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1.
Nat Microbiol ; 9(7): 1764-1777, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38849624

RESUMO

Influenza virus infection is initiated by the attachment of the viral haemagglutinin (HA) protein to sialic acid receptors on the host cell surface. Most virus particles enter cells through clathrin-mediated endocytosis (CME). However, it is unclear how viral binding signals are transmitted through the plasma membrane triggering CME. Here we found that metabotropic glutamate receptor subtype 2 (mGluR2) and potassium calcium-activated channel subfamily M alpha 1 (KCa1.1) are involved in the initiation and completion of CME of influenza virus using an siRNA screen approach. Influenza virus HA directly interacted with mGluR2 and used it as an endocytic receptor to initiate CME. mGluR2 interacted and activated KCa1.1, leading to polymerization of F-actin, maturation of clathrin-coated pits and completion of the CME of influenza virus. Importantly, mGluR2-knockout mice were significantly more resistant to different influenza subtypes than the wild type. Therefore, blocking HA and mGluR2 interaction could be a promising host-directed antiviral strategy.


Assuntos
Endocitose , Camundongos Knockout , Receptores de Glutamato Metabotrópico , Animais , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/genética , Camundongos , Humanos , Internalização do Vírus , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Clatrina/metabolismo , Infecções por Orthomyxoviridae/virologia , Infecções por Orthomyxoviridae/metabolismo , Células HEK293 , Actinas/metabolismo , Cães , Células Madin Darby de Rim Canino , Receptores Virais/metabolismo , Receptores Virais/genética , Influenza Humana/virologia , Influenza Humana/metabolismo , Orthomyxoviridae/fisiologia , Orthomyxoviridae/genética , Orthomyxoviridae/metabolismo
2.
Viruses ; 16(5)2024 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-38793634

RESUMO

Avian influenza viruses (AIVs) of the H5 subtype rank among the most serious pathogens, leading to significant economic losses in the global poultry industry and posing risks to human health. Therefore, rapid and accurate virus detection is crucial for the prevention and control of H5 AIVs. In this study, we established a novel detection method for H5 viruses by utilizing the precision of CRISPR/Cas12a and the efficiency of RT-RPA technologies. This assay facilitates the direct visualization of detection results through blue light and lateral flow strips, accurately identifying H5 viruses with high specificity and without cross-reactivity against other AIV subtypes, NDV, IBV, and IBDV. With detection thresholds of 1.9 copies/µL (blue light) and 1.9 × 103 copies/µL (lateral flow strips), our method not only competes with but also slightly surpasses RT-qPCR, demonstrating an 80.70% positive detection rate across 81 clinical samples. The RT-RPA/CRISPR-based detection method is characterized by high sensitivity, specificity, and independence from specialized equipment. The immediate field applicability of the RT-RPA/CRISPR approach underscores its importance as an effective tool for the early detection and management of outbreaks caused by the H5 subtype of AIVs.


Assuntos
Sistemas CRISPR-Cas , Influenza Aviária , Sensibilidade e Especificidade , Animais , Influenza Aviária/virologia , Influenza Aviária/diagnóstico , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Virus da Influenza A Subtipo H5N1/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/classificação , Aves Domésticas/virologia , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/diagnóstico , Galinhas/virologia , Aves/virologia
3.
Emerg Microbes Infect ; 13(1): 2343912, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38629574

RESUMO

Human infections with the H7N9 influenza virus have been eliminated in China through vaccination of poultry; however, the H7N9 virus has not yet been eradicated from poultry. Carefully analysis of H7N9 viruses in poultry that have sub-optimal immunity may provide a unique opportunity to witness the evolution of highly pathogenic avian influenza virus in the context of vaccination. Between January 2020 and June 2023, we isolated 16 H7N9 viruses from samples we collected during surveillance and samples that were sent to us for disease diagnosis. Genetic analysis indicated that these viruses belonged to a single genotype previously detected in poultry. Antigenic analysis indicated that 12 of the 16 viruses were antigenically close to the H7-Re4 vaccine virus that has been used since January 2022, and the other four viruses showed reduced reactivity with the vaccine. Animal studies indicated that all 16 viruses were nonlethal in mice, and four of six viruses showed reduced virulence in chickens upon intranasally inoculation. Importantly, the H7N9 viruses detected in this study exclusively bound to the avian-type receptors, having lost the capacity to bind to human-type receptors. Our study shows that vaccination slows the evolution of H7N9 virus by preventing its reassortment with other viruses and eliminates a harmful characteristic of H7N9 virus, namely its ability to bind to human-type receptors.


