Borrelia burgdorferi is the causative agent of Lyme disease, a multisystemic and chronic tick-borne spirochetosis characterized by a transient initial rash and erythema migrans, followed by an inflammatory process at the level of the joints, nervous system, and heart.
Phagocytes are the cells primarily involved in first-line host defenses against bacterial pathogens.
A dense infiltrate of mature neutrophils has been found at the site of tick bites. However, knowledge about the interaction between borrelia burgdorferi and phagocytes is fragmentary. In fact, immune opsonization of borrelia burgdorferi is not essential, although it facilitates its uptake. Spirochetes are engulfed by conventional or coiling phagocytosis and in either case are finally found inside closed phagosomes, where structural alterations of the microorganisms are apparent on microscopical observation. The bactericidal mechanisms activated during engulfment include the generation of oxygen metabolites and the release of granule proteins into the phagocytic vacuole.