Activated macrophages distinguish undifferentiated-tumorigenic from differentiated-nontumorigenic murine erythroleukemia cells.
The interaction between macrophages and differentiating cells was examined using murine erythroleukemia cells (MELC). Inflammatory macrophages activated with recombinant murine interferon-gamma (rMuIFN-gamma) and lipopolysaccharide (LPS) first specifically recognized and bound tumorigenic-undifferentiated MELC and then produced their lysis. MELC that were induced to differentiate by a 5-day treatment with 5 mM N,N'-hexamethylene-bis-acetamide (HMBA) accumulated hemoglobin (benzidine positive) and were not recognized by the macrophages. Qualitative examination by light and electron microscopy confirmed the specific nature of the macrophage-MELC interaction. Quantitative assessment showed that the binding was dependent on the temperature and divalent cations and independent of serum components. A 24-h treatment of MELC with HMBA resulted in decreased binding, prior to hemoglobin accumulation and commitment to differentiation. The lack of binding of nontumorigenic-differentiated cells by macrophages was not due to residual HMBA. It thus appears that macrophages can distinguish MELC at different stages of differentiation.
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Department of Cell Biology, University of Texas, M.D. Anderson Cancer Center, Houston 77030.
Fidler
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D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D002478:Cells, Cultured; D015672:Erythroid Precursor Cells / Q000378:metabolism / Q000473:pathology*; D005622:Friend murine leukemia virus; D006454:Hemoglobins / Q000378:metabolism; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism / Q000473:pathology*; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C
D006454:Hemoglobins