Flow-cytometric analysis of recipient leukocyte replacement in orthotopic liver transplant recipients. As an alternative approach to the analysis of KC turnover, livers from B6.CD45.2 animals were transplanted orthotopically into B6.CD45.1 recipients. By this experimental design, the bone marrow compartment of the recipient was spared from experimental manipulation. (A) The replacement of CD45.2 intrahepatic leukocytes by CD45.1 BM-derived cells was evaluated 30 and 60 days after liver transplantation by flow-cytometric analysis. Similar to bone marrow chimeras, CD11b/F4/80-positive KCs were all CD45.1⁺ in cell isolates from intrahepatic leukocytes. This indicated their origin from the bone marrow of the liver transplant recipient. (B) As seen in radiation bone marrow chimeras, a small percentage of CD45.2/TCR⁺ cells remained within the transplanted livers. Numbers in plots are percentages of lymphocytes.