| West Nile Fever(WNF) is a severe zoonosis caused by West Nile virus(WNV). The clinical symptoms includes fever, encephalitis, cephalomeningitis, and even death. WNV has caused the extensive concern all over the world. In 2012, West Nile Fever broke out with 118 death in USA. In our couWest Nile virus(WNV)ntry, there has been no reports of clinical cases caused by WNV yet.However, because of the complex natural geography environment of our country, mosquitoes breeding and natural conditions of bird-migration benefit the replication and transmission of WNV. Therefore,WNV has important research value in entry and exit supervision and prevention system of our country.WNV is a member of Flaviviridae, genus Flavivirus, Japanese encephalitis serum group. It is a RNA virus which is a single-strand, negative-sense and non-segmented genome. There are three structural proteins of WNV : capsid(C), envelope(E) and membrane(M). Researches show that expressing E protein and premembrane protein(prM) at the same time under certain conditions can form virus-like particles(VLP). E protein is the most important structural protein of WNV. The epitope on the surface is related to neutralizing activity, tissue tropism, serum specificity, virulence of the virus and host range. LaSota, low pathogenic strain of Newcastle disease virus(NDV), can replication only in poultry tissues and cause abortional infection in mammals. Meanwhile, exogenous protein can express in high efficiency and cost in a low level..The safety and efficiency of recombinant NDV vaccine was proved in a wide variety of animals, including pigs, dogs, cats, African green monkeys and so on. NDV live vector vaccine can induce the body to produce effective mucosa, humoral and cellular immune response.Although there have been no reports about WNV injection so far, the reseach of safe and effective potential vaccine is significant because of the high infectivity and pathogenicity of WNV to human.From the epidemic status of WNV in recent years, epidemic area trends to proglobalism and the cases of neurologic symptoms becomes more. Disadvantages of the vaccines against WNV developed by many countries appeared successively. We constructed and gained the recombinant NDV expressing AIV(H5)-HA, RABV-GP or NiV-GP/FP by reverse genetics of NDV, and the safety and effectivity of these recombinant viruses have been proved on laboratory animals and original animals. All of these canprove that recombinant NDV is advanced and promising as a live virus vaccine vector for new generation vaccine.This study generated a recombinant Newcastle disease virus(NDV) of LaSota vaccine strain expressing the codon-optimized envelope protein(E) and premembrane protein(prM) of West Nile virus(WNV) by reverse genetics, designated rLa-WNV-prM/E, and evaluation of immune in mice which produced humoral and cellular immune responses was to test the immunogenicity of the recombinant virus. RT-PCR, indirect immunofluorescence(IFA), ELISA, plaque reduction neutralization test and Fluorescence Activated Cell Sorting(FACS) were used for measuring the expression of WNV prM/E and immune response. Results showed that the rLa-WNV-prM/E expressed the prM/E protein effectively and induced high levels of specific IgG against prM/E and specific CD4 +and CD8 + T cells anti-WNV E protein epitope in immune response. These results demonstrated that rLa-WNV-prM/E was efficient to stimulate high level humoral and cellular immunoresponses, which could be used a potential vaccine candidate against WNV infection. |
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