Development of flavivirus vaccine by using the adenoviral vector system

• Main Authors: CHAO, YU-HUA, 趙育華
• Other Authors: YEN, LI-CHEN
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/3pgh4k

碩士 === 國防醫學院 === 微生物及免疫學研究所 === 107 === Dengue fever is a mosquito-borne viral disease. People who were infected with dengue virus would get arthralgia, rashes, or other severe diseases, such as Mild Dengue Fever, Dengue hemorrhagic fever, and Dengue Shock Syndrome. As a result, it was necessary to develop a safe and efficacious vaccine for dengue virus. According to previous studies, E protein is usually a good choice due to its site on the viral surface and the relationship of virus entry. Based on the recent research in our lab, there is a segment of sequence located in E protein with excellent effect on neutralizing four types of dengue viruses. Therefore, we expressed the epitope by using the adenoviral vector system to induce active immunity since an active immune response usually led to better protection. We first constructed the recombinant adenovirus containing the DENV neutralizing epitope and amplified it in 293A cells. Then, we determined the viral titer by plaque-forming assay and confirmed the expression of DENV neutralizing epitope by western blot. Moreover, we immunized rAd-DENV epitope to BALB/c mice and collected the sera to perform 50% plaque reduction neutralization test. However, the neutralization capacity of rAd-DENV epitope for JEV was slightly lower to be 1:32. Furthermore, we tested the survival rates of BALB/c mice immunized with rAd-DENV epitope and challenged with JEV. The survival rates of rAd-DENV epitope group was 100% while the control rAd-lacZ group was 60% and vehicle PBS group had all died. In summary, rAd-DENV epitope showed protective efficacy for JEV and its effectiveness for DENV and ZIKV need further investigation.