Assuntos
Galinhas , Subtipo H7N9 do Vírus da Influenza A , Vacinas contra Influenza , Influenza Aviária , Vacinação , Animais , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/imunologia , Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Galinhas/virologia , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Aviária/virologia , Influenza Aviária/prevenção & controle , Influenza Aviária/imunologia , Camundongos , Humanos , China , Evolução Molecular , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Influenza Humana/imunologia , Camundongos Endogâmicos BALB C , Virulência , Filogenia , Feminino , Doenças das Aves Domésticas/virologia , Doenças das Aves Domésticas/prevenção & controle , Aves Domésticas/virologia
4.
Emerg Microbes Infect ; 13(1): 2284301, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37966272

RESUMO

Due to the fact that many avian influenza viruses that kill chickens are not lethal to ducks, farmers are reluctant to use avian influenza inactivated vaccines on ducks. Large numbers of unvaccinated ducks play an important role in the transmission of avian influenza viruses from wild birds to domestic poultry, creating a substantial challenge to vaccination strategies for avian influenza control. To solve this problem, we constructed a recombinant duck enteritis virus (DEV), rDEV-dH5/H7, using a live attenuated DEV vaccine strain (vDEV) as a vector. rDEV-dH5/H7 carries the hemagglutinin gene of two H5 viruses [GZ/S4184/17 (H5N6) (clade 2.3.4.4 h) and LN/SD007/17 (H5N1) (clade 2.3.2.1d)] and an H7 virus [GX/SD098/17 (H7N9)]. These three hemagglutinin genes were stably inherited in rDEV-dH5/H7 and expressed in rDEV-dH5/H7-infected cells. Animal studies revealed that rDEV-dH5/H7 and vDEV induced similar neutralizing antibody responses and protection against lethal DEV challenge. Importantly, rDEV-dH5/H7 induced strong and long-lasting hemagglutinin inhibition antibodies against different H5 and H7 viruses and provided complete protection against challenges with homologous and heterologous highly pathogenic H5 and H7 influenza viruses in ducks. Our study shows that rDEV-dH5/H7 could serve as an ideal live attenuated vaccine to protect ducks against infection with lethal DEV and highly pathogenic avian influenza viruses.


Assuntos
Enterite , Virus da Influenza A Subtipo H5N1 , Subtipo H7N9 do Vírus da Influenza A , Vacinas contra Influenza , Influenza Aviária , Animais , Patos , Hemaglutininas , Galinhas , Virus da Influenza A Subtipo H5N1/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Subtipo H7N9 do Vírus da Influenza A/genética , Vacinas contra Influenza/genética , Vetores Genéticos
5.
Emerg Microbes Infect ; 13(1): 2284294, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37966008

RESUMO

H5N1 avian influenza viruses bearing the clade 2.3.2.1 hemagglutinin (HA) gene have been widely detected in birds and poultry in several countries. During our routine surveillance, we isolated 28 H5N1 viruses between January 2017 and October 2020. To investigate the genetic relationship of the globally circulating H5N1 viruses and the biological properties of those detected in China, we performed a detailed phylogenic analysis of 274 representative H5N1 strains and analyzed the antigenic properties, receptor-binding preference, and virulence in mice of the H5N1 viruses isolated in China. The phylogenic analysis indicated that the HA genes of the 274 viruses belonged to six subclades, namely clades 2.3.2.1a to 2.3.2.1f; these viruses acquired gene mutations and underwent complicated reassortment to form 58 genotypes, with G43 being the dominant genotype detected in eight Asian and African countries. The 28 H5N1 viruses detected in this study carried the HA of clade 2.3.2.1c (two strains), 2.3.2.1d (three strains), or 2.3.2.1f (23 strains), and formed eight genotypes. These viruses were antigenically well-matched with the H5-Re12 vaccine strain used in China. Animal studies showed that the pathogenicity of the H5N1 viruses ranged from non-lethal to highly lethal in mice. Moreover, the viruses exclusively bound to avian-type receptors and have not acquired the ability to bind to human-type receptors. Our study reveals the overall picture of the evolution of clade 2.3.2.1 H5N1 viruses and provides insights into the control of these viruses.


