Characterization of human thymic epithelial cells grown in serum-free medium

Thymic epithelial cells have a critical influence on T-cell differentiation. In order to characterize these cells in humans, a serum-free growth medium was developed for their long-term culture. Important components of this medium included transferrin, epidermal growth factor, prostaglandin E1, and selenious acid. The presence of a keratin cytoskeleton, tonofilaments, and desmosomes confirmed the epithelial nature of these cells. Indirect immunofluorescence study of these epithelial cells demonstrated the presence of Ia and B-2 microglobulin antigens. The availability of highly enriched thymic epithelial cultures should simplify the functional characterization of this cell.