title: Determination of antibody concentration as the main parameter in a dengue virus antibody-dependent enhancement assay using FcγR-expressing BHK cells.
abstract: Dengue virus (DENV) causes a life-threatening illness, with a wide range of symptoms from mild febrile illness, dengue fever (DF), to life-threatening illness, dengue hemorrhagic fever (DHF). Antibody-dependent enhancement (ADE) is considered to be a risk factor for DHF. In the present study, we determined the parameters for ADE assays using FcγR-expressing BHK cells. Monoclonal antibodies and human serum samples were used in the assays. We examined antibody concentration and virus concentration and analyzed whether antibody concentration or DENV-antibody ratio determines ADE activity. Virus growth was quantified by a conventional plaque titration method using FcγR-expressing BHK cells. The assay allowed the detection of DENV growth with inoculation doses ranging from 10(2) PFU/ml to 10(6) PFU/ml using monoclonal antibodies and undiluted or diluted serum samples. The results indicate that antibody concentration rather than DENV-antibody ratio determines the demonstration of ADE activity. Thus, antibody concentration rather than multiplicity of infection was defined as the main determinant in ADE assays using FcγR-expressing BHK cells.
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo, 162-8640, Japan.
authors.forename: Meng Ling
authors.initials: ML
authors.lastname: Moi
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Takasaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saijo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kurane
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000276:immunology*; D019067:Antibody-Dependent Enhancement; D002460:Cell Line; D006224:Cricetinae; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology*; D012698:Serologic Tests / Q000379:methods*; D019595:Severe Dengue / Q000175:diagnosis / Q000276:immunology* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D017452:Receptors, IgG