title: An assay that predicts the ability of monoclonal antibodies to form potent ricin A chain-containing immunotoxins.
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 assay"). The cytotoxicity of the indirect assay is compared to that of the direct assay where the monoclonal 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.
authors.affiliation: Department of Microbiology, Southwestern Medical School, University of Texas Health Science Center, Dallas 75235.
authors.forename: M
authors.initials: M
authors.lastname: Till
authors.forename: R D
authors.initials: RD
authors.lastname: May
authors.forename: J W
authors.initials: JW
authors.lastname: Uhr
authors.forename: P E
authors.initials: PE
authors.lastname: Thorpe
authors.forename: E S
authors.initials: ES
authors.lastname: Vitetta
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D002460:Cell Line; D003601:Cytotoxicity Tests, Immunologic; D006801:Humans; D000922:Immunotoxins / Q000494:pharmacology*; D012276:Ricin / Q000494:pharmacology*
chemical_list: D000911:Antibodies, Monoclonal; D000922:Immunotoxins; D012276:Ricin