Pyolysin (PLO)

Pyolysin (PLO) is a cholesterol-dependent cytolysin (CDC) produced by the Gram-positive bacterium Trueperella pyogenes, a significant pathogen in veterinary medicine. As a pore-forming toxin, PLO specifically targets and binds to cholesterol in the plasma membranes of host cells, such as macrophages, neutrophils, and endometrial cells. Upon binding, the toxin undergoes a conformational change to form large, stable pores that disrupt the osmotic balance of the cell, leading to rapid lysis and death. This process is the primary mechanism by which T. pyogenes causes diseases like bovine metritis and mastitis, as the destruction of immune cells allows the bacteria to evade the host's defense systems. Because PLO is essential for the pathogenicity of the bacterium, it is a key target for the development of veterinary vaccines and neutralizing antibody therapies. Current research focuses on inhibiting the toxin's binding or oligomerization phases to protect livestock from infection-related reproductive and systemic damage.

Other names

Pyolysin OPLO toxinTrueperella pyogenes pore-forming toxinArcanobacterium pyogenes cytolysin

Pyolysin acts as a pore-forming toxin by binding to cholesterol in the host cell membrane, where it oligomerizes to form large transmembrane pores that lead to osmotic lysis and cell death.