1
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Mettier J, Prompt C, Bruder E, Da Costa B, Chevalier C, Le Goffic R. Comparison of PB1-F2 Proximity Interactomes Reveals Functional Differences between a Human and an Avian Influenza Virus. Viruses 2023; 15:v15020328. [PMID: 36851542 PMCID: PMC9961899 DOI: 10.3390/v15020328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/13/2023] [Accepted: 01/21/2023] [Indexed: 01/27/2023] Open
Abstract
Most influenza viruses express the PB1-F2 protein which is regarded as a virulence factor. However, PB1-F2 behaves differently in avian and mammalian hosts, suggesting that this protein may be involved in the species barrier crossings regularly observed in influenza viruses. To better understand the functions associated with this viral protein, we decided to compare the BioID2-derived proximity interactome of a human PB1-F2 from an H3N2 virus with that of an avian PB1-F2 from an H7N1 strain. The results obtained reveal that the two proteins share only a few interactors and thus common functions. The human virus protein is mainly involved in signaling by Rho GTPases while the avian virus protein is mainly involved in ribonucleoprotein complex biogenesis. PB1-F2 H3N2 interactors include several members of the 14-3-3 protein family, a family of regulatory proteins involved in many signaling pathways. We then validated the interaction with 14-3-3 proteins and were able to show that the association of H3N2-PB1-F2 with YWHAH increased the activity of the antiviral sensor MDA5, while H7N1-PB1-F2 had no effect. Collectively, these results show that PB1-F2 can associate with a large range of protein complexes and exert a wide variety of functions. Furthermore, PB1-F2 interactome differs according to the avian or human origin of the protein.
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2
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Wang Y, Wang J. PB1F2 from Influenza A Virus Regulates the Interaction between Cytochrome C and Cardiolipin. MEMBRANES 2022; 12:795. [PMID: 36005710 PMCID: PMC9414537 DOI: 10.3390/membranes12080795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
PB1F2 is a membrane associated protein encoded by the influenza virus gene in the host. Similar to endogenous pro-apoptotic proteins, it acts on the mitochondria of the host immune cells, inducing apoptosis of the cells. The PB1F2 protein has been demonstrated to facilitate the release of cytochrome c in addition to impairing the integrity of the inner mitochondrial membrane. This investigation focused on how the protein PB1F2 interacted with cardiolipin and cytochrome c. The regulation of PB1F2 on the binding of cytochrome c to cardiolipin in two kinds of in vitro membrane mimics was investigated by biophysical techniques. PB1F2 aids in the dissociation of cytochrome c-cardiolipin complexes in liposomes and nanodiscs. The results provide novel explanations and evidence for how PB1F2 functions as a viral virulence factor by inducing immune cell death.
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Affiliation(s)
- Yujuan Wang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
| | - Junfeng Wang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
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3
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Rochman ND, Wolf YI, Koonin EV. Molecular adaptations during viral epidemics. EMBO Rep 2022; 23:e55393. [PMID: 35848484 PMCID: PMC9346483 DOI: 10.15252/embr.202255393] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/18/2022] [Accepted: 06/27/2022] [Indexed: 07/20/2023] Open
Abstract
In 1977, the world witnessed both the eradication of smallpox and the beginning of the modern age of genomics. Over the following half-century, 7 epidemic viruses of international concern galvanized virologists across the globe and led to increasingly extensive virus genome sequencing. These sequencing efforts exerted over periods of rapid adaptation of viruses to new hosts, in particular, humans provide insight into the molecular mechanisms underpinning virus evolution. Investment in virus genome sequencing was dramatically increased by the unprecedented support for phylogenomic analyses during the COVID-19 pandemic. In this review, we attempt to piece together comprehensive molecular histories of the adaptation of variola virus, HIV-1 M, SARS, H1N1-SIV, MERS, Ebola, Zika, and SARS-CoV-2 to the human host. Disruption of genes involved in virus-host interaction in animal hosts, recombination including genome segment reassortment, and adaptive mutations leading to amino acid replacements in virus proteins involved in host receptor binding and membrane fusion are identified as the key factors in the evolution of epidemic viruses.
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Affiliation(s)
- Nash D Rochman
- National Center for Biotechnology InformationNational Library of MedicineBethesdaMDUSA
| | - Yuri I Wolf
- National Center for Biotechnology InformationNational Library of MedicineBethesdaMDUSA
| | - Eugene V Koonin
- National Center for Biotechnology InformationNational Library of MedicineBethesdaMDUSA
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4
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Xia X, Cheng A, Wang M, Ou X, Sun D, Mao S, Huang J, Yang Q, Wu Y, Chen S, Zhang S, Zhu D, Jia R, Liu M, Zhao XX, Gao Q, Tian B. Functions of Viroporins in the Viral Life Cycle and Their Regulation of Host Cell Responses. Front Immunol 2022; 13:890549. [PMID: 35720341 PMCID: PMC9202500 DOI: 10.3389/fimmu.2022.890549] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Viroporins are virally encoded transmembrane proteins that are essential for viral pathogenicity and can participate in various stages of the viral life cycle, thereby promoting viral proliferation. Viroporins have multifaceted effects on host cell biological functions, including altering cell membrane permeability, triggering inflammasome formation, inducing apoptosis and autophagy, and evading immune responses, thereby ensuring that the virus completes its life cycle. Viroporins are also virulence factors, and their complete or partial deletion often reduces virion release and reduces viral pathogenicity, highlighting the important role of these proteins in the viral life cycle. Thus, viroporins represent a common drug-protein target for inhibiting drugs and the development of antiviral therapies. This article reviews current studies on the functions of viroporins in the viral life cycle and their regulation of host cell responses, with the aim of improving the understanding of this growing family of viral proteins.
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Affiliation(s)
- Xiaoyan Xia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China.,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
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5
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Viral PB1-F2 and host IFN-γ guide ILC2 and T cell activity during influenza virus infection. Proc Natl Acad Sci U S A 2022; 119:2118535119. [PMID: 35169077 PMCID: PMC8872759 DOI: 10.1073/pnas.2118535119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2022] [Indexed: 12/28/2022] Open
Abstract
The regulation of functional immune cell plasticity is poorly understood. Host environmental cues are critical, but the possible influence of pathogen-derived virulence factors has not been described. We have used reverse-engineered influenza A viruses that differ in PB1-F2 activity to analyze influenza in mice in the presence or absence of host interferon (IFN)-γ. In the absence of functional PB1-F2 and IFN-γ, lung ILC2s initiated robust IL-5 responses following viral challenge, which led to improved tissue integrity and survival. Conversely, functional PB1-F2 suppressed IL-5+ ILC2 responses and induced a dominant IL-13+ CD8 T cell response regardless of host IFN-γ. These findings demonstrate the critical interplay between the viral virulence factors and host cytokines in regulating protective pulmonary immunity during influenza virus infection. Functional plasticity of innate lymphoid cells (ILCs) and T cells is regulated by host environmental cues, but the influence of pathogen-derived virulence factors has not been described. We now report the interplay between host interferon (IFN)-γ and viral PB1-F2 virulence protein in regulating the functions of ILC2s and T cells that lead to recovery from influenza virus infection of mice. In the absence of IFN-γ, lung ILC2s from mice challenged with the A/California/04/2009 (CA04) H1N1 virus, containing nonfunctional viral PB1-F2, initiated a robust IL-5 response, which also led to improved tissue integrity and increased survival. Conversely, challenge with Puerto Rico/8/1934 (PR8) H1N1 virus expressing fully functional PB1-F2, suppressed IL-5+ ILC2 responses, and induced a dominant IL-13+ CD8 T cell response, regardless of host IFN-γ expression. IFN-γ–deficient mice had increased survival and improved tissue integrity following challenge with lethal doses of CA04, but not PR8 virus, and increased resistance was dependent on the presence of IFN-γR+ ILC2s. Reverse-engineered influenza viruses differing in functional PB1-F2 activity induced ILC2 and T cell phenotypes similar to the PB1-F2 donor strains, demonstrating the potent role of viral PB1-F2 in host resistance. These results show the ability of a pathogen virulence factor together with host IFN-γ to regulate protective pulmonary immunity during influenza infection.
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6
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Xiang B, Song J, Chen L, Liang J, Li X, Yu D, Lin Q, Liao M, Ren T, Xu C. Duck-origin H5N6 avian influenza viruses induce different pathogenic and inflammatory effects in mice. Transbound Emerg Dis 2021; 68:3509-3518. [PMID: 33316151 DOI: 10.1111/tbed.13956] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 10/19/2020] [Accepted: 12/09/2020] [Indexed: 12/28/2022]
Abstract
Since 2013, H5N6 highly pathogenic avian influenza viruses have caused considerable economic losses in the poultry industry and have caused 24 laboratory-confirmed human cases. In this study, we isolated nine (B1-B9) H5N6 viruses from healthy ducks in Guangdong Province, Southern China from December 2018 to April 2019. Phylogenetic analysis revealed that B1, B2, B3, B4, B5, B7, B8, and B9 clustered into the G1.1 genotype and shared high sequence similarity with human H5N6 isolates from Southern China in 2017 and 2018. Meanwhile, B6 clustered into the G1.1.9 genotype. The hemagglutinin (HA), neuraminidase (NA) and nonstructural protein (NS) gene segments of B6 were closely related to the human H5N6 isolates, while the other genomic segments were closely related to H5N6 viruses isolated from waterfowl in Southern China. Compared to B7, B6 had higher pathogenicity and induced stronger inflammatory responses in mice. B6 carried a full-length PB1-F2 protein (90 aa), while the rest carried an 11-amino acid C-terminal-truncated PB1-F2. The PB1-F2 protein may increase the virulence of B6 compared to that of B7. Our findings provide insight into the pathogenic mechanisms of H5N6 viruses in mammals and emphasize the need for continued surveillance of circulating H5N6 viruses in ducks.
