1
|
Guo Y, Bai X, Liu Z, Liang B, Zheng Y, Dankar S, Ping J. Exploring the alternative virulence determinants PB2 S155N and PA S49Y/D347G that promote mammalian adaptation of the H9N2 avian influenza virus in mice. Vet Res 2023; 54:97. [PMID: 37858267 PMCID: PMC10588254 DOI: 10.1186/s13567-023-01221-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/07/2023] [Indexed: 10/21/2023] Open
Abstract
The occurrence of human infections caused by avian H9N2 influenza viruses has raised concerns regarding the potential for human epidemics and pandemics. The molecular basis of viral adaptation to a new host needs to be further studied. Here, the bases of nucleotides 627 and 701 of PB2 were changed according to the uncoverable purine-to-pyrimidine transversion to block the development of PB2 627K and 701N mutations during serial passaging in mice. The purpose of this experiment was to identify key adaptive mutations in polymerase and NP genes that were obscured by the widely known host range determinants PB2 627K and 701N. Mouse-adapted H9N2 variants were obtained via twelve serial lung-to-lung passages. Sequence analysis showed that the mouse-adapted viruses acquired several mutations within the seven gene segments (PB2, PB1, PA, NP, HA, NA, and NS). One variant isolate with the highest polymerase activity possessed three substitutions, PB2 S155N, PA S49Y and D347G, which contributed to the highly virulent and mouse-adaptative phenotype. Further studies demonstrated that these three mutations resulted in increased polymerase activity, viral transcription and replication in mammalian cells, severe interstitial pneumonia, excessive inflammatory cellular infiltration and increased growth rates in mice. Our results suggest that the substitution of these three amino acid mutations may be an alternative strategy for H9N2 avian influenza viruses to adapt to mammalian hosts. The continued surveillance of zoonotic H9N2 influenza viruses should also include these mammalian adaptation markers as part of our pandemic preparedness efforts.
Collapse
Affiliation(s)
- Yanna Guo
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xuebing Bai
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhiyuan Liu
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Bing Liang
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yiqing Zheng
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Samar Dankar
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ONK1V 8M5, Canada
| | - Jihui Ping
- MOE International Joint Collaborative Research Laboratory for Animal Health and Food Safety & Jiangsu Engineering Research Center of Animal Immunology, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
2
|
An SH, Hong SM, Song JH, Son SE, Lee CY, Choi KS, Kwon HJ. Engineering an Optimal Y280-Lineage H9N2 Vaccine Strain by Tuning PB2 Activity. Int J Mol Sci 2023; 24:ijms24108840. [PMID: 37240186 DOI: 10.3390/ijms24108840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/13/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
H9N2 avian influenza A viruses (AIVs) cause economic losses in the poultry industry and provide internal genomic segments for the evolution of H5N1 and H7N9 AIVs into more detrimental strains for poultry and humans. In addition to the endemic Y439/Korea-lineage H9N2 viruses, the Y280-lineage spread to Korea since 2020. Conventional recombinant H9N2 vaccine strains, which bear mammalian pathogenic internal genomes of the PR8 strain, are pathogenic in BALB/c mice. To reduce the mammalian pathogenicity of the vaccine strains, the PR8 PB2 was replaced with the non-pathogenic and highly productive PB2 of the H9N2 vaccine strain 01310CE20. However, the 01310CE20 PB2 did not coordinate well with the hemagglutinin (HA) and neuraminidase (NA) of the Korean Y280-lineage strain, resulting in a 10-fold lower virus titer compared to the PR8 PB2. To increase the virus titer, the 01310CE20 PB2 was mutated (I66M-I109V-I133V) to enhance the polymerase trimer integrity with PB1 and PA, which restored the decreased virus titer without causing mouse pathogenicity. The reverse mutation (L226Q) of HA, which was believed to decrease mammalian pathogenicity by reducing mammalian receptor affinity, was verified to increase mouse pathogenicity and change antigenicity. The monovalent Y280-lineage oil emulsion vaccine produced high antibody titers for homologous antigens but undetectable titers for heterologous (Y439/Korea-lineage) antigens. However, this defect was corrected by the bivalent vaccine. Therefore, the balance of polymerase and HA/NA activities can be achieved by fine-tuning PB2 activity, and a bivalent vaccine may be more effective in controlling concurrent H9N2 viruses with different antigenicities.
