Figure 4.

Schematic illustration of immunomodulatory activities of AMPs. Pathogen recognition via pathogen recognition receptors (PRRs), such as TLRs, by epithelial cells, macrophages, and dendritic cells, leads to killing via phagocytosis as well as release of proinflammatory cytokines and chemokines by these cells, that subsequently stimulates the recruitment of additional immune cells to the site of infection. In addition, pathogen insult will lead to maturation of dendritic cells and subsequent initiation of adaptive immunity. AMPs indirectly promote pathogen clearance by stimulating chemotaxis and immune cell differentiation, while also preventing harmful inflammation and sepsis by inhibition of proinflammatory cytokine release and direct scavenging of bacterial endotoxins such as LPS. Up- or down-regulation of responses by AMPs is indicated by green arrows.