Biological activities of a human pluripotent hemopoietic colony stimulating factor on normal and leukemic cells

Recombinant human granulocyte colony-stimulating factor: effects on normal and leukemic myeloid cells

Experiments were conducted to isolate and characterize the gene and gene product of a human hematopoietic colony-stimulating factor with pluripotent biological activities. This factor has the ability to induce differentiation of a murine myelomonocytic leukemia cell line WEHI-3B(D+) and cells from patients with newly diagnosed acute nonlymphocytic leukemia (ANLL). A complementary DNA copy of the gene encoding a pluripotent human granulocyte colony-stimulating factor (hG-CSF) was cloned and expressed in Escherichia coli. The recombinant form of hG-CSF is capable of supporting neutrophil proliferation in a CFU-GM assay. In addition, recombinant hG-CSF can support early erythroid colonies and mixed colony formation. Competitive binding studies done with 125I-labeled hG-CSF and cell samples from two patients with newly diagnosed human leukemias as well as WEHI-3B(D+) cells showed that one of the human leukemias (ANLL, classified as M4) and the WEHI-3B(D+) cells have receptors for hG-CSF. Furthermore, the murine WEHI-3B(D+) cells and human leukemic cells classified as M2, M3, and M4 were induced by recombinant hG-CSF to undergo terminal differentiation to macrophages and granulocytes. The secreted form of the protein produced by the bladder carcinoma cell line 5637 was found to be O-glycosylated and to have a molecular weight of 19,600.

Pluripoietin alpha: a second human hematopoietic colony-stimulating factor produced by the human bladder carcinoma cell line 5637

We have identified a factor constitutively produced by the human bladder carcinoma cell line 5637, which has the following capacities: to induce the differentiation of the human promyelocytic leukemic cell line HL-60; to induce the expression of chemotactic peptide receptors in leukemic cells as well as in normal peripheral blood granulocytes; to function as a chemoattractant for neutrophils as well as, under certain conditions, inhibiting their migration; to support the growth of eosinophil and granulocyte/macrophage progenitors, which is maximal when scored at day 14; and to support the growth of human mixed pluripotent progenitors and erythroid bursts from normal human bone marrow. This factor has a molecular size of 32 kDa by gel filtration and 16.5 kDa by NaDodSO4/PAGE. We have termed this factor pluripoietin alpha.