title: Cross protection against lethal West Nile virus challenge in mice immunized with recombinant E protein domain III of Japanese encephalitis virus.
abstract: Japanese encephalitis virus (JEV) and West Nile virus (WNV) are closely related mosquito-borne flaviviruses that cause severe encephalitic diseases with global impact. Cross protection among JEV and WNV has been previously described, and most cross reactive epitopes were identified within the domain II of E protein (EDII). In this study, the E protein domain III (EDIII) of JEV was successfully expressed in Escherichia coli, purified by a Ni-NTA column and characterized by Western blotting assay. Competitive inhibition assay showed that this recombinant JEV EDIII blocks the entry of JEV into BHK-21 cells. Mice immunized with the recombinant JEV EDIII developed high IgG and neutralizing antibodies titers against JEV. Most importantly, antibodies induced by JEV EDIII could neutralize WNV in vitro and partially protected mice against lethal WNV challenge. These results demonstrate that immunization with JEV EDIII induces cross-protective immunity against WNV infection, indicating a possible role of EDIII for the cross-protection among flavivirus.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, No. 20 Dongda Street, Beijing 100071, China.
authors.forename: Shi-Hua
authors.initials: SH
authors.lastname: Li
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Li
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Deng
authors.forename: Xue-Dong
authors.initials: XD
authors.lastname: Yu
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: Zhu
authors.forename: E-De
authors.initials: ED
authors.lastname: Qin
authors.forename: Cheng-Feng
authors.initials: CF
authors.lastname: Qin
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D001667:Binding, Competitive; D015153:Blotting, Western; D002460:Cell Line; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D006224:Cricetinae; D056738:Cross Protection / Q000276:immunology*; D003429:Cross Reactions; D004664:Encephalitis Virus, Japanese / Q000502:physiology*; D004672:Encephalitis, Japanese / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D004926:Escherichia coli; D005260:Female; D007114:Immunization; D007073:Immunoglobulin E / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D014162:Transfection; D053586:Virus Internalization / Q000187:drug effects*; D014901:West Nile Fever / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D014902:West Nile virus / Q000502:physiology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D011994:Recombinant Proteins; D007073:Immunoglobulin E