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Copyright ©2012 Baishideng Publishing Group Co.
World J Orthop. Sep 18, 2012; 3(9): 142-150
Published online Sep 18, 2012. doi: 10.5312/wjo.v3.i9.142
Figure 2
Figure 2 Regulation of the development and function of medullary thymic epithelial cells by receptor activator of NF-κB ligand signaling. Receptor activator of NF-κB ligand (RANKL) signaling mediates the development of mature medullary thymic epithelial cells (mTECs) expressing Autoimmune regulator (Aire) and a wide variety of tissue-specific antigens (TSAs) from the potential progenitors. RANKL is expressed in several types of cells, including αβ T cells, lymphoid tissue inducer cells (LTi) and a subset of γδ T cells. The signal transducers NF-κB inducing kinase (NIK) and TNF receptor-associated factor 6 (TRAF6) mediate RANK signaling, culminating in activation of the NF-κB transcription factor member RelB. mTECs present peptides are derived from TSAs to eliminate self-antigen reactive T cells by apoptosis. The TSAs can be transferred to dendritic cells by mechanisms that are not yet fully identified. The dendritic cells receiving TSAs also induce the apoptosis of self-reactive T cells in the thymus.