Osteoimmunology represents a link between skeletal and immune system

There is a complex interplay between the cells of the immune system and bone. These inter-actions are not only mediated by the release of cytokines and chemokines but also by direct cell–cell contact. Studies of intracellular signaling mechanisms in osteoclasts have revealed that numerous immunomodulatory molecules are involved in the regulation of bone metabolism. Recently, it was proposed that immunoreceptors found in the immune cells are also an essen-tial signal for osteoclasts activation, along with receptor activator of NF-κB (RANK) ligand (RANKL). Collectively, these and similar observations regarding cross-regulation between the immune and skeletal systems constitute the field of osteoimmunology.