Osteoimmunology: Interactions of the Bone and Immune System

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Osteoimmunology: Interactions of the Bone and Immune System

Abstract
Bone and the immune system are both complex tissues that respectively regulate the skeleton and the body’s response to invading pathogens. It has now become clear that these organ systems often interact in their function. This is particularly true for the development of immune cells in the bone marrow and for the function of bone cells in health and disease. Because these two disciplines developed independently, investigators in each don’t always fully appreciate the significance that the other system has on the function of the tissue they are studying. This review is meant to provide a broad overview of the many ways that bone and immune cells interact so that a better understanding of the role that each plays in the development and function of the other can develop. It is hoped that an appreciation of the interactions of these two organ systems will lead to better therapeutics for diseases that affect either or both.

I. Introduction
II. The Origins of Bone Cells
A. Osteoclasts
B. Osteoblasts
III. Role of Osteoblasts in Hematopoiesis
IV. Role of Osteoblasts in Bone Marrow Cell Transplantation
V. B Lymphocyte Differentiation
A. PU.1
B. Early B cell factor (Ebf)
C. Pax5
VI. Role of Megakaryocytes in Bone Turnover
VII. Cytokines and Local Immune Cell Factors as Regulators of Bone Cell Functions
A. Receptor activator of nuclear factor-κB ligand (RANKL), receptor activator of nuclear factor-κB (RANK), and osteoprotegerin (OPG)
B. RANKL-RANK mediated signals for osteoclast differentiation
C. Costimulation in RANKL-induced osteoclast differentiation
D. Macrophage colony-stimulating factor
E. Additional colony stimulating factors
F. Interleukin-1
G. Tumor necrosis factor
H. Additional TNF superfamily members
I. Interleukin-6
J. Additional interleukin-6 family members
K. Interleukin-7
L. Interleukin-8 and other chemokines
M. Interleukin-10
N. Interleukin-12
O. Interleukin-15
P. Interleukin-17 and interleukin-23
Q. Interleukin-18
R. Interferons
S. Additional cytokines
VIII. Regulation of Osteoblasts by Immune Cells and Cytokines
IX. Role of Osteoclasts in Regulating Osteoblasts
X. Role of the Immune System in Bone Disease: the Birth of Osteoimmunology
XI. Role of Immune Cells in Estrogen-Withdrawal-Induced Bone Loss
XII. Modulation of Immunity by the RANKL-RANK-OPG Axis
XIII. Toll-Like Receptors, Inflammation, and Osteoimmunology

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528852/