Isolation of thymic epithelial cells and analysis by flow cytometry.

The epithelial cells of the thymus govern the differentiation of hematopoietic precursors into T cells, which are critical for acquired immunity. Thymic epithelial cells (TEC) provide molecular cues that direct precursor recruitment, commitment to the T cell lineage, thymocyte proliferation, and the processes of positive and negative selection. Despite the importance of TEC to the immune system, fundamental questions regarding their differentiation, turnover, and function throughout life remain unanswered. This knowledge gap is largely due to technical difficulties in isolating, quantifying, and purifying this rare cell type. Here, we describe methods for the enzymatic digestion of the thymus to obtain single-cell suspensions of TEC, their analysis by flow cytometry, enrichment using magnetic beads, and purification for a variety of downstream applications.