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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.
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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
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Kim H, Cho HK, Kang YM, Sagong M, An S, Kim S, Lee YJ, Kang HM. Protective efficacy of a bivalent H5 influenza vaccine candidate against both clades 2.3.2.1 and 2.3.4.4 high pathogenic avian influenza viruses in SPF chickens. Vaccine 2023; 41:2816-2823. [PMID: 37024409 DOI: 10.1016/j.vaccine.2023.03.028] [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: 09/21/2022] [Revised: 02/27/2023] [Accepted: 03/14/2023] [Indexed: 04/08/2023]
Abstract
Worldwide, high pathogenic avian influenza viruses belonging to clades 2.3.4.4 and 2.3.2.1 have been circulating in both poultry and wild birds. Since 2018, Korea has built a national antigen bank to ensure preparedness in an emergency. In this study, we developed a bivalent vaccine candidate containing antigens derived from two reassortant KA435/2.3.2.1d and H35/2.3.4.4b strains for Korean national antigen bank. We evaluated its immunogenicity and protective efficacy in specific pathogen free chickens. The two vaccine strains, rgKA435-H9N2 PB2/2.3.2.1d and rgH35/2.3.4.4b, both of which were generated successfully by reverse genetics, were highly immunogenic (titres of haemagglutination inhibition: 8.3 and 8.4 log2, respectively) and showed good protective efficacy (100 and 147 50% protective dose, respectively) against lethal challenge with wild-type virus when delivered as a 1:1 mixture. Notably, the vaccine provided complete protection against viral shedding at a full dose (512 HAU) and a 1/10 dose (51.2 HAU), with no clinical signs, after challenge with H35/2.3.4.4b. The bivalent vaccine developed in this study may reduce the cost of vaccine production and could be used as a H5 subtype avian influenza vaccine candidate against two clades simultaneously.
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Affiliation(s)
- Hyunjun Kim
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Hyun-Kyu Cho
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Yong-Myung Kang
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Mingeun Sagong
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Sungjun An
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Sungyeop Kim
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Youn-Jeong Lee
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea
| | - Hyun-Mi Kang
- Avian Influenza Research & Diagnostic Division, Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea.
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How to maintain and transport equine adipose tissue for isolating mesenchymal stem cells? BMC Vet Res 2022; 18:284. [PMID: 35864533 PMCID: PMC9306088 DOI: 10.1186/s12917-022-03379-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 07/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Adipose tissue (AT) is one of the most important mesenchymal stem cell (MSC) sources because of its high quantities, availability and ease of collection. After being collected samples, they should be transported to a laboratory for stem cell (SC) isolation, culture and expansion for future clinical application. Usually, laboratories are distant from animal husbandry centers; therefore, it is necessary to provide suitable conditions for adipose tissue transportation, such that adipose-derived MSCs are minimally affected. In the current study, the impact of tissue maintenance under different conditions on MSCs derived from these tissues was evaluated. We aimed at finding suitable and practical transportation methods in which ASCs go through the slightest changes. RESULTS In the current study, after being collected, equine AT was randomized into eight groups: four samples were maintained in stem cell culture media at 25 οC and 4 οC for 6 and 12 hrs. as transportation via SC media groups. Three samples were frozen at three different temperatures (- 20, - 75 and - 196 οC) as cryopreserved groups; these samples were defrosted 1 week after cryopreservation. Fresh and unfrozen AT was evaluated as a control group. The tissue samples were then initiated into enzymatic digestion, isolation and the culturing of SCs. Cells at passage three were used to evaluate the ability to form colonies, proliferation rate, plotting of the cell growth curve, and viability rate. All experiments were performed in triplicate. Stem cell isolation was successful in all groups, although purification of SCs from the first series of cryopreservation at - 196 οC and two series of - 20 οC was unsuccessful. There was no significant difference between the surface area of colonies in all groups except for - 20 οC. The growth rate of transportation via stem cell media at 25 οC for 6 hrs. was similar to that of the control group. MTT analysis revealed a significant difference between 25 οC 12 hrs. Group and other experimental groups except for control, 4 οC 12 hrs. and - 196 οC group. CONCLUSION Data have shown freezing at - 75 οC, transportation via stem cell media at 4 οC for 12 hrs. and 25 οC for 6 hrs. are acceptable tissue preservation and transportation methods due to minor effects on MSCs features.
