Optimizing encephalomyocarditis virus VP1 protein assembly on pseudorabies virus envelope via US9 protein anchoring
Bao Ru Ren,
Hui Qin,
Yan Fang Zhang,
Xuan Ying Du,
Hao Chen Sun,
Yang Luo,
Yan Zi Gan,
Jian Long Wang,
Wei Hu,
Sheng Bo Cao,
Yang Yang
Affiliations
Bao Ru Ren
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Hui Qin
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Yan Fang Zhang
The National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Xuan Ying Du
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Hao Chen Sun
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Yang Luo
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Yan Zi Gan
Department of Pediatric Health Care Outpatient Clinic, The Third Hospital of Hohhot, Hohhot, Inner Mongolia, China
Jian Long Wang
Department of Epidemic Prevention and Control, Inner Mongolia Autonomous Region Animal Disease Prevention and Control Center, Hohhot, Inner Mongolia, China
Wei Hu
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Sheng Bo Cao
The National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
Yang Yang
The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
Live herpesvirus-vectored vaccines are critical in veterinary medicine, but they can sometimes offer insufficient protection due to suboptimal antigen expression or localization. Encephalomyocarditis virus (EMCV) is a significant zoonotic threat, with VP1 protein as a key immunogen on its capsid. To enhance immunogenicity, we explored the use of recombinant pseudorabies virus (rPRV) as a vaccine vector against EMCV. In silico analysis indicated that fusing VP1 with US9 enhances the formation of a type II transmembrane heterodimer. We constructed six rPRV groups expressing different VP1 variants and found that VP1 fused with US9’s C-terminal (US9-VP1) enhances VP1’s membrane localization and its incorporation into the PRV envelope, unlike wild-type VP1. Immunogold electron microscopy illustrated that rPRV with deleted US8 and US9, supplemented with US8 regulatory sequence (rΔ89-U9VP1), improved VP1 incorporation into the viral envelope. Post-immunization, only rΔ89-U9VP1 provided 100% protection against EMCV in mice and induced high levels of virus-neutralizing antibodies in piglets. Additionally, rPRV expressing VP1 stimulated robust T-cell responses, as demonstrated by flow cytometry and ELISpot assays. This study introduces rPRV as a potential EMCV vaccine, demonstrating that the selection of the US9 C-terminal domain and US8 regulatory sequence significantly enhances the presentation of heterologous antigens, improving vaccine efficacy.
