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He Y, Song S, Wu J, Wu J, Zhang L, Sun L, Li Z, Wang X, Kou Z, Liu T. Emergence of Eurasian Avian-Like Swine Influenza A (H1N1) virus in a child in Shandong Province, China. BMC Infect Dis 2024; 24:550. [PMID: 38824508 PMCID: PMC11143696 DOI: 10.1186/s12879-024-09441-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 05/27/2024] [Indexed: 06/03/2024] Open
Abstract
BACKGROUND Influenza A virus infections can occur in multiple species. Eurasian avian-like swine influenza A (H1N1) viruses (EAS-H1N1) are predominant in swine and occasionally infect humans. A Eurasian avian-like swine influenza A (H1N1) virus was isolated from a boy who was suffering from fever; this strain was designated A/Shandong-binzhou/01/2021 (H1N1). The aims of this study were to investigate the characteristics of this virus and to draw attention to the need for surveillance of influenza virus infection in swine and humans. METHODS Throat-swab specimens were collected and subjected to real-time fluorescent quantitative polymerase chain reaction (RT‒PCR). Positive clinical specimens were inoculated onto Madin-Darby canine kidney (MDCK) cells to isolate the virus, which was confirmed by a haemagglutination assay. Then, whole-genome sequencing was carried out using an Illumina MiSeq platform, and phylogenetic analysis was performed with MEGA X software. RESULTS RT‒PCR revealed that the throat-swab specimens were positive for EAS-H1N1, and the virus was subsequently successfully isolated from MDCK cells; this strain was named A/Shandong-binzhou/01/2021 (H1N1). Whole-genome sequencing and phylogenetic analysis revealed that A/Shandong-binzhou/01/2021 (H1N1) is a novel triple-reassortant EAS-H1N1 lineage that contains gene segments from EAS-H1N1 (HA and NA), triple-reassortant swine influenza H1N2 virus (NS) and A(H1N1) pdm09 viruses (PB2, PB1, PA, NP and MP). CONCLUSIONS The isolation and analysis of the A/Shandong-binzhou/01/2021 (H1N1) virus provide further evidence that EAS-H1N1 poses a threat to human health, and greater attention should be given to the surveillance of influenza virus infections in swine and humans.
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Affiliation(s)
- Yujie He
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Shaoxia Song
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Jie Wu
- Binzhou Center for Disease Prevention and Control, Binzhou, China
| | - Julong Wu
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Lifang Zhang
- Binzhou Center for Disease Prevention and Control, Binzhou, China
| | - Lin Sun
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Zhong Li
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Xianjun Wang
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Zengqiang Kou
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China
| | - Ti Liu
- Shandong Provincial Center for Disease Prevention and Control, Jinan, China.
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Ferrando VA, Friedrich ME, Gandhi S, Mellmann A, Masemann D, Christersson A, Anhlan D, Brunotte L, Stoll M, Harder T, Beer M, Boergeling Y, Ludwig S. Cell-intrinsic genomic reassortment of pandemic H1N1 2009 and Eurasian avian-like swine influenza viruses results in potentially zoonotic variants. Emerg Microbes Infect 2023; 12:2212809. [PMID: 37191590 DOI: 10.1080/22221751.2023.2212809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Influenza A viruses (IAV) cause annual epidemics and occasional pandemics in humans. The most recent pandemic outbreak occurred in 2009 with H1N1pdm09. This virus, which most likely reassorted in swine before its transmission to humans, was reintroduced into the swine population and continues circulating ever since. In order to assess its potential to cause reassortants on a cellular level, human origin H1N1pdm09 and a recent Eurasian avian-like H1N1 swine IAV were (co-)passaged in the newly generated swine lung cell line C22. Co-infection with both viruses gave rise to numerous reassortants that additionally carry different mutations which can partially be found in nature as well. Reassortment most frequently affected the PB1, PA and NA segments with the swine IAV as recipient. These reassortants reached higher titers in swine lung cells and were able to replicate in genuine human lung tissue explants ex vivo, suggesting a possible zoonotic potential. Interestingly, reassortment and mutations in the viral ribonucleoprotein complex influence the viral polymerase activity in a cell type and species-specific manner. In summary, we demonstrate reassortment promiscuity of these viruses in a novel swine lung cell model and indicate a possible zoonotic potential of the reassortants.
