MYCOBACTERICIDAL ACTIVITY OF HUMAN NATURAL, MONOCLONAL, AND RECOMBINANT YEAST KILLER TOXIN-LIKE ANTIBODIES

Human natural (KTAb), murine monoclonal (KTMAb), and single-chain reco mbinant (KTScFV) candidacidal antibodies representing the internal ima ge of a killer toxin from the yeast Pichia anomala (KT), characterized by a wide spectrum of antibiotic activity, exerted a lethal effect ag ainst a KT-sensitive multidrug-resistant isolate of Mycobacterium tube rculosis. KTMAb and KTScFV were produced by the hybridoma and DNA tech nologies, respectively, from the spleen lymphocytes of animals immuniz ed with the idiotype of a KT-neutralizing MAb (MAb KT4), while KTAb we re purified against MAb KT4 from the vaginal fluid of women infected w ith Candida albicans cells bearing an idiotype-like KT cell wall recep tor. Mycobactericidal activity was related to the binding of KTAb, KTM Ab, and KTScFV to the cell surface of KT-sensitive bacterial cells and was prevented by specific absorption of KT-like antibodies onto MAb K T4. These data identify a novel potentially useful immunotherapeutic a pproach to tuberculosis.