title: Development of a double antibody sandwich ELISA for West Nile virus detection using monoclonal antibodies against non-structural protein 1.
abstract: The early diagnosis of West Nile virus (WNV) infection is important for successful clinical management and epidemiological control. The non-structural protein 1 (NS1) of flavivirus, a highly conserved and secreted glycoprotein, is abundant in the serum of flavivirus-infected patients and represents a useful early diagnostic marker. We developed a WNV-specific NS1 antigen-capture ELISA using two mouse monoclonal antibodies (MAbs) that recognised distinct epitopes of the NS1 protein of WNV as capture and detection antibodies. The antigen-capture ELISA displayed exclusive specificity to WNV without cross-reaction with other related members of the flavivirus family, including the dengue virus, yellow fever virus, Japanese encephalitis virus, and tick-borne encephalitis virus. Additionally, the specificity was presented as no false positive in normal (0/1003) and DENV-infected (0/107) human serum specimens. The detection limit of the antigen-capture ELISA was as low as 15 pg/ml of recombinant WNV NS1 protein (rWNV-NS1) and 6.1 plaque-forming units (PFU)/0.1 ml of WNV-infected culture supernatant. In mice infected with WNV, the NS1 protein was readily detected in serum as early as one day after WNV infection, prior to the development of clinical signs of the disease. The sensitivity of the NS1 capture ELISA (93.7%) was significantly higher (79.4%) than that of real-time reverse transcription polymerase chain reaction in 63 serum samples from WNV-infected mice (p = 0.035). This newly developed NS1 antigen-capture ELISA with high sensitivity and specificity could be used as an efficient method for the early diagnosis of WNV infection in animals or humans.
authors.affiliation: Laboratory of Emerging Infectious Diseases and Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Xi-Xia
authors.initials: XX
authors.lastname: Ding
authors.affiliation: Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Li
authors.affiliation: Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Yong-Qiang
authors.initials: YQ
authors.lastname: Deng
authors.affiliation: Laboratory of Emerging Infectious Diseases and Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Guo
authors.affiliation: Laboratory of Emerging Infectious Diseases and Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Hao
authors.affiliation: Laboratory of Emerging Infectious Diseases and Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Che
authors.affiliation: Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
authors.forename: Cheng-Feng
authors.initials: CF
authors.lastname: Qin
authors.affiliation: Laboratory of Emerging Infectious Diseases and Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Fu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D012680:Sensitivity and Specificity; D017361:Viral Nonstructural Proteins / Q000097:blood / Q000276:immunology* / Q000302:isolation & purification*; D014901:West Nile Fever / Q000097:blood / Q000175:diagnosis* / Q000821:virology; D014902:West Nile virus / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D000911:Antibodies, Monoclonal; D017361:Viral Nonstructural Proteins; C531936:nonstructural protein 1, West Nile virus