AN ASSAY THAT PREDICTS THE ABILITY OF MONOCLONAL-ANTIBODIES TO FORM POTENT RICIN-A CHAIN-CONTAINING IMMUNOTOXINS

  • 1 March 1988
    • journal article
    • research article
    • Vol. 48  (5) , 1119-1123
Abstract
In this report, we describe an assay for screening monoclonal antibodies for their cytotoxic potential as ricin A chain-containing immunotoxins. The assay involves treating cells with dilutions of the test antibody followed by a Fab fragment of a secondary antibody coupled to ricin A chain ("indirect asssay"). The cytotoxicity of the indirect assay is compared to that of the direct assay where the monclonal antibody is coupled to ricin A chain. Indirect and direct assays were carried out using 14 antibodies and a panel of 8 human and mouse cell types. The two assays showed virtually 100% correlation. The indirect assay, therefore, predicts the potency of a given monoclonal antibody to make an effective immunotoxin and should be useful in screening monoclonal antibodies for use as immunotoxins.