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Affiliation(s)
- Bin Xiang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Jie Song
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Libin Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Jianpeng Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Xin Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Deshui Yu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Qiuyan Lin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Ming Liao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Tao Ren
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Chenggang Xu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- Key Laboratory of Animal Vaccine Development, Ministry of Agriculture, Guangzhou, China
- National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
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7
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Influenza Virus Infection Impairs the Gut's Barrier Properties and Favors Secondary Enteric Bacterial Infection through Reduced Production of Short-Chain Fatty Acids. Infect Immun 2021; 89:e0073420. [PMID: 33820816 DOI: 10.1128/iai.00734-20] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Along with respiratory tract disease per se, viral respiratory infections can also cause extrapulmonary complications with a potentially critical impact on health. In the present study, we used an experimental model of influenza A virus (IAV) infection to investigate the nature and outcome of the associated gut disorders. In IAV-infected mice, the signs of intestinal injury and inflammation, altered gene expression, and compromised intestinal barrier functions peaked on day 7 postinfection. As a likely result of bacterial component translocation, gene expression of inflammatory markers was upregulated in the liver. These changes occurred concomitantly with an alteration of the composition of the gut microbiota and with a decreased production of the fermentative, gut microbiota-derived products short-chain fatty acids (SCFAs). Gut inflammation and barrier dysfunction during influenza were not attributed to reduced food consumption, which caused in part gut dysbiosis. Treatment of IAV-infected mice with SCFAs was associated with an enhancement of intestinal barrier properties, as assessed by a reduction in the translocation of dextran and a decrease in inflammatory gene expression in the liver. Lastly, SCFA supplementation during influenza tended to reduce the translocation of the enteric pathogen Salmonella enterica serovar Typhimurium and to enhance the survival of doubly infected animals. Collectively, influenza virus infection can remotely impair the gut's barrier properties and trigger secondary enteric infections. The latter phenomenon can be partially countered by SCFA supplementation.
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Chevalier C, Leymarie O, Sedano L, Da Costa B, Richard CA, Maisonnasse P, Réfregiers M, Jamme F, Le Goffic R. PB1-F2 amyloid-like fibers correlate with proinflammatory signaling and respiratory distress in influenza-infected mice. J Biol Chem 2021; 297:100885. [PMID: 34146545 PMCID: PMC8294585 DOI: 10.1016/j.jbc.2021.100885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/04/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022] Open
Abstract
PB1-F2 is a virulence factor of influenza A virus known to increase viral pathogenicity in mammalian hosts. PB1-F2 is an intrinsically disordered protein displaying a propensity to form amyloid-like fibers. However, the correlation between PB1-F2 structures and the resulting inflammatory response is unknown. Here, we used synchrotron-coupled Fourier transform-IR and deep UV microscopies to determine the presence of PB1-F2 fibers in influenza A virus–infected mice. In order to study the correlation between PB1-F2 structure and the inflammatory response, transgenic mice expressing luciferase under the control of an NF-κB promotor, allowing in vivo monitoring of inflammation, were intranasally instilled with monomeric, fibrillated, or truncated forms of recombinant PB1-F2. Our intravital NF-κB imaging, supported by cytokine quantification, clearly shows the proinflammatory effect of PB1-F2 fibers compared with N-terminal region of PB1-F2 unable to fibrillate. It is noteworthy that instillation of monomeric PB1-F2 of H5N1 virus induced a stronger inflammatory response when compared with prefibrillated PB1-F2 of H1N1 virus, suggesting mechanisms of virulence depending on PB1-F2 sequence. Finally, using whole-body plethysmography to measure volume changes in the lungs, we quantified the effects of the different forms of PB1-F2 on respiratory parameters. Thus, we conclude that PB1-F2–induced inflammation and respiratory distress are tightly correlated with sequence polymorphism and oligomerization status of the protein.
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Affiliation(s)
| | - Olivier Leymarie
- Université Paris-Saclay, UVSQ, INRAE, VIM, Jouy-en-Josas, France
| | - Laura Sedano
- Université Paris-Saclay, UVSQ, INRAE, VIM, Jouy-en-Josas, France
| | - Bruno Da Costa
- Université Paris-Saclay, UVSQ, INRAE, VIM, Jouy-en-Josas, France
| | | | | | - Matthieu Réfregiers
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, Gif-sur-Yvette, France
| | - Frédéric Jamme
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, Gif-sur-Yvette, France
| | - Ronan Le Goffic
- Université Paris-Saclay, UVSQ, INRAE, VIM, Jouy-en-Josas, France.
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9
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Mettier J, Marc D, Sedano L, Da Costa B, Chevalier C, Le Goffic R. Study of the host specificity of PB1-F2-associated virulence. Virulence 2021; 12:1647-1660. [PMID: 34125653 PMCID: PMC8205076 DOI: 10.1080/21505594.2021.1933848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Influenza A viruses cause important diseases in both human and animal. The PB1-F2 protein is a virulence factor expressed by some influenza viruses. Its deleterious action for the infected host is mostly described in mammals, while the available information is scarce in avian hosts. In this work, we compared the effects of PB1-F2 in avian and mammalian hosts by taking advantage of the zoonotic capabilities of an avian H7N1 virus. In vitro, the H7N1 virus did not behave differently when PB1-F2 was deficient while a H3N2 virus devoid of PB1-F2 was clearly less inflammatory. Likewise, when performing in vivo challenges of either chickens or embryonated eggs, with the wild-type or the PB1-F2 deficient virus, no difference could be observed in terms of mortality, host response or tropism. PB1-F2 therefore does not appear to play a major role as a virulence factor in the avian host. However, when infecting NF-κB-luciferase reporter mice with the H7N1 viruses, a massive PB1-F2-dependent inflammation was quantified, highlighting the host specificity of PB1-F2 virulence. Surprisingly, a chimeric 7:1 H3N2 virus harboring an H7N1-origin segment 2 (i.e. expressing the avian PB1-F2) induced a milder inflammatory response than its PB1-F2-deficient counterpart. This result shows that the pro-inflammatory activity of PB1-F2 is governed by complex mechanisms involving components from both the virus and its infected host. Thus, a mere exchange of segment 2 between strains is not sufficient to transmit the deleterious character of PB1-F2.
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Affiliation(s)
- Joëlle Mettier
- Université Paris-Saclay, INRAE, UVSQ, UMR892 VIM, Jouy-en-Josas, France
| | - Daniel Marc
- UMR1282 Infectiologie Et Santé Publique, INRAE, Nouzilly, France
| | - Laura Sedano
- Université Paris-Saclay, INRAE, UVSQ, UMR892 VIM, Jouy-en-Josas, France
| | - Bruno Da Costa
- Université Paris-Saclay, INRAE, UVSQ, UMR892 VIM, Jouy-en-Josas, France
| | | | - Ronan Le Goffic
- Université Paris-Saclay, INRAE, UVSQ, UMR892 VIM, Jouy-en-Josas, France
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10
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Topham DJ, DeDiego ML, Nogales A, Sangster MY, Sant A. Immunity to Influenza Infection in Humans. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a038729. [PMID: 31871226 PMCID: PMC7919402 DOI: 10.1101/cshperspect.a038729] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review discusses the human immune responses to influenza infection with some insights from studies using animal models, such as experimental infection of mice. Recent technological advances in the study of human immune responses have greatly added to our knowledge of the infection and immune responses, and therefore much of the focus is on recent studies that have moved the field forward. We consider the complexity of the adaptive response generated by many sequential encounters through infection and vaccination.
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Affiliation(s)
- David J. Topham
- David H. Smith Center for Vaccine Biology and Immunology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Marta L. DeDiego
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, 28049 Madrid, Spain
| | - Aitor Nogales
- Instituto Nacional de Investigación y Tecnologia Agraria y Ailmentaria, 28040 Madrid, Spain
| | - Mark Y. Sangster
- David H. Smith Center for Vaccine Biology and Immunology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Andrea Sant
- David H. Smith Center for Vaccine Biology and Immunology, Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, USA
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11
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Roles of the Non-Structural Proteins of Influenza A Virus. Pathogens 2020; 9:pathogens9100812. [PMID: 33023047 PMCID: PMC7600879 DOI: 10.3390/pathogens9100812] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022] Open
Abstract
Influenza A virus (IAV) is a segmented, negative single-stranded RNA virus that causes seasonal epidemics and has a potential for pandemics. Several viral proteins are not packed in the IAV viral particle and only expressed in the infected host cells. These proteins are named non-structural proteins (NSPs), including NS1, PB1-F2 and PA-X. They play a versatile role in the viral life cycle by modulating viral replication and transcription. More importantly, they also play a critical role in the evasion of the surveillance of host defense and viral pathogenicity by inducing apoptosis, perturbing innate immunity, and exacerbating inflammation. Here, we review the recent advances of these NSPs and how the new findings deepen our understanding of IAV–host interactions and viral pathogenesis.
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12
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Influenza A virus PB1‐F2 protein: An ambivalent innate immune modulator and virulence factor. J Leukoc Biol 2020; 107:763-771. [DOI: 10.1002/jlb.4mr0320-206r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/14/2022] Open
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13
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Different Subtypes of Influenza Viruses Target Different Human Proteins and Pathways Leading to Different Pathogenic Phenotypes. BIOMED RESEARCH INTERNATIONAL 2019; 2019:4794910. [PMID: 31772934 PMCID: PMC6854240 DOI: 10.1155/2019/4794910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/17/2019] [Indexed: 12/11/2022]
Abstract
Different subtypes of influenza A viruses (IAVs) cause different pathogenic phenotypes after infecting human bodies. Analysis of the interactions between viral proteins and the host proteins may provide insights into the pathogenic mechanisms of the virus. In this paper, we found that the same proteins (nucleoprotein and neuraminidase) of H1N1 and H5N1 have different impacts on the NF-κB activation. By further examining the virus–host protein–protein interactions, we found that both NP and NA proteins of the H1N1 and H5N1 viruses target different host proteins. These results indicate that different subtypes of influenza viruses target different human proteins and pathways leading to different pathogenic phenotypes.
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14
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Ma J, Li S, Li K, Wang X, Li S. Effects of the PA-X and PB1-F2 Proteins on the Virulence of the 2009 Pandemic H1N1 Influenza A Virus in Mice. Front Cell Infect Microbiol 2019; 9:315. [PMID: 31552197 PMCID: PMC6734165 DOI: 10.3389/fcimb.2019.00315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/21/2019] [Indexed: 12/13/2022] Open
Abstract
There have been several previous reports showing that PA-X and PB1-F2 proteins can regulate innate immune responses and may play roles in the adaptation of influenza viruses to new hosts. In this research, we investigated, for the first time, the combined effects of PA-X and PB1-F2 proteins on viral virulence in mice. Based on the 2009 pH1N1 A/Guangdong/1057/2010 virus backbone, four viruses encoding different combinations of full-length or truncated PA-X and PB1-F2 proteins were rescued by a reverse genetic engineering system. We analyzed viral replication, host-shutoff activity, in vitro viral pathogenicity and in vivo host immune response. We found that simultaneously expressing the full-length PA-X and PB1-F2 proteins enhanced viral replication in vitro through increasing the accumulation of the RNP complex protein and enhanced viral pathogenicity in mice during the early stage of infection. Furthermore, PA-X and PB1-F2 simultaneously regulated the host innate response, and different forms of PB1-F2 proteins may have impacts on the host shutoff activity induced by the PA-X protein. Our results provide a better understanding of the mechanisms of PA-X and PB1-F2 proteins during viral replication, pathogenicity and host immune response.
