Repopulation potential of thymocytes forming rosettes with phagocytic cells of the thymic reticulum.

Thymocytes binding in vitro to phagocytic cells of the thymic reticulum (P-TR), termed 'rosetting thymocytes', were injected intravenously into irradiated congenic mice and their migration patterns were compared with those that do not bind to P-TR, called 'non-rosetting thymocytes', similarly transferred. Donor cells, C57BL/Ka Thy 1.2, were distinguished from recipient cells, C57BL/Ka Thy 1.1 by a direct immunofluorescence technique using an anti-Thy 1.2 monoclonal antibody. The results demonstrate that the rosetting thymocytes have a greater capacity for homing back to the thymus and for populating the mesenteric lymph node and the spleen. Intrathymic transfer assay revealed that the donor-derived cells detected in the peripheral organs were of thymic origin.