Presentation of the L2 epitope of Human papillomavirus on the surface of Grapevine fan-leaf Virus-like particles
The application of plant viruses in nanomedicine has evolved rapidly. Virus-like particle (VLP) technology represents a promising approach for generation of efficient peptide vaccines and materials for use in nanotechnological applica structures, that are ideally suited for eliciting an immune response. The vast majority of plant viruses are non-infectious toward other organisms and therefore their use in biomedicine presents no biological hazard. Therefore, plant viruses used as a platforms for insert heterologous epitopes. To test the feasibility of Grapevine fan-leaf Virus (GFLV) particles, as a scaffold for epitope presentation and identify sites for epitope fusion or insertion that would not interfere with virus-like-particle formation, chimeric GFLV coat protein (CP) gene construct was investigated and engineered by using bioinformatics information. The L2 epitope secondary structure was modeled by MODELLER software and was genetically inserted at the predicted external loop structures of GFLV coat protein. GFLV-L2 was cloned and expressed in Escherichia coli (BL21and Shuffle) cells. High levels of insoluble protein expression, relative to protein from the entire cell lysate, were obtained for GFLV-L2 in E. coli. The purified protein was identified by Western blotting analysis. The GFLV-L2 self-assembles into GFLV-L2-like particles in in vitro. Transmission electron microscopy was used to visualize the morphology of the particles that the particles were similar in size and morphology. Our results detail the successful expression of GFLV-L2 and formation VLPs in E. coli, improving their candidacy as a vaccine platform.