ADCC Assay Protocol

Abstract

Antibody-dependent cell-mediated cytotoxicity (ADCC) bridges innate and adaptive immunity, and it involves both humoral and cellular immune responses. ADCC has been found to be a main route of immune protection against viral infections and cancers in vivo. Here we developed a flow cytometry based protocol for ADCC assay using human peripheral blood mononuclear cells (PBMCs) as effector cells. Using this protocol, we determined the ADCC activity of convalescent plasma IgGs from six H1N1-infected human subjects in China, and identified two dominant ADCC epitopes, designated E1 [amino acid (AA) 92-117] and E2 (AA 124-159), on haemagglutinin of pandemic H1N1 influenza virus by epitope mapping of the convalescent plasma IgGs with different levels of ADCC activity. Our study may aid in designing immunogens that can elicit antibodies with high ADCC activity. Vaccine immunogens designed to include the structural determinants of potent broadly neutralizing antibodies and ADCC epitopes may confer a comprehensive immune protection against viral infections.