Figure 3.

Immunopathology of the thyroid glands from control TxX rats and those reconstituted with CD4⁺CD45RC⁻ T cells. In experiments similar to those described in Fig. 2, thyroid glands were taken at the time of peak disease, sectioned, and stained with hematoxylin and eosin. Thyroids from control TxX PVG rats (A; original magnification ×200) show extensive mononuclear cell infiltrate and loss of follicular structure. In contrast, thyroid glands from TxX PVG rats reconstituted with 10⁷ CD4⁺CD45RC⁻ cells shortly after their last irradiation are of normal morphology with no signs of infiltration (B; original magnification ×200). Similarly, thyroids of TxX PVG rats protected by their reconstitution with CD4⁺CD8⁻ thymocytes were of normal morphology with no signs of infiltration (data not shown).