Vertebrate innate immunity resembles a mosaic of invertebrate immune responses

Research on the innate immune response of mammals has revealed similarities with the invertebrate immune system. Thus, insects have developed an acute response resembling that seen in humans, implicating similar effectors, receptors and regulation of gene expression. Mussels have developed intracellular phagocytosis resembling that seen in mammalian neutrophils, using cationic antibacterial peptides in phagolysosomes. Leeches, like amphibians, contain antibacterial peptides and immune stimulators that derive from the processing of neuropeptide precursors. This pattern of similarities suggests that the vertebrate innate immune response resembles a patchwork of those responses seen in several invertebrate models.