Microbicidal Mechanisms

Macrophages and neutrophils are white blood cells essential for microbe elimination. Killing is achieved by the ability of these cells to rapidly ingest microorganisms via a process called phagocytosis. After microbes are internalized, an array of defense mechanisms are deployed that act in concert to maximize killing and degradation of the engulfed prey. Processes that contribute to this include generation of toxic oxidants by the NADPH oxidase, iron sequestration, and the ability of cationic antimicrobial peptides and various enzymes to damage and degrade microbe components. Regulated forms of cell death including apoptosis, pyroptosis and necroptosis also contribute to host defense.