Collapse
Affiliation(s)
- Se-Hee An
- Laboratory of Avian Diseases, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Seung-Min Hong
- Laboratory of Avian Diseases, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin-Ha Song
- Laboratory of Avian Diseases, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Seung-Eun Son
- Laboratory of Avian Diseases, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Chung-Young Lee
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kang-Seuk Choi
- Laboratory of Avian Diseases, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyuk-Joon Kwon
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
- Laboratory of Poultry Medicine, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, Seoul 88026, Republic of Korea
- Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, Pyeongchang 25354, Republic of Korea
- GeNiner Ltd., Seoul 08826, Republic of Korea
| |
Collapse
|
3
|
An SH, Son SE, Song JH, Hong SM, Lee CY, Lee NH, Jeong YJ, Choi JG, Lee YJ, Kang HM, Choi KS, Kwon HJ. Selection of an Optimal Recombinant Egyptian H9N2 Avian Influenza Vaccine Strain for Poultry with High Antigenicity and Safety. Vaccines (Basel) 2022; 10:vaccines10020162. [PMID: 35214621 PMCID: PMC8876024 DOI: 10.3390/vaccines10020162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 02/05/2023] Open
Abstract
For the development of an optimized Egyptian H9N2 vaccine candidate virus for poultry, various recombinant Egyptian H9N2 viruses generated by a PR8-based reverse genetics system were compared in terms of their productivity and biosafety since Egyptian H9N2 avian influenza viruses already possess mammalian pathogenicity-related mutations in the hemagglutinin (HA), neuraminidase (NA), and PB2 genes. The Egyptian HA and NA genes were more compatible with PR8 than with H9N2 AIV (01310) internal genes, and the 01310-derived recombinant H9N2 strains acquired the L226Q reverse mutation in HA after passages in eggs. Additionally, the introduction of a strong promoter at the 3′-ends of PB2 and PB1 genes induced an additional mutation of P221S. When recombinant Egyptian H9N2 viruses with intact or reverse mutated HA (L226Q and P221S) and NA (prototypic 2SBS) were compared, the virus with HA and NA mutations had high productivity in ECES but was lower in antigenicity when used as an inactivated vaccine due to its high binding affinity into non-specific inhibitors in eggs. Finally, we substituted the PB2 gene of PR8 with 01310 to remove the replication ability in mammalian hosts and successfully generated the best recombinant vaccine candidate in terms of immunogenicity, antigenicity, and biosafety.
Collapse
Affiliation(s)
- Se-Hee An
- Laboratory of Avian Diseases, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea; (S.-H.A.); (S.-E.S.); (J.-H.S.); (S.-M.H.)
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 88026, Korea
| | - Seung-Eun Son
- Laboratory of Avian Diseases, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea; (S.-H.A.); (S.-E.S.); (J.-H.S.); (S.-M.H.)
| | - Jin-Ha Song
- Laboratory of Avian Diseases, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea; (S.-H.A.); (S.-E.S.); (J.-H.S.); (S.-M.H.)
| | - Seung-Min Hong
- Laboratory of Avian Diseases, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea; (S.-H.A.); (S.-E.S.); (J.-H.S.); (S.-M.H.)
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 88026, Korea
| | - Chung-Young Lee
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Nak-Hyung Lee
- KBNP, Inc., 235-9, Chusa-ro, Sinam-myeon, Yesan-gun 32417, Korea; (N.-H.L.); (Y.-J.J.)
| | - Young-Ju Jeong
- KBNP, Inc., 235-9, Chusa-ro, Sinam-myeon, Yesan-gun 32417, Korea; (N.-H.L.); (Y.-J.J.)
| | - Jun-Gu Choi
- Animal and Plant Quarantine Agency, Gimcheon-si 39960, Korea; (J.-G.C.); (Y.-J.L.); (H.-M.K.)
| | - Youn-Jeong Lee
- Animal and Plant Quarantine Agency, Gimcheon-si 39960, Korea; (J.-G.C.); (Y.-J.L.); (H.-M.K.)
| | - Hyun-Mi Kang
- Animal and Plant Quarantine Agency, Gimcheon-si 39960, Korea; (J.-G.C.); (Y.-J.L.); (H.-M.K.)
| | - Kang-Seuk Choi
- Laboratory of Avian Diseases, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea; (S.-H.A.); (S.-E.S.); (J.-H.S.); (S.-M.H.)
