Location: Endemic Poultry Viral Diseases ResearchTitle: Codon pair deoptimization of the HN and F of NDV LaSota strain does not significantly attenuate the virus for in ovo vaccination
|ELDEMERY, FATMA - ORISE FELLOW|
|OU, CHANGBO - HENAN INSTITUTE OF SCIENCE AND TECHNOLOGY|
Submitted to: Proceedings of Southern Conference on Avian Diseases
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2019
Publication Date: 1/28/2020
Citation: Eldemery, F., Ou, C., Kim, T.N., Spatz, S.J., Dunn, J.R., Silva, R.F., Yu, Q. 2020. Codon pair deoptimization of the HN and F of NDV LaSota strain does not significantly attenuate the virus for in ovo vaccination. Proceedings of Southern Conference on Avian Diseases. In: ABSTRACTS of 2020 International Poultry Scientific Forum, p73. Atlanta, GA, 28-30 January 2020.
Technical Abstract: In ovo vaccination is an attractive immunization approach for poultry industry. Currently available Newcastle disease virus (NDV) vaccines cannot be administered in ovo because of the reduced hatchability and embryo mortality. Codon pair deoptimization (CPD) approach has been used for efficient and rapid attenuation of a variety of RNA viruses by targeting the virulence genes through synonymous substitutions to reduce protein production of the target genes. In this study, we aimed to attenuate the NDV LaSota (LS) strain for in ovo vaccination by CPD of the fusion (F) or/and hemagglutinin neuraminidase (HN) genes. Three NDV LS recombinants expressing codon deoptimized LS F (rLS/F-d), HN (rLS/HN-d) or both genes (rLS/F+HN-d) were generated by using reverse genetics technology. Biological assays showed that the codon deoptimized viruses maintained similar growth kinetics and hemagglutination activity in embryonated eggs as the parental rLaSota virus. The pathogenicity of the rLS/HN-d and rLS/F+HN-d viruses were slightly attenuated with a lower intracerebral pathogenicity index than the rLaSota and rLS/F-d viruses. However, all three codon deoptimized viruses were still lethal to 10-day-old specific-pathogen-free chicken embryos with a mean death time less than 128 hours. These data suggested that the CPD of the surface glycoprotein genes of the LaSota strain does not significantly attenuated the virus for in ovo vaccination. Apparently, other virus attenuation approaches are needed to develop a safe in ovo NDV vaccine.