotein (NP) as a primary determinant of the different replication capacities observed between these two nearly identical viruses. Mechanistic investigation further revealed that a mutation at NP position 381 evidently modulated virus fitness. Taken together, these observations indicate that IDV NP protein performs a critical role in infectious virus particle production. Our study thus illustrates an NP-based mechanism for efficient IDV infection and production in vitro.


Assuntos
Aminoácidos/genética , Genoma Viral , Mutação , Nucleoproteínas/metabolismo , Infecções por Orthomyxoviridae/virologia , Thogotovirus/fisiologia , Replicação Viral , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Anticorpos Antivirais , Bovinos , Cães , Especificidade de Hospedeiro , Células Madin Darby de Rim Canino , Nucleoproteínas/química , Nucleoproteínas/genética , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/metabolismo , Filogenia , Conformação Proteica , Homologia de Sequência de Aminoácidos , Suínos
20.
Vet Microbiol ; 257: 109067, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33862331

RESUMO

Respiratory diseases negatively impact the global goat industry, but are understudied. There is a shortage of established and biological relevant in vitro or ex vivo assays to study caprine respiratory infections. Here, we describe the establishment of an in vitro system based on well-differentiated caprine airway epithelial cell (AEC) cultures grown under air liquid interface conditions as an experimental platform to study caprine respiratory pathogens. The functional differentiation of the AEC cultures was monitored and confirmed by light and immunofluorescence microscopy, scanning electron microscopy and examination of histological sections. We validated the functionality of the platform by studying Influenza D Virus (IDV) infection and Mycoplasma mycoides subsp. capri (Mmc) colonization over 5 days, including monitoring of infectious agents by titration and qPCR as well as colour changing units, respectively. The inoculation of caprine AEC cultures with IDV showed that efficient viral replication takes place, and revealed that IDV has a marked cell tropism for ciliated cells. Furthermore, AEC cultures were successfully infected with Mmc using a multiplicity of infection of 0.1 and colonization was monitored over several days. Altogether, these results demonstrate that our newly-established caprine AEC cultures can be used to investigate host-pathogen interactions of caprine respiratory pathogens.


Assuntos
Técnicas de Cultura de Células/métodos , Técnicas de Cultura de Células/veterinária , Células Epiteliais/microbiologia , Células Epiteliais/virologia , Mucosa Respiratória/microbiologia , Mucosa Respiratória/virologia , Sistema Respiratório/citologia , Animais , Brônquios/citologia , Diferenciação Celular , Células Cultivadas , Cabras , Interações Hospedeiro-Patógeno , Microscopia Eletrônica de Varredura , Mycoplasma/fisiologia , Thogotovirus/fisiologia , Tropismo Viral , Replicação Viral/fisiologia
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