Construction and immune efficacy of recombinant pseudorabies virus expressing PrM-E proteins of Japanese encephalitis virus genotype І

BACKGROUND: Japanese encephalitis (JE) is an arboviral disease with high case fatality rates and neurologic or psychiatric sequelae among survivors in Asia, western Pacific countries and northern Australia. Japanese encephalitis virus (JEV) is the cause of JE and the emergence of genotype І (GI) JEV has displaced genotype III (GIII) as the dominant strains circulating in some Asian regions. The currently available JE vaccines are safe and effective in preventing this disease, but they are developed based on the GIII JEV strains. METHODS: The recombinant virus PRV TK(−)/gE(−)/PrM-E(+) which expressed the premembrane (prM) and envelope (E) proteins of JEV SX09S-01 strain (genotype I, GI) was constructed by homologous recombination between the genome of PRV TK(−)/gE(−)/LacZ(+) digested with EcoRI and plasmid pIE-CAG-PrM-E-BGH. Expression of JEV PrM and E proteins was analyzed by Western blot analysis. Immune efficacy of PRV TK(−)/gE(−)/PrM-E(+) was further evaluated in mouse model. RESULTS: A recombinant pseudorabies virus (PRV TK(−)/gE(−)/PrM-E(+)) was successfully constructed. Mice experiments showed that PRV TK(−)/gE(−)/PrM-E(+) could induce a high level of ELISA antibodies against PRV and JEV, as well as high titer of PRV neutralizing antibodies. After challenge with 1 × 10(7) PFU virulent JEV SX09S-01 strain, the time of death was delayed and the survival rate was improved in PRV TK(−)/gE(−)/PrM-E(+) vaccinated mice. CONCLUSIONS: PRV TK(−)/gE(−)/PrM-E(+) is a potential vaccine candidate against PRV and JEV GI infection in the future.