In vitro culture of functional human thymic epithelium

Cultures of pure epithelial cells have been obtained from human thymus. Incubation of spleen cells from adult thymectomized mice on these cultures rendered RFC sensitive to inhibition by anti-theta serum, whereas no effect was obtained with fibroblasts or spleen cell cultures. The fact that theta conversion was obtained when spleen cells were incubated in the thymic culture placed within a Millipore chamber indicates that theta conversion was due to the effect of a humoral factor.