Human prothymocytes. Membrane properties, differentiation patterns, glucocorticoid sensitivity, and ultrastructural features.

Thymic precursor cells (prothymocytes) comprise a large proportion of the fetal thymic cell population, but are less frequently encountered in the postnatal thymus, where they compose < 1% of the entire population. In the present study we attempted to characterize a number of properties of the prothymocytes obtained from human fetal thymic tissues after depletion of the E-rosette thymocyes on a Ficoll-Hypaque gradient. The prothymocytes are larger than the thymocytes and show a different nuclear chromatin pattern.