|GOLDENBERG, DANA - Binational Agricultural Research And Development (BARD)|
Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2019
Publication Date: N/A
Technical Abstract: Newcastle disease virus (NDV) has two surface glycoproteins that induce neutralizing antibodies: the hemagglutinin-neuraminidase (HN) and the fusion (F). All NDVs are members of one serotype, yet, despite heavy vaccination, NDV causes devastating disease in poultry worldwide. Several studies have concluded that homologous (genotype matched) vaccines, have been demonstrated to have advantages in control of viral shedding and survival after challenge of sub-optimally vaccinated chickens. Virulent field strains isolated in the Middle East belonging mainly to class II genotype VII, sub-genotypes VIId predominant during (2007 to 2010), VIIi during (2011 to 2013) and more recently, sub-genotypes VIIj is becoming the dominant genotypes (2011 to 2018). All genotype VII viruses are predicted to be virulent. Here we describe the utilization of a reverse-genetics technique to develop a recombinant NDV that expresses the HN and F genes of genotype VIIj virus, using the LaSota vaccine strain as a backbone. We amplified and cloned the genomic region comprising the HN and F genes of the sub-genotype VIIj. In addition, we altered the virulent cleavage site of the VIIj F gene to match the sequence of the low-virulent vaccine strain LaSota, and rescued the recombinant virus. Evaluation of the immunogenic efficiency and protective capacity of the new recombinant virus in vaccination-challenge animal experiments will discussed.