Only BM-derived KCs participate in focal intrahepatic inflammation. Liver sections of bone marrow transplant recipients were stained with CD45.2-FITC (green), CD45.1-Cy5 (displayed in false color blue), and F4/80-PE (red). Inflammatory foci developed during peptide-activated intrahepatic accumulation of adoptively transferred TCR-tg OT-I cells (A-D) or with accumulation of endogenous CD8⁺ T cells during pulmonary influenza infection (E-H). (A,E) In both models, sessile KCs (orange, closed arrow) were only detectable outside the foci. Kupffer cells within the foci are all BM derived (purple) with multiple BM-derived and recipient-type non-KC leukocytes within the foci (blue and green). Original magnification, ×200. (B,F) Enlarged (×400) inflammatory focus following adoptive OT-I transfer and peptide activation (B) or during pulmonary influenza infection (F). (C,D,G,H) Two-color reproductions of the same foci with F4/80-CD45.1 costaining for BM-derived KCs (C,G) and F4/80-CD45.2 costaining for sessile KCs (D,H) confirmed the absence of sessile KCs within inflammatory foci.