China Animal Husbandry and Veterinary Medicine ›› 2022, Vol. 49 ›› Issue (2): 650-659.doi: 10.16431/j.cnki.1671-7236.2022.02.027

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Construction of Recombinant Heat-resistant Newcastle Disease Virus Expressing Fiber2 Protein of Fowl Adenovirus Serotype 4 and Evaluation of Its Immune Effect

SHANG Yu, LI Lintao, LI Li, XU Yingying, FENG Helong, WANG Hongcai, ZHANG Rongrong, ZENG Zhe, WANG Honglin, LUO Qingping, SHAO Huabin, WEN Guoyuan   

  1. Key Laboratory of Prevention and Control Agents for Animal Bacteriosis, Ministry of Agriculture and Rural Affairs, Hubei Provincial Key Laboratory of Animal Pathogenic Microbiology, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
  • Received:2021-07-09 Online:2022-02-05 Published:2022-01-27

Abstract: 【Objective】 This study was aimed to develop a heat-resistant genetically engineered vaccine against Newcastle disease virus (NDV) and Fowl adenovirus (FAdV).【Method】 Using reverse genetic manipulation techniques, the HN gene of NDV heat-resistant strain was substituted into the LaSota vaccine strain and then the Fiber2 gene of FAdV serotype 4 (FAdV-4) was inserted into its genome to generate a recombinant heat-resistant NDV plasmid pTS-HN-Fiber2, expressing Fiber2 protein.Recombinant NDV rTS-HN-Fiber2 was rescued by virus rescue technology, and its biological characteristics, immunogenicity and challenge protection as a vaccine candidate was determined.【Result】 The mean death time of rTS-HN-Fiber2 was > 168 h and the intracerebral pathogenicity index was 0, which belonged to the category of lentogenic strain.The results of growth curve on BHK-21 cells showed that rTS-HN-Fiber2 had similar growth curve with LaSota strain, but the final growth titer was slightly lower than LaSota strain.The titer of rTS-HN-Fiber2 decreased by about 103 TCID50/mL after treatment at 56 ℃ for 15 min, while NDV LaSota strain showed almost no infection after treatment at 56 ℃ for 5 min.Indirect immunofluorescence assay result showed that rTS-HN-Fiber2 could express Fiber2 protein efficiently.The results of immunization and challenge test showed that rTS-HN-Fiber2 could produce NDV antibody, significantly improve the survival rate of chicks exposed to FAdV-4, reduce the tissue lesions caused by FAdV-4 virulence and reduce the virus load in the tissues.【Conclusion】 The recombinant heat-resistant NDV expressing FAdV-4 Fiber2 protein was successfully constructed.The recombinant virus maintained the lentogenic strain characteristics of the LaSota strain, but the thermal stability was significantly improved.Chickens immunized with recombinant NDV could produce protection against NDV and FAdV-4.The recombinant NDV could be used as a candidate virus strain for the development of dual genetic engineering vaccine against FAdV-4 and NDV.

Key words: Fowl adenovirus serotype 4 (FAdV-4); Newcastle disease virus (NDV); Fiber2 protein; recombinant virus; heat-resisting

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