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Affiliation(s)
- Jun Ma
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, China.,Guangdong Technological Engineering Research Center for Pet, Guangzhou, China
| | - Shun Li
- School of Life Science and Engineering, Foshan University, Foshan, China
| | - Kangjian Li
- School of Life Science and Engineering, Foshan University, Foshan, China
| | - Xiangbin Wang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, China.,Guangdong Technological Engineering Research Center for Pet, Guangzhou, China
| | - Shoujun Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, China.,Guangdong Technological Engineering Research Center for Pet, Guangzhou, China
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15
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H7N9 influenza A virus activation of necroptosis in human monocytes links innate and adaptive immune responses. Cell Death Dis 2019; 10:442. [PMID: 31165725 PMCID: PMC6549191 DOI: 10.1038/s41419-019-1684-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/06/2019] [Accepted: 05/23/2019] [Indexed: 12/16/2022]
Abstract
We previously demonstrated that avian influenza A H7N9 virus preferentially infected CD14+ monocyte in human peripheral blood mononuclear cells (PBMCs), which led to apoptosis. To better understand H7N9 pathogenesis in relation to monocyte cell death, we showed here that extensive phosphorylation of mixed lineage kinase domain-like (MLKL) protein occurred concurrently with the activation of caspases-8, -9 and -3 in H7N9-infected monocytes at 6 h post infection (hpi), indicating that apoptosis and necroptosis pathways were simultaneously activated. The apoptotic morphology was readily observed in H7N9-infected monocytes with transmission electron microscopy (TEM), while the pan-caspase inhibitor, IDN6556 (IDN), accelerated cell death through necroptosis as evidenced by the increased level of pMLKL accompanied with cell swelling and plasma membrane rupture. Most importantly, H7N9-induced cell death could only be stopped by the combined treatment of IDN and necrosulfonamide (NSA), a pMLKL membrane translocation inhibitor, but not by individual inhibition of caspase or RIPK3. Our data further showed that activation of apoptosis and necroptosis pathways in monocytes differentially contributed to the immune response of monocytes upon H7N9 infection. Specifically, caspase inhibition significantly enhanced, while RIPK3 inhibition reduced the early expression of type I interferons and cytokine/chemokines in H7N9-infected monocytes. Moreover, culture supernatants from IDN-treated H7N9-infected monocyte promoted the expression of co-stimulatory molecule CD80, CD83 and CD86 on freshly isolated monocytes and monocyte-derived dendritic cells (MDCs) and enhanced the capacity of MDCs to induce CD3+ T-cell proliferation in vitro. In contrast, these immune stimulatory effects were abrogated by using culture supernatants from H7N9-infected monocyte with RIPK3 inhibition. In conclusion, our findings indicated that H7N9 infection activated both apoptosis and necroptosis in monocytes. An intact RIPK3 activity is required for upregulation of innate immune responses, while caspase activation suppresses the immune response.
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16
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Fujikura D, Miyazaki T. Programmed Cell Death in the Pathogenesis of Influenza. Int J Mol Sci 2018; 19:ijms19072065. [PMID: 30012970 PMCID: PMC6073994 DOI: 10.3390/ijms19072065] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/04/2018] [Accepted: 07/12/2018] [Indexed: 12/17/2022] Open
Abstract
Influenza is a respiratory disease induced by infection by the influenza virus, which is a member of Orthomyxoviridae family. This infectious disease has serious impacts on public health systems and results in considerable mortality and economic costs throughout the world. Based on several experimental studies, massive host immune reaction is associated with the disease severity of influenza. Programmed cell death is typically induced during virus infection as a consequence of host immune reaction to limit virus spread by eliminating niches for virus propagation without causing inflammation. However, in some viral infectious diseases, such as influenza, in the process of immune reaction, aberrant induction of programmed cell death disturbs the maintenance of organ function. Current reports show that there are different types of programmed cell death that vary in terms of molecular mechanisms and/or associations with inflammation. In addition, these novel types of programmed cell death are associated with pathogenesis rather than suppressing virus propagation in the disease course. Here, we review our current understanding of mechanisms of programmed cell death in the pathogenesis of influenza.
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Affiliation(s)
- Daisuke Fujikura
- Center for Advanced Research and Education (CARE), Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa 078-8510, Japan.
| | - Tadaaki Miyazaki
- Department of Probiotics Immunology, Institute for Genetic Medicine, Hokkaido University, North-15, West-7, Kita-ku, Sapporo 060-0815, Japan.
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17
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Hu J, Ma C, Liu X. PA-X: a key regulator of influenza A virus pathogenicity and host immune responses. Med Microbiol Immunol 2018; 207:255-269. [PMID: 29974232 PMCID: PMC7086933 DOI: 10.1007/s00430-018-0548-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/28/2018] [Indexed: 02/07/2023]
Abstract
PA-X, a fusion protein belonging to influenza A viruses (IAVs), integrating the N-terminal 191 amino acids of PA gene and the ribosomal frame-shifting product that lengthens out to 41 or 61 amino acids. Since its discovery in 2012, multiple functions have been attributed to this small protein, including a process, where wide-spread protein synthesis in infected host cells is shut down (called host shutoff), and viral replication, polymerase activity, viral-induced cell apoptosis, PA nuclear localization, and virulence are modulated. However, many of its proposed functions may be specific to strain, subtype, host, or cell line. In this review, we start by describing the well-defined global host-shutoff ability of PA-X and the potential mechanisms underlying it. We move on to the role played by PA-X in modulating innate and acquired immune responses in the host. We then systematically discuss the role played by PA-X in modulating the virulence of influenza viruses of different subtypes and host origins, and finish with a general overview of the research advances made in identifying the host cell partners that interact with PA-X. To uncover possible clues about the differential effects of PA-X in modulating viral virulence, we focus on systemically evaluating polymorphisms in PA-X from various viral subtypes and hosts, including avian and human H5N1, H5N6, H9N2, and H7N9 viruses. Finally, we conclude with a proposition regarding the possible future research directions for this important protein.
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Affiliation(s)
- Jiao Hu
- Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, 225009, Jiangsu Province, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China (26116120), Yangzhou University, Yangzhou, China
| | - Chunxi Ma
- Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, 225009, Jiangsu Province, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China (26116120), Yangzhou University, Yangzhou, China
| | - Xiufan Liu
- Animal Infectious Disease Laboratory, School of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, 225009, Jiangsu Province, China.
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, Jiangsu, China.
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China (26116120), Yangzhou University, Yangzhou, China.
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18
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Virulent PB1-F2 residues: effects on fitness of H1N1 influenza A virus in mice and changes during evolution of human influenza A viruses. Sci Rep 2018; 8:7474. [PMID: 29749408 PMCID: PMC5945659 DOI: 10.1038/s41598-018-25707-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/26/2018] [Indexed: 11/25/2022] Open
Abstract
Specific residues of influenza A virus (IAV) PB1-F2 proteins may enhance inflammation or cytotoxicity. In a series of studies, we evaluated the function of these virulence-associated residues in the context of different IAV subtypes in mice. Here, we demonstrate that, as with the previously assessed pandemic 1968 (H3N2) IAV, PB1-F2 inflammatory residues increase the virulence of H1N1 IAV, suggesting that this effect might be a universal feature. Combining both inflammatory and cytotoxic residues in PB1-F2 enhanced virulence further, compared to either motif alone. Residues from these virulent motifs have been present in natural isolates from human seasonal IAV of all subtypes, but there has been a trend toward a gradual reduction in the number of virulent residues over time. However, human IAV of swine and avian origin tend to have more virulent residues than do the human-adapted seasonal strains, raising the possibility that donation of PB1 segments from these zoonotic viruses may increase the severity of some seasonal human strains. Our data suggest the value of surveillance of virulent residues in both human and animal IAV to predict the severity of influenza season.
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19
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Kamal RP, Alymova IV, York IA. Evolution and Virulence of Influenza A Virus Protein PB1-F2. Int J Mol Sci 2017; 19:E96. [PMID: 29286299 PMCID: PMC5796046 DOI: 10.3390/ijms19010096] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 12/20/2017] [Accepted: 12/25/2017] [Indexed: 02/05/2023] Open
Abstract
PB1-F2 is an accessory protein of most human, avian, swine, equine, and canine influenza A viruses (IAVs). Although it is dispensable for virus replication and growth, it plays significant roles in pathogenesis by interfering with the host innate immune response, inducing death in immune and epithelial cells, altering inflammatory responses, and promoting secondary bacterial pneumonia. The effects of PB1-F2 differ between virus strains and host species. This can at least partially be explained by the presence of multiple PB1-F2 sequence variants, including premature stop codons that lead to the expression of truncated PB1-F2 proteins of different lengths and specific virulence-associated residues that enhance susceptibility to bacterial superinfection. Although there has been a tendency for human seasonal IAV to gradually reduce the number of virulence-associated residues, zoonotic IAVs contain a reservoir of PB1-F2 proteins with full length, virulence-associated sequences. Here, we review the molecular mechanisms by which PB1-F2 may affect influenza virulence, and factors associated with the evolution and selection of this protein.
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Affiliation(s)
- Ram P Kamal
- Battelle Memorial Institute, Atlanta, GA 30329, USA.
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
| | - Irina V Alymova
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
| | - Ian A York
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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20
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21
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Host Response Comparison of H1N1- and H5N1-Infected Mice Identifies Two Potential Death Mechanisms. Int J Mol Sci 2017; 18:ijms18081631. [PMID: 28749409 PMCID: PMC5578021 DOI: 10.3390/ijms18081631] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/12/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022] Open
Abstract
Highly pathogenic influenza A viruses (IAV) infections represent a serious threat to humans due to their considerable morbidity and mortality capacities. A good understanding of the molecular mechanisms responsible for the acute lung injury observed during this kind of infection is essential to design adapted therapies. In the current study, using an unbiased transcriptomic approach, we compared the host-responses of mice infected with two different subtypes of IAV: H1N1 vs. H5N1. The host-response comparison demonstrated a clear difference between the transcriptomic profiles of H1N1- and H5N1-infected mice despite identical survival kinetics and similar viral replications. The ontological analysis of the two transcriptomes showed two probable causes of death: induction of an immunopathological state of the lung for the H1N1 strain vs. development of respiratory dysfunction in the case of the H5N1 IAV. Finally, a clear signature responsible for lung edema was specifically associated with the H5N1 infection. We propose a potential mechanism of edema development based on predictive bioinformatics tools.
