Complement

Galen Erso representing the complement system Galen Erso was the architect of the Death Star, which represents a bacterial infection in Immunology Wars. Erso created a weakness in the Death Star, which led to its destruction. He also dispatched an Imperial pilot to carry a message to the Rebels alerting them to the threat and highlighting the weakness.

Complement proteins are present in the blood and help flag pathogens for removal, as well as directly killing pathogens and infected cells by punching holes in their surface. The complement system has to be tightly controlled as it is capable of huge damage, but equally is a very powerful defence mechanism against invading microbes. The complement system can be activated by three different pathways, the classical pathway requires antibodies to bind to a pathogen, the alternative pathway is activated by foreign surfaces and the lectin pathway responds to specific markers on the surface of pathogens.

As well as directly killing pathogens, the complement sytem is able to recruit other cells of the immune system to the site of infection. The complement system plays a critical role in inflammation and the defence against bacterial infections and deficiencies in this system can lead to severe bacterial infections or autoimmune diseases.

Cells

Tissues

Soluble Mediators

Pathogens

Vaccination