Membrane Attack Complex (MAC) Kills By Punching Holes in Target Cells.

The membrane attack complex, also known as MAC, is an important part of the innate immune system. It is comprised of several proteins, including complement factors C5b, C6, C7, C8, and C9. These proteins work together to form a pore-like structure that punches holes in the target cell membrane, ultimately leading to cell lysis and death.

MAC is triggered by the presence of certain microbial components like lipopolysaccharides (LPS), which are typically found on the outer membrane of Gram-negative bacteria. Upon recognizing the presence of LPS, the complement cascade is activated, resulting in the expression of several MAC proteins and the eventual formation of the membrane attack complex.

Once the membrane attack complex is formed, it binds to the target cell membrane and creates a pore-like structure. This structure is not only capable of punching holes in the target cell membrane, but it can also disrupt the cell’s normal functions by allowing ions and other substances to freely pass through.

The disruption of the cell’s normal functioning is followed by the release of intracellular contents into the extracellular space and subsequently leads to cell lysis and death. This is why the membrane attack complex is so effective against a wide range of pathogens, as it can effectively stop the spread of an infection by killing the infected cells.

To sum up, the membrane attack complex is an important part of the innate immune system and is responsible for killing target cells by punching holes in their membrane. This is done by the formation of a pore-like structure that disrupts the cell’s normal functioning and ultimately leads to cell lysis and death.