Which system consists of proteins that activate to cause inflammation and cell lysis?

The complement system plays a crucial role in the immune response by consisting of a series of proteins that, when activated, contribute to inflammation and the destruction of pathogens. This system can enhance the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism. The complement proteins are involved in several pathways, including the classical pathway (triggered by antibodies), the lectin pathway, and the alternative pathway, all of which lead to the formation of a membrane attack complex that can lyse target cells.

Moreover, the activation of the complement system promotes inflammation through the production of anaphylatoxins, leading to increased blood vessel permeability and recruitment of immune cells to the site of infection. This multifaceted role makes the complement system a vital component of the innate immune response, distinguishing it from other systems that do not primarily focus on direct cell lysis and inflammation in this manner.