MEASLES-VIRUS FUSION-PROTEIN-TRANSFECTED AND HEMAGGLUTININ-TRANSFECTED CELL-LINES ARE A SENSITIVE TOOL FOR THE DETECTION OF SPECIFIC ANTIBODIES BY A FACS-MEASURED IMMUNOFLUORESCENCE ASSAY

A FAGS-measured immunofluorescence assay was developed for the detecti on of antibodies directed against the hemagglutinin (H) and fusion (F) glycoproteins of measles virus (MV). Human melanoma cell lines transf ected with either the MV H or F genes, which showed a high surface exp ression of the respective proteins in their native conformation, were used as target cells. The cells were incubated with diluted plasma sam ples, and stained subsequently with FITC-conjugated secondary antibodi es. The FAGS-measured fluorescence signals correlated directly with th e amount of specific immunoglobulins over a wide concentration range. The use of different conjugates enabled the separate detection of MV-s pecific IgG, ISM, IgA and IgG subclasses: with relatively low backgrou nds. Hemagglutinin-specific IgG, IgM and IgA fluorescence signals were shown to correlate well with MV-specific IgG ELISA titers and MV-spec ific IgM or IgA capture ELISA OD450-values, respectively. The polyclon al conjugates with specificity for human immunoglobulins offered suffi cient cross-reactivity to detect MV-specific IgG, IgM and IgA in plasm a samples of cynomolgus macaques, making this technique a useful tool for studying serological responses in vaccination and challenge experi ments in non-human primate models. (C) 1998 Elsevier Science B.V. All rights reserved.