Stable Display of Artificially Long Foreign Antigens on Chimeric Bamboo mosaic virus Particles.

Tsung-Hsien Chen,Chin-Wei Lee,Chung-Chi Hu,Yau-Heiu Hsu,Yu-Min Feng,Na-Sheng Lin

doi:10.3390/v13040572

Abstract

Plant viruses can be genetically modified to generate chimeric virus particles (CVPs) carrying heterologous peptides fused on the surface of coat protein (CP) subunits as vaccine candidates. However, some factors may be especially significant in determining the properties of chimeras. In this study, peptides from various sources and of various lengths were inserted into the Bamboo mosaic virus-based (BaMV) vector CP N-terminus to examine the chimeras infecting and accumulating in plants. Interestingly, it was found that the two different strains Foot-and-mouth disease virus (FMDV) VP1 antigens with flexible linker peptides (77 or 82 amino acids) were directly expressed on the BaMV CP, and the chimeric particles self-assembled and continued to express FMDV antigens. The chimeric CP, when directly fused with a large foreign protein (117 amino acids), can self-fold into incomplete virus particles or disks. The physicochemical properties of heterologus peptides N-terminus, complex strand structures of heterologus peptides C-terminus and different flexible linker peptides, can affect the chimera accumulation. Based on these findings, using plant virus-based chimeras to express foreign proteins can increase their length limitations, and engineered plant-made CVP-based vaccines have increasing potential for further development as novel vaccines.

Highlights

Molecular agricultural technology, utilizing plants as bioreactors to produce valuable proteins, has increased in recent years [1,2,3]
A panel of polypeptides was selected from influenza A virus M2 extracellular domain (M2e), influenza A virus hemagglutinin (HA), influenza A virus HA2, foot-and-mouth disease virus (FMDV) VP1, T-cell epitopes, or Japanese encephalitis virus envelope protein domain III (JEV EDIII) epitopes (Table S1)
We evaluated the sum of the hydropathy values for all the amino acids based on the GRAVY score program, which are extensions of the Bamboo mosaic virus (BaMV) coat protein (CP), and the heterologous peptide hydrophilicity values, both of which are key factors for chimera infection and accumulation in plants

Summary

Introduction

Molecular agricultural technology, utilizing plants as bioreactors to produce valuable proteins, has increased in recent years [1,2,3]. Among the commonly used approaches, virus-based transient expression vector systems are the most promising for rapid recombinant protein expression, having higher potential than stable transgenic plants [2]. Among plant virus-based vectors, through the epitope presentation system, plant-made chimeric virus particles (CVPs) displaying pathogenic antigens on their surfaces as fusions to the coat proteins (CPs) can be potential vaccine candidates [2,3,4,5]. The CVP strategy has been used extensively to display target peptides on the CVP surface to enhance immunogenicity [6,7]. CPs can enhance immunogenicity [6,8] and facilitate easy antigen purification [5]. Plant-made CVPs have the potential to be developed into vaccines against various diseases

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