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Affiliation(s)
- Verónica A Ferrando
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Marcel E Friedrich
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Shrey Gandhi
- Department of Genetic Epidemiology, Institute of Human Genetics, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Alexander Mellmann
- Institute of Hygiene Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Dörthe Masemann
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Anmari Christersson
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Darisuren Anhlan
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Linda Brunotte
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Monika Stoll
- Department of Genetic Epidemiology, Institute of Human Genetics, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Timm Harder
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute 17493 Greifswald, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institute 17493 Greifswald, Germany
| | - Yvonne Boergeling
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
| | - Stephan Ludwig
- Institute of Virology Münster, Westfälische Wilhelms-University 48149 Münster, Germany
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Adaptation of Two Wild Bird-Origin H3N8 Avian Influenza Viruses to Mammalian Hosts. Viruses 2022; 14:v14051097. [PMID: 35632838 PMCID: PMC9147613 DOI: 10.3390/v14051097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
Wild birds play an important role in the emergence, evolution, and spread of zoonotic avian influenza viruses (AIVs). However, there are few studies on the cross-species transmission of the H3N8 AIV originating from wild birds. In this study, we investigated the transmissibility and pathogenicity of two H3N8 low pathogenic avian influenza viruses (LPAIVs) isolated from wild birds, GZA1 and XJ47, to mammals. The HA genes of both strains belonged to Eurasian isolates, while the other genes were derived from a variety of other subtypes of AIVs. Both strains can infect specific-pathogen-free (SPF) chickens, BALB/c mice, and guinea pigs. The XJ47 strain spread horizontally in SPF chickens and guinea pigs. The GZA1 strain did not spread horizontally but caused higher weight loss and mild lung inflammation in mice. P12-GZA1- and P12-XJ47-adapted strains obtained after 12 passages in the lung of mice showed enhanced pathogenicity in mice, which led to obvious clinical symptoms, lung inflammation, and 100% death. Both adapted strains have the reported mutation T97I in the PA, and the reported mutation D701N in PB2 has been found in the P12-GZA1-adapted strain. This study provides an important scientific basis for the continuous monitoring of wild AIVs and the mechanism underlying AIV cross-species transmission.
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4
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Substitution of I222L-E119V in neuraminidase from highly pathogenic avian influenza H7N9 virus exhibited synergistic resistance effect to oseltamivir in mice. Sci Rep 2021; 11:16293. [PMID: 34381119 PMCID: PMC8358046 DOI: 10.1038/s41598-021-95771-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 07/29/2021] [Indexed: 11/08/2022] Open
Abstract
That the high frequency and good replication capacity of strains with reduced susceptibility to neuraminidase inhibitors (NAIs) in highly pathogenic avian influenza H7N9 (HPAI H7N9) virus made it a significance to further study its drug resistance. HPAI H7N9 viruses bearing NA I222L or E119V substitution and two mutations of I222L-E119V as well as their NAIs-sensitive counterpart were generated by reverse genetics for NA inhibition test and replication capability evaluation in vitro. The attenuated H7N9/PR8 recombinant viruses were developed to study the pathogenicity and drug resistance brought by the above substitutions to mice. The IC50 fold change of oseltamivir to HPAI H7N9 with NA222L-119V is 306.34 times than that of its susceptible strain, and 3.5 times than the E119V mutant virus. HPAI H7N9 bearing NA222L-119V had good replication ability with peak value of more than 6log10 TCID50/ml in MDCK cells. H7N9/PR8 virus bearing NA222L-119V substitutions leaded to diffuse pneumonia, significant weight loss and fatality in mice. NA E119V made H7N9/PR8 virus resistant to oseltamivir, and I222L-E119V had synergistic resistance to oseltamivir in mice. Due to the good fitness of drug resistant strains of HPAI H7N9 virus, it is necessary to strengthen drug resistance surveillance and new drug research.
