Development of an antibody-dependent enhancement assay for dengue virus using stable BHK-21 cell lines expressing FcγRIIA

Dengue virus (DENV) causes a wide range of symptoms, from mild febrile illness, dengue fever (DF), to severe life threatening illness, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Subneutralizing concentrations of antibody to DENV enhance DENV infection in Fc gamma R positive cells. This phenomenon is known as antibody-dependent enhancement (ADE). ADE is considered to be a risk factor for DHF and DSS. To develop an AIDE assay for DENV, two stable BHK-21 cell lines were established that express Fc gamma RIIA (BHK-Fc gamma RIIA). The BHK-Fc gamma RIIA cell lines were used in an ADE assay with monoclonal antibody (4G2) to DENV, and DENV antibody-positive human sera. Virus growth was quantified directly in BHK-Fc gamma RIIA cells with a standard plaque assay procedure. AIDE was detected with monoclonal antibody (4G2) to DENV. ADE was also detected with DENV antibody-positive human sera, but not with DENV antibody-negative human sera. The new AIDE assay using BHK-Fc gamma RIIA cells is simple and practical, and is useful for defining the role of AIDE in the pathogenesis of DENV infection. (C) 2009 Elsevier B.V. All rights reserved.