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22
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Abstract
Our antiviral arsenal to fight influenza viruses is limited and we need novel anti-flu drugs. Recently, cellular drug targets came into focus and omics analysis were instrumental to suggest candidate factors. In this issue of The FEBS Journal, Kainov and colleagues used transcriptome data to investigate virus-induced changes in tryptophan metabolism that may serve as immunomodulatory approach against viruses.
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Affiliation(s)
- Yvonne Boergeling
- Institute of Virology (IVM), Westfaelische-Wilhelms University, Muenster, Germany
| | - Stephan Ludwig
- Institute of Virology (IVM), Westfaelische-Wilhelms University, Muenster, Germany
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23
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Leymarie O, Meyer L, Tafforeau L, Lotteau V, Costa BD, Delmas B, Chevalier C, Le Goffic R. Influenza virus protein PB1-F2 interacts with CALCOCO2 (NDP52) to modulate innate immune response. J Gen Virol 2017; 98:1196-1208. [PMID: 28613140 DOI: 10.1099/jgv.0.000782] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PB1-F2 is a viral protein encoded by influenza A viruses (IAVs). PB1-F2 is implicated in virulence by triggering immune cell apoptosis and enhancing inflammation. To obtain an insight into the molecular mechanisms of PB1-F2-mediated virulence, we used the yeast two-hybrid approach to find new PB1-F2 cellular interactors. This allowed us to identify calcium-binding and coiled-coil domain 2 (CALCOCO2, also known as NDP52) as a binding partner of PB1-F2. Binding of PB1-F2 to CALCOCO2 was confirmed by pull-down. Surface plasmon resonance binding experiments enabled us to estimate the dissociation constant (Kd) of the two partners to be around 20 nM. Using bioinformatics tools, we designed a CALCOCO2 interaction map based on previous knowledge and showed a strong connection between this protein and the type I interferon production pathways and the I-κB kinase/NF-κB signalling pathway. NF-κB reporter assays in which CALCOCO2, MAVS and PB1-F2 were co-expressed showed a cooperation of these three proteins to increase the inflammatory response. By contrast, PB1-F2 inhibits the TBK1-dependent activation of an ISRE reporter plasmid. We also demonstrated that the signal transducer TRAF6 is implicated in the enhancement of NF-κB activity mediated by PB1-F2/CALCOCO2 binding. Altogether, this report provides evidence of an interaction link between PB1-F2 and human proteins, and allows a better understanding of the involvement of PB1-F2 in the pathologic process mediated by IAV.
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Affiliation(s)
- Olivier Leymarie
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Léa Meyer
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Lionel Tafforeau
- IMAP Team, Inserm Unit 851, 21, Av. T. Garnier, 69007 Lyon, France.,Present address: Laboratory of Cellular Biology, Research Institute for Biosciences, University of Mons-UMONS, Belgium
| | - Vincent Lotteau
- INSERM U1111, Lyon, France.,CIRI, Centre de Recherche en Infectiologie, Lyon, France.,Université de Lyon, France
| | - Bruno Da Costa
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Bernard Delmas
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Ronan Le Goffic
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
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24
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Cheng YY, Yang SR, Wang YT, Lin YH, Chen CJ. Amino Acid Residues 68-71 Contribute to Influenza A Virus PB1-F2 Protein Stability and Functions. Front Microbiol 2017; 8:692. [PMID: 28484439 PMCID: PMC5399091 DOI: 10.3389/fmicb.2017.00692] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 04/04/2017] [Indexed: 11/13/2022] Open
Abstract
Influenza A virus PB1-F2, encoding a multi-functional protein, is regarded as a virulent gene. Variation in expression pattern and protein stability among PB1-F2 proteins derived from different strains may explain why PB1-F2 functions in a strain- and cell type-specific manner. Because the protein stability of PB1-F2 affects its biological functions, we looked for sequences important for this property. By comparing variants and chimeric of PB1-F2 proteins from A/Hong Kong/156/1997 (H5N1) and A/Puerto Rico/8/1934 (H1N1), we identified amino acid residues 68-71 affect its protein stability. PB1-F2 with T68, Q69, D70, and S71 has a shorter protein half-life than its I68, L69, V70, and F71 counterpart. This is likely to do with proteasome-mediated degradation. Swapping amino acids 68-71 between two proteins reversed not only the length of protein half-life and sensitivity to MG132, but also subcellular localization and interferon antagonization. Our data suggested that composition of amino acids 68-71, which regulates protein stability and therefore its functions, can be a major factor determining strain-specificity of PB1-F2.
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Affiliation(s)
- Yi-Ying Cheng
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, Taiwan.,Program in Molecular Medicine, National Yang-Ming University and Academia SinicaTaipei, Taiwan
| | - Shih-Rang Yang
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, Taiwan
| | - Ying-Ting Wang
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, Taiwan
| | - Yu-Hsin Lin
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, Taiwan
| | - Chi-Ju Chen
- Institute of Microbiology and Immunology, National Yang-Ming UniversityTaipei, Taiwan
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25
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Gaelings L, Söderholm S, Bugai A, Fu Y, Nandania J, Schepens B, Lorey MB, Tynell J, Vande Ginste L, Le Goffic R, Miller MS, Kuisma M, Marjomäki V, De Brabander J, Matikainen S, Nyman TA, Bamford DH, Saelens X, Julkunen I, Paavilainen H, Hukkanen V, Velagapudi V, Kainov DE. Regulation of kynurenine biosynthesis during influenza virus infection. FEBS J 2016; 284:222-236. [PMID: 27860276 DOI: 10.1111/febs.13966] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 11/08/2016] [Accepted: 11/15/2016] [Indexed: 01/03/2023]
Abstract
Influenza A viruses (IAVs) remain serious threats to public health because of the shortage of effective means of control. Developing more effective virus control modalities requires better understanding of virus-host interactions. It has previously been shown that IAV induces the production of kynurenine, which suppresses T-cell responses, enhances pain hypersensitivity and disturbs behaviour in infected animals. However, the regulation of kynurenine biosynthesis during IAV infection remains elusive. Here we showed that IAV infection induced expression of interferons (IFNs), which upregulated production of indoleamine-2,3-dioxygenase (IDO1), which catalysed the kynurenine biosynthesis. Furthermore, IAV attenuated the IDO1 expression and the production of kynurenine through its NS1 protein. Interestingly, inhibition of viral replication prior to IFN induction limited IDO1 expression, while inhibition after did not. Finally, we showed that kynurenine biosynthesis was activated in macrophages in response to other stimuli, such as influenza B virus, herpes simplex virus 1 and 2 as well as bacterial lipopolysaccharides. Thus, the tight regulation of the kynurenine biosynthesis by host cell and, perhaps, pathogen might be a basic signature of a wide range of host-pathogen interactions, which should be taken into account during development of novel antiviral and antibacterial drugs.
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Affiliation(s)
- Lana Gaelings
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland
| | - Sandra Söderholm
- Institute of Biotechnology (BI), University of Helsinki, Finland.,Finnish Institute of Occupational Health (TTL), Helsinki, Finland
| | - Andrii Bugai
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Finland
| | - Yu Fu
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland
| | - Jatin Nandania
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland
| | - Bert Schepens
- Medical Biotechnology Center, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Belgium
| | - Martina B Lorey
- Finnish Institute of Occupational Health (TTL), Helsinki, Finland
| | - Janne Tynell
- National Institute for Health and Welfare (THL), Helsinki, Finland
| | - Liesbeth Vande Ginste
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Finland.,Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Ronan Le Goffic
- Centre de Recherche de Jouy-en-Josas UR0892 Unité VIM - Virologie & Immunologie Moléculaires, Domaine de Vilvert, Jouy-en-Josas, France
| | - Matthew S Miller
- Department of Biochemistry and Biomedical Sciences, Institute for Infectious Diseases Research, McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
| | - Marika Kuisma
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Finland
| | - Varpu Marjomäki
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, Finland
| | - Jef De Brabander
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Tuula A Nyman
- Institute of Clinical Medicine, Rikshospitalet, Oslo, Norway
| | - Dennis H Bamford
- Institute of Biotechnology (BI), University of Helsinki, Finland
| | - Xavier Saelens
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Finland.,Medical Biotechnology Center, VIB, Ghent, Belgium
| | - Ilkka Julkunen
- National Institute for Health and Welfare (THL), Helsinki, Finland.,Department of Virology, University of Turku, Finland
| | | | | | - Vidya Velagapudi
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland
| | - Denis E Kainov
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland
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26
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Vidy A, Maisonnasse P, Da Costa B, Delmas B, Chevalier C, Le Goffic R. The Influenza Virus Protein PB1-F2 Increases Viral Pathogenesis through Neutrophil Recruitment and NK Cells Inhibition. PLoS One 2016; 11:e0165361. [PMID: 27798704 PMCID: PMC5087861 DOI: 10.1371/journal.pone.0165361] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/11/2016] [Indexed: 12/12/2022] Open
Abstract
The influenza A virus (IAV) PB1-F2 protein is a virulence factor contributing to the pathogenesis observed during IAV infections in mammals. In this study, using a mouse model, we compared the host response associated with PB1-F2 with an early transcriptomic signature that was previously associated with neutrophils and consecutively fatal IAV infections. This allowed us to show that PB1-F2 is partly involved in neutrophil-related mechanisms leading to death. Using neutropenic mice, we confirmed that the harmful effect of PB1-F2 is due to an excessive inflammation mediated by an increased neutrophil mobilization. We identified the downstream effects of this PB1-F2-exacerbated neutrophil recruitment. PB1-F2 had no impact on the lymphocyte recruitment in the airways at day 8 pi. However, functional genomics analysis and flow cytometry in broncho-alveolar lavages at 4 days pi revealed that PB1-F2 induced a NK cells deficiency. Thus, our results identify PB1-F2 as an important immune disruptive factor during the IAV infection.