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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.
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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.)
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Improvement of PR8-Derived Recombinant Clade 2.3.4.4c H5N6 Vaccine Strains by Optimization of Internal Genes and H103Y Mutation of Hemagglutinin. Vaccines (Basel) 2020; 8:vaccines8040781. [PMID: 33419331 PMCID: PMC7766170 DOI: 10.3390/vaccines8040781] [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: 11/25/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/04/2022] Open
Abstract
Clade 2.3.4.4c H5N6 avian influenza A viruses (AIVs) may have originally adapted to infect chickens and have caused highly pathogenic avian influenza (HPAI) in poultry and human fatalities. Although A/Puerto Rico/8/1934 (H1N1) (PR8)-derived recombinant clade 2.3.4.4c H5N6 vaccine strains have been effective in embryonated chicken eggs-based vaccine production system, they need to be improved in terms of immunogenicity and potential mammalian pathogenicity. We replaced the PB2 gene alone or the PB2 (polymerase basic protein 2), NP (nucleoprotein), M (matrix protein) and NS (non-structural protein) genes together in the PR8 strain with corresponding genes from AIVs with low pathogenicity to remove mammalian pathogenicity and to match CD8+ T cell epitopes with contemporary HPAI viruses, respectively, without loss of viral fitness. Additionally, we tested the effect of the H103Y mutation of hemagglutinin (HA) on antigen productivity, mammalian pathogenicity and heat/acid stability. The replacement of PB2 genes and the H103Y mutation reduced the mammalian pathogenicity but increased the antigen productivity of the recombinant vaccine strains. The H103Y mutation increased heat stability but unexpectedly decreased acid stability, probably resulting in increased activation pH for HA. Interestingly, vaccination with inactivated recombinant virus with replaced NP, M and NS genes halted challenge virus shedding earlier than the recombinant vaccine without internal genes replacement. In conclusion, we successfully generated recombinant clade 2.3.4.4c H5N6 vaccine strains that were less pathogenic to mammals and more productive and heat stable than conventional PR8-derived recombinant strains by optimization of internal genes and the H103Y mutation of HA.
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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.
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An SH, Lee CY, Hong SM, Choi JG, Lee YJ, Jeong JH, Kim JB, Song CS, Kim JH, Kwon HJ. Bioengineering a highly productive vaccine strain in embryonated chicken eggs and mammals from a non-pathogenic clade 2·3·4·4 H5N8 strain. Vaccine 2019; 37:6154-6161. [PMID: 31495597 DOI: 10.1016/j.vaccine.2019.08.074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/17/2019] [Accepted: 08/28/2019] [Indexed: 11/18/2022]
Abstract
The clade 2·3·4·4 H5Nx is a highly pathogenic avian influenza (HPAI) virus, which first appeared in China and has spread worldwide since then, including Korea. It is divided into subclades a - d, but the PR8-derived recombinant clade 2·3·4·4 a viruses replicate inefficiently in embryonated chicken eggs (ECEs). High virus titer in ECEs and no mammalian pathogenicity are the most important prerequisites of efficacious and safer vaccine strains against HPAI. In this study, we have synthesized hemagglutinin (HA) and neuraminidase (NA) genes based on the consensus amino acid sequences of the clade 2·3·4·4a and b H5N8 HPAIVs, using the GISAID database. We generated PR8-derived H5N8 recombinant viruses with single point mutations in HA and NA, which are related to efficient replication in ECEs. The H103Y mutation in HA increased mammalian pathogenicity as well as virus titer in ECEs, by 10-fold. We also successfully eradicated mammalian pathogenicity in H103Y-bearing H5N8 recombinant virus by exchanging PB2 genes of PR8 and 01310 (Korean H9N2 vaccine strain). The final optimized H5N8 vaccine strain completely protected against a heterologous clade 2·3·4·4c H5N6 HPAIV in chickens, and induced hemagglutination inhibition (HI) antibody in ducks. However, the antibody titer of ducks showed age-dependent results. Thus, H103Y and 01310PB2 gene have been successfully applied to generate a highly productive, safe, and efficacious clade 2·3·4·4 H5N8 vaccine strain in ECEs.