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5
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Ryt-Hansen P, Krog JS, Breum SØ, Hjulsager CK, Pedersen AG, Trebbien R, Larsen LE. Co-circulation of multiple influenza A reassortants in swine harboring genes from seasonal human and swine influenza viruses. eLife 2021; 10:60940. [PMID: 34313225 PMCID: PMC8397370 DOI: 10.7554/elife.60940] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 07/21/2021] [Indexed: 12/11/2022] Open
Abstract
Since the influenza pandemic in 2009, there has been an increased focus on swine influenza A virus (swIAV) surveillance. This paper describes the results of the surveillance of swIAV in Danish swine from 2011 to 2018. In total, 3800 submissions were received with a steady increase in swIAV-positive submissions, reaching 56% in 2018. Full-genome sequences were obtained from 129 swIAV-positive samples. Altogether, 17 different circulating genotypes were identified including six novel reassortants harboring human seasonal IAV gene segments. The phylogenetic analysis revealed substantial genetic drift and also evidence of positive selection occurring mainly in antigenic sites of the hemagglutinin protein and confirmed the presence of a swine divergent cluster among the H1pdm09Nx (clade 1A.3.3.2) viruses. The results provide essential data for the control of swIAV in pigs and emphasize the importance of contemporary surveillance for discovering novel swIAV strains posing a potential threat to the human population.
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Affiliation(s)
- Pia Ryt-Hansen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.,University of Copenhagen, Department of Health Sciences, Institute for Animal and Veterinary Sciences, Frederiksberg, Denmark
| | | | | | | | - Anders Gorm Pedersen
- Department of Health Technology, Section for Bioinformatics, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Lars Erik Larsen
- Technical University of Denmark, National Veterinary Institute, Lyngby, Denmark.,University of Copenhagen, Department of Health Sciences, Institute for Animal and Veterinary Sciences, Frederiksberg, Denmark
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6
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Zhou L, Feng Z, Liu J, Chen Y, Yang L, Liu S, Li X, Gao R, Zhu W, Wang D, Shu Y. A single N342D substitution in Influenza B Virus NA protein determines viral pathogenicity in mice. Emerg Microbes Infect 2021; 9:1853-1863. [PMID: 32746754 PMCID: PMC7473139 DOI: 10.1080/22221751.2020.1806005] [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] [Indexed: 12/02/2022]
Abstract
Influenza B virus (IBV) is one of the most important human respiratory viruses: it causes approximately one-third of the global influenza-related disease burden each year. However, compared with the several pathogenicity-related molecular markers that have been identified for influenza A virus (IAV), little is known about potential IBV pathogenicity-related markers. Here, although the IBV strain B/Anhui-Tunxi/1528/2014 (AH1528/14) exhibited a more efficient replication ability in vitro and higher pathogenicity in vivo compared with IBV strain B/Anhui-Baohe/127/2015 (AH127/15), only three amino acids differences (HAA390E, NAN342D and PB1V212I) were observed among their full genomes. The contributions of each amino acid difference to the virus pathogenicity were further investigated. Compared with the wild type IBV virus rAH127, the recombinant virus harbouring a single substitution of HAA390E had a similar phenotype, whereas the recombinant virus harbouring PB1V212I replicated to a moderately higher titre in both MDCK cells and in mice. Notably, the virus harbouring NAN342D showed significantly better growth properties in MDCK cells and higher fatality rates in mice. In addition, the presence of NAN342D dramatically enhanced the viral neuraminidase activity. In conclusion, our study identified a novel IBV molecular marker, NAN342D, that could significantly increase the virulence of IBV in mice.
