title: Macrophage inflammatory protein-1 alpha receptors are present on cells enriched for CD34 expression from patients with chronic myeloid leukemia.
abstract: The response of normal and chronic myeloid leukemia (CML), CD34+ cells to human macrophage inflammatory protein-1 alpha (MIP-1 alpha or LD78) was assessed. In tritiated thymidine incorporation assays, stem cell factor plus granulocyte-macrophage colony-stimulating factor stimulated thymidine incorporation in normal CD34+ cells was reduced to 72% of control values in the presence of MIP-1 alpha, whereas incorporation by CML CD34+ cells exposed to the same factors was not altered. In clonogenic assays, the presence of MIP-1 alpha gave a level of colony formation that was 71% of control values for normal progenitor cells, whereas for CML CD34+ cells colony formation was enhanced by 25%. These results suggest that, in vitro, CML progenitor cells are relatively refractory to the growth inhibitory effects of MIP-1 alpha. Using flow cytometry, the specific binding of a biotinylated human MIP-1 alpha/avidin fluorescein (FITC) conjugate to normal and CML mononuclear and CD34+ cell populations was quantified. The data indicate that (for both normal and CML CD34+ cells) there was a single population of cells that express cell surface receptors for MIP-1 alpha and this receptor expression was independent of cell cycle status. CML progenitor cells may be refractory to the effects of MIP-1 alpha as a result of events downstream from receptor expression.
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D001483:Base Sequence; D002453:Cell Cycle; D054407:Chemokine CCL4; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D019402:Macrophage Inflammatory Proteins; D008969:Molecular Sequence Data; D015846:Monokines / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D014411:Neoplastic Stem Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D019707:Receptors, Chemokine; D011971:Receptors, Immunologic / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism; D014410:Tumor Stem Cell Assay
chemical_list: D018952:Antigens, CD34; D054407:Chemokine CCL4; D016207:Cytokines; D017931:DNA Primers; D019402:Macrophage Inflammatory Proteins; D015846:Monokines; D019707:Receptors, Chemokine; D011971:Receptors, Immunologic; C080633:macrophage inflammatory protein 1alpha receptor; D013936:Thymidine