Factors influencing release of granulocyte-macrophage colony-stimulating activity from human mononuclear phagocytes

Increase in granulocyte-macrophage-colony-stimulating factor secretion and the respiratory burst with decreased L-selectin expression in hyper-IgE syndrome patients

BACKGROUND

The hyper-IgE syndrome is a primary immunodeficiency characterized by severe recurrent abscesses, pneumonia with pneumatocele formation, and elevated serum IgE. Eosinophilia, neutrophil chemotactic defects, and marked tissue damage are frequently present in this syndrome.

OBJECTIVE

To study whether functional changes in cytokines, adhesion molecules, and neutrophils might help explain these clinical observations.

METHODS

The following functions were analyzed in patients with the hyper-IgE syndrome and in controls: (1) production of granulocyte-macrophage-colony-stimulating factor by peripheral blood mononuclear cells by ELISA; (2) respiratory burst and reactive oxygen intermediates production by peripheral neutrophils using the luminol-enhanced chemiluminescense technique; and (3) expression of L-selectin on granulocytes and lymphocytes by flow cytometry.

RESULTS

Patients with hyper-IgE syndrome had significantly increased production of granulocyte-macrophage-colony-stimulating factor by resting or stimulated mononuclear cells, increased generation of reactive oxygen intermediates by neutrophils treated with opsonized zymosan, and reduced L-selectin expression on quiescent and activated granulocytes and lymphocytes.

CONCLUSIONS

Our results suggest that an important feature of the hyper-IgE syndrome is the increased production of granulocyte-macrophage-colony-stimulating factor, which may explain the reduced L-selectin expression, decreased chemotaxis, and increased oxygen radical production and tissue damage in this disease.

Inhibition of GM-CSF production by recombinant human interleukin-4: negative regulator of hematopoiesis

Interleukin-4 (IL-4), also known as B-cell stimulatory factor-1 (BSF-1), was initially identified as a T-cell product that mediates anti-IgM-induced DNA synthesis in B-lymphocytes. Various aspects of this highly pleiotropic cytokine have been described, including those on hematopoietic progenitor cells. However, the role of IL-4 in the hematopoietic system has been given different interpretations. Normal human hematopoietic progenitor cells do not proliferate under control of the autocrine system and cytokines are needed for proliferation and differentiation. However, IL-4 in itself does not support proliferation of these cells and if this is the case, the effects of IL-4 on hematopoietic progenitor cells still need to be investigated from the point of view of synergism with other cytokines as well as the control of accessory cells in the production of cytokines. We describe here some properties of IL-4 in association with cytokine production, with special emphasis on granulocyte-macrophage colony-stimulating factor (GM-CSF) production.

The effects of granulocyte-macrophage colony-stimulating factor on tumour-infiltrating lymphocytes from renal cell carcinoma

It has been shown that granulocyte-macrophage colony-stimulating factor (GM-CSF) can induce specific and non-specific anti-tumour cytotoxicity and also stimulates the proliferation and function of peripheral lymphocytes and thymocytes. GM-CSF and interleukin 2 (IL-2) act synergistically on peripheral lymphocytes for the induction of a highly effective cytotoxic cell population. Thus, the goal of our investigation was to study the effects of GM-CSF upon expansion, proliferation and in vitro killing activity of tumour-infiltrating lymphocytes (TILs) from renal cell carcinoma (RCC). TILs from seven consecutive tumours were cultured with GM-CSF (500 or 1000 nmol ml-1) without IL-2 supplementation, with suboptimal doses of IL-2 (8 and 40 U ml-1) plus GM-CSF (1000 nmol ml-1), and with a dose of IL-2 (400 U ml-1) which sufficed alone to induce TIL development plus GM-CSF (500 or 1000 nmol ml-1). GM-CSF alone or together with suboptimal doses of IL-2 was not able to induce or facilitate TIL development in these cultures. When GM-CSF at both concentrations studied was added to optimal doses of IL-2 the resulting TIL populations proliferated significantly better and faster (+66%), resulting in a higher cell yield (+24%) at the time of maximal expansion of the TIL cultures. The length of the culture periods of TILs was not affected by GM-CSF when compared with the control cultures supplemented with IL-2 alone. In vitro killing activity of TIL populations stimulated with IL-2 and GM-CSF remained unspecific, but lysis of the autologous tumour targets as well as the allogeneic renal tumour targets was significantly enhanced (+138%) as compared with the corresponding control TILs stimulated with IL-2 alone. Lysis of the natural killer (NK)-sensitive control cell line K562 and the NK-resistant Daudi cell line remained unchanged even though FACS analysis of TILs cultured with IL-2 and 1000 nmol of GM-CSF demonstrated a significantly higher proportion of cells expressing the CD56 molecule (+50%). Specific receptors for GM-CSF could not be demonstrated on TILs from RCC. Our data demonstrate that GM-CSF alters the biological behaviour of IL-2-activated TILs from renal cell carcinoma in terms of proliferation, in vitro killing activity and cell-surface molecule expression.(ABSTRACT TRUNCATED AT 400 WORDS)

