BIOLOGICAL PROPERTIES AND MEDICAL APPLICATION OF DIPHTHERIA TOXIN DERIVATIVES

The aim of the review was to analyze the literature data related to the application of a variety of diphtheria toxin derivatives. Although studies of the diphtheria toxin interaction with sensitive and resistant mammalian cells have been held for a relatively long time, there are still some unresolved issues concerning the molecular mechanisms of diphtheria toxin functioning. Native diphtheria toxin and parts of its molecule which preserves toxicity are used as instruments in the newest biotechnological methods of specific cell subtype ablation in multicellular organisms. New recombinant derivatives of diphtheria toxin are periodically obtained in the laboratories throughout the world. Most of these analogs of diphtheria toxin are used in biological studies as convenient tools for analysis of the functions of the natural toxin. A non-toxic analog of diphtheria toxin, protein CRM197, is used in clinical practice as a component of vaccines and as an anticancer agent. Diphtheria toxin -based targeted toxin therapy is another perspective trend for cancer therapy. Therefore, studying of diphtheria toxin derivatives is of a great relevance for biotechnology and medicine.