Convenient Auto-Processing Vector Based on Bamboo Mosaic Virus for Presentation of Antigens Through Enzymatic Coupling.

Ming-Hao Yang,Meng-Hsun He,Na-Sheng Lin,Chung-Chi Hu,Yi-Ling Lin,Chi-Hzeng Wong,Yau-Heiu Hsu,Jian-Jong Liang,Hui-Ying Ko

doi:10.3389/fimmu.2021.739837

Abstract

We have developed a new binary epitope-presenting CVP platform based on bamboo mosaic virus (BaMV) by using the sortase A (SrtA)-mediated ligation technology. The reconstructed BaMV genome harbors two modifications: 1) a coat protein (CP) with N-terminal extension of the tobacco etch virus (TEV) protease recognition site plus 4 extra glycine (G) residues as the SrtA acceptor; and 2) a TEV protease coding region replacing that of the triple-gene-block proteins. Inoculation of such construct, pKB5G, on Nicotiana benthamiana resulted in the efficient production of filamentous CVPs ready for SrtA-mediated ligation with desired proteins. The second part of the binary platform includes an expression vector for the bacterial production of donor proteins. We demonstrated the applicability of the platform by using the recombinant envelope protein domain III (rEDIII) of Japanese encephalitis virus (JEV) as the antigen. Up to 40% of the BaMV CP subunits in each CVP were loaded with rEDIII proteins in 1 min. The rEDIII-presenting BaMV CVPs (BJLPET5G) could be purified using affinity chromatography. Immunization assays confirmed that BJLPET5G could induce the production of neutralizing antibodies against JEV infections. The binary platform could be adapted as a useful alternative for the development and mass production of vaccine candidates.

Highlights

Virus-like particles (VLPs) or chimeric virus particles (CVPs) have been utilized extensively as effective scaffolds for the presentation of epitopes or antigens in the development of vaccine candidates [1,2,3,4]
We have developed an efficient epitope presentation CVP system based on Bamboo mosaic virus (BaMV), a member of the genus Potexvirus, and validated its applicability in stimulating protective immunity against foot-andmouth disease virus (FMDV) [11, 12], infectious bursal disease virus (IBDV) [13], or Japanese encephalitis virus (JEV) [14] in different animal models
We hypothesized that the low expression level might be due to the replacement of the original BaMV RNA silencing suppressor, TGBp1, by the tobacco etch virus (TEV) protease in pKB5G construct, leading to the silencing of the expressions of B5G coat protein (CP)

Summary

Introduction

Virus-like particles (VLPs) or chimeric virus particles (CVPs) have been utilized extensively as effective scaffolds for the presentation of epitopes or antigens in the development of vaccine candidates [1,2,3,4]. We have developed an efficient epitope presentation CVP system based on Bamboo mosaic virus (BaMV), a member of the genus Potexvirus, and validated its applicability in stimulating protective immunity against foot-andmouth disease virus (FMDV) [11, 12], infectious bursal disease virus (IBDV) [13], or Japanese encephalitis virus (JEV) [14] in different animal models. These previously developed BaMV-based epitope presenting systems, as well as other VLP or CVP systems, still face several challenges that require further improvement

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Discussion

Conclusion