Assuntos
Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Animais , Humanos , Camundongos , Hemaglutininas/genética , Aves , Aves Domésticas , Filogenia , Galinhas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química
6.
Sci China Life Sci ; 67(3): 579-595, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38038885

RESUMO

Influenza A virus (IAV) commandeers numerous host cellular factors for successful replication. However, very few host factors have been revealed to be involved in the fusion of viral envelope and late endosomal membranes. In this study, we identified cation-dependent mannose-6-phosphate receptor (M6PR) as a crucial host factor for the replication of IAV. We found that siRNA knockdown of M6PR expression significantly reduced the growth titers of different subtypes of IAV, and that the inhibitory effect of M6PR siRNA treatment on IAV growth was overcome by the complement of exogenously expressed M6PR. When A549 cells were treated with siRNA targeting M6PR, the nuclear accumulation of viral nucleoprotein (NP) was dramatically inhibited at early timepoints post-infection, indicating that M6PR engages in the early stage of the IAV replication cycle. By investigating the role of M6PR in the individual entry and post-entry steps of IAV replication, we found that the downregulation of M6PR expression had no effect on attachment, internalization, early endosome trafficking, or late endosome acidification. However, we found that M6PR expression was critical for the fusion of viral envelope and late endosomal membranes. Of note, M6PR interacted with the hemagglutinin (HA) protein of IAV, and further studies showed that the lumenal domain of M6PR and the ectodomain of HA2 mediated the interaction and directly promoted the fusion of the viral and late endosomal membranes, thereby facilitating IAV replication. Together, our findings highlight the importance of the M6PR-HA interaction in the fusion of viral and late endosomal membranes during IAV replication.


Assuntos
Vírus da Influenza A , Influenza Humana , Humanos , Vírus da Influenza A/genética , Endossomos/metabolismo , Membranas Intracelulares , Células A549 , RNA Interferente Pequeno/metabolismo , Replicação Viral , Influenza Humana/genética
7.
Viruses ; 15(11)2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-38005926

RESUMO

The H5 subtype highly pathogenic avian influenza viruses bearing the clade 2.3.4.4 HA gene have been pervasive among domestic poultry and wild birds worldwide since 2014, presenting substantial risks to human and animal health. Continued circulation of clade 2.3.4.4 viruses has resulted in the emergence of eight subclades (2.3.4.4a-h) and multiple distinct antigenic groups. However, the key antigenic substitutions responsible for the antigenic change of these viruses remain unknown. In this study, we analyzed the HA gene sequences of 5713 clade 2.3.4.4 viruses obtained from a public database and found that 23 amino acid residues were highly variable among these strains. We then generated a series of single-amino-acid mutants based on the H5-Re8 (a vaccine seed virus) background and tested their reactivity with a panel of eight monoclonal antibodies (mAbs). Six mutants bearing amino acid substitutions at positions 120, 126, 141, 156, 185, or 189 (H5 numbering) led to reduced or lost reactivity to these mAbs. Further antigenic cartography analysis revealed that the amino acid residues at positions 126, 156, and 189 acted as immunodominant epitopes of H5 viruses. Collectively, our findings offer valuable guidance for the surveillance and early detection of emerging antigenic variants.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Animais , Humanos , Hemaglutininas , Virus da Influenza A Subtipo H5N1/genética , Aminoácidos , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A/genética , Anticorpos Monoclonais
8.
Emerg Microbes Infect ; 12(2): 2270073, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37823597

