Abstract
In vitro stimulation of human peripheral blood mononuclear cells with X31 influenza virus antigen has been used to enrich for specific anti-X31 antibody-producing cells. Following EpsteinBarr virus transformation of these stimulated cells, a cell line which produces human antibody to X31 virus was derived and subsequently cloned. The cloned cells secrete an IgG1 κ antibody which is directed against the nucleoprotein of A type influenza virus. Culture supernatants contain 10 to 20 µg/ml of specific antibody which is now used as a standard for the ELISA assay used in our laboratory to detect antibodies to influenza virus.