diphtheria toxin

Diphtheria toxin is a potent protein toxin produced by *Corynebacterium diphtheriae*. In the provided contexts, it is utilized as a research tool in genetically engineered mouse models that express the human diphtheria toxin receptor (hDTR). By binding to hDTR on specific cell types, the toxin is internalized, leading to the ADP-ribosylation of elongation factor 2 (eEF2) and subsequent inhibition of protein synthesis, ultimately causing cell death and depletion. This mechanism allows researchers to selectively ablate specific cell populations, such as urothelial cells or Foxp3+ regulatory T cells, to study their roles in various physiological and pathological processes like renal injury, autoimmune responses, cachexia, and anemia.