Streptolysin O (SLO)

Streptolysin O, A Group A streptococcal toxin, is an oxygen-unstable prototype of cholesterol-binding bacterial exotoxin. Apoptosis of neutrophils and macrophages can be induced approximately 4 hours after infection. Streptococcal hemolysin O is known to promote resistance of Group A streptococcus (GAS) to neutrophil phagocytosis clearance, a key first element of host defense against invasive bacterial infections. A metabolite produced by hemolytic streptococcus can dissolve red blood cells, so this product is named "O" hemolysin. After the human body is infected with Group A hemolytic streptococcus, "O" hemolysin exists in the body as an antigenic substance. Streptolysin O can cause cell lysis and cardiotoxicity. In order to fight against this antigenic substance, the body correspondingly produces another antibody to neutralize this "O" hemolysin, so as not to endanger life. Streptolysin O exists in two forms, the reductively active state and the oxidationally reversible inactive state.