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Biomedical subjects

C A Sieff

Publications and source records attributed to C A Sieff.

At least 55 records · Page 3Linked to original sources
PubMed1988

The biology of the colony stimulating factors.

Previous in vitro studies with recombinant human Interleukin 3 (IL-3) in serum-replete culture conditions suggested that IL-3 induced the complete differentiation of multipotent and both, erythroid and myeloid progenitor cells. In contrast, serum-free cultures have shown that alone, IL-3, and to a lesser extent granulocyte-macrophage colony-stimulating factor (GM-CSF), are inadequate differentiation stimuli. However, in combination with the lineage-specific growth factors, erythropoietin, granulocyte colony stimulating factor (G-CSF), and macrophage CSF (M-CSF), complete recovery of erythroid, granulocyte, and macrophage colonies, respectively, was obtained. GM-CSF is produced by a variety of mesenchymal cells as well as monocytes and T lymphocytes; in contrast, IL-3 production appears to be restricted to lectin stimulated T lymphocytes. These studies indicate that the CSFs may be more effective in vivo when used as combinations rather than as single factors. The restricted production of IL-3 by activated T cells suggests that IL-3 may be released during infections and may play an important role during stress.

Animals↗
PubMed1987

Interleukin 1 induces cultured human endothelial cell production of granulocyte-macrophage colony-stimulating factor.

Monokine-stimulated endothelial cells are known to produce both burst- and colony-stimulating activities, but neither the nature of the monokine nor the hematopoietic growth factor(s) produced is known. We show by mRNA analysis that an immortalized line of human endothelial cells constitutively produce granulocyte-macrophage colony-stimulating factor. Furthermore, interleukin 1 and tumor necrosis factor induce early passage human umbilical endothelial cells to produce the same growth factor.

Bone Marrow Cells↗
PubMed1987

Stimulation of human hematopoietic colony formation by recombinant gibbon multi-colony-stimulating factor or interleukin 3.

Recently, the gene for a novel mammalian hematopoietic growth factor homologous to murine interleukin 3 was isolated from a gibbon T cell line and expressed in monkey COS cells. The factor, termed multi-colony stimulating factor (multi-CSF) or interleukin 3, is stimulatory to human target cells. We investigated the range of enriched human bone marrow and fetal liver hematopoietic progenitors responsive to multi-CSF; compared the colony types observed with those obtained in the presence of recombinant granulocyte-macrophage CSF (GM-CSF); and analyzed the effects on colony formation of combining multi-CSF with GM-CSF or granulocyte-CSF (G-CSF). The results show that multi-CSF acts as a multipoietin. Alone it stimulates the formation of colonies derived from granulocyte, macrophage, eosinophil, and megakaryocyte progenitors. In combination with erythropoietin it supports the development of both erythroid and mixed colonies. Furthermore, the data show that multi-CSF is a more potent stimulus of erythroid progenitors than GM-CSF. In combination with G-CSF multi-CSF substantially increases granulocyte colony number over the number obtained with each factor alone. We conclude that multi-CSF may prove to have important therapeutic potential in vivo as a stimulus for hematopoiesis.

Animals↗
PubMed1987

Decreased hematopoietic accessory cell function following bone marrow transplantation.

Hematologic engraftment following bone marrow transplantation requires not only pluripotent stem cells but also functioning accessory cells whose trophic factors support the proliferation and differentiation of stem cells and progenitors to mature blood cells. To better understand the regulation of hematopoiesis following transplantation, we studied hemopoietic accessory cell function in bone marrow transplant recipients 3 weeks to 10 months following transplantation. In general, hematopoietic accessory cell function was decreased following bone marrow transplantation. Sequential fractionation of accessory cells demonstrated that adherent cells often produced near-normal functional burst-promoting activity (BPA) and granulocyte-macrophage colony-stimulating activity (GM-CSA), but Fc receptor-positive (Fc+) cells and T cells uniformly produced greatly reduced BPA and GM-CSA, as compared to transplant donor cells. This cellular deficiency was corrected by soluble burst-promoting activity and granulocyte-macrophage colony-stimulating activity and so appeared to be due to the failure of accessory cells to produce trophic hormones. Limiting-dilution analysis (LDA) for proliferating T-cell precursors demonstrated a greatly reduced frequency in phytohemagglutinin-responsive cells, supporting the role of deficient hematopoietic growth factor production by activated T cells in transplant recipients. This hemopoietic accessory cell defect may thus reflect more generalized lymphocyte dysfunction in these patients. Hematopoiesis following bone marrow transplantation appears to rely upon growth factors released by accessory cells in the adherent layer.

