The Generation Of A Vesicular Stomatitis Virus-based Vaccine For Zika Virus

Zika virus(ZIKV)together with Dengue virus,West Nile virus,Yellow fever virus,Japanese encephalitis virus belongs to the Flaviviridae.It was isolated for the first time in Uganda rhesus monkeys,and then only sporadic reports occurred.In 2015 there was an outbreak of ZIKV in the Americas and a number of countries have been reported to have infection cases.The symptoms ZIKV caused are mild in clinical,such as fatigue,fever,conjunctivitis,muscle pain and so on.Patients generally recover 7 days post infection.However,recent studies indicated that ZIKV infection is related to the neonatal head malformations and adult Guillain-Barre syndrome.ZIKV is a single-stranded positive strand RNA virus and transmitted by mosquito-borne.The virus has icosahedral structure consisting of capsular protein(E),membrane protein(M),nucleocapsid(C)and viral genome.E protein is responsible for cellular receptor binding and viral entry.This protein contains multiple epitopes,which are the potential targets for vaccine design.The vesicular stomatitis virus(VSV)is a single stranded negative RNA virus of Rhabdoviridae.VSV has the advantages for vaccine delivery,such as simple operation,high viral titer and single immunization.It now has been wildly used in the vaccine study.In this paper,we generated a recombinant virus vaccine VSV-ZikaE260-425,which expressed 260-425 amino acids of ZIKV E protein using VSV reverse genetic system,and we tested the immune response and protection induced by the vaccine in mice.Firstly,we constructed the plasmid XN2-ZikaE260-425 encoding the E gene260-425 amino acid.Then,we packaged the recombinant virus VSV-ZikaE260-425 by co-transfection the plasmids pN,pL,pP and pXN2-ZikaE260-425 in BHK cells.The expression of ZikaE260-425 protein was confirmed in infection cells by western blotting and indirect immune staining.Intranasal immuniztion mice with recombinant VSV-ZikaE260-425 induced a high level of fecal IgA antibody one week after immunization and high level of IgG antibody three weeks after immunization.Compared with the control group,VSV-ZikaE260-425 group can induce stronger antigen-specific lymphocyte proliferation detected by Brdu method as well as IFN-γ~+CD8~+T cells.We also intraperitoneally injected mice with ZikaPRVABC59 to establish a ZIKV infection model.Real-time PCR results showed that ZIKV was most replicated in the brain,spinal cord and testis tissue.We then infected the male BALB/c mice five weeks after immunization.The viral replication was measured four days after infection in brain,spinal cord and testis.The results showed that VSV-ZikaE260-425immunization can effectively reduce the viral replication and have a specific immune protection.In summary,we successfully produced the recombinant virus VSV-ZikaE260-425expressing ZikaE260-425,and the vaccine induced the ZIKV-specific immune response in mice.Moreover,immunization with VSV-ZikaE260-425 could protect the mice from infection.Our research provides a new strategy for the development of the ZIKV vaccine.