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Author Spotlight: Advancing Thymic Epithelial Cells and T-Cell Research with Human Thymic Organoids
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Thymus Inception: Molecular Network in the Early Stages of Thymus Organogenesis

Marta Figueiredo1, Rita Zilhão2, Hélia Neves1

  • 1Instituto de Histologia e Biologia do Desenvolvimento, Faculdade de Medicina da Universidade de Lisboa, Edifício Egas Moniz, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal.

International Journal of Molecular Sciences
|August 16, 2020
PubMed

The thymus generates central immune tolerance by producing self-restricted and self-tolerant T-cells as a result of interactions between the developing thymocytes and the stromal microenvironment, mainly formed by the thymic epithelial cells. The thymic epithelium derives from the endoderm of the pharyngeal pouches, embryonic structures that rely on environmental cues from the surrounding mesenchyme for its development. Here, we review the most recent advances in our understanding of the molecular mechanisms involved in early thymic organogenesis at stages preceding the expression of the transcription factor Foxn1, the early marker of thymic epithelial cells identity. Foxn1-independent developmental stages, such as the specification of the pharyngeal endoderm, patterning of the pouches, and thymus fate commitment are discussed, with a special focus on epithelial-mesenchymal interactions.

Keywords:
T/PT common primordiummesodermmolecular networkneural crestpharyngeal pouch endodermsignaling moleculesthymustranscription factors

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