Adolescent↗
PubMed1987

The production of hematopoietic growth factors by endothelial accessory cells.

Monocytes are known to produce both hematopoietic growth factors and other factors, monokines, which do not directly stimulate hematopoiesis. Monokines such as interleukin-1 (IL-1) and tumor necrosis factor (TNF) may indirectly stimulate mesenchymal cells to produce hematopoietic growth factors. The identity of all the factors produced by monocytes or mesenchymal cells has not been established because of overlapping activities on biologic assay. The purpose of this study was to identify the individual growth factors produced by endothelial cells before and after stimulation with various monokines. We prepared conditioned media and extracted RNA from endothelial cells before and after stimulation with monokines. The results show that immortalized endothelial cells produce maximal detectable amounts of granulocyte-macrophage colony-stimulating factor (GM-CSF) constitutively. In contrast, GM-CSF production by primary endothelial cells requires induction with either IL-1 or TNF.

Bone Marrow↗
PubMed1987

Differential binding of erythroid and myeloid progenitors to fibroblasts and fibronectin.

Using a novel coverslip-transfer culture technique, we recently demonstrated that primitive erythroid burst-forming units (BFU-E) can migrate, proliferate, and differentiate in intimate association with stromal fibroblastoid cells in the presence of serum proteins and erythropoietin. No other exogenous hemopoietic growth factors are required. Most of the colonies that develop in this system are very large erythroid bursts, and very few granulocyte-macrophage (GM) colonies are observed. In this report, we present data indicating that the predominance of erythroid burst colonies in this culture system is due to preferential binding of primitive erythroid progenitors to the stromal fibroblastoid cells and not to differential stimulation of these erythroid progenitors by these cells. We next show that the binding of BFU-E to stromal cells is blocked by anti-fibronectin antibodies. Finally, we demonstrate the preferential binding of BFU-E to fibronectin by using glass coverslips or Petri dishes coated with purified human plasma fibronectin. The binding is blocked by a monoclonal antibody specific for the cell-binding domain of fibronectin. We conclude that: primitive erythroid progenitors bind strongly whereas G and/or M progenitors (CFU-G/M) bind only weakly to fibronectin; primitive erythroid progenitors bind to the cell-binding domain on the fibronectin molecule; and erythroid progenitors and precursors remain bound to fibronectin throughout differentiation.

Bone Marrow Cells↗
PubMed1986

Isolation of a human stromal cell strain secreting hemopoietic growth factors.

A diploid fibroblastoid cell strain, termed "ST-1," has been established from a long-term liquid culture of human fetal liver cells. ST-1 cells are nonphagocytic, nonspecific esterase negative and do not possess factor VIII-related antigen but stain with antibodies specific for fibronectin and type I collagen. The ST-1 cells produce nondialyzable hemopoietic growth factors capable of stimulating the development of erythroid bursts, mixed granulocyte-macrophage colonies, pure granulocyte colonies, and pure macrophage colonies. These factors are active on both human fetal liver and human adult bone marrow progenitors. When liquid cultures of human fetal liver hemopoietic progenitors are established with a preformed monolayer of ST-1 cells, the yields of nonadherent cells, erythroid progenitors, and myeloid progenitors are greatly increased. These studies demonstrate that the fibroblastoid ST-1 cells support hemopoiesis in vitro and may be a critical element in the stromal microenviroment in vivo.

Cell Division↗
PubMed1986

Membrane antigen expression during hemopoietic differentiation.

