How do cationic peptides contribute to the immune response against bacteria?

Cationic peptides, also known as antimicrobial peptides, play a crucial role in the immune response against bacteria primarily by disrupting bacterial membranes. These peptides have a positive charge that allows them to interact with the negatively charged components of bacterial cell membranes. When cationic peptides bind to these membranes, they insert themselves and create pores. This disruption of the membrane integrity leads to cell lysis and ultimately results in the death of bacterial cells.

This mechanism is particularly effective against a wide range of bacteria, including both Gram-positive and Gram-negative species. By directly targeting the bacterial membranes, cationic peptides can rapidly reduce bacterial populations, thereby functioning as a first line of defense in the immune system. Their rapid action complements other immune responses, and their ability to act on a broad spectrum of pathogens makes them a vital component of innate immunity.