A novel subunit vaccine based on Fiber1/2 knob domain provides full protection against fowl adenovirus serotype 4 and induces stronger immune responses than a Fiber2 subunit vaccine.

Autor:	Liu S; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China., Dong X; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China., Lei B; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China., Zhang W; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China., Wang X; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China., Yuan W; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China; Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding, China., Zhao K; College of Veterinary Medicine, Hebei Agricultural University, Baoding, China; Hebei Veterinary Biotechnology Innovation Center, Hebei Agricultural University, Baoding, China. Electronic address: zhaokuan519@126.com.
Jazyk:	angličtina
Zdroj:	Poultry science [Poult Sci] 2024 Aug; Vol. 103 (8), pp. 103888. Date of Electronic Publication: 2024 May 23.
DOI:	10.1016/j.psj.2024.103888
Abstrakt:	Outbreaks of hepatitis-hydropericardium syndrome (HHS) caused by fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry in China since 2015. However, commercially available vaccines against the FAdV-4 infection remain scarce. In our study, subunit vaccine candidates derived from the bacterially expressed recombinant Fiber1 knob domain and Fiber2 knob domain fusion protein (termed as Fiber1/2 knob subunit vaccine) and Fiber2 protein (termed as Fiber2 subunit vaccine) of the FAdV-4 SDSX strain were developed. Immunogenicity evaluation showed that the Fiber1/2 knob subunit vaccine induced the production of antibodies at 7 d postvaccination (dpv), earlier than the Fiber2 subunit vaccine. Moreover, the neutralizing antibody level of the Fiber1/2 subunit vaccine group was higher than the Fiber2 subunit vaccine group, showing significant differences at 14, 21, and 28 dpv. Immune protection test results revealed that both Fiber1/2 knob subunit and Fiber2 subunit vaccines could protect chickens from death against FAdV-4 challenge, although the weight of chickens in the Fiber1/2 knob subunit vaccine group decreased less. Furthermore, analysis of plasma Glutamic oxaloacetic transaminase (AST) and blood glutamic pyruvic transaminase (ALT) levels suggested that the Fiber1/2 subunit vaccine can significantly inhibit liver damage caused by FAdV-4 infection and is more effective in blocking the pathogenicity of FAdV-4 in target organs. In addition, the Fiber1/2 knob subunit vaccine further reduced the viral load in different tissues and virus shedding in chickens than the Fiber2 subunit vaccine. Overall, the Fiber1/2 knob subunit vaccine was more effective than the Fiber2 subunit vaccine. These findings lay the foundation for the development of more effective FAdV-4 subunit vaccines. Competing Interests: DISCLOSURES The authors declare no conflicts of interest. (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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