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Affiliation(s)
- Lijuan Zhou
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, People's Republic of China.,National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Zhaomin Feng
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Jia Liu
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Yongkun Chen
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, People's Republic of China
| | - Lei Yang
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Suli Liu
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, People's Republic of China
| | - Xiyan Li
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Rongbao Gao
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Wenfei Zhu
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Dayan Wang
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Yuelong Shu
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangdong, People's Republic of China.,National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
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7
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Liu Y, Fu C, Ye S, Liang Y, Qi Z, Yao C, Wang Z, Wang J, Cai S, Tang S, Chen Y, Li S. The inactivated vaccine of reassortant H3N2 canine influenza virus based on internal gene cassette from PR8 is safe and effective. Vet Microbiol 2021; 254:108997. [PMID: 33524810 DOI: 10.1016/j.vetmic.2021.108997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/16/2021] [Indexed: 11/28/2022]
Abstract
Canine influenza (CI) is a contagious respiratory disease in dogs, which poses a threat to canine health. A safe, high-yield vaccine seed virus is critical for CI vaccine development. We developed a PR8-based reassortant H3N2 canine influenza virus (RT CIV) using the reverse genetic method and evaluated its yield in canine kidney epithelial (MDCK) cells, Vero cells, and specific pathogen-free (SPF) chicken embryos. Mice and dogs were infected with RT CIV, and the pathogenicity was evaluated. The viral titers of RT CIV increased in MDCK cells, Vero cells, and SPF chicken embryos; the HA yield in SPF chicken embryos increased 4-fold. However, RT CIV was not lethal to mice, and it showed similar virulence as wild-type CIV. RT CIV also showed minimal pathogenicity in dogs, which manifested as mild fever and rhinorrhea for the first two days post-infection. Thus, RT CIV carrying the internal gene cassette from PR8 showed almost no pathogenicity in dogs. And the reassortant virus inactivated vaccine could provide complete protection against H3N2 CIV. To our knowledge, this is the first report on the pathogenicity of PR8-based reassortant H3N2 CIV in dogs. These studies are relevant for developing a high-yield and safe CI vaccine.
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Affiliation(s)
- Yongbo Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Cheng Fu
- College of Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Shaotang Ye
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Yingxin Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Zhonghe Qi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Congwen Yao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Zhen Wang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Ji Wang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Siqi Cai
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Shiyu Tang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Ying Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China
| | - Shoujun Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China; Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, 510642, China; Guangdong Technological Engineering Research Center for Pet, Guangzhou, 510642, China.
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8
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Epidemiology and Genotypic Diversity of Eurasian Avian-Like H1N1 Swine Influenza Viruses in China. Virol Sin 2020; 36:43-51. [PMID: 32638231 DOI: 10.1007/s12250-020-00257-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/10/2020] [Indexed: 10/23/2022] Open
Abstract
Eurasian avian-like H1N1 (EA H1N1) swine influenza virus (SIV) outside European countries was first detected in Hong Kong Special Administrative Region (Hong Kong, SAR) of China in 2001. Afterwards, EA H1N1 SIVs have become predominant in pig population in this country. However, the epidemiology and genotypic diversity of EA H1N1 SIVs in China are still unknown. Here, we collected the EA H1N1 SIVs sequences from China between 2001 and 2018 and analyzed the epidemic and phylogenic features, and key molecular markers of these EA H1N1 SIVs. Our results showed that EA H1N1 SIVs distributed in nineteen provinces/municipalities of China. After a long-time evolution and transmission, EA H1N1 SIVs were continuously reassorted with other co-circulated influenza viruses, including 2009 pandemic H1N1 (A(H1N1)pdm09), and triple reassortment H1N2 (TR H1N2) influenza viruses, generated 11 genotypes. Genotype 3 and 5, both of which were the reassortments among EA H1N1, A(H1N1)pdm09 and TR H1N2 viruses with different origins of M genes, have become predominant in pig population. Furthermore, key molecular signatures were identified in EA H1N1 SIVs. Our study has drawn a genotypic diversity image of EA H1N1 viruses, and could help to evaluate the potential risk of EA H1N1 for pandemic preparedness and response.
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9
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Chen S, Xie Y, Su X, Xue J, Wang X, Du Y, Qin T, Peng D, Liu X. Substitutions in the PB2 methionine 283 residue affect H5 subtype avian influenza virus virulence. Transbound Emerg Dis 2020; 67:2554-2563. [PMID: 32351035 DOI: 10.1111/tbed.13601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/09/2020] [Accepted: 04/17/2020] [Indexed: 12/31/2022]
Abstract
The influenza A virus (IAV) PB2 subunit modulates viral polymerase activity, replication kinetics and pathogenicity. Here we identified novel PB2 substitutions at position 283 of H5 subtype IAV and evaluated their biological characteristics and virulence. The substitution PB2-M283L enhanced the growth capacity and polymerase activity in human and mammalian cells in comparison to the rWT virus. The substitution PB2-M283L displayed high virulence, resulting in a greater virus load in different tissues, more severe histopathological lesions and proinflammatory cytokines burst in mice. The substitution PB2-M283I had an opposite phenotype. Our data extend the important role of PB2 substitutions in the adaptation of H5 subtype IAVs to mammalian hosts.
