Facilitated in vivo synthesis of ribonucleic acid and protein via T7 RNA polymerase

Research progress in the development of porcine reproductive and respiratory syndrome virus as a viral vector for foreign gene expression and delivery

INTRODUCTION

Porcine reproductive and respiratory syndrome (PRRS) is an infectious disease of swine characterized by respiratory disorders in growing and finishing pigs and reproductive failure in pregnant sows. PRRSV has been recognized as one of the most economically significant pathogens affecting the global pig industry.

AREAS COVERED

Currently, commercially available vaccines, including traditional killed virus (KV) vaccines and modified live virus (MLV) vaccines, are the cardinal approaches to prevent and control porcine reproductive and respiratory syndrome virus (PRRSV) infection. However, the protective efficacy of these vaccines is not satisfactory, resulting in the continuous evolution and recurrent appearance of the virus as well as the emergence of new variants. A safe and effective vaccine against PRRSV is in dire need. Here, we review the research progress in recent years in the development and use of PRRSV as a viral vector to express foreign genes, and their potential application in gene delivery and vaccine development.

EXPERT OPINION

The potential of using PRRSV-based vectors to express multiple antigens would be particularly instrumental for the development of a new generation of multivalent vaccines against PRRSV and other porcine viruses.

The use of 10-23 DNAzyme to selectively destroy the allele of mRNA with a unique purine-pyrimidine dinucleotide

10-23 DNAzyme is an oligodeoxyribonucleotide-based ribonuclease. It consists of a 15-nt catalytic domain flanked by two target-specific complementary arms. It has been shown to cleave target mRNA effectively at purine (R)-pyrimidine (Y) dinucleotide. Taking advantage of this specific property, 10-23 DNAzyme was designed to cleave mRNA of a given allele at a unique RY dinucleotide while leaving the mRNA encoded from other alleles of the same gene intact. In this study, a p53-R249S (AGG-->AGT) mutant was tested. 10-23 DNAzyme was used to cut mutant mRNA at GT dinucleotide of codon 249. Both in vitro and in vivo studies showed that this DNAzyme could specifically cut the mutant p53 allele, leaving the wild-type unaffected. This proof-of-concept experiment provided a new way to knock down expression of a given allele with special single-base transversion.