Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2008
Publication Date: July 10, 2008
Citation: Yu, Q., Estevez, C. N., King, D. J., Kapczynski, D. R., Zsak, L. 2008. Generation of recombinant avian metapneumovirus subgroup C viruses for pathogenesis studies and vaccine development [abstract]. In: Proceedings of the 27th Annual Meeting of American Society for Virology, Cornell, New York. p. 296. Technical Abstract: Avian metapneumovirus subgroup C (aMPV-C), a member of the Paramyxoviridae family, causes an upper respiratory disease in turkeys, resulting in significant economic losses for the US turkey industry. To study the disease pathogenesis and to eventually develop a safe and effective vaccine against aMPV-C disease, we developed a reverse genetics system for rescue of recombinant aMPV-C viruses from cloned DNAs. A full length cDNA clone of aMPV-C and plasmids expressing the N, P, M2-1, and L proteins of aMPV-C were constructed. Co-transfection of the full length clone and the viral protein expression plasmids in vaccinia/T7 (MVA-T7) virus-infected HEp-2 cells resulted in rescue of infectious aMPV-C. By using this system, we generated an aMPV-C and Newcastle disease virus (NDV) chimera, raMPV/NDV F-HN, in which the aMPV-C fusion (F) and attachment (G) protein genes were exchanged with the F and Hemagglutinin-Neuraminidase (HN) genes of the mesogenic NDV Anhinga strain. In addition, we generated a foreign gene expression recombinant virus, raMPV/GFP/NDV F-HN, by inserting a green fluorescence protein (GFP) gene into the aMPV/NDV F-HN chimera. The pathogenicity of these aMPV recombinants was assessed by conducting the intracerebral pathogenicity index (ICPI) assay and inoculation of susceptible day-old SPF chickens and 2-week-old SPF turkeys via natural routes of infection. The ICPI results indicated that the aMPV/NDV F-HN and aMPV/GFP/NDV F-HN chimeras were attenuated when compared with the NDV Anhinga strain, the donor of F and HN protein genes. Neither day-old SPF chickens nor 2 week-old SPF turkeys produced any clinical signs of disease after the natural route inoculation of these chimeras. The successful development of the reverse genetic technology for aMPV-C provides a powerful tool for developing bivalent or multivalent recombinant vaccines and identifying pathogenic determinants of the virus.