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Affiliation(s)
- Aurore Vidy
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Bruno Da Costa
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Bernard Delmas
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Ronan Le Goffic
- VIM, INRA, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- * E-mail:
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Chevalier C, Le Goffic R, Jamme F, Leymarie O, Réfrégiers M, Delmas B. Synchrotron Infrared and Deep UV Fluorescent Microspectroscopy Study of PB1-F2 β-Aggregated Structures in Influenza A Virus-infected Cells. J Biol Chem 2016; 291:9060-72. [PMID: 26896002 DOI: 10.1074/jbc.m115.710533] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Indexed: 11/06/2022] Open
Abstract
PB1-F2 is a virulence factor of influenza A virus (IAV) whose functions remain misunderstood. The different roles of PB1-F2 may be linked to its structural polymorphism and to its propensity to assemble into oligomers and amyloid fibers in the vicinity of the membrane of IAV-infected cells. Here, we monitored the impact of PB1-F2 on the biochemical composition and protein structures of human epithelial pulmonary cells (A549) and monocytic cells (U937) upon IAV infection using synchrotron Fourier-transform infrared (FTIR) and deep UV (DUV) microscopies at the single-cell level. Cells were infected with a wild-type IAV and its PB1-F2 knock-out mutant for analyses at different times post-infection. IR spectra were recorded in each condition and processed to evaluate the change in the component band of the spectra corresponding to the amide I (secondary structure) and the CH stretching region (membrane). The IR spectra analysis revealed that expression of PB1-F2 in U937 cells, but not in A549 cells, results in the presence of a specific β-aggregate signature. Furthermore, the lipid membrane composition of U937 cells expressing PB1-F2 was also altered in a cell type-dependent manner. Using DUV microscopy and taking advantage of the high content of tryptophan residues in the sequence of PB1-F2 (5/90 aa), we showed that the increase of the autofluorescent signal recorded in monocytic cells could be correlated with the IR detection of β-aggregates. Altogether, our results constitute an important step forward in the understanding of the cell type-dependent function of PB1-F2.
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Affiliation(s)
| | - Ronan Le Goffic
- From the VIM, UR892, INRA, Université PARIS-SACLAY, 78350 Jouy-en-Josas and
| | - Frédéric Jamme
- the DISCO and SMIS Beamlines, Synchrotron SOLEIL, L'Orme des Merisiers, 91190 Saint-Aubin, Gif-sur Yvette, France
| | - Olivier Leymarie
- From the VIM, UR892, INRA, Université PARIS-SACLAY, 78350 Jouy-en-Josas and
| | - Matthieu Réfrégiers
- the DISCO and SMIS Beamlines, Synchrotron SOLEIL, L'Orme des Merisiers, 91190 Saint-Aubin, Gif-sur Yvette, France
| | - Bernard Delmas
- From the VIM, UR892, INRA, Université PARIS-SACLAY, 78350 Jouy-en-Josas and
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28
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Codon Deletions in the Influenza A Virus PA Gene Generate Temperature-Sensitive Viruses. J Virol 2016; 90:3684-93. [PMID: 26792748 DOI: 10.1128/jvi.03101-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/14/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The influenza virus RNA-dependent RNA polymerase, which is composed of three subunits, PB1, PB2, and PA, catalyzes genome replication and transcription within the cell nucleus. The PA linker (residues 197 to 256) can be altered by nucleotide substitutions to engineer temperature-sensitive (ts), attenuated mutants that display a defect in the transport of the PA-PB1 complex to the nucleus at a restrictive temperature. In this study, we investigated the ability of the PA linker to tolerate deletion mutations for further in vitro and in vivo characterization. Four viable mutants with single-codon deletions were generated; all of them exhibited a ts phenotype that was associated with the reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using fluorescently tagged PB1, we observed that the deletion mutants did not efficiently recruit PB1 to reach the nucleus at a restrictive temperature (39.5°C). Mouse infections showed that the four mutants were attenuated and induced antibodies that were able to protect mice from challenge with a lethal homologous wild-type virus. Serial in vitro passages of two deletion mutants at 39.5°C and 37°C did not allow the restoration of a wild-type phenotype among virus progeny. Thus, our results identify codons that can be deleted in the PA gene to engineer genetically stable ts mutants that could be used to design novel attenuated vaccines. IMPORTANCE In order to generate genetically stable live influenza A virus vaccines, we constructed viruses with single-codon deletions in a discrete domain of the RNA polymerase PA gene. The four rescued viruses exhibited a temperature-sensitive phenotype that we found was associated with a defect in the transport of the PA-PB1 dimer to the nucleus, where viral replication occurs. These ts deletion mutants were shown to be attenuated and to be able to produce antibodies in mice and to protect them from a lethal challenge. Assays to select revertants that were able to grow efficiently at a restrictive temperature failed, showing that these deletion mutants are genetically more stable than conventional substitution mutants. These results are of interest for the design of genetically stable live influenza virus vaccines.
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Wang Q, Wu Y, Cai Y, Zhuang Y, Xu L, Wu B, Zhang Y. Spleen Transcriptome Profile of Muscovy Ducklings in Response to Infection With Muscovy Duck Reovirus. Avian Dis 2015; 59:282-90. [PMID: 26473680 DOI: 10.1637/10992-112514-reg] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Muscovy duck reovirus (MDRV) causes high morbidity and mortality in ducklings. However, the molecular basis for pathogenesis of this virus remains poorly understood, and the complete genome sequence of Muscovy duck is lacking. Here we report the transcriptome profile of Muscovy ducks in response to MDRV infection. RNA sequencing technology was employed to obtain a representative complement of transcripts from the spleen of ducklings, and then differential gene expression was analyzed between MDRV-YB strain infected ducks and noninfected ducks. This analysis generated 65,536 unigenes. Of these, 6458 genes were found to be significantly differentially expressed between the infected and noninfected groups. The symptom and pathology of ducks infected with MDRV-YB was correlated with the greater proportion of decreased expression genes (4906) than increased expression (1552) level. Gene ontology analysis assigned differentially expressed genes to the categories: "biological processes," "cellular functions," and "molecular functions." Differentially expressed genes involved in the innate immune system were analyzed further, and 128 of these genes showed decreased expression and 86 showed increased expression between the infected and noninfected groups. These genes represented the Janus kinase-signal transducer and activator of transcription signaling pathway, and the retinoic acid-inducible gene I (RIG-I)-like and Toll-like receptor (TLR) signaling pathways and included interferon (IFN) α, IFNγ, interleukin 6, RIG-I, and TLR4. The data were verified by SYBR fluorescence quantitative polymerase chain reaction (SYBR-qPCR). Our findings offer new insight into the host immune response to MDRV infection.
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Affiliation(s)
- Quanxi Wang
- A College of Life Science, Fujian Normal University, Fuzhou, Fujian 350119, China.,B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yijian Wu
- B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yilong Cai
- B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yubin Zhuang
- B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Lihui Xu
- B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Baocheng Wu
- B College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yanding Zhang
- A College of Life Science, Fujian Normal University, Fuzhou, Fujian 350119, China
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Vidic J, Richard CA, Péchoux C, Da Costa B, Bertho N, Mazerat S, Delmas B, Chevalier C. Amyloid Assemblies of Influenza A Virus PB1-F2 Protein Damage Membrane and Induce Cytotoxicity. J Biol Chem 2015; 291:739-51. [PMID: 26601953 DOI: 10.1074/jbc.m115.652917] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 01/10/2023] Open
Abstract
PB1-F2 is a small accessory protein encoded by an alternative open reading frame in PB1 segments of most influenza A virus. PB1-F2 is involved in virulence by inducing mitochondria-mediated immune cells apoptosis, increasing inflammation, and enhancing predisposition to secondary bacterial infections. Using biophysical approaches we characterized membrane disruptive activity of the full-length PB1-F2 (90 amino acids), its N-terminal domain (52 amino acids), expressed by currently circulating H1N1 viruses, and its C-terminal domain (38 amino acids). Both full-length and N-terminal domain of PB1-F2 are soluble at pH values ≤6, whereas the C-terminal fragment was found soluble only at pH ≤ 3. All three peptides are intrinsically disordered. At pH ≥ 7, the C-terminal part of PB1-F2 spontaneously switches to amyloid oligomers, whereas full-length and the N-terminal domain of PB1-F2 aggregate to amorphous structures. When incubated with anionic liposomes at pH 5, full-length and the C-terminal part of PB1-F2 assemble into amyloid structures and disrupt membrane at nanomolar concentrations. PB1-F2 and its C-terminal exhibit no significant antimicrobial activity. When added in the culture medium of mammalian cells, PB1-F2 amorphous aggregates show no cytotoxicity, whereas PB1-F2 pre-assembled into amyloid oligomers or fragmented nanoscaled fibrils was highly cytotoxic. Furthermore, the formation of PB1-F2 amyloid oligomers in infected cells was directly reflected by membrane disruption and cell death as observed in U937 and A549 cells. Altogether our results demonstrate that membrane-lytic activity of PB1-F2 is closely linked to supramolecular organization of the protein.
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Affiliation(s)
- Jasmina Vidic
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas,
| | - Charles-Adrien Richard
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas
| | - Christine Péchoux
- the Génétique Animale et Biologie Intégrative, INRA, UMR1313, Domaine de Vilvert, 78350 Jouy en Josas, and
| | - Bruno Da Costa
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas
| | - Nicolas Bertho
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas
| | - Sandra Mazerat
- the Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, CNRS, UMR 8182, 91400 Orsay, France
| | - Bernard Delmas
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas
| | - Christophe Chevalier
- From the Unité de Virologie et Immunologie Moléculaires, INRA, UR892, Domaine de Vilvert, 78350 Jouy en Josas
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Influenza virus polymerase: Functions on host range, inhibition of cellular response to infection and pathogenicity. Virus Res 2015; 209:23-38. [DOI: 10.1016/j.virusres.2015.03.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Revised: 03/25/2015] [Accepted: 03/26/2015] [Indexed: 01/06/2023]
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Stobart CC, Moore ML. Development of next-generation respiratory virus vaccines through targeted modifications to viral immunomodulatory genes. Expert Rev Vaccines 2015; 14:1563-72. [PMID: 26434947 DOI: 10.1586/14760584.2015.1095096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vaccines represent one of the greatest contributions of the scientific community to global health. Yet, many pathogens remain either unchallenged or inadequately hindered by commercially available vaccines. Respiratory viruses pose distinct and difficult challenges due to their ability to rapidly spread, adapt, and modify the host immune response. Considerable research has been directed to understand the role of respiratory virus immunomodulatory proteins and how they influence the host immune response. We review here efforts to develop next-generation vaccines through targeting these key immunomodulatory genes in influenza virus, coronaviruses, respiratory syncytial virus, measles virus, and mumps virus.
