Pang Ee Leen, Peyret Hadrien, Ramirez Alex, Loh Hwei-San, Lai Kok-Song, Fang Chee-Mun, Rosenberg William M, Lomonossoff George P
School of Biosciences, University of Nottingham Malaysia, Semenyih, Malaysia.
Department of Biological Chemistry, John Innes Centre, Norwich, United Kingdom.
Front Plant Sci. 2019 Apr 16;10:455. doi: 10.3389/fpls.2019.00455. eCollection 2019.
Dengue fever is currently ranked as the top emerging tropical disease, driven by increased global travel, urbanization, and poor hygiene conditions as well as global warming effects which facilitate the spread of mosquitoes beyond their current distribution. Today, more than 100 countries are affected most of which are tropical Asian and Latin American nations with limited access to medical care. Hence, the development of a dengue vaccine that is dually cost-effective and able to confer a comprehensive protection is ultimately needed. In this study, a consensus sequence of the antigenic dengue viral glycoprotein domain III (cEDIII) was used aiming to provide comprehensive coverage against all four circulating dengue viral serotypes and potential clade replacement event. Utilizing hepatitis B tandem core technology, the cEDIII sequence was inserted into the immunodominant c/e1 loop region so that it could be displayed on the spike structures of assembled particles. The tandem core particles displaying cEDIII epitopes (tHBcAg-cEDIII) were successfully produced in via -mediated transient expression strategy to give a protein of ∼54 kDa, detected in both soluble and insoluble fractions of plant extracts. The assembled tHBcAg-cEDIII virus-like particles (VLPs) were also visualized from transmission electron microscopy. These VLPs had diameters that range from 32 to 35 nm, presenting an apparent size increment as compared to tHBcAg control particles without cEDIII display (namely tEL). Mice immunized with tHBcAg-cEDIII VLPs showed a positive seroconversion to cEDIII antigen, thereby signifying that the assembled tHBcAg-cEDIII VLPs have successfully displayed cEDIII antigen to the immune system. If it is proven to be successful, tHBcAg-cEDIII has the potential to be developed as a cost-effective vaccine candidate that confers a simultaneous protection against all four infecting dengue viral serotypes.
登革热目前被列为首要的新兴热带疾病，其原因包括全球旅行增加、城市化、卫生条件差以及全球变暖效应，这些因素促进了蚊子向当前分布范围以外的地区传播。如今，超过100个国家受到影响，其中大多数是热带亚洲和拉丁美洲国家，这些国家获得医疗保健的机会有限。因此，最终需要开发一种具有双重成本效益且能够提供全面保护的登革热疫苗。在本研究中，使用了抗原性登革热病毒糖蛋白结构域III（cEDIII）的共有序列，旨在提供针对所有四种流行的登革热病毒血清型以及潜在的进化枝替代事件的全面覆盖。利用乙肝串联核心技术，将cEDIII序列插入免疫显性的c/e1环区域，使其能够展示在组装颗粒的刺突结构上。通过病毒介导的瞬时表达策略成功产生了展示cEDIII表位的串联核心颗粒（tHBcAg-cEDIII），得到了一种约54 kDa的蛋白质，在植物提取物的可溶性和不溶性部分均能检测到。通过透射电子显微镜也观察到了组装好的tHBcAg-cEDIII病毒样颗粒（VLP）。这些VLP的直径范围为32至35 nm，与未展示cEDIII的tHBcAg对照颗粒（即tEL）相比，呈现出明显的尺寸增加。用tHBcAg-cEDIII VLP免疫的小鼠对cEDIII抗原呈现阳性血清转化，这表明组装好的tHBcAg-cEDIII VLP已成功地将cEDIII抗原展示给免疫系统。如果被证明是成功的，tHBcAg-cEDIII有可能被开发成为一种具有成本效益的候选疫苗，能够同时针对所有四种感染性登革热病毒血清型提供保护。
