Antibody-Dependent Cell-Mediated Cytotoxicity against Cells Infected with Respiratory Syncytial Virus: Characterization of in Vitro and in Vivo Properties

An in vitro 51 Cr release assay for human antibody-dependent cell-mediated cytotoxicity (ADCC) against HeLa cells infected with respiratory syncytial virus (RSV) has been characterized by using leukophoresed and adherent cell-depleted adult lymphocytes. Lymphocytes from RSV seronegative children were also competent as effector cells. Sera from children with: 1) primary and recurrent natural RSV infections, or 2) live attenuated RSV vaccine infection were examined to characterize the behavior of ADCC antibody in vivo . After natural RSV infection ADCC antibody rose and fell more rapidly than neutralizing antibody. In two children undergoing primary RSV infection with attenuated vaccine, neutralizing antibody was formed in the absence of detectable ADCC antibody. The nonparallel behavior of ADCC and neutralizing antibodies suggests the heterogeneity of either the antigen involved or the mechanism of antibody production in the two antibody systems.