title: Present potential of immunotoxins.
abstract: Immuno-a-toxins (I-a-T) are hybrid molecules designed for a more selective therapy of cancer, which combine an antibody preferentially directed against tumour cells and the A-chain of the toxin ricin. Although a majority of them are highly and selectively cytotoxic to their target cells in vitro, only some of them gave rise to a therapeutic effect in animal models. In vitro kinetics studies suggested the importance of a rapid mode of action for in vivo efficacy, which is not the property of all I-a-T. Ways of accelerating and potentiating such conjugates are proposed, such as the use of lysosomotropic amines like ammonium chloride. Whereas the in vivo use of these activators is still under research, their in vitro use gives rise to a 99.99% cytoreduction of leukemic cells and thus is directly applicable to clinical situations such as bone marrow transplantations.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use*; D000972:Antineoplastic Agents, Phytogenic / Q000276:immunology* / Q000627:therapeutic use; D001711:Biotransformation; D016026:Bone Marrow Transplantation; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy; D007700:Kinetics; D007942:Leukemia, Experimental / Q000276:immunology; D051379:Mice; D008819:Mice, Nude; D009369:Neoplasms / Q000628:therapy*; D012276:Ricin / Q000276:immunology* / Q000627:therapeutic use
chemical_list: D000911:Antibodies, Monoclonal; D000972:Antineoplastic Agents, Phytogenic; D012276:Ricin