Virus-Based Vectors: A New Approach for Production of Recombinant Proteins

Zahid Naseri,Ghaffar Khezri,Seyed Javad Davarpanah,Hamideh Ofoghi

doi:10.29252/jabr.06.01.02

Abstract

Recombinant proteins have become one of the basic human needs today for pharmaceutical, industrial and research purposes. The conventional methods of producing recombinant proteins, including bacterial systems, yeast, and human cells, have led to rising prices and biosafety problems for these products. Research on commercial production of recombinant proteins prompted a new method based on plant RNA viruses and plant hosts, which is known as Transient Expression System. Accordingly, a viral vector based on the plant RNA virus genome was designed in which the target gene is placed underneath a viral subgenomic promoter. In these vectors, despite the genetic manipulation, the ability to infect the entire plant that was present in the virus was preserved and, several days after plant infestation, it became bioreactor for the production of recombinant protein. The advances made in this field led to the creation of hybrid vectors based on plant viruses and Agrobacterium T-DNA (Transfer DNA). The amount of recombinant protein produced by these vectors was up to 5 grams per kilogram of fresh weight, which is considered a reliable record. The abundant benefits of this method have attracted the attention of researchers in this way, including the rapid and high production rate, reduced production costs and bio-safety of manufactured products. Several recombinant drugs are currently produced by the transient expression system, either delivered to the consumer or by clinical trials. This review presents how to discover, creation and development of viral vectors in transient expression systems in order to produce recombinant proteins.

Highlights

The recombinant protein is a protein that its coding gene is expressed in a heterologous host
The first pharmaceutical recombinant protein was human insulin that was approved for human use by regulatory organizations in 1982.1 Pharmaceutical proteins are very powerful drugs with no side effects, requiring less production time compared to small molecule drugs.[2]
Low production cost and safety of products due to the lack of common pathogens between plants and animals are the advantages of recombinant protein production by plants.[3,5]

Summary

Introduction

The recombinant protein is a protein that its coding gene is expressed in a heterologous host. First Generation Virus-Based Vectors: Full Virus Strategy The first generation of virus-based vectors are the viruses that express the gene of interest in addition to their own natural genes In this process, the gene of interest is expressed by a promoter/strong viral promoter like subgenomic of capsid promoter which has been doubled by genetic engineering in addition of its presence in virus genome, or by fusion to a coding sequence of capsid protein as a fusion protein that can be used for expression of immunogenic epitopes.[31] The gene of interest is sent to plant cells as a transcript of infecting DNA or preferably as mature virus particles. Infiltration of the whole plant or detached leaves is performed in different ways; the simplest one is shoot infiltration in a bacterial suspension followed by a weak vacuum (approximately 0.8-0.9 Bar) for 10-30 seconds.[27,41,46] Another way to infiltrate is the injection of Agrobacterium

Second Generation No No No Yes Yes Yes Yes

Findings

Influenza virus