Membrane attack complex MAC

The membrane-attack complex (MAC) is the cytolytic end product of the complement cascade it forms a transmembrane channel, leading to osmotic lysis of the target cell (Fignre 15.1). 

The first line of defense is accomplished through the generation of the membrane attack complex (MAC), which is assembled at the end of the complement cascade from the components generated by the proteolytic steps along the cascade. The MAC is directly involved in lysing the membranes of foreign microorganisms. 

Lysis of the target cell membrane. This involves a collection of complement proteins associating upon the surface of a microbial membraneto form a membrane attack complex (MAC), which leads to the formation of membrane pores and, ultimately, microbial cell lysis. 

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