RESUMO

Influenza A viruses (IAVs) continue to cause tremendous economic losses to the global animal industry and respiratory diseases and deaths among humans. The nuclear import of the vRNP complex, composed of polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), polymerase acidic protein (PA), nucleoprotein (NP), and viral RNA, is essential for the efficient replication of IAV. Host factors involved in this process can be targeted for the development of countermeasures against IAV infection. Here, we found that Ankyrin Repeat and BTB Domain Containing 1 (ABTB1) promotes the replication of IAV, and positively regulates the nuclear import of the vRNP complex. ABTB1 did not interact directly with NP, indicating that ABTB1 plays an indirect role in facilitating the nuclear import of the vRNP complex. Immunoprecipitation and mass spectrometry revealed that Tripartite Motif Containing 4 (TRIM4) interacts with ABTB1. We found that TRIM4 relies on its E3 ubiquitin ligase activity to inhibit the replication of IAV by targeting and degrading NP within the incoming vRNP complex as well as the newly synthesized NP. ABTB1 interacted with TRIM4, leading to TRIM4 degradation through the proteasome system. Notably, ABTB1-mediated degradation of TRIM4 blocked the effect of TRIM4 on NP stability, and largely counteracted the inhibitory effect of TRIM4 on IAV replication. Our findings define a novel role for ABTB1 in aiding the nuclear import of the vRNP complex of IAV by counteracting the destabilizing effect of TRIM4 on the viral NP protein.


Assuntos
Vírus da Influenza A , Nucleoproteínas , Animais , Humanos , Nucleoproteínas/genética , Nucleoproteínas/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Vírus da Influenza A/fisiologia , Proteínas do Core Viral/genética , Proteínas do Core Viral/metabolismo , Ligação Proteica , Replicação Viral/fisiologia , Proteínas Repressoras/metabolismo
9.
Euro Surveill ; 28(41)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37824247

RESUMO

BackgroundTwo human cases of avian influenza A (H3N8) virus infection were reported in China in 2022.AimTo characterise H3N8 viruses circulating in China in September 2021-May 2022.MethodsWe sampled poultry and poultry-related environments in 25 Chinese provinces. After isolating H3N8 viruses, whole genome sequences were obtained for molecular and phylogenetic analyses. The specificity of H3N8 viruses towards human or avian receptors was assessed in vitro. Their ability to replicate in chicken and mice, and to transmit between guinea pigs was also investigated.ResultsIn total, 98 H3N8 avian influenza virus isolates were retrieved from 38,639 samples; genetic analysis of 31 representative isolates revealed 17 genotypes. Viruses belonging to 10 of these genotypes had six internal genes originating from influenza A (H9N2) viruses. These reassorted viruses could be found in live poultry markets and comprised the strains responsible for the two human infections. A subset of nine H3N8 viruses (including six reassorted) that replicated efficiently in mice bound to both avian-type and human-type receptors in vitro. Three reassorted viruses were shed by chickens for up to 9 days, replicating efficiently in their upper respiratory tract. Five reassorted viruses tested on guinea pigs were transmissible among these by respiratory droplets.ConclusionAvian H3N8 viruses with H9N2 virus internal genes, causing two human infections, occurred in live poultry markets in China. The low pathogenicity of H3N8 viruses in poultry allows their continuous circulation with potential for reassortment. Careful monitoring of spill-over infections in humans is important to strengthen early-warning systems and maintain influenza pandemic preparedness.


Assuntos
Vírus da Influenza A Subtipo H3N8 , Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Influenza Humana , Doenças das Aves Domésticas , Animais , Humanos , Camundongos , Cobaias , Influenza Humana/epidemiologia , Aves Domésticas , Influenza Aviária/epidemiologia , Vírus da Influenza A Subtipo H9N2/genética , Filogenia , Galinhas , China/epidemiologia , Doenças das Aves Domésticas/epidemiologia
10.
Emerg Infect Dis ; 29(7): 1367-1375, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37347504

