Newcastle disease virus (NDV) recombinant expressing Marek’s disease virus (MDV) glycoprotein B protects chickens against MDV and NDV challenges

Authors: HE, LEI - Orise Fellow; Spatz, Stephen; Dunn, John; Yu, Qingzhong

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2023
Publication Date: 9/15/2023
Citation: He, L., Spatz, S.J., Dunn, J.R., Yu, Q. 2023. Newcastle disease virus (NDV) recombinant expressing Marek’s disease virus (MDV) glycoprotein B protects chickens against MDV and NDV challenges. Vaccine. 41(40):5884-5891. https://doi.org/10.1016/j.vaccine.2023.08.038.
DOI: https://doi.org/10.1016/j.vaccine.2023.08.038

Interpretive Summary: Marek’s disease (MD) is a highly contagious viral tumor disease of chickens, causing significant economic losses to the poultry industry worldwide. The commonly used MD vaccines are expensive to produce and difficult to handle due to the requirement of liquid nitrogen for manufacturing and delivering. In this study, we aimed to develop a Newcastle disease virus (NDV) vectored MD vaccine that can be lyophilized, stored, and transported at an ambient temperature. Four NDV LaSota (LS) vaccine strain-based recombinant viruses expressing the glycoproteins gB, gC, gE, or gI of Marek's disease virus (MDV) were generated using reverse genetics technology. Vaccination of leghorn chickens with these recombinant viruses conferred different levels of protection against virulent MDV challenge. The recombinant expressing the MDV gB protein protected vaccinated birds significantly against MDV-induced tumor formation when challenged at 14 days post-vaccination (DPV) and moderately at 5 DPV. The other three recombinants provided little protection against the MDV challenge. All four recombinants conferred complete protection against the virulent NDV challenge. These results demonstrated that the rLS/MDV-gB virus is a promising dual vaccine candidate that can be potentially mass-administered via aerosol or drinking water to large chicken populations at a meager cost.

Technical Abstract: Marek's disease (MD) is a highly contagious viral neoplastic disease of chickens caused by Marek's disease virus (MDV), resulting in significant economic losses to the poultry industry worldwide. The commonly used live and/or vectored MDV vaccines are expensive to produce and difficult to handle due to the requirement of liquid nitrogen for manufacturing and delivering frozen infected cells that are viable. In this study, we aimed to develop a Newcastle disease virus (NDV) vectored MDV vaccine that can be lyophilized, stored, and transported at 4 °C. Four NDV LaSota (LS) vaccine strain-based recombinant viruses expressing MDV glycoproteins gB, gC, gE, or gI were generated using reverse genetics technology. The biological assessments showed that these recombinant viruses were slightly attenuated in vivo yet retained similar growth kinetics and virus titers in vitro compared to the parental LaSota virus. Vaccination of leghorn chickens (Lines 15I5x71 F1 cross) with these recombinant viruses via intranasal and intraocular routes conferred different levels of protection against virulent MDV challenge. The recombinant expressing the MDV gB protein, rLS/MDV-gB, protected vaccinated birds significantly against MDV-induced tumor formation when challenged at 14 days post-vaccination (DPV) but moderately at 5 DPV. Whereas the other three recombinants provided little protection against the MDV challenge. All four recombinants conferred complete protection against the velogenic NDV challenge. These results demonstrated that the rLS/MDV-gB virus is a safe and efficacious dual vaccine candidate that can be lyophilized and potentially mass-administered via aerosol or drinking water to large chicken populations at a meager cost.