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Affiliation(s)
- Christopher C Stobart
- a 1 Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA.,b 2 Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Martin L Moore
- a 1 Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA.,b 2 Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
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Neumann G. H5N1 influenza virulence, pathogenicity and transmissibility: what do we know? Future Virol 2015; 10:971-980. [PMID: 26617665 DOI: 10.2217/fvl.15.62] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Highly pathogenic influenza viruses of the H5N1 subtype have infected more than 600 people since 1997, resulting in the deaths of approximately 60% of those infected. Multiple studies have established the viral hemagglutinin (HA) surface glycoprotein as the major determinant of H5N1 virulence. HA mediates host-specific virus binding to cells, and mutations that allow efficient binding to viral receptors on mammalian cells are critical (although not sufficient) for H5N1 transmissibility among mammals. The viral polymerase PB2 protein is also a critical virulence determinant, and adaptive mutations in this protein are crucial for efficient H5N1 virus replication in mammals. Additionally, viral proteins (such as NS1 and PB1-F2) with roles in innate immune responses also affect the virulence of highly pathogenic H5N1 viruses.
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Affiliation(s)
- Gabriele Neumann
- Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 575 Science Drive, Madison, WI 53711, USA; Tel.: +1 608 890 2907; ;
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Košík I, Práznovská M, Košíková M, Bobišová Z, Hollý J, Varečková E, Kostolanský F, Russ G. The ubiquitination of the influenza A virus PB1-F2 protein is crucial for its biological function. PLoS One 2015; 10:e0118477. [PMID: 25866881 PMCID: PMC4395099 DOI: 10.1371/journal.pone.0118477] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 01/18/2015] [Indexed: 12/24/2022] Open
Abstract
The aim of the present study was to identify what influences the short half-life of the influenza A virus PB1-F2 protein and whether a prolonged half-life affects the properties of this molecule. We hypothesized that the short half-life of PB1-F2 could conceal the phenotype of the protein. Because proteasome degradation might be involved in PB1-F2 degradation, we focused on ubiquitination, a common label for proteasome targeting. A cluster of lysine residues was demonstrated as an ubiquitination acceptor site in evolutionary and functionally distinct proteins. The PB1-F2 sequence alignment revealed a cluster of lysines on the carboxy terminal end of PB1-F2 in almost all of the GenBank sequences available to date. Using a proximity ligation assay, we identified ubiquitination as a novel posttranslational modification of PB1-F2. Changing the lysines at positions 73, 78, and 85 to arginines suppressed the ubiquitination of A/Puerto Rico/8/1934 (H1N1)-derived PB1-F2. The mutation of the C-terminal lysine residue cluster positively affected the overall expression levels of avian A/Honk Kong/156/1997 (H5N1)- and mammalian A/Puerto Rico/8/1934 (H1N1)-derived PB1-F2. Moreover, increased PB1-F2 copy numbers strengthened the functions of this virus in the infected cells. The results of a minigenome luciferase reporter assay revealed an enhancement of viral RNA-dependent RNA polymerase activity in the presence of stabilized PB1-F2, regardless of viral origin. IFNβ antagonism was enhanced in 293T cells transfected with a plasmid expressing stabilized K→R mutant variants of PB1-F2. Compared with PB1-F2 wt, the loss of ubiquitination enhanced the antibody response after DNA vaccination. In summary, we revealed that PB1-F2 is an ubiquitinated IAV protein, and this posttranslational modification plays a central role in the regulation of the biological functions of this protein.
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Affiliation(s)
- Ivan Košík
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
- * E-mail:
| | - Margaréta Práznovská
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - Martina Košíková
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - Zuzana Bobišová
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - Jaroslav Hollý
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - Eva Varečková
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - František Kostolanský
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
| | - Gustáv Russ
- Institute of Virology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 05, Bratislava, Slovak Republic
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Temperature-Sensitive Mutants in the Influenza A Virus RNA Polymerase: Alterations in the PA Linker Reduce Nuclear Targeting of the PB1-PA Dimer and Result in Viral Attenuation. J Virol 2015; 89:6376-90. [PMID: 25855727 DOI: 10.1128/jvi.00589-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 03/30/2015] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED The influenza virus RNA-dependent RNA polymerase catalyzes genome replication and transcription within the cell nucleus. Efficient nuclear import and assembly of the polymerase subunits PB1, PB2, and PA are critical steps in the virus life cycle. We investigated the structure and function of the PA linker (residues 197 to 256), located between its N-terminal endonuclease domain and its C-terminal structured domain that binds PB1, the polymerase core. Circular dichroism experiments revealed that the PA linker by itself is structurally disordered. A large series of PA linker mutants exhibited a temperature-sensitive (ts) phenotype (reduced viral growth at 39.5°C versus 37°C/33°C), suggesting an alteration of folding kinetic parameters. The ts phenotype was associated with a reduced efficiency of replication/transcription of a pseudoviral reporter RNA in a minireplicon assay. Using a fluorescent-tagged PB1, we observed that ts and lethal PA mutants did not efficiently recruit PB1 to reach the nucleus at 39.5°C. A protein complementation assay using PA mutants, PB1, and β-importin IPO5 tagged with fragments of the Gaussia princeps luciferase showed that increasing the temperature negatively modulated the PA-PB1 and the PA-PB1-IPO5 interactions or complex stability. The selection of revertant viruses allowed the identification of different types of compensatory mutations located in one or the other of the three polymerase subunits. Two ts mutants were shown to be attenuated and able to induce antibodies in mice. Taken together, our results identify a PA domain critical for PB1-PA nuclear import and that is a "hot spot" to engineer ts mutants that could be used to design novel attenuated vaccines. IMPORTANCE By targeting a discrete domain of the PA polymerase subunit of influenza virus, we were able to identify a series of 9 amino acid positions that are appropriate to engineer temperature-sensitive (ts) mutants. This is the first time that a large number of ts mutations were engineered in such a short domain, demonstrating that rational design of ts mutants can be achieved. We were able to associate this phenotype with a defect of transport of the PA-PB1 complex into the nucleus. Reversion substitutions restored the ability of the complex to move to the nucleus. Two of these ts mutants were shown to be attenuated and able to produce antibodies in mice. These results are of high interest for the design of novel attenuated vaccines and to develop new antiviral drugs.
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PA-X decreases the pathogenicity of highly pathogenic H5N1 influenza A virus in avian species by inhibiting virus replication and host response. J Virol 2015; 89:4126-42. [PMID: 25631083 DOI: 10.1128/jvi.02132-14] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED PA-X is a newly discovered protein that decreases the virulence of the 1918 H1N1 virus in a mouse model. However, the role of PA-X in the pathogenesis of highly pathogenic avian influenza viruses (HPAIV) of the H5N1 subtype in avian species is totally unknown. By generating two PA-X-deficient viruses and evaluating their virulence in different animal models, we show here that PA-X diminishes the virulence of the HPAIV H5N1 strain A/Chicken/Jiangsu/k0402/2010 (CK10) in mice, chickens, and ducks. Expression of PA-X dampens polymerase activity and virus replication both in vitro and in vivo. Using microarray analysis, we found that PA-X blunts the global host response in chicken lungs, markedly downregulating genes associated with the inflammatory and cell death responses. Correspondingly, a decreased cytokine response was recapitulated in multiple organs of chickens and ducks infected with the wild-type virus relative to those infected with the PA-X-deficient virus. In addition, the PA-X protein exhibits antiapoptotic activity in chicken and duck embryo fibroblasts. Thus, our results demonstrated that PA-X acts as a negative virulence regulator and decreases virulence by inhibiting viral replication and the host innate immune response. Therefore, we here define the role of PA-X in the pathogenicity of H5N1 HPAIV, furthering our understanding of the intricate pathogenesis of influenza A virus. IMPORTANCE Influenza A virus (IAV) continues to pose a huge threat to global public health. Eight gene segments of the IAV genome encode as many as 17 proteins, including 8 main viral proteins and 9 accessory proteins. The presence of these accessory proteins may further complicate the pathogenesis of IAV. PA-X is a newly identified protein in segment 3 that acts to decrease the virulence of the 1918 H1N1 virus in mice by modulating host gene expression. Our study extends these functions of PA-X to H5N1 HPAIV. We demonstrated that loss of PA-X expression increases the virulence and replication of an H5N1 virus in mice and avian species and alters the host innate immune and cell death responses. Our report is the first to delineate the role of the novel PA-X protein in the pathogenesis of H5N1 viruses in avian species and promotes our understanding of H5N1 HPAIV.
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Alymova IV, York IA, McCullers JA. Non-avian animal reservoirs present a source of influenza A PB1-F2 proteins with novel virulence-enhancing markers. PLoS One 2014; 9:e111603. [PMID: 25368997 PMCID: PMC4219726 DOI: 10.1371/journal.pone.0111603] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 10/05/2014] [Indexed: 01/26/2023] Open
Abstract
PB1-F2 protein, expressed from an alternative reading frame of most influenza A virus (IAV) PB1 segments, may possess specific residues associated with enhanced inflammation (L62, R75, R79, and L82) and cytotoxicity (I68, L69, and V70). These residues were shown to increase the pathogenicity of primary viral and secondary bacterial infections in a mouse model. In contrast to human seasonal influenza strains, virulence-associated residues are present in PB1-F2 proteins from pandemic H1N1 1918, H2N2 1957, and H3N2 1968, and highly pathogenic H5N1 strains, suggesting their contribution to viruses' pathogenic phenotypes. Non-human influenza strains may act as donors of virulent PB1-F2 proteins. Previously, avian influenza strains were identified as a potential source of inflammatory, but not cytotoxic, PB1-F2 residues. Here, we analyze the frequency of virulence-associated residues in PB1-F2 sequences from IAVs circulating in mammalian species in close contact with humans: pigs, horses, and dogs. All four inflammatory residues were found in PB1-F2 proteins from these viruses. Among cytotoxic residues, I68 was the most common and was especially prevalent in equine and canine IAVs. Historically, PB1-F2 from equine (about 75%) and canine (about 20%) IAVs were most likely to have combinations of the highest numbers of residues associated with inflammation and cytotoxicity, compared to about 7% of swine IAVs. Our analyses show that, in addition to birds, pigs, horses, and dogs are potentially important sources of pathogenic PB1-F2 variants. There is a need for surveillance of IAVs with genetic markers of virulence that may be emerging from these reservoirs in order to improve pandemic preparedness and response.
