Avian Paramyxovirus Type-3 as a Vaccine Vector: Identification of a Genome Location for High Level Expression of a Foreign Gene

Abstract

Avian paramyxovirus serotype 3 (APMV-3) causes infection in a wide variety of avian species, but it does not cause apparent diseases in chickens. On the contrary, APMV-1, also known as Newcastle disease virus (NDV), can cause severe disease in chickens. Currently, natural low virulence strains of NDV are used as live-attenuated vaccines throughout the world. NDV is also being evaluated as a vaccine vector against poultry pathogens. However, due to routine vaccination programs, chickens often possess pre-existing antibodies against NDV, which may cause the chickens to be less sensitive to recombinant NDV vaccines expressing antigens of other avian pathogens. Therefore, it may be possible for an APMV-3 vector vaccine to circumvent this issue. In this study, we determined the optimal insertion site in the genome of APMV-3 for high level expression of a foreign gene. We generated recombinant APMV-3 viruses expressing the green fluorescent protein (GFP) by inserting the GFP gene at five different intergenic regions in the genome. The levels of GFP transcription and translation were evaluated. Interestingly, the levels of GFP transcription and translation did not follow the 3′-to-5′ attenuation mechanism of non-segmented, negative-sense RNA viruses. The insertion of GFP gene into the P-M gene junction resulted in higher level of expression of GFP than when the gene was inserted into the upstream N-P gene junction. Unlike NDV, insertion of GFP did not attenuate the growth efficiency of AMPV-3. Thus, APMV-3 could be a more useful vaccine vector for avian pathogens than NDV.

A recombinant avian paramyxovirus serotype 3 expressing the hemagglutinin protein protects chickens against H5N1 highly pathogenic avian influenza virus challenge

“…antigenomic cDNA of APMV-3 strain Netherlands was constructed previously 41,42 and later the viral protein 2 (VP2) gene of infectious bursal disease virus (IBDV) was flanked between P and M genes of APMV-3 using this plasmid. Here we replaced the VP2 gene with HA gene of HPAIV strain A/Vietnam/1203/2004 (H5N1) using SacII restriction enzyme site.…”

Newcastle Disease Virus as a Vaccine Vector for 20 Years: A Focus on Maternally Derived Antibody Interference

“…In 2015, the green fluorescence protein (GFP) gene was inserted in five different sites of NDV (VG/GA strain) and the non-coding region between the P and M genes was identified as the optimal insertion site for foreign genes [ 29 ]. Consistently, the P-M junction was also determined as the optimal insertion site for the transgene in the APMV-3 backbone [ 30 ]. Currently, the P-M junction is used as the insertion site of foreign genes for most vaccines based on the NDV vector.…”

Engineering of Live Chimeric Vaccines against Human Metapneumovirus

“…Insertions in either 1 st or 2 nd genomic positions are the most privileged for PIV3-based vectors, with the 2 nd position usually providing better virus recovery, higher viral replication, and better exogene expression [147]. For some vectors, namely, NDV and Avian paramyxovirus serotype 3 (APMV3), the 3 rd position is the most advantageous, whereas the insertion at the 2 nd one results in delayed viral replication and the largest reduction in virus recovery [148][149][150]. The 4 th and the 5 th positions are not frequently used, so as to not influence the expression of vector's surface proteins (F and HN) [146], with the exception of studies on SeV bearing either RSV-F or HMPV-F at the 5 th position [151][152][153].…”