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Affiliation(s)
- Sujuan Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Yizhang Xie
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Xiang Su
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Jing Xue
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Xiao Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Yinping Du
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Tao Qin
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Daxin Peng
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
| | - Xiufan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.,Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China.,Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.,Joint Laboratory Safety of International Cooperation of Agriculture & Agricultural-Products, Yangzhou, Jiangsu, PR China
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10
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Higher virulence of swine H1N2 influenza viruses containing avian-origin HA and 2009 pandemic PA and NP in pigs and mice. Arch Virol 2020; 165:1141-1150. [PMID: 32222822 PMCID: PMC7223331 DOI: 10.1007/s00705-020-04572-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/31/2020] [Indexed: 01/08/2023]
Abstract
Pigs are capable of harbouring influenza A viruses of human and avian origin in their respiratory tracts and thus act as an important intermediary host to generate novel influenza viruses with pandemic potential by genetic reassortment between the two viruses. Here, we show that two distinct H1N2 swine influenza viruses contain avian-like or classical swine-like hemagglutinins with polymerase acidic (PA) and nucleoprotein (NP) genes from 2009 pandemic H1N1 influenza viruses that were found to be circulating in Korean pigs in 2018. Swine H1N2 influenza virus containing an avian-like hemagglutinin gene had enhanced pathogenicity, causing severe interstitial pneumonia in infected pigs and mice. The mortality rate of mice infected with swine H1N2 influenza virus containing an avian-like hemagglutinin gene was higher by 100% when compared to that of mice infected with swine H1N2 influenza virus harbouring classical swine-like hemagglutinin. Further, chemokines attracting inflammatory cells were strongly induced in lung tissues of pigs and mice infected by swine H1N2 influenza virus containing an avian-like hemagglutinin gene. In conclusion, it is necessary for the well-being of humans and pigs to closely monitor swine influenza viruses containing avian-like hemagglutinin with PA and NP genes from 2009 pandemic H1N1 influenza viruses.
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11
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Li X, Guo L, Liu C, Cheng Y, Kong M, Yang L, Zhuang Z, Liu J, Zou M, Dong X, Su X, Gu Q. Human infection with a novel reassortant Eurasian-avian lineage swine H1N1 virus in northern China. Emerg Microbes Infect 2020; 8:1535-1545. [PMID: 31661383 PMCID: PMC6830285 DOI: 10.1080/22221751.2019.1679611] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Influenza A virus infections occur in different species, causing mild to severe respiratory symptoms that lead to a heavy disease burden. Eurasian avian-like swine influenza A(H1N1) viruses (EAS-H1N1) are predominant in pigs and occasionally infect humans. An influenza A(H1N1) virus was isolated from a boy who was suffering from fever and headache and designated as A/Tianjin-baodi/1606/2018(H1N1). Full-genome sequencing and phylogenetic analysis revealed that A/Tianjin-baodi/1606/2018(H1N1) is a novel reassortant EAS-H1N1 containing gene segments from EAS-H1N1 (HA and NA), classical swine H1N1(NS) and A(H1N1)pdm09(PB2, PB2, PA, NP and M) viruses. The isolation and analysis of A/Tianjin-baodi/1606/2018(H1) provide further evidence that EAS-H1N1 poses a threat to human health and greater attention should be paid to surveillance of influenza virus infection in pigs and humans.
