Title: A novel approach for a foreign gene expression by Newcastle disease virus Authors
Submitted to: Southeastern Regional Virology Conference
Publication Type: Abstract Only
Publication Acceptance Date: April 10, 2014
Publication Date: April 25, 2014
Citation: Zhang, Z., Li, D., Zsak, L., Yu, Q. 2014. A novel approach for a foreign gene expression by Newcastle disease virus [abstract]. In: Proceedings of the Southeastern Regional Virology Conference, April 25-27, 2014, Atlanta, Georgia. p. 23. Technical Abstract: Newcastle disease virus (NDV) has been developed as vectors using reverse genetics technology to express foreign genes for vaccine, anticancer and gene therapy purposes. The foreign genes are usually inserted into the intergenic region of the NDV genome as an additional transcription unit. Based on the well accepted “start-stop” transcription mechanism, NDV is believed to transcribe its genes into mRNAs in a gradient of decreasing mRNA abundance according to the position of the gene relative to the 3’ end of the genome. Therefore, addition of a transcription unit in the viral genome would alter the transcription patterns of the virus, subsequently, affect virus replication and the level of foreign gene expression. In the present study, we developed a novel approach for foreign gene expression by inserting a red fluorescence protein (RFP) gene, along with the internal ribosomal entry site (IRES) sequences, into the NP, P, M, F, HN, and L genes of the NDV LaSota virus genome as a second open reading frame (2nd ORF), using reverse genetics technology. Quantitative measurement of the RFP expression from DF-1 cells infected with these recombinant viruses showed that the insertion of the 2nd ORF did not alter the transcription patterns of the virus and virus replication. The recombinant virus with RFP inserted in the NP gene expressed the highest level of RFP. These results suggest that expression of a foreign gene from a 2nd ORF is a voluble alternative approach to develop NDV recombinants as vaccines, and anticancer and gene therapy reagents.