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Affiliation(s)
- Irina V. Alymova
- Influenza Division, National Center for Immunization & Respiratory Diseases, Centers for Disease Control & Prevention, Atlanta, Georgia, United States of America
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Ian A. York
- Influenza Division, National Center for Immunization & Respiratory Diseases, Centers for Disease Control & Prevention, Atlanta, Georgia, United States of America
| | - Jonathan A. McCullers
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
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Miodek A, Sauriat-Dorizon H, Chevalier C, Delmas B, Vidic J, Korri-Youssoufi H. Direct electrochemical detection of PB1-F2 protein of influenza A virus in infected cells. Biosens Bioelectron 2014; 59:6-13. [DOI: 10.1016/j.bios.2014.02.037] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/06/2014] [Accepted: 02/14/2014] [Indexed: 10/25/2022]
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39
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Miodek A, Vidic J, Sauriat-Dorizon H, Richard CA, Le Goffic R, Korri-Youssoufi H, Chevalier C. Electrochemical Detection of the Oligomerization of PB1-F2 Influenza A Virus Protein in Infected Cells. Anal Chem 2014; 86:9098-105. [DOI: 10.1021/ac5018056] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anna Miodek
- CNRS UMR-8182,
Institut de Chimie Moléculaire et de Matériaux d’Orsay,
Equipe de Chimie Bioorganique et Bioinorganique, Bâtiment 420, 91405 Orsay, France
- INRA, Unité
de Virologie et Immunologie Moléculaires, UR892, Domaine de Vilvert, F-78350 Centre de Jouy-en-Josas, France
| | - Jasmina Vidic
- INRA, Unité
de Virologie et Immunologie Moléculaires, UR892, Domaine de Vilvert, F-78350 Centre de Jouy-en-Josas, France
| | - Helene Sauriat-Dorizon
- CNRS UMR-8182,
Institut de Chimie Moléculaire et de Matériaux d’Orsay,
Equipe de Chimie Bioorganique et Bioinorganique, Bâtiment 420, 91405 Orsay, France
| | - Charles-Adrien Richard
- INRA, Unité
de Virologie et Immunologie Moléculaires, UR892, Domaine de Vilvert, F-78350 Centre de Jouy-en-Josas, France
| | - Ronan Le Goffic
- INRA, Unité
de Virologie et Immunologie Moléculaires, UR892, Domaine de Vilvert, F-78350 Centre de Jouy-en-Josas, France
| | - Hafsa Korri-Youssoufi
- CNRS UMR-8182,
Institut de Chimie Moléculaire et de Matériaux d’Orsay,
Equipe de Chimie Bioorganique et Bioinorganique, Bâtiment 420, 91405 Orsay, France
| | - Christophe Chevalier
- INRA, Unité
de Virologie et Immunologie Moléculaires, UR892, Domaine de Vilvert, F-78350 Centre de Jouy-en-Josas, France
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40
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Schmitz ML, Kracht M, Saul VV. The intricate interplay between RNA viruses and NF-κB. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2754-2764. [PMID: 25116307 PMCID: PMC7114235 DOI: 10.1016/j.bbamcr.2014.08.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 08/01/2014] [Accepted: 08/02/2014] [Indexed: 12/19/2022]
Abstract
RNA viruses have rapidly evolving genomes which often allow cross-species transmission and frequently generate new virus variants with altered pathogenic properties. Therefore infections by RNA viruses are a major threat to human health. The infected host cell detects trace amounts of viral RNA and the last years have revealed common principles in the biochemical mechanisms leading to signal amplification that is required for mounting of a powerful antiviral response. Components of the RNA sensing and signaling machinery such as RIG-I-like proteins, MAVS and the inflammasome inducibly form large oligomers or even fibers that exhibit hallmarks of prions. Following a nucleation event triggered by detection of viral RNA, these energetically favorable and irreversible polymerization events trigger signaling cascades leading to the induction of antiviral and inflammatory responses, mediated by interferon and NF-κB pathways. Viruses have evolved sophisticated strategies to manipulate these host cell signaling pathways in order to ensure their replication. We will discuss at the examples of influenza and HTLV-1 viruses how a fascinating diversity of biochemical mechanisms is employed by viral proteins to control the NF-κB pathway at all levels.
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Affiliation(s)
- M Lienhard Schmitz
- Institute of Biochemistry, Medical Faculty, Friedrichstrasse 24, Justus-Liebig-University, 35392 Giessen, Germany.
| | - Michael Kracht
- Rudolf-Buchheim-Institute of Pharmacology, Justus-Liebig-University Giessen, D-35392 Giessen, Germany
| | - Vera V Saul
- Institute of Biochemistry, Medical Faculty, Friedrichstrasse 24, Justus-Liebig-University, 35392 Giessen, Germany
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41
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PB1-F2 attenuates virulence of highly pathogenic avian H5N1 influenza virus in chickens. PLoS One 2014; 9:e100679. [PMID: 24959667 PMCID: PMC4069075 DOI: 10.1371/journal.pone.0100679] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 05/30/2014] [Indexed: 01/08/2023] Open
Abstract
Highly pathogenic avian influenza virus (HPAIV) is a permanent threat due to its capacity to cross species barriers and generate severe infections and high mortality in humans. Recent findings have highlighted the potential role of PB1-F2, a small accessory influenza protein, in the pathogenesis process mediated by HPAIV in mammals. In this study, using a recombinant H5N1 HPAIV (wt) and its PB1-F2-deleted mutant (ΔF2), we studied the effects of PB1-F2 in a chicken model. Unexpectedly, when using low inoculation dose we observed that the wt-infected chickens had a higher survival rate than the ΔF2-infected chickens, a feature that contrasts with what is usually observed in mammals. High inoculation dose had similar mortality rate for both viruses, and comparison of the bio-distribution of the two viruses indicated that the expression of PB1-F2 allows a better spreading of the virus within chicken embryos. Transcriptomic profiles of lungs and blood cells were characterized at two days post-infection in chickens inoculated with the wild type (wt) or the ΔF2 mutant viruses. In lungs, the expression of PB1-F2 during the infection induced pathways related to calcium signaling and repressed a large panel of immunological functions. In blood cells, PB1-F2 was associated with a gene signature specific for mitochondrial dysfunction and down-modulated leucocytes activation. Finally we compared the effect of PB1-F2 in lungs of chickens and mice. We identified that gene signature associated to tissue damages is a PB1-F2 feature shared by the two species; by contrast, the early inhibition of immune response mediated by PB1-F2 observed in chickens is not seen in mice. In summary, our data suggest that PB1-F2 expression deeply affect the immune response in chickens in a way that may attenuate pathogenicity at low infection dose, a feature differing from what was previously observed in mammal species.
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42
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NLRX1 prevents mitochondrial induced apoptosis and enhances macrophage antiviral immunity by interacting with influenza virus PB1-F2 protein. Proc Natl Acad Sci U S A 2014; 111:E2110-9. [PMID: 24799673 DOI: 10.1073/pnas.1322118111] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
To subvert host immunity, influenza A virus (IAV) induces early apoptosis in innate immune cells by disrupting mitochondria membrane potential via its polymerase basic protein 1-frame 2 (PB1-F2) accessory protein. Whether immune cells have mechanisms to counteract PB1-F2-mediated apoptosis is currently unknown. Herein, we define that the host mitochondrial protein nucleotide-binding oligomerization domain-like receptor (NLR)X1 binds to viral protein PB1-F2, preventing IAV-induced macrophage apoptosis and promoting both macrophage survival and type I IFN signaling. We initially observed that Nlrx1-deficient mice infected with IAV exhibited increased pulmonary viral replication, as well as enhanced inflammatory-associated pulmonary dysfunction and morbidity. Analysis of the lungs of IAV-infected mice revealed markedly enhanced leukocyte recruitment but impaired production of type I IFN in Nlrx1(-/-) mice. Impaired type I IFN production and enhanced viral replication was recapitulated in Nlrx1(-/-) macrophages and was associated with increased mitochondrial mediated apoptosis. Through gain- and loss-of-function strategies for protein interaction, we identified that NLRX1 directly bound PB1-F2 in the mitochondria of macrophages. Using a recombinant virus lacking PB1-F2, we confirmed that deletion of PB1-F2 abrogated NLRX1-dependent macrophage type I IFN production and apoptosis. Thus, our results demonstrate that NLRX1 acts as a mitochondrial sentinel protecting macrophages from PB1-F2-induced apoptosis and preserving their antiviral function. We further propose that NLRX1 is critical for macrophage immunity against IAV infection by sensing the extent of viral replication and maintaining a protective balance between antiviral immunity and excessive inflammation within the lungs.
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43
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Wei H, Wang S, Chen Q, Chen Y, Chi X, Zhang L, Huang S, Gao GF, Chen JL. Suppression of interferon lambda signaling by SOCS-1 results in their excessive production during influenza virus infection. PLoS Pathog 2014; 10:e1003845. [PMID: 24391501 PMCID: PMC3879354 DOI: 10.1371/journal.ppat.1003845] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 11/05/2013] [Indexed: 12/25/2022] Open
Abstract
Innate cytokine response provides the first line of defense against influenza virus infection. However, excessive production of cytokines appears to be critical in the pathogenesis of influenza virus. Interferon lambdas (IFN-λ) have been shown to be overproduced during influenza virus infection, but the precise pathogenic processes of IFN-λ production have yet to be characterized. In this report, we observed that influenza virus induced robust expression of IFN-λ in alveolar epithelial cells (A549) mainly through a RIG-I-dependent pathway, but IFN-λ-induced phosphorylation of the signal transducer and activator of transcription protein 1 (STAT1) was dramatically inhibited in the infected cells. Remarkably, influenza virus infection induced robust expression of suppressor of cytokine signaling-1 (SOCS-1), leading to inhibition of STAT1 activation. Interestingly, the virus-induced SOCS-1 expression was cytokine-independent at early stage of infection both in vitro and in vivo. Using transgenic mouse model and distinct approaches altering the expression of SOCS-1 or activation of STAT signaling, we demonstrated that disruption of the SOCS-1 expression or expression of constitutively active STAT1 significantly reduced the production of IFN-λ during influenza virus infection. Furthermore, we revealed that disruption of IFN-λ signaling pathway by increased SOCS-1 protein resulted in the activation of NF-κB and thereby enhanced the IFN-λ expression. Together, these data imply that suppression of IFN-λ signaling by virus-induced SOCS-1 causes an adaptive increase in IFN-λ expression by host to protect cells against the viral infection, as a consequence, leading to excessive production of IFN-λ with impaired antiviral response. Influenza virus infection triggers innate immune responses. However, aberrant host immune responses such as excessive production of cytokines contribute to the pathogenesis of influenza virus. Type III interferons (IFN-λ) constitute the major innate immune response to influenza virus infection, but the precise pathogenic processes of IFN-λ production and mechanistic underpinnings are not well understood. In this study, we report that influenza virus induces robust IFN-λ expression mainly through a RIG-I-dependent pathway, but signaling activated by IFN-λ was dramatically inhibited by virus-induced SOCS-1. Importantly, we found that disruption of the SOCS-1 expression or forced activation of STAT1 significantly reduced the expression of IFN-λ in vitro and in vivo, suggesting that suppression of IFN-λ signaling by SOCS-1 results in their excessive production during influenza virus infection. Furthermore, our experiments revealed that disruption of IFN-λ signaling pathway resulted in the activation of NF-κB that governs the IFN-λ expression. Together these findings, we propose that impaired antiviral response of IFN-λ due to the inhibitory effect of SOCS-1 causes an adaptive increase in IFN-λ expression by host to protect cells against the viral infection. This is a novel mechanism that may be critical in the pathogenesis of the influenza virus strains that induce hypercytokinemia.
