Production and characterization of virus-like particles of grapevine fanleaf virus presenting L2 epitope of human papillomavirus minor capsid protein

Razieh Yazdani,Anne-Catherine Servais,Nicolas Thelen,Alain Brans,Afshin Hassani-Mehraban,Nathalie Jacobs,Seyed Shahriar Arab,Marc Thiry,Jacques Crommen,Marianne Fillet,Masoud Shams-Bakhsh

doi:10.1186/s12896-019-0566-y

Razieh Yazdani, Anne-Catherine Servais + Show 9 more

Open Access

https://doi.org/10.1186/s12896-019-0566-y

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Abstract

BackgroundVirus-like particle (VLP) platform represents a promising approach for the generation of efficient and immunogenic subunit vaccines. Here, the feasibility of using grapevine fanleaf virus (GFLV) VLPs as a new carrier for the presentation of human papillomavirus (HPV) L2 epitope was studied. To achieve this goal, a model of the HPV L2 epitope secondary structure was predicted and its insertion within 5 external loops in the GFLV capsid protein (CP) was evaluated.ResultsThe epitope sequence was genetically inserted in the αB-αB” domain C of the GFLV CP, which was then over-expressed in Pichia pastoris and Escherichia coli. The highest expression yield was obtained in E. coli. Using this system, VLP formation requires a denaturation-refolding step, whereas VLPs with lower production yield were directly formed using P. pastoris, as confirmed by electron microscopy and immunostaining electron microscopy. Since the GFLV L2 VLPs were found to interact with the HPV L2 antibody under native conditions in capillary electrophoresis and in ELISA, it can be assumed that the inserted epitope is located at the VLP surface with its proper ternary structure.ConclusionsThe results demonstrate that GFLV VLPs constitute a potential scaffold for surface display of the epitope of interest.

Highlights

Virus-like particle (VLP) platform represents a promising approach for the generation of efficient and immunogenic subunit vaccines
In the absence of a resolved structure for the human papillomavirus (HPV) L2 epitope as well as of potential structural templates in Protein Data Bank (PDB) using the selected sequence, the secondary structure model of the HPV L2 epitope was constructed by examining small epitope fragment secondary structures in Protein Design Assistant (ProDA) and by using information about HPV L2 structure obtained from a previous study performed by Tumban and coworkers [21]
The HPV L2 epitope sequence was divided into three parts, namely QLYKT, CKQAGTC and CPPD, which were used as query sequences in ProDA

Summary

Introduction

Virus-like particle (VLP) platform represents a promising approach for the generation of efficient and immunogenic subunit vaccines. The feasibility of using grapevine fanleaf virus (GFLV) VLPs as a new carrier for the presentation of human papillomavirus (HPV) L2 epitope was studied. To achieve this goal, a model of the HPV L2 epitope secondary structure was predicted and its insertion within 5 external loops in the GFLV capsid protein (CP) was evaluated. The highest expression yield was obtained in E. coli. Using this system, VLP formation requires a denaturation-refolding step, whereas VLPs with lower production yield were directly formed using P. pastoris, as confirmed by electron microscopy and immunostaining electron microscopy. Since the GFLV L2 VLPs were found to interact with the HPV L2 antibody under native conditions in capillary electrophoresis and in ELISA, it can be assumed that the inserted epitope is located at the VLP surface with its proper ternary structure

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Conclusion