Abstract
Although the maturation and export of T cells from the thymus has been extensively studied,
the movement of cells in the opposite direction has been less well documented. In particular,
the question of whether T cells which have been activated by antigen in the periphery are
more likely to return to the thymus had been raised but not clearly answered. We examined
this issue by activating T cells present in the periphery with their cognate antigen, and assessing migration to the thymus. TCR-transgenic cells from OT-I mice (Thy1.2+), which recognise the ovalbumin peptide OVA257–264 in the context of H-2Kb, were transferred into otherwise unmanipulated Thy1.1+ C57BL/6 mice. Recipient mice were injected i.v. with 5