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Affiliation(s)
- Haitao Wei
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Song Wang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qinghuang Chen
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuhai Chen
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaojuan Chi
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lianfeng Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Shile Huang
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - George F. Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ji-Long Chen
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, China
- * E-mail:
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44
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Abstract
Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the following characteristics of infection: (1) higher or more prolonged virus replication, (2) excessive cytokine induction, and (3) replication in the lower respiratory tract. Nearly all the viral proteins contribute to virulence. Pigs are susceptible to infection with both human and avian viruses, which often results in gene reassortment between these viruses and endemic swine viruses. The receptors on the epithelial cells lining the respiratory tract are major determinants of infection by influenza viruses from other hosts. The polymerases, especially PB2, also influence cross-species infection. Methods of diagnosis and characterization of influenza viruses that infect swine have improved over the years, driven both by the availability of new technologies and by the necessity of keeping up with changes in the virus. Testing of oral fluids from pigs for virus and antibody is a recent development that allows efficient sampling of large numbers of animals.
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Affiliation(s)
- B H Janke
- DVM, PhD, Veterinary Diagnostic Laboratory, Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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45
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Josset L, Tisoncik-Go J, Katze MG. Moving H5N1 studies into the era of systems biology. Virus Res 2013; 178:151-67. [PMID: 23499671 PMCID: PMC3834220 DOI: 10.1016/j.virusres.2013.02.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/24/2013] [Indexed: 12/20/2022]
Abstract
The dynamics of H5N1 influenza virus pathogenesis are multifaceted and can be seen as an emergent property that cannot be comprehended without looking at the system as a whole. In past years, most of the high-throughput studies on H5N1-host interactions have focused on the host transcriptomic response, at the cellular or the lung tissue level. These studies pointed out that the dynamics and magnitude of the innate immune response and immune cell infiltration is critical to H5N1 pathogenesis. However, viral-host interactions are multidimensional and advances in technologies are creating new possibilities to systematically measure additional levels of 'omic data (e.g. proteomic, metabolomic, and RNA profiling) at each temporal and spatial scale (from the single cell to the organism) of the host response. Natural host genetic variation represents another dimension of the host response that determines pathogenesis. Systems biology models of H5N1 disease aim at understanding and predicting pathogenesis through integration of these different dimensions by using intensive computational modeling. In this review, we describe the importance of 'omic studies for providing a more comprehensive view of infection and mathematical models that are being developed to integrate these data. This review provides a roadmap for what needs to be done in the future and what computational strategies should be used to build a global model of H5N1 pathogenesis. It is time for systems biology of H5N1 pathogenesis to take center stage as the field moves toward a more comprehensive view of virus-host interactions.
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Affiliation(s)
- Laurence Josset
- Department of Microbiology, School of Medicine, University of Washington, Seattle, WA 98195, United States
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46
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Tripathi S, White MR, Hartshorn KL. The amazing innate immune response to influenza A virus infection. Innate Immun 2013; 21:73-98. [PMID: 24217220 DOI: 10.1177/1753425913508992] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Influenza A viruses (IAVs) remain a major health threat and a prime example of the significance of innate immunity. Our understanding of innate immunity to IAV has grown dramatically, yielding new concepts that change the way we view innate immunity as a whole. Examples include the role of p53, autophagy, microRNA, innate lymphocytes, endothelial cells and gut commensal bacteria in pulmonary innate immunity. Although the innate response is largely beneficial, it also contributes to major complications of IAV, including lung injury, bacterial super-infection and exacerbation of reactive airways disease. Research is beginning to dissect out which components of the innate response are helpful or harmful. IAV uses its limited genetic complement to maximum effect. Several viral proteins are dedicated to combating innate responses, while other viral structural or replication proteins multitask as host immune modulators. Many host innate immune proteins also multitask, having roles in cell cycle, signaling or normal lung biology. We summarize the plethora of new findings and attempt to integrate them into the larger picture of how humans have adapted to the threat posed by this remarkable virus. We explore how our expanded knowledge suggests ways to modulate helpful and harmful inflammatory responses, and develop novel treatments.
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Affiliation(s)
- Shweta Tripathi
- Boston University School of Medicine, Department of Medicine, Boston, MA, USA
| | - Mitchell R White
- Boston University School of Medicine, Department of Medicine, Boston, MA, USA
| | - Kevan L Hartshorn
- Boston University School of Medicine, Department of Medicine, Boston, MA, USA
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47
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A novel cytotoxic sequence contributes to influenza A viral protein PB1-F2 pathogenicity and predisposition to secondary bacterial infection. J Virol 2013; 88:503-15. [PMID: 24173220 DOI: 10.1128/jvi.01373-13] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enhancement of cell death is a distinguishing feature of H1N1 influenza virus A/Puerto Rico/8/34 protein PB1-F2. Comparing the sequences (amino acids [aa] 61 to 87 using PB1-F2 amino acid numbering) of the PB1-F2-derived C-terminal peptides from influenza A viruses inducing high or low levels of cell death, we identified a unique I68, L69, and V70 motif in A/Puerto Rico/8/34 PB1-F2 responsible for promotion of the peptide's cytotoxicity and permeabilization of the mitochondrial membrane. When administered to mice, a 27-mer PB1-F2-derived C-terminal peptide with this amino acid motif caused significantly greater weight loss and pulmonary inflammation than the peptide without it (due to I68T, L69Q, and V70G mutations). Similar to the wild-type peptide, A/Puerto Rico/8/34 elicited significantly higher levels of macrophages, neutrophils, and cytokines in the bronchoalveolar lavage fluid of mice than its mutant counterpart 7 days after infection. Additionally, infection of mice with A/Puerto Rico/8/34 significantly enhanced the levels of morphologically transformed epithelial and immune mononuclear cells recruited in the airways compared with the mutant virus. In the mouse bacterial superinfection model, both peptide and virus with the I68, L69, and V70 sequence accelerated development of pneumococcal pneumonia, as reflected by increased levels of viral and bacterial lung titers and by greater mortality. Here we provide evidence suggesting that the newly identified cytotoxic sequence I68, L69, and V70 of A/Puerto Rico/8/34 PB1-F2 contributes to the pathogenesis of both primary viral and secondary bacterial infections.
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48
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Jang YH, Byun YH, Lee KH, Park ES, Lee YH, Lee YJ, Lee J, Kim KH, Seong BL. Host defense mechanism-based rational design of live vaccine. PLoS One 2013; 8:e75043. [PMID: 24098364 PMCID: PMC3788757 DOI: 10.1371/journal.pone.0075043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 08/08/2013] [Indexed: 12/14/2022] Open
Abstract
Live attenuated vaccine (LAV), mimicking natural infection, provides an excellent protection against microbial infection. The development of LAV, however, still remains highly empirical and the rational design of clinically useful LAV is scarcely available. Apoptosis and caspase activation are general host antiviral responses in virus-infected cells. Utilizing these tightly regulated host defense mechanisms, we present a novel apoptosis-triggered attenuation of viral virulence as a rational design of live attenuated vaccine with desired levels of safety, efficacy, and productivity. Mutant influenza viruses carrying caspase recognition motifs in viral NP and the interferon-antagonist NS1 proteins were highly attenuated both in vitro and in vivo by caspase-mediated cleavage of those proteins in infected cells. Both viral replication and interferon-resistance were substantially reduced, resulting in a marked attenuation of virulence of the virus. Despite pronounced attenuation, the viruses demonstrated high growth phenotype in embryonated eggs at lower temperature, ensuring its productivity. A single dose vaccination with the mutant virus elicited high levels of systemic and mucosal antibody responses and provided complete protection against both homologous and heterologous lethal challenges in mouse model. While providing a practical means to generate seasonal or pandemic influenza live vaccines, the sensitization of viral proteins to pathogen-triggered apoptotic signals presents a potentially universal, mechanism-based rational design of live vaccines against many viral infections.
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Affiliation(s)
- Yo Han Jang
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
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49
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An insight into the PB1F2 protein and its multifunctional role in enhancing the pathogenicity of the influenza A viruses. Virology 2013; 440:97-104. [DOI: 10.1016/j.virol.2013.02.025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 01/18/2013] [Accepted: 02/27/2013] [Indexed: 02/01/2023]
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50
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Reis AL, McCauley JW. The influenza virus protein PB1-F2 interacts with IKKβ and modulates NF-κB signalling. PLoS One 2013; 8:e63852. [PMID: 23704945 PMCID: PMC3660569 DOI: 10.1371/journal.pone.0063852] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 04/07/2013] [Indexed: 11/22/2022] Open
Abstract
PB1-F2, a protein encoded by a second open reading frame of the influenza virus RNA segment 2, has emerged as a modulator of lung inflammatory responses but the molecular mechanisms underlying this are only poorly understood. Here we show that PB1-F2 inhibits the activation of NF-κB dependent signalling pathways in luciferase reporter assays. PB1-F2 proteins from four different viruses interact with IKKβ in yeast two-hybrid assays and by co-immunoprecipitation. PB1-F2 expression did not inhibit IKKβ kinase activity or NF-κB translocation into the nucleus, but NF-κB binding to DNA was severely impaired in PB1-F2 transfected cells as assessed by Electrophoretic Mobility Shift Assay. Neither the N-terminal 57 amino acid truncated forms nor the C-terminus of PB1-F2 were able to inhibit NF-κB dependent signalling, indicating that the full length protein is necessary for the inhibition.
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Affiliation(s)
- Ana Luísa Reis
- Division of Virology, MRC National Institute for Medical Research, London, United Kingdom
| | - John W. McCauley
- Division of Virology, MRC National Institute for Medical Research, London, United Kingdom
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