RESUMO

Highly pathogenic avian influenza (HPAI) subtype H5N1 clade 2.3.4.4b virus has spread globally, causing unprecedented large-scale avian influenza outbreaks since 2020. In 2021, we isolated 17 highly pathogenic avian influenza H5N1 viruses from wild birds in China. To determine virus origin, we genetically analyzed 1,529 clade 2.3.4.4b H5N1 viruses reported globally since October 2020 and found that they formed 35 genotypes. The 17 viruses belonged to genotypes G07, which originated from eastern Asia, and G10, which originated from Russia. The viruses were moderately pathogenic in mice but were highly lethal in ducks. The viruses were in the same antigenic cluster as the current vaccine strain (H5-Re14) used in China. In chickens, the H5/H7 trivalent vaccine provided complete protection against clade 2.3.4.4b H5N1 virus challenge. Our data indicate that vaccination is an effective strategy for preventing and controlling the globally prevalent clade 2.3.4.4b H5N1 virus.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Influenza Aviária , Animais , Camundongos , Virus da Influenza A Subtipo H5N1/genética , Galinhas , Animais Selvagens , Vírus da Influenza A/genética , China/epidemiologia , Filogenia
11.
J Infect ; 86(2): e36-e39, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36273641

RESUMO

We present the phylogeny, receptor binding property, growth in mammal cells and pathogenicity in mammal model of H3N8 viruses, which were isolated from wild birds in China. The human receptor preference and efficient replication in mice without prior adaption highlight that the H3N8 virus possesses the public threat potential.


Assuntos
Vírus da Influenza A Subtipo H3N8 , Influenza Aviária , Animais , Humanos , Camundongos , Aves , Animais Selvagens , China , Filogenia , Mamíferos
12.
Cell Mol Immunol ; 19(10): 1168-1184, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36056146

RESUMO

As a major component of the viral ribonucleoprotein (vRNP) complex in influenza A virus (IAV), nucleoprotein (NP) interacts with isoforms of importin α family members, leading to the import of itself  and vRNP complex into the nucleus, a process pivotal in the replication cycle of IAV. In this study, we found that BinCARD1, an isoform of Bcl10-interacting protein with CARD (BinCARD), was leveraged by IAV for efficient viral replication. BinCARD1 promoted the nuclear import of the vRNP complex and newly synthesized NP and thus enhanced vRNP complex activity. Moreover, we found that BinCARD1 interacted with NP to promote NP binding to importin α7, an adaptor in the host nuclear import pathway. However, we also found that BinCARD1 promoted RIG-I-mediated innate immune signaling by mediating Lys63-linked polyubiquitination of TRAF3, and that TBK1 appeared to degrade BinCARD1. We showed that BinCARD1 was polyubiquitinated at residue K103 through a Lys63 linkage, which was recognized by the TBK1-p62 axis for autophagic degradation. Overall, our data demonstrate that IAV leverages BinCARD1 as an important host factor that promotes viral replication, and two mechanisms in the host defense system are triggered-innate immune signaling and autophagic degradation-to mitigate the promoting effect of BinCARD1 on the life cycle of IAV.


Assuntos
Vírus da Influenza A , Animais , Autofagia , Proteína DEAD-box 58/metabolismo , Cães , Carioferinas/metabolismo , Células Madin Darby de Rim Canino , Nucleoproteínas/química , Nucleoproteínas/metabolismo , Ligação Proteica , Ribonucleoproteínas/química , Ribonucleoproteínas/metabolismo , Fator 3 Associado a Receptor de TNF/metabolismo , Proteínas do Core Viral/metabolismo , Replicação Viral , alfa Carioferinas/metabolismo
13.
Emerg Microbes Infect ; 11(1): 1693-1704, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35699072

