Evasion of the terminal complement pathway by human pathogens

Abstract

The complement system is an important part of the human immune system. It can react quickly to entering micro-organisms and eliminate them. Therefore, pathogens have to evade the complement attack in order to have a chance at survival within the host. This can be done by preventing recognition or controlling the complement cascade. Viruses, bacteria, fungi and parasites all developed escape strategies. Many of the proteins involved are targeted against the activation stage of complement, but it is also interesting for pathogens to defend themselves from the terminal pathway. In the final stage the membrane attack complex is formed which causes death through osmotic lysis. The many proteins involved in the terminal complement pathway provide several sites for pathogens to interfere with. Here, an overview is given of all the complement evasion mechanisms related to the terminal pathway known to date.