Abstract
Immune response in periprosthetic joint infection (PJI) is diverse. Resident macrophage and/or wandering monocyte are superb guardians to sense microbial attacks, take invaders and alarm the danger. Neutrophils are refined but momentary fighters to kill microbes with projectile weapons as well as predation. The swift action is usually effective at the forefront to prevent expansion of infectious foci. However, such characteristics often evokes overshooting via self-defeating of pus, thus leading to crucial soft tissue damage in the acute phase. Intervention of monocyte/macrophages follow and act as wise organizers. In addition, stromal fibroblasts also act in front for host defence. They equip innate immune sensors (TLRs, NLRs), which can sense dangers and trigger off inflammatory response, but also is usually self-regulated. These sensors not only interact each other, but also have possible contribution to selective autophagy (xenophagy and lysophagy) in PJI. In this presentation, overview of pathology in PJI will be summarized with a special attention to innate immune sensors (TLRs and NLRs), and selective autophagy.
