Thymic Epithelial Cell Development and Its Dysfunction in Human Diseases

Figure 3

The molecular regulating network of Foxn1 in TECs. Foxn1 in TECs regulates a series of genes involved in the thymus development and function, and the expression of Foxn1 itself is strictly under control. Wingless (Wnt), provided by TECs and thymocytes, positively regulate Foxn1 expression in TECs. Bone morphogenic proteins (BMPs) expressed in the third pharyngeal pouch modulate Foxn1 expression during fetal thymopoiesis. Genes are regulated by Foxn1 in TECs are determined so far: Pax1, regulating TEC differentiation and proliferation during thymopoiesis; CCL25 and CXCL12, for hematopoietic stem cell localization in the thymus; SCF, Dll4 and CathepsinL, participating in T cell development and selection; CD40 and MHCII, involved in TEC development and function.