RESUMO

H5N1 avian influenza viruses bearing the clade 2.3.4.4b hemagglutinin gene have been widely circulating in wild birds and are responsible for the loss of over 70 million domestic poultry in Europe, Africa, Asia, and North America since October 2020. During our routine surveillance, 13 H5N1 viruses were isolated from 26,767 wild bird and poultry samples that were collected between September 2021 and March 2022 in China. To investigate the origin of these Chinese isolates and understand their genetic relationship with the globally circulating H5N1 viruses, we performed a detailed phylogenic analysis of 233 representative H5N1 strains that were isolated from 28 countries. We found that, after they emerged in the Netherlands, the H5N1 viruses encountered complicated gene exchange with different viruses circulating in wild birds and formed 16 genotypes. Genotype one (G1) was predominant, being detected in 22 countries, whereas all other genotypes were only detected in one or two continents. H5N1 viruses of four genotypes (G1, G7, G9, and G10) were detected in China; three of these genotypes have been previously reported in other countries. The H5N1 viruses detected in China replicated in mice, with pathogenicity varying among strains; the G1 virus was highly lethal in mice. Moreover, we found that these viruses were antigenically similar to and well matched with the H5-Re14 vaccine strain currently used in China. Our study reveals the overall picture of H5N1 virus evolution and provides insights for the control of these viruses.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vacinas contra Influenza , Influenza Aviária , Influenza Humana , Animais , Animais Selvagens , Aves , Galinhas , China/epidemiologia , Humanos , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Camundongos , Filogenia , Aves Domésticas
14.
Emerg Microbes Infect ; 11(1): 1174-1185, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35380505

RESUMO

The globally circulating H5N8 avian influenza viruses bearing the clade 2.3.4.4b hemagglutinin (HA) gene are responsible for the loss of more than 33 million domestic poultry since January 2020. Moreover, the H5N8 viruses have reassorted with other avian influenza viruses and formed H5N1, H5N2, H5N3, H5N4, and H5N5 viruses in Europe, Africa, and North America. In this study, we analyzed 15 H5N6 viruses isolated from poultry and seven H5N6 viruses isolated from humans, and found these viruses formed seven different genotypes by deriving the clade 2.3.4.4b HA gene of H5N8 viruses, the neuraminidase of domestic duck H5N6 viruses, and internal genes of different viruses that previously circulated in domestic ducks and wild birds in China. Two of these genotypes (genotype 3 and genotype 6) have caused human infections in multiple provinces. The H5N6 viruses isolated from poultry have distinct pathotypes in mice; some of them replicate systemically and are highly lethal in mice. Although these viruses exclusively bind to avian-type receptors, it is worrisome that they may obtain key mutations that would increase their affinity for human-type receptors during replication in humans. Our study indicates that the novel H5N6 reassortants bearing the clade 2.3.4.4b HA gene of H5N8 viruses were generated through reassortment in domestic ducks and may have spread across a wide area of China, thereby posing a new challenge to the poultry industry and human health. Our findings emphasize the importance of careful monitoring, evaluation, and control of the H5N6 viruses circulating in nature.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A Subtipo H5N2 , Vírus da Influenza A Subtipo H5N8 , Vírus da Influenza A , Influenza Aviária , Doenças das Aves Domésticas , Animais , Aves , China/epidemiologia , Patos , Hemaglutininas , Humanos , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Camundongos , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia
15.
PLoS Pathog ; 18(4): e1010446, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35377920

RESUMO

Host defense systems employ posttranslational modifications to protect against invading pathogens. Here, we found that protein inhibitor of activated STAT 1 (PIAS1) interacts with the nucleoprotein (NP), polymerase basic protein 1 (PB1), and polymerase basic protein 2 (PB2) of influenza A virus (IAV). Lentiviral-mediated stable overexpression of PIAS1 dramatically suppressed the replication of IAV, whereas siRNA knockdown or CRISPR/Cas9 knockout of PIAS1 expression significantly increased virus growth. The expression of PIAS1 was significantly induced upon IAV infection in both cell culture and mice, and PIAS1 was involved in the overall increase in cellular SUMOylation induced by IAV infection. We found that PIAS1 inhibited the activity of the viral RNP complex, whereas the C351S or W372A mutant of PIAS1, which lacks the SUMO E3 ligase activity, lost the ability to suppress the activity of the viral RNP complex. Notably, the SUMO E3 ligase activity of PIAS1 catalyzed robust SUMOylation of PB2, but had no role in PB1 SUMOylation and a minimal role in NP SUMOylation. Moreover, PIAS1-mediated SUMOylation remarkably reduced the stability of IAV PB2. When tested in vivo, we found that the downregulation of Pias1 expression in mice enhanced the growth and virulence of IAV. Together, our findings define PIAS1 as a restriction factor for the replication and pathogenesis of IAV.