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Affiliation(s)
- Xiaoyan Li
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Liru Guo
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Caixia Liu
- Jizhou District Center for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Yanhui Cheng
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Mei Kong
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Lei Yang
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Zhichao Zhuang
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Jia Liu
- Chinese National Influenza Center, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Ming Zou
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Xiaochun Dong
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Xu Su
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
| | - Qing Gu
- Tianjin Centers for Disease Control and Prevention, Tianjin, People's Republic of China
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12
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The R251K Substitution in Viral Protein PB2 Increases Viral Replication and Pathogenicity of Eurasian Avian-like H1N1 Swine Influenza Viruses. Viruses 2020; 12:v12010052. [PMID: 31906472 PMCID: PMC7019279 DOI: 10.3390/v12010052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 12/21/2022] Open
Abstract
The Eurasian avian-like swine (EA) H1N1 virus has affected the Chinese swine industry, and human infection cases have been reported occasionally. However, little is known about the pathogenic mechanism of EA H1N1 virus. In this study, we compared the mouse pathogenicity of A/swine/Guangdong/YJ4/2014 (YJ4) and A/swine/Guangdong/MS285/2017 (MS285) viruses, which had similar genotype to A/Hunan/42443/2015 (HuN-like). None of the mice inoculated with 106 TCID50 of YJ4 survived at 7 days post infection, while the survival rate of the MS285 group was 100%. Therefore, a series of single fragment reassortants in MS285 background and two rescued wild-type viruses were generated by using the reverse genetics method, and the pathogenicity analysis revealed that the PB2 gene contributed to the high virulence of YJ4 virus. Furthermore, there were 11 amino acid differences in PB2 between MS285 and YJ4 identified by sequence alignment, and 11 single amino acid mutant viruses were generated in the MS285 background. We found that the R251K mutation significantly increased the virulence of MS285 in mice, contributed to high polymerase activity and enhanced viral genome transcription and replication. These results indicate that PB2-R251K contributes to the virulence of the EA H1N1 virus and provide new insight into future molecular epidemiological surveillance strategies.
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13
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Identification, Genetic Analysis, and Pathogenicity of Classical Swine H1N1 and Human-Swine Reassortant H1N1 Influenza Viruses from Pigs in China. Viruses 2020; 12:v12010055. [PMID: 31906591 PMCID: PMC7019673 DOI: 10.3390/v12010055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/22/2019] [Accepted: 12/31/2019] [Indexed: 12/20/2022] Open
Abstract
Swine influenza virus causes a substantial disease burden to swine populations worldwide and poses an imminent threat to the swine industry and humans. Given its importance, we characterized two swine influenza viruses isolated from Shandong, China. The homology and phylogenetic analyses showed that all eight gene segments of A/swine/Shandong/AV1522/2011(H1N1) were closely related to A/Maryland/12/1991(H1N1) circulating in North America. The HA, NA, M, and NS genes of the isolate were also confirmed to have a high homology to A/swine/Hubei/02/2008(H1N1) which appeared in China in 2008, and the virus was clustered into the classical swine lineage. The gene segments of A/swine/Shandong/AV1523/2011(H1N1) were highly homologous to the early human H1N1 and H2N2 influenza viruses, except for the HA gene, and the virus was a reassortant H1N1 virus containing genes from the classical swine (HA) and human (NA, PB2, PB1, PA, NP, M, and NS) lineages. Both the viruses could cause lethal infection and replicate efficiently in the lungs, brains, spleens, and kidneys of mice. Histopathological examinations showed that AV1522 and AV1523 viruses caused a spectrum of marked pneumonia and meningoencephalitis according to the duration of infection, demonstrating a progression of respiratory disease and neurological disease over the course of infection that ultimately resulted in lethality for the infected mice. The changes in the pathogenicity of swine influenza viruses to mammals, accompanied with the continuous reassortment and evolution of the viruses, highlights the importance of ongoing epidemiological investigation.
