What is the primary function of defensins in the immune system?

Defensins play a crucial role in the innate immune system, primarily functioning as antimicrobial peptides. Their main job is to directly kill a variety of pathogens, including bacteria and fungi. Defensins achieve this by disrupting the microbial cell membranes, which leads to cell lysis and ultimately results in the death of the pathogen. They are part of the first line of defense, quickly acting to prevent the establishment of infections by harmful microorganisms.

While the other options all relate to different aspects of immune function, they do not accurately describe the primary role of defensins. For example, enhancing cell division pertains to growth and repair processes rather than direct pathogen targeting. Stimulating antibody production involves a completely different mechanism, primarily the activation of B cells in the adaptive immune response. Suppressing inflammation is a function typically associated with certain anti-inflammatory mediators or cells in the immune system and does not align with the direct antimicrobial action of defensins. Therefore, the correct description of defensins firmly establishes their essential role in combating bacterial and fungal infections.