BACKGROUND Virus-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. RESULTS The 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. CONCLUSIONS The results demonstrate that GFLV VLPs constitute a potential scaffold for surface display of the epitope of interest.

中文翻译：

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呈现人乳头瘤病毒小衣壳蛋白L2表位的葡萄扇状病毒病毒样颗粒的生产和鉴定。

背景技术病毒样颗粒（VLP）平台代表了用于产生有效和免疫原性亚单位疫苗的有前途的方法。在这里，研究了使用葡萄扇状叶病毒（GFLV）VLP作为表达人乳头瘤病毒（HPV）L2表位的新载体的可行性。为实现此目标，预测了HPV L2表位二级结构的模型，并评估了其在GFLV衣壳蛋白（CP）的5个外部环中的插入。结果将表位序列遗传插入到GFLV CP的αB-αB”结构域C中，然后在巴斯德毕赤酵母和大肠杆菌中过表达，在大肠杆菌中获得最高的表达量。需要变性-复性步骤，而产量较低的VLP是使用巴斯德毕赤酵母直接形成的，经电子显微镜和免疫染色电子显微镜确认。由于在天然条件下在毛细管电泳和ELISA中发现GFLV L2 VLP与HPV L2抗体相互作用，因此可以假定插入的表位以其适当的三元结构位于VLP表面。结论结果表明，GFLV VLPs构成了潜在的表位感兴趣的表位的潜在支架。