Development of a Japanese encephalitis virus-like particle vaccine in silkworms using codon-optimised prM and envelope genes

• Main Authors: Sayaka Matsuda, Reiko Nerome, Kenichi Maegawa, Akira Kotaki, Shigeo Sugita, Kazunori Kawasaki, Kazumichi Kuroda, Ryoji Yamaguchi, Tomohiko Takasaki, Kuniaki Nerome
• Format: Article
• Language: English
• Published: Elsevier 2017-04-01
• Series: Heliyon
• Subjects: Immunology; Vaccines; Infectious disease
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405844016323453

We have successfully prepared a Japanese encephalitis virus (JEV) − Nakayama virus like particle (NVLP) vaccine using synthetic codon-optimized prM and E genes. The expression of the recombinant JEV Nakayama-BmNPV (JEV-NNPV) virus was determined in infected silkworm Bm-N cells by fluorescence and Western blot analysis. The recombinant was inoculated into silkworm pupae and the yield of Nakayama VLP (NVLP) reached a peak in the homogenates after 3 days. Additionally, in the peptide analysis of infected pupae homogenate, it appeared approximately 300–500 μg E protein/pupa were produced. When purified the above eluates on the discontinuous sucrose density gradient centrifugation, NVLP showed a strong hemagglutination (HA) activity by using chicken red blood cell in phosphate-buffered saline (PBS) free from Mg++ and Ca++ ions. The immune antisera against NVLP strain could efficiently neutralize the plaque formation of Nakayama, Beijing-1 and Muar strains, showing tendency of much higher reaction with heterologous Muar strain than homologous Nakayama strain. Our findings suggest that the JEV-NVLP may be useful for JEV epidemic control in many endemic areas of Asian countries as a widely effective and less expensive JE vaccine.