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14
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Venkatesh D, Bianco C, Núñez A, Collins R, Thorpe D, Reid SM, Brookes SM, Essen S, McGinn N, Seekings J, Cooper J, Brown IH, Lewis NS. Detection of H3N8 influenza A virus with multiple mammalian-adaptive mutations in a rescued Grey seal ( Halichoerus grypus) pup. Virus Evol 2020; 6:veaa016. [PMID: 32211197 PMCID: PMC7079721 DOI: 10.1093/ve/veaa016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Avian influenza A viruses (IAVs) in different species of seals display a spectrum of pathogenicity, from sub-clinical infection to mass mortality events. Here we present an investigation of avian IAV infection in a 3- to 4-month-old Grey seal (Halichoerus grypus) pup, rescued from St Michael's Mount, Cornwall in 2017. The pup underwent medical treatment but died after two weeks; post-mortem examination and histology indicated sepsis as the cause of death. IAV NP antigen was detected by immunohistochemistry in the nasal mucosa, and sensitive real-time reverse transcription polymerase chain reaction assays detected trace amounts of viral RNA within the lower respiratory tract, suggesting that the infection may have been cleared naturally. IAV prevalence among Grey seals may therefore be underestimated. Moreover, contact with humans during the rescue raised concerns about potential zoonotic risk. Nucleotide sequencing revealed the virus to be of subtype H3N8. Combining a GISAID database BLAST search and time-scaled phylogenetic analyses, we inferred that the seal virus originated from an unsampled, locally circulating (in Northern Europe) viruses, likely from wild Anseriformes. From examining the protein alignments, we found several residue changes in the seal virus that did not occur in the bird viruses, including D701N in the PB2 segment, a rare mutation, and a hallmark of mammalian adaptation of bird viruses. IAVs of H3N8 subtype have been noted for their particular ability to cross the species barrier and cause productive infections, including historical records suggesting that they may have caused the 1889 pandemic. Therefore, infections such as the one we report here may be of interest to pandemic surveillance and risk and help us better understand the determinants and drivers of mammalian adaptation in influenza.
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Affiliation(s)
- Divya Venkatesh
- Department of Pathobiology and Population Scienes, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, UK
| | - Carlo Bianco
- Pathology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
- Diagnostic & Consultant Avian Pathology, Pathology Department, Animal and Plant Health Agency (APHA-Lasswade), Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Alejandro Núñez
- Pathology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
| | - Rachael Collins
- Starcross Veterinary Investigation Centre, Animal and Plant Health Agency, Staplake Mount, Starcross, Devon, EX6 8PE, UK
| | - Darryl Thorpe
- British Divers Marine Life Rescue, Lime House, Regency Close, Uckfield, East Sussex TN22 1DS, UK
| | - Scott M Reid
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
| | - Sharon M Brookes
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
| | - Steve Essen
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
- OIE/FAO/EURL International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA) - Weybridge, Addlestone, Surrey, KT15 3NB, UK
| | - Natalie McGinn
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
- OIE/FAO/EURL International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA) - Weybridge, Addlestone, Surrey, KT15 3NB, UK
| | - James Seekings
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
- OIE/FAO/EURL International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA) - Weybridge, Addlestone, Surrey, KT15 3NB, UK
| | - Jayne Cooper
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
| | - Ian H Brown
- Virology Department, Animal and Plant Health Agency (APHA-Weybridge), Woodham Lane, New Haw, Addlestone KT15 3NB, UK
- OIE/FAO/EURL International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA) - Weybridge, Addlestone, Surrey, KT15 3NB, UK
| | - Nicola S Lewis
- Department of Pathobiology and Population Scienes, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, UK
- OIE/FAO/EURL International Reference Laboratory for avian influenza, swine influenza and Newcastle Disease, Animal and Plant Health Agency (APHA) - Weybridge, Addlestone, Surrey, KT15 3NB, UK
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15
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Cao Z, Zeng W, Hao X, Huang J, Cai M, Zhou P, Zhang G. Continuous evolution of influenza A viruses of swine from 2013 to 2015 in Guangdong, China. PLoS One 2019; 14:e0217607. [PMID: 31323023 PMCID: PMC6641472 DOI: 10.1371/journal.pone.0217607] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/16/2019] [Indexed: 01/03/2023] Open
Abstract
Southern China is considered an important source of influenza virus pandemics because of the large, diverse viral reservoirs in poultry and swine. To examine the trend in influenza A virus of swine (IAV-S), an active surveillance program has been conducted from 2013 to 2015 in Guangdong, China. The phylogenetic analyses showed that the external genes of the isolates were assigned to the Eurasian avian-like swine (EA) H1N1 and/or human-like H3N2 lineages with multiple substitutions, indicating a notable genetic shift. Moreover, the internal genes derived from different origins (PB2, PB1, PA, NP: pdm/09 (pandemic influenza virus 2009)-origin, M: pdm/09- or EA-origin, NS: North American Triple Reassortant (TR)-origin have become the dominant backbone of IAV-S in southern China. According to the origins of the eight gene segments, the isolates can be categorized into five genotypes. The results of mice experiment showed that the YJ4 (genotype 1) and DG2 (genotype 4) are the most pathogenic to mice, and the viruses are observed in kidneys and brains, indicating the systemic infection. The alterations of the IAV-S gene composition supported the continued implementation of the intensive surveillance of IAV-S and the greater attention focused on potential shifts toward transmission to humans.