The pattern of certain groups of antigens expressed on the surface of hemopoietic cells changes either during the course of differentiation from pluripotent stem cells to mature functional cells or as a function of the proliferative state of the cells. A map of these changes is emerging and is providing valuable information for selecting and purifying rare stem cells and for classifying the acute leukemias. This knowledge is also beginning to provide insights into physiological and pathological cellular interactions affecting the early stages of hemopoiesis, and is being exploited to remove T lymphocytes from allogeneic bone marrow grafts in order to prevent graft-vs.-host disease as well as leukemic cells from bone marrow before autologous reinfusion. In this article I will briefly review the cellular basis of hemopoiesis and then discuss the methods used to determine the presence of antigens on normal hemopoietic cells. I will then summarize the pattern of membrane antigens expressed during differentiation and conclude by discussing the biological and therapeutic implications.

Animals↗
PubMed1986

Dependence of highly enriched human bone marrow progenitors on hemopoietic growth factors and their response to recombinant erythropoietin.

Human bone marrow cells were sequentially fractionated by three negative selection steps to remove adherent cells and Fc receptor-bearing cells, followed by immune adsorption (panning) to deplete maturing cells that react with a panel of monoclonal antibodies. This nonadherent Fc receptor and antibody negative fraction could be further enriched by a positive selection "panning" step, using an antibody to HLA-DR antigen; 12-27% of the cells formed erythroid burst-forming unit (BFU-E), erythroid colony-forming unit, granulocyte-monocyte colony-forming unit, and erythroid and granulocyte and/or monocyte colony-forming unit-derived colonies with recovery of 0.5-1% of the cells and 20-100% of the colony-forming cells. Sequential fractionation resulted in increasing dependence of a subset of BFU-E-derived colonies on exogenous burst-promoting activity (BPA) for proliferation in culture, but the most enriched progenitor fraction still contained a proportion of accessory cell or BPA-independent BFU-E that responded to either natural or biosynthetic erythropoietin when added to cultures on day 0 in the absence of BPA. If the addition of erythropoietin was delayed until day 3, the data suggest that this population of BFU-E either died or became unresponsive to erythropoietin. Delayed addition of erythropoietin to cultures of enriched progenitors provided a sensitive BPA assay, since BPA-independent but erythropoietin-responsive BFU-E were eliminated. The surviving BFU-E that were dependent for their proliferation on the presence of both BPA and erythropoietin showed a characteristic dose response to increasing BPA concentrations.

Adult↗
PubMed1986

Human recombinant granulocyte-macrophage colony-stimulating factor increases cell-to-cell adhesion and surface expression of adhesion-promoting surface glycoproteins on mature granulocytes.

Human granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to inhibit migration of mature granulocytes and to enhance their antibody-dependent cellular cytotoxicity. We found that human recombinant GM-CSF also enhanced granulocyte-granulocyte adhesion and increased by two- to threefold the surface expression of Mo1 and LeuM5 (P150, 95), two members of a family of leukocyte adhesion molecules (Leu-CAM). Increased Mo1 surface expression occurred within 15 min at 37 degrees C and was maximal at the migration inhibitory concentration of 500 pM. One-half maximal rise in the expression of Mo1 on the cell surface occurred at 5 pM. The chemotactic peptide f-Met-Leu-Phe produced a comparable rise in surface Mo1 with one-half maximal expression occurring at 7 nM. Both GM-CSF and f-Met-Leu-Phe produced optimal granulocyte-granulocyte adhesion at 500 pM and 100 nM, respectively. This adhesion-promoting effect induced by either stimulus was inhibited by a mouse monoclonal antibody directed against Mo1 antigen. These data indicate that GM-CSF promotes cell-to-cell adhesion, presumably through enhanced expression of leukocyte adhesion molecules. This mechanism may explain, in part, the known effects of GM-CSF on the function of mature granulocytes.

Animals↗
PubMed1986

Stromal cell-associated erythropoiesis.

