Preparation of Single-cell Suspension of Mouse Thymic Epithelial Cells and Staining of Intracellular Molecules for Flow Cytometric Analysis.

Thymic epithelial cells (TECs) play an essential role in promoting the development and repertoire selection of T cells. Cortical TECs (cTECs) in the thymic cortex induce early T cell development and positive selection of cortical thymocytes. In contrast, medullary TECs (mTECs) in the thymic medulla attract positively selected thymocytes from the cortex and establish self-tolerance in T cells. A variety of molecules, including DLL4 and beta5t expressed in cTECs, as well as Aire and CCL21 expressed in mTECs, contribute to thymus function supporting T cell development and selection. Flow cytometric analysis of functionally relevant molecules in cTECs and mTECs is useful to improve our understanding of the biology of TECs, even though current methods for the preparation of single-cell suspensions of TECs can retrieve only a small fraction of TECs (approximately 1% for cTECs and approximately 10% for mTECs) from young adult mouse thymus. Because many of these functionally relevant molecules in TECs are localized within the cells, we describe our protocols for the preparation of single-cell suspension of mouse TECs and the staining of intracellular molecules for flow cytometric analysis.