title: Cytokine crosstalk for thymic medulla formation.
abstract: The medullary microenvironment of the thymus plays a crucial role in the establishment of self-tolerance through the deletion of self-reactive thymocytes and the generation of regulatory T cells. Crosstalk or bidirectional signal exchanges between developing thymocytes and medullary thymic epithelial cells (mTECs) contribute to the formation of the thymic medulla. Recent studies have identified the molecules that mediate thymic crosstalk. Tumor necrosis factor superfamily cytokines, including RANKL, CD40L, and lymphotoxin, produced by positively selected thymocytes and lymphoid tissue inducer cells promote the proliferation and differentiation of mTECs. In return, CCR7 ligand chemokines produced by mTECs facilitate the migration of positively selected thymocytes to the medulla. The cytokine crosstalk between developing thymocytes and mTECs nurtures the formation of the thymic medulla and thereby regulates the establishment of self-tolerance.
authors.affiliation: Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nitta
authors.forename: Izumi
authors.initials: I
authors.lastname: Ohigashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Takahama
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D016207:Cytokines / Q000276:immunology*; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D020239:Receptor Cross-Talk; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D016207:Cytokines