Title: Development of a Recombinant Newcastle Disease Virus VG/GA Strain Infectious Clone as an Enterotropic Vaccine Vector Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 2, 2011
Publication Date: N/A
Technical Abstract: The Villegas-Glisson/University of Georgia (VG/GA) vaccine strain of Newcastle disease virus (NDV) is commonly used worldwide to prevent Newcastle disease. The VG/GA strain is thought to preferentially replicate in intestinal tract of chickens and induce local mucosal immunoresponse. In the present study, we aimed to develop an infectious clone of the VG/GA strain of NDV as an enterotropic vaccine vector. A full-length copy of deoxyribonucleic acid (cDNA) clone (FLC) of the VG/GA C5 strain was constructed by assembling four reverse transcriptase-polymerase chain reaction (RT-PCR) fragments of the virus into a transcription vector. A reporter gene coding for the green fluorescence protein (GFP) was inserted between the matrix (M) and phosphoprotein (P) genes of the viral genome in the FLC as an extra transcription unit. An infectious recombinant VG/GA-GFP virus (rVG/GA-GFP) was rescued by co-transfecting the FLC and supporting plasmids expressing the nucleoprotein (NP), P, and large polymerase (L) proteins of NDV into the HEp-2 cells that had been infected with modified vaccinia T7 recombinant virus (MVA-T7). In vitro and in vivo characterization showed that the rescued rVG/GA-GFP virus remained its lentogenic pathotype and tissue tropism. Expression of the GFP was detected from the rVG/GA-GFP infected DF-1 cells and embryonated chicken intestinal tract by fluorescence microscopy and imaging. The results suggest that the VG/GA infectious clone is a potential enterotropic vaccine vector to deliver foreign enteric virus antigens as bivalent vaccines.