Identification of neutrophil alkaline phosphatase-inducing factor in cystic fluid of a human squamous cell carcinoma as granulocyte colony-stimulating factor

We have previously shown that a factor termed neutrophil alkaline phosphatase-inducing factor (NAP-IF) has the capacity to induce neutrophil alkaline phosphatase (NAP) in postmitotic granulocytes (PMGs). This factor has characteristics similar to those of granulocyte colony-stimulating factor (G-CSF), suggesting that the two factors assayed by different methods may be attributable to an identical macromolecule. In a preliminary experiment, we showed that purified natural G-CSF (nG-CSF) could induce NAP in vitro in the presence of 10% (v/v) fetal calf serum (FCS). In this study, purified human nG-CSF and recombinant G-CSF (rG-CSF) induced NAP in granulocytes from both normal individuals and patients with chronic myelogenous leukemia in a dose-dependent fashion in serum-free and serum-containing culture conditions. The induction of NAP by G-CSF was detectable at 0.4 ng/ml and became maximal between 10 and 20 ng/ml. Anti-G-CSF serum incubated with either NAP-IF or rG-CSF inhibited induction of NAP. Morphological examinations revealed that granulocytes cultured with G-CSF were more mature than those cultured without G-CSF, indicating that G-CSF promoted maturation of granulocytes in parallel with NAP induction. These results indicate that NAP-IF in the cystic fluid of a human squamous cell carcinoma is identical to G-CSF and that induction of NAP by G-CSF is really a reflection of cell maturation promoted by G-CSF.     

A recombinant human G-CSF/GM-CSF fusion protein from E. coli showing colony stimulating activity on human bone marrow cells

Granulocyte-Macrophage colony stimulating factor (GM-CSF) and Granulocyte colony stimulating factor (G-CSF) are cytokines involved in the differentiation of bone marrow progenitor cells into myeloid cells. They also activate mature myeloid cells to mediate a variety of antimicrobial activities and inflammatory responses. Recombinant GM-CSF and G-CSF proteins have been used to treat various diseases including cancer and hematopoietic diseases and to isolate peripheral blood progenitor cells for bone marrow transplantation. A plasmid construct expressing recombinant human G-CSF/GM-CSF fusion protein has now been prepared by linking the human G-CSF and GM-CSF coding regions and the recombinant fusion protein has been successfully expressed in E. coli. The recombinant human G-CSF/GM-CSF fusion protein was extracted and purified from the cellular inclusion and refolded into the biologically active form to show colony stimulating activity. The recombinant fusion protein exhibited colony stimulating activity on human bone marrow cell cultures, indicating that the linkage of GM-CSF and G-CSF by a linker peptide may not interrupt activities of the cytokines in the fusion protein. The colony forming unit of the fusion protein was also higher than those of the cultures treated with the same molar numbers of the recombinant human GM-CSF and G-CSF separately, which suggests that the fusion protein presumably retains both G-CSF and GM-CSF activities.     

Levels of human serum granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor under pathological conditions

Levels of serum granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF) in patients with various leukocyte disorders were estimated by enzyme linked immunosorbent assay (ELISA). Some cases of acute myelogenous leukemia and aplastic anemia showed elevated serum levels of G-CSF and/or GM-CSF, whereas almost all of 23 healthy controls showed G-CSF and GM-CSF levels lower than 100 pg/ml. High levels of both types of CSF were noted in patients with granulocytosis due to infection. These levels became lower after resolution of the infection. Daily changes in serum CSF levels were also examined in a patient with autoimmune neutropenia, and it was found that the peripheral neutrophilic granulocyte count changed almost in parallel with the serum G-CSF level but not with GM-CSF, following the pattern with a delay of about 4–5 h, suggesting the possibility that G-CSF mainly regulates peripheral neutrophil circulation.     

Stimulation and priming of human neutrophils by granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor: qualitative and quantitative differences.

Granulocyte colony-stimulating factor(G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) increased neutrophil C3bi-receptor expression and adherence and rapidly (less than 10 min) primed neutrophils to enhanced O2- release and membrane depolarization stimulated by chemotactic peptide. Direct triggering of O2- release in suspended neutrophils was also provoked by GM-CSF but not by G-CSF. GM-CSF-induced O2- release was inhibited by cyclic AMP agonists and cytochalasin B. The biological activity was greater in non-glycosylated GM-CSF than in glycosylated GM-CSF, whereas it was identical in glycosylated and non-glycosylated G-CSFs. Direct stimulation and priming by GM-CSF were consistently greater than those by G-CSF and the combined addition of the optimal concentrations of G-CSF and GM-CSF resulted in the effects of GM-CSF alone. These findings indicate that the effects of G-CSF and GM-CSF on neutrophil functions are qualitatively and quantitatively different from each other.     