A novel cover slip-transfer culture system was designed to study the functional roles of stromal cells in hemopoiesis, particularly erythropoiesis. Human bone marrow stromal cell colonies were allowed to develop on small glass cover slips in liquid medium. The cover slips, along with the stromal cell colonies and progenitors attached to them were then transferred to a new tissue culture dish and overlaid with methylcellulose culture medium. No exogenous colony-stimulating factors except erythropoietin were supplied. Large erythroid bursts, comprising multiple subcolonies, developed on the stromal cells. In order to determine if stromal fibroblasts together with erythropoietin and serum proteins could support erythroid development, human bone marrow cells depleted of monocytes, macrophages, and T lymphocytes were allowed to adhere to monolayers of a homogeneous fibroblastoid human stromal cell strain ST-1 grown on cover slips. The cover slips were then washed to remove nonadherent cells, transferred to a new culture dish, and overlaid with methylcellulose culture medium containing fetal calf serum and erythropoietin. In this modified system as well, primitive erythroid progenitors migrated extensively on and within the stroma to form huge colonies of hemoglobinized erythroblasts that proceeded to enucleate. Our results indicate that (1) ST-1 cells together with serum proteins and erythropoietin can support the development of large erythroid bursts; (2) erythroid progenitors and precursors adhere to and migrate on and within the extracellular matrix elaborated by ST-1 cells; (3) erythroid progenitors are more adherent to the ST-1 cells or the extracellular matrix than are the more mature cells and possibly the myeloid progenitors.

Blood Proteins↗
PubMed1985

Human recombinant granulocyte-macrophage colony-stimulating factor: a multilineage hematopoietin.

Human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) was tested for its ability to induce colony formation in human bone marrow that had been enriched for progenitor cells. In addition to its expected granulocyte-monocyte colony-stimulating activity, the recombinant GM-CSF had burst-promoting activity for erythroid burst-forming units and also stimulated colonies derived from multipotent (mixed) progenitors. In contrast, recombinant erythroid-potentiating activity did not stimulate erythroid progenitors. The experiments prove that human GM-CSF has multilineage colony-stimulating activity.

Animals↗
PubMed1985

Purification of fetal hematopoietic progenitors and demonstration of recombinant multipotential colony-stimulating activity.

To facilitate the direct study of progenitor cell biology, we have developed a simple and efficient procedure based upon negative selection by panning to purify large numbers of committed erythroid and myeloid progenitors from human fetal liver. The nonadherent, panned cells constitute a highly enriched population of progenitor cells, containing 30.4 +/- 13.1% erythrocyte burst forming units (BFU-E), 5.5 +/- 1.9% granulocyte-macrophage colony forming units (CFU-GM), and 1.4 +/- 0.7% granulocyte-erythroid-macrophage-megakaryocyte colony forming units (CFU-GEMM) as assayed in methylcellulose cultures. These cells are morphologically immature blasts with prominent Golgi. This preparative method recovers 60-100% of the committed progenitors detectable in unfractionated fetal liver and yields 2-30 X 10(6) progenitors from each fetal liver sample, and thus provides sufficient numbers of enriched progenitors to allow direct biochemical and immunologic manipulation. Using this technique, a purified recombinant protein previously thought to have only granulocyte-macrophage colony stimulating activity (GM-CSA) is shown to have both burst promoting activity and multipotential colony stimulating activity. Progenitor purification by panning thus appears to be a simple, efficient method that should facilitate the direct study of committed hematopoietic progenitors and their differentiation.

Cell Count↗
PubMed1983

Allogeneic bone-marrow transplantation in infantile malignant osteopetrosis.

Two infants with malignant osteopetrosis were treated by allogeneic bone-marrow transplantation after marrow ablation with busulphan and cyclophosphamide. Engraftment without graft-vs-host disease occurred in both cases. The first child established stable chimerism and is clinically well 30 months after receiving a histocompatible sibling bone-marrow graft: haematological, radiological, and biochemical features of osteopetrosis have completely resolved. The second child was non-identical with the marrow donor (his older sister) at a single HLA-B locus and received cyclosporin A as prophylaxis for graft-vs-host disease. 11 months after transplantation haematological abnormalities have resolved and radiological features have improved. The findings indicate that allogeneic bone-marrow transplantation should be considered the treatment of choice for infants with severe osteopetrosis who have histocompatible siblings.

Blood Grouping and Crossmatching↗