Assuntos
Vírus da Influenza A , Proteínas Inibidoras de STAT Ativados , Sumoilação , Replicação Viral , Animais , Vírus da Influenza A/patogenicidade , Vírus da Influenza A/fisiologia , Camundongos , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Virulência
16.
Natl Sci Rev ; 9(1): nwab137, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35087672

RESUMO

The H7N9 influenza virus emerged in China in 2013, causing more than 1560 human infections, 39% of which were fatal. A 'cytokine storm' in the lungs of H7N9 patients has been linked to a poor prognosis and death; however, the underlying mechanism that triggers the cytokine storm is unknown. Here, we found that efficient replication of the H7N9 virus in mouse lungs activates gasdermin E (GSDME)-mediated pyroptosis in alveolar epithelial cells, and that the released cytosolic contents then trigger a cytokine storm. Knockout of Gsdme switched the manner of death of A549 and human primary alveolar epithelial cells from pyroptosis to apoptosis upon H7N9 virus infection, and Gsdme knockout mice survived H7N9 virus lethal infection. Our findings reveal that GSDME activation is a key and unique mechanism for the pulmonary cytokine storm and lethal outcome of H7N9 virus infection and thus opens a new door for the development of antivirals against the H7N9 virus.

17.
Transbound Emerg Dis ; 69(4): 2156-2172, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34192815

RESUMO

H6 avian influenza virus (AIV) is one of the most prevalent AIV subtypes in the world. Our previous studies have demonstrated that H6 AIVs isolated from live poultry markets pose a potential threat to human health. In recent years, increasing number of H6 AIVs has been constantly isolated from poultry farms. In order to understand the biological characteristics of H6 AIVs in the context of farms, here, we analyzed the phylogenetic relationships, antigenicity, replication in mice and receptor binding properties of H6 AIVs isolated from farms in China between 2014 and 2018. Phylogenetic analysis showed that 19 different genotypes were formed among 20 representative H6 viruses. Notably, the internal genes of these H6 viruses exhibited complicated relationships with different subtypes of AIVs worldwide, indicating that these viruses are the products of complex and frequent reassortment events. Antigenic analysis revealed that 13 viruses tested were divided into three antigenic groups. 10 viruses examined could all replicate in the respiratory organs of infected mice without prior adaptation. Receptor binding analysis demonstrated that some of the H6 AIVs bound to both α-2, 3-linked glycans (avian-type receptor) and α-2, 6-linked glycans (human-type receptor), thereby posing a potential threat to human health. Together, these findings revealed the prevalence, complicated genetic evolution, diverse antigenicity, and dual receptor binding specificity of H6 AIVs in the settings of poultry farms, which emphasize the importance to continuously monitor the evolution and biological properties of H6 AIVs in nature.


Assuntos
Vírus da Influenza A , Influenza Aviária , Doenças dos Roedores , Animais , China/epidemiologia , Fazendas , Humanos , Influenza Aviária/epidemiologia , Camundongos , Filogenia , Aves Domésticas
18.
Sci China Life Sci ; 65(4): 795-808, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34757542

RESUMO

The H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor the invasion and spread of the H5N8 virus in China, we performed active surveillance by analyzing 317 wild bird samples and swab samples collected from 41,172 poultry all over the country. We isolated 22 H5N8 viruses from wild birds and 14 H5N8 viruses from waterfowls. Genetic analysis indicated that the 36 viruses formed two different genotypes: one genotype viruses were widely detected from different wild birds and domestic waterfowls; the other genotype was isolated from a whopper swan. We further revealed the origin and spatiotemporal spread of these two distinct H5N8 virus genotypes in 2020 and 2021. Animal studies indicated that the H5N8 isolates are highly pathogenic to chickens, mildly pathogenic in ducks, but have distinct pathotypes in mice. Moreover, we found that vaccinated poultry in China could be completely protected against H5N8 virus challenge. Given that the H5N8 viruses are likely to continue to spread in wild birds, vaccination of poultry is highly recommended in high-risk countries to prevent H5N8 avian influenza.


