Retroviral Infection of T-Cell Precursors in Thymic Organ Culture

The ex vivo culture of intact fetal thymus lobes, fetal thymic organ culture (FTOC) has proven to be a useful technique for the elucidation of the molecular and cellular bases of T-cell development and T-cell receptor (TCR) repertoire selection (reviewed in ref. 1 . Most dramatically, FTOC has been used to determine the role of peptides in positive and negative selection, which has helped to shed light on the complex mechanism whereby the T-cell repertoire is tolerized to self (reviewed in ref. 2 ).