Pathologic changes in symptomatic animals at 6 to 9 weeks after transplantation.

Animals transplanted with TβRII^−/− donor bone marrow are compared with control animals (TβRII^+/− donor bone marrow) analyzed by 7 to 15 weeks after transplantation. (A) Normal colon of control animal. (B) Pronounced inflammation of the colon mucosa indicated by extensive infiltration of lymphocytes, plasma cells, and granulocytes, and tissue destruction in lamina propria. Note the few remaining abnormal glands (arrow) invaded by inflammatory cells. TβRII^−/− donor bone marrow. (C) Normal lung of control animal. (D) Lymphocytic infiltration of the lung parenchyma (arrow) surrounding vessels and bronchioli. The lymphocytes are infiltrating the wall of a venule. They are also seen in the epithelium of a bronchiolus and in the walls of the alveoli. TβRII^−/− donor bone marrow. (E) Normal pancreas of control animal. (F) Extensive pancreatitis with massive infiltration of lymphocytes destroying large parts of the exocrine pancreas with insulitis (arrow). TβRII^−/− donor bone marrow. (G) Normal liver of control animal. (H) Perivenular infiltrates of lymphocytes in the liver with extension to the liver parenchyma. TβRII^−/− donor bone marrow. (A) and (B): × 40 magnification. (C) through (H): × 20 magnification. Lu indicates lumen; Br, bronchioli. Sections were stained with Erlich eosin.