Assuntos
Vírus da Influenza A Subtipo H5N8 , Vírus da Influenza A , Influenza Aviária , Doenças das Aves Domésticas , Vacinas , Animais , Animais Selvagens , Galinhas , China/epidemiologia , Vírus da Influenza A Subtipo H5N8/genética , Influenza Aviária/epidemiologia , Camundongos , Filogenia , Aves Domésticas
19.
Vet Microbiol ; 263: 109268, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34781191

RESUMO

Low pathogenic avian influenza virus, H5 or H7 subtype, possesses the potential capability to change to highly pathogenic variant, which damages wild waterfowl, domestic poultry, and mammalian hosts. In regular active surveillance of avian influenza virus from wild birds in China in 2020, we isolated six H5 avian influenza viruses, including one H5N2, two H5N3, and three H5N8. Phylogenetic analysis indicated that the H5N2 and H5N3 isolates clustered into Eurasian lineage, whereas the H5N8 viruses were originated in North America. The HA proteins of six viruses carried the cleavage-site motif PQRETR↓GLF, which indicated low pathogenicity of the viruses in chickens. However, the N30D, I43M, and T215A mutations in M1 protein and the P42S, I106M, and C138F residues changed in NS1 protein, implying all viruses could exhibit increased virulence in mice. Viral replication kinetics in mammalian cells demonstrated that the three representative viruses had the ability to replicate in both MDCK cells and A549 cells with low titers. Even though two of three representatives, WS/SX/S3-620/2020(H5N3) and ML/AH/A3-770/2020(H5N8), did not replicate and transmit efficiently in poultry (chickens), they did replicate and transmit efficiently in waterfowl (ducks). Viral pathogenicity in mice indicated that both H5N2 and H5N3 viruses are able to replicate in the nasal turbinates and lungs of mice without prior adaptation, while the H5N8 virus could not. The intercontinental and cross-species transmission of viruses may continuously exist in China, thereby providing constant opportunities for virus reassortment with local resident AIVs. Thus, it is crucial to continuously monitor migration routes for AIVs by systematic surveillance.


Assuntos
Vírus da Influenza A , Influenza Aviária , Animais , Animais Selvagens , Galinhas , China , Vírus da Influenza A Subtipo H5N2/classificação , Vírus da Influenza A Subtipo H5N2/genética , Vírus da Influenza A Subtipo H5N2/patogenicidade , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/patogenicidade , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Aviária/virologia , Camundongos , Filogenia
20.
Emerg Microbes Infect ; 10(1): 2052-2061, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34686117

RESUMO

The highly pathogenic avian influenza H5N6 viruses are widely circulating in poultry and wild birds, and have caused 38 human infections including 21 deaths; however, the key genetic determinants of the pathogenicity of these viruses have yet to be fully investigated. Here, we characterized two H5N6 avian influenza viruses - A/duck/Guangdong/S1330/2016 (GD/330) and A/environment/Fujian/S1160/2016 (FJ/160) - that have similar viral genomes but differ markedly in their lethality in mice. GD/330 is highly pathogenic with a 50% mouse lethal dose (MLD50) of 2.5 log10 50% egg infectious doses (EID50), whereas FJ/160 exhibits low pathogenicity with an MLD50 of 7.4 log10 EID50. We explored the molecular basis for the difference in virulence between these two viruses. By using reverse genetics, we created a series of reassortants and mutants in the GD/330 background and assessed their virulence in mice. We found that the HA gene of FJ/160 substantially attenuated the virulence of GD/330 and that the mutation of glycine (G) to tryptophan (W) at position 225 (H3 numbering) in HA played a key role in this function. We further found that the amino acid mutation G225W in HA decreased the acid and thermal stability and increased the pH of HA activation, thereby attenuating the H5N6 virus in mice. Our study thus identifies a novel molecular determinant in the HA protein and provides a new target for the development of live attenuated vaccines and antiviral drugs against H5 influenza viruses.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/virologia , Mutação de Sentido Incorreto , Animais , Feminino , Genoma Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Humanos , Vírus da Influenza A/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Virulência
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