“Immunoporosis”: Immunology of Osteoporosis

Bone is a dynamic organ that maintains its proper architecture and function by undergoing continuous cycles of modelling and remodelling during normal host physiology. Any dysregulation in the bone remodelling process leads to the development of bone-related disorders including osteoporosis. Osteoporosis is considered as one of the most commonly occurring but often neglected bone diseases leading to enhanced fragility and morbidity in large number of populations. Presently, available drugs (strontium, bisphosphonates, oestrogen replacement therapy, etc.) that are being used as a therapy for treating osteoporosis come with higher side effects and complications later in life. Thus, newer therapies are need of the hour for better management and treatment of osteoporosis-related bone loss. Various studies indicate that immune responses (both innate and adaptive) play crucial role in the development and maintenance of inflammatory conditions including osteoporosis. Thus, in present review we specifically discuss about the role of innate (DCs, NK cells, macrophages and ILCs) and adaptive (Th1, Th2, Th17, Tregs and B cells) immune cells in progression of osteoporosis. This novel field recently proposed and coined as “Immunoporosis” (Immunology of Osteoporosis) by our group, deals with the cross talk between immune and bone cells providing excellent dedicated interface for understanding the complexity of these two unique systems in osteoporosis with potential for providing novel molecular insights in the development of effective therapeutics for osteoporosis.