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Affiliation(s)
- Se-Hee An
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea
| | - Chung-Young Lee
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Road, Atlanta, GA 30322, USA
| | - Seung-Min Hong
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea
| | - Jun-Gu Choi
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do 39660, Republic of Korea
| | - Youn-Jeong Lee
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do 39660, Republic of Korea
| | - Jei-Hyun Jeong
- Laboratory of Avian Diseases, College of Veterinary Medicine, Konkuk University, 05029 Seoul, Republic of Korea
| | - Jun-Beom Kim
- Laboratory of Avian Diseases, College of Veterinary Medicine, Konkuk University, 05029 Seoul, Republic of Korea
| | - Chang-Seon Song
- Laboratory of Avian Diseases, College of Veterinary Medicine, Konkuk University, 05029 Seoul, Republic of Korea
| | - Jae-Hong Kim
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea
| | - Hyuk-Joon Kwon
- Laboratory of Poultry Medicine, Department of Farm Animal Medicine, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826 Seoul, Republic of Korea; Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, Kangwon-do, Republic of Korea.
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An SH, Lee CY, Choi JG, Lee YJ, Kim JH, Kwon HJ. Generation of highly productive and mammalian nonpathogenic recombinant H9N2 avian influenza viruses by optimization of 3'end promoter and NS genome. Vet Microbiol 2018; 228:213-218. [PMID: 30593370 DOI: 10.1016/j.vetmic.2018.11.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/22/2018] [Accepted: 11/30/2018] [Indexed: 01/02/2023]
Abstract
We developed A/PR/8/34 (PR8) virus-based reverse genetics system in which six internal genes of PR8 and attenuated hemagglutinin and intact neuraminidase genes of field avian influenza viruses (AIVs) have been used for the generation of highly productive recombinant vaccine strains. The 6 + 2 recombinant vaccine strains can induce protective humoral immunity against intended field AIVs; however, the epitopes of B and T cells encoded by internal genes may be important for heterosubtypic protection. Therefore, it is advantageous to use homologous internal genes of field AIVs for recombinant vaccine strains. However, the rescue of recombinant viruses having whole internal genes of field AIVs by the PR8-based reverse genetics system was unsuccessful in some cases. Although partial replacement of an internal gene has been successful for generation of highly productive and mammalian nonpathogenic recombinant viruses, complete replacement of internal genes may be more favorable. In this study, we successfully generated complete recombinant H9N2 AIVs possessing 8 genomes of H9N2 AIVs by optimal combinations of 3' end promoter sequences of polymerase genomes, and a NS genome. All the generated recombinant viruses showed highly productive and mammalian nonpathogenic traits but some of them showed much higher virus titers in embryonated chicken eggs. Additionally, we found the same mutations of NS1 gene determined pathogenicity of AIVs in chicken embryos as well as mammals. Thus, the 3' end promoter optimization, and highly productive and mammalian nonpathogenic internal genes may be useful to develop vaccines against AIVs.
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Affiliation(s)
- Se-Hee An
- Laboratory of Avian Diseases, Republic of Korea
| | | | - Jun-Gu Choi
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Youn-Jeong Lee
- Avian Disease Division, Animal and Plant Quarantine Agency, 177, Hyeoksin 8-ro, Gyeongsangbuk-do, 39660, Republic of Korea
| | - Jae-Hong Kim
- Laboratory of Avian Diseases, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea
| | - Hyuk-Joon Kwon
- Department of Farm Animal Medicine, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 08826, Seoul, Republic of Korea; Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, 25354, Pyeongchangdae-ro, Kangwon-do, Republic of Korea.
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