Polymyxin B stimulates production of complement components and cytokines in human monocytes

Polymyxin B (PmB), an agent often used to neutralize the effects of bacterial lipopolysaccharide (LPS), was shown to exert a dose-dependent stimulatory effect on the biosynthesis of C3, factor B, interleukin-6 (IL-6), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in human monocytes. A low dose of PmB (1 to 5 micrograms/ml) efficiently suppressed the LPS-induced (1 or 100 ng/ml) production of IL-6, GM-CSF, and factor B, but not the C3 production induced by 100 ng of LPS per ml. A reduced level of GM-CSF may have contributed to the persisting high C3 concentrations and the apparent lack of LPS inhibition in the latter situation, since GM-CSF is an inhibitor of monocyte C3 biosynthesis.

Endogenous production and peripheral blood levels of granulocyte-macrophage (GM-) and granulocyte (G-) colony-stimulating factors

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) are two important granulopoietic growth factors. This review will focus on the endogenous production of human GM-CSF and human G-CSF and its possible reflection in circulating levels in peripheral blood. When adequately stimulated a variety of cell-types such as monocytes/macrophages. T-lymphocytes, endothelial cells and fibroblasts can produce CSFs in vitro. G-CSF can increase to detectable levels in peripheral blood when there is a demand for granulocyte production such as acute neutropenic in conjunction with hematological disorders, chronic neutropenic conditions and acute infectious diseases in patients with or without underlying hematological disorders. G-CSF in peripheral blood is detected more often and in higher concentrations than GM-CSF. An independent regulation of GM-CSF and G-CSF secretion, quantitative differences in production and/or differences in elimination or distribution might be of importance.

The biology of granulocyte-macrophage colony-stimulating factor: effects on hematopoietic and nonhematopoietic cells

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of a family of glycoprotein cytokines that have potent effects in stimulating the proliferation, maturation, and function of hematopoietic cells. Deriving its name from its ability to stimulate the formation of macroscopic colonies containing neutrophils, eosinophils, macrophages, or mixtures of these cell types, GM-CSF stimulates the proliferation and maturation of myeloid progenitors, as well as functionally activating mature neutrophils, eosinophils, and macrophages. As most of the effects observed using GM-CSF in vitro have been shown to occur in vivo either in animal models or in human subjects, it is important to consider that GM-CSF may also exert some biological effects on nonhematopoietic cells. In response to immunologic stimuli, immunologic surveillance cells and cells of the microenvironment are capable of producing GM-CSF. In vitro experiments indicate that GM-CSF production is tightly regulated. In that regard, GM-CSF is not present in measurable quantities in normal serum, but little is known about the in vivo process of GM-CSF production and regulation. The biologic capabilities of GM-CSF have triggered its widespread clinical use in situations where hematopoiesis is compromised. GM-CSF can act as a potent growth factor in vivo, increasing the number and enhancing the function of hematopoietic progenitors and mature cells. However, the precise in vivo effect that GM-CSF may have on normal and neoplastic cells of nonhematopoietic origin remains undefined. The full range of GM-CSF bioactivity is mediated following binding to its receptor. The presence of specific receptors for GM-CSF has been demonstrated in all responsive cells of hematopoietic lineage, as well as in nonhematopoietic cells, both responsive and unresponsive. In conclusion, a large body of work from a number of laboratories has defined the biology of GM-CSF. Currently available reagents and technology will provide additional insights into the biology of this molecule, thereby expanding our present definition and allowing us to explore the mechanisms regulating hematopoiesis.

Colony-stimulating factors

Recombinant hematopoietic colony-stimulating factors have profound effects on developing and mature granulocytes, macrophages, and lymphocytes. Use of these agents for treatment of disease may result in a variety of adverse cutaneous reactions. The recent discovery of colony-stimulating factor production by keratinocytes and dermal cells suggests that these agents may also be significant in cutaneous homeostasis and in the pathogenesis of cutaneous diseases.