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Affiliation(s)
- Zhenpeng Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Weijie Zeng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xiangqi Hao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Junming Huang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Mengkai Cai
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Pei Zhou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- * E-mail: (GZ); (PZ)
| | - Guihong Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
- * E-mail: (GZ); (PZ)
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16
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Low Polymerase Activity Attributed to PA Drives the Acquisition of the PB2 E627K Mutation of H7N9 Avian Influenza Virus in Mammals. mBio 2019; 10:mBio.01162-19. [PMID: 31213560 PMCID: PMC6581862 DOI: 10.1128/mbio.01162-19] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The emergence of the PB2 E627K substitution is critical in the mammalian adaptation and pathogenesis of AIV. H7N9 AIVs that emerged in 2013 possess a prominent ability in gaining the PB2 E627K mutation in humans. Here, we demonstrate that the acquisition of the H7N9 PB2 E627K mutation is driven by the low polymerase activity conferred by the viral PA protein in human cells, and four PA residues are collectively involved in this process. Notably, the H7N9 PA protein leads to significant dependence of viral polymerase function on human ANP32A protein, and Anp32a knockout abolishes PB2 E627K acquisition in mice. These findings reveal that viral PA and host ANP32A are crucial for the emergence of PB2 E627K during adaptation of H7N9 AIVs to humans. Avian influenza viruses (AIVs) must acquire mammalian-adaptive mutations before they can efficiently replicate in and transmit among humans. The PB2 E627K mutation is known to play a prominent role in the mammalian adaptation of AIVs. The H7N9 AIVs that emerged in 2013 in China easily acquired the PB2 E627K mutation upon replication in humans. Here, we generate a series of reassortant or mutant H7N9 AIVs and test them in mice. We show that the low polymerase activity attributed to the viral PA protein is the intrinsic driving force behind the emergence of PB2 E627K during H7N9 AIV replication in mice. Four residues in the N-terminal region of PA are critical in mediating the PB2 E627K acquisition. Notably, due to the identity of viral PA protein, the polymerase activity and growth of H7N9 AIV are highly sensitive to changes in expression levels of human ANP32A protein. Furthermore, the impaired viral polymerase activity of H7N9 AIV caused by the depletion of ANP32A led to reduced virus replication in Anp32a−/− mice, abolishing the acquisition of the PB2 E627K mutation and instead driving the virus to acquire the alternative PB2 D701N mutation. Taken together, our findings show that the emergence of the PB2 E627K mutation of H7N9 AIV is driven by the intrinsic low polymerase activity conferred by the viral PA protein, which also involves the engagement of mammalian ANP32A.
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17
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Rajao DS, Vincent AL, Perez DR. Adaptation of Human Influenza Viruses to Swine. Front Vet Sci 2019; 5:347. [PMID: 30723723 PMCID: PMC6349779 DOI: 10.3389/fvets.2018.00347] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/31/2018] [Indexed: 12/24/2022] Open
Abstract
A large diversity of influenza A viruses (IAV) within the H1N1/N2 and H3N2 subtypes circulates in pigs globally, with different lineages predominating in specific regions of the globe. A common characteristic of the ecology of IAV in swine in different regions is the periodic spillover of human seasonal viruses. Such human viruses resulted in sustained transmission in swine in several countries, leading to the establishment of novel IAV lineages in the swine host and contributing to the genetic and antigenic diversity of influenza observed in pigs. In this review we discuss the frequent occurrence of reverse-zoonosis of IAV from humans to pigs that have contributed to the global viral diversity in swine in a continuous manner, describe host-range factors that may be related to the adaptation of these human-origin viruses to pigs, and how these events could affect the swine industry.
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Affiliation(s)
- Daniela S Rajao
- Department of Population Health, University of Georgia, Athens, GA, United States
| | - Amy L Vincent
- Virus and Prion Research Unit, USDA-ARS, National Animal Disease Center, Ames, IA, United States
| | - Daniel R Perez
- Department of Population Health, University of Georgia, Athens, GA, United States
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