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 88026, Korea
- Correspondence: (K.-S.C.); (H.-J.K.); Tel.: +82-2-880-1266 (K.-S.C. & H.-J.K.); Fax: +82-2-885-6614 (H.-J.K.)
| | - Hyuk-Joon Kwon
- Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 88026, Korea
- Laboratory of Poultry Medicine, Department of Farm Animal Medicine, College of Veterinary Medicine and BK21 PLUS for Veterinary Science, Seoul National University, 1, Gwanak-ro, Seoul 88026, Korea
- Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, Seoul 88026, Korea
- Correspondence: (K.-S.C.); (H.-J.K.); Tel.: +82-2-880-1266 (K.-S.C. & H.-J.K.); Fax: +82-2-885-6614 (H.-J.K.)
| |
Collapse
|
4
|
Novel Mutations Evading Avian Immunity around the Receptor Binding Site of the Clade 2.3.2.1c Hemagglutinin Gene Reduce Viral Thermostability and Mammalian Pathogenicity. Viruses 2019; 11:v11100923. [PMID: 31600990 PMCID: PMC6832455 DOI: 10.3390/v11100923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/06/2019] [Accepted: 10/08/2019] [Indexed: 11/22/2022] Open
Abstract
Since 2007, highly pathogenic clade 2.3.2 H5N1 avian influenza A (A(H5N1)) viruses have evolved to clade 2.3.2.1a, b, and c; currently only 2.3.2.1c A(H5N1) viruses circulate in wild birds and poultry. During antigenic evolution, clade 2.3.2.1a and c A(H5N1) viruses acquired both S144N and V223I mutations around the receptor binding site of hemagglutinin (HA), with S144N generating an N-glycosylation sequon. We introduced single or combined reverse mutations, N144S and/or I223V, into the HA gene of the clade 2.3.2.1c A(H5N1) virus and generated PR8-derived, 2 + 6 recombinant A(H5N1) viruses. When we compared replication efficiency in embryonated chicken eggs, mammalian cells, and mice, the recombinant virus containing both N144S and I223V mutations showed increased replication efficiency in avian and mammalian hosts and pathogenicity in mice. The N144S mutation significantly decreased avian receptor affinity and egg white inhibition, but not all mutations increased mammalian receptor affinity. Interestingly, the combined reverse mutations dramatically increased the thermostability of HA. Therefore, the adaptive mutations possibly acquired to evade avian immunity may decrease viral thermostability as well as mammalian pathogenicity.
Collapse
|
5
|
Structures of influenza A virus RNA polymerase offer insight into viral genome replication. Nature 2019; 573:287-290. [PMID: 31485076 PMCID: PMC6795553 DOI: 10.1038/s41586-019-1530-7] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/07/2019] [Indexed: 12/24/2022]
Abstract
Influenza A viruses are responsible for seasonal epidemics, and pandemics can arise from the transmission of novel zoonotic influenza A viruses to humans1,2. Influenza A viruses contain a segmented negative-sense RNA genome, which is transcribed and replicated by the viral-RNA-dependent RNA polymerase (FluPolA) composed of PB1, PB2 and PA subunits3-5. Although the high-resolution crystal structure of FluPolA of bat influenza A virus has previously been reported6, there are no complete structures available for human and avian FluPolA. Furthermore, the molecular mechanisms of genomic viral RNA (vRNA) replication-which proceeds through a complementary RNA (cRNA) replicative intermediate, and requires oligomerization of the polymerase7-10-remain largely unknown. Here, using crystallography and cryo-electron microscopy, we determine the structures of FluPolA from human influenza A/NT/60/1968 (H3N2) and avian influenza A/duck/Fujian/01/2002 (H5N1) viruses at a resolution of 3.0-4.3 Å, in the presence or absence of a cRNA or vRNA template. In solution, FluPolA forms dimers of heterotrimers through the C-terminal domain of the PA subunit, the thumb subdomain of PB1 and the N1 subdomain of PB2. The cryo-electron microscopy structure of monomeric FluPolA bound to the cRNA template reveals a binding site for the 3' cRNA at the dimer interface. We use a combination of cell-based and in vitro assays to show that the interface of the FluPolA dimer is required for vRNA synthesis during replication of the viral genome. We also show that a nanobody (a single-domain antibody) that interferes with FluPolA dimerization inhibits the synthesis of vRNA and, consequently, inhibits virus replication in infected cells. Our study provides high-resolution structures of medically relevant FluPolA, as well as insights into the replication mechanisms of the viral RNA genome. In addition, our work identifies sites in FluPolA that could be targeted in the development of antiviral drugs.
Collapse
|