Specific binding of radioiodinated granulocyte-macrophage colony-stimulating factor to hemopoietic cells

The hemopoietic growth factor granulocyte-macrophage colony-stimulating factor, GM-CSF, specifically controls the production of granulocytes and macrophages. This report describes the binding of biologically-active 125I-labeled murine GM-CSF to a range of hemopoietic cells. Specific binding was restricted to murine cells and neither rat nor human bone marrow cells appeared to have surface receptors for 125I-labeled GM-CSF. 125I-Labeled GM-CSF only appeared to bind specifically to cells in the myelomonocytic lineage. The binding of 125I-labeled GM-CSF to both bone marrow cells and WEHI-3B(D+) was rapid (50% maximum binding was attained within 5 min at both 20 degrees C and 37 degrees C). Unlabeled GM-CSF was the only polypeptide hormone which completely inhibited the binding of 125I-labeled GM-CSF to bone marrow cells, however, multi-CSF (also called IL-3) and G-CSF partially reduced the binding of 125I-labeled GM-CSF to bone marrow cells. Interestingly, the binding of 125I-labeled GM-CSF to a myelomonocytic cell line, WEHI-3B(D+), was inhibited by unlabeled GM-CSF but not by multi-CSF or G-CSF. Scatchard analysis of the binding of 125I-labeled GM-CSF to WEHI-3B(D+) cells, bone marrow cells and peritoneal neutrophils indicated that there were two classes of binding sites: one of high affinity (Kd1 = 20 pM) and one of low affinity (Kd2 = 0.8-1.2 nM). Multi-CSF only inhibited the binding of 125I-labeled GM-CSF to the high affinity receptor on bone marrow cells: this inhibition appeared to be a result of down regulation or modification of the GM-CSF receptor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Notch1 and Notch2 Inhibit Myeloid Differentiation in Response to Different Cytokines

We have compared the ability of two mammalian Notch homologs, mouse Notch1 and Notch2, to inhibit the granulocytic differentiation of 32D myeloid progenitor cells. 32D cells undergo granulocytic differentiation when stimulated with either granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). Expression of the activated intracellular domain of Notch1 inhibits the differentiation induced by G-CSF but not by GM-CSF; conversely, the corresponding domain of Notch2 inhibits differentiation in response to GM-CSF but not to G-CSF. The region immediately C-terminal to the cdc10 domain of Notch confers cytokine specificity on the cdc10 domain. The cytokine response patterns of Notch1 and Notch2 are transferred with this region, which we have termed the Notch cytokine response (NCR) region. The NCR region is also associated with differences in posttranslational modification and subcellular localization of the different Notch molecules. These findings suggest that the multiple forms of Notch found in mammals have structural differences that allow their function to be modulated by specific differentiation signals.     

Granulocyte interactions with GM-CSF and G-CSF secretion by endothelial cells and monocytes

We have, in previous studies, characterized the cytokine and cellular regulation of GM-CSF and G-CSF production by monocytes and endothelial cells. In this study, we investigated the regulatory role of granulocytes. The addition of granulocytes to endotoxin-stimulated monocytes dose-dependently decreased both GM-CSF and G-CSF concentrations, presumably by absorbing the cytokines. A similar dose-dependent decrease in GM-CSF concentration was found when granulocytes were added to IL-1-stimulated endothelial cells. In contrast, G-CSF secretion by endothelial cells responded to granulocytes in a biphasic fashion. At low granulocyte concentrations, endothelial cells responded with an increased G-CSF secretion, but at high concentrations of granulocytes G-CSF secretion was down modulated. Our results suggest that there exist two loops between granulocytes and endothelial cells for regulating G-CSF activity. Granulocytes can stimulate G-CSF secretion by activated endothelial cells but can also decrease the biological activity by absorbing the cytokine. These mechanisms might be involved in the regulation of the local and systemic levels of granulocytes.     

Hypothesis: the target cell of GM-CSF is a macrophage precursor capable to produce cells with the property to secrete a G-CSF like activity.

The induction of granulocyte and macrophage colony formation by the granulocyte-macrophage colony stimulating factor (GM-CSF) on bone marrow cells (BMC) was evaluated as a function of time in agar cultures. We found that while macrophage cell clusters were very abundant on the first two days of culture, granulocytic cell clusters did not appear until the third day. We also found that macrophage colonies were present from the fourth day of culture, while granulocyte colonies did not appear until the fifth day. When two day cell clusters were transferred to cultures with GM-CSF we observed that only macrophage-colonies developed. On the other hand, when four day clusters were transferred, both granulocyte and macrophage colony formation was obtained in a similar way as the one obtained when using GM-CSF with fresh BMC. Two day clusters did not respond to granulocyte colony stimulating factor (G-CSF) while fourth day clusters generated granulocytic colonies in a similar way as when G-CSF was used with fresh BMC. In order to test the hypothesis that granulocyte colony formation in these assays could be a result of the secretion of G-CSF by the macrophages previously induced by GM-CSF, lysates from macrophage colonies were used to induce colony formation on BMC. We observed that colonies, mainly granulocytic, were induced in a similar way as when G-CSF was used. Finally, the possibility that GM-CSF is just a macrophage inducer with the property to produce cells that secrete G-CSF is discussed.     

IL-1α and TNFα act synergistically to stimulate production of myeloid colony-stimulating factors by cultured human bone marrow stromal cells and cloned stromal cell strains

Human bone marrow stromal cells repond to stimulation by the monokines IL-1 and TNF by producing colony-stimulating factors such as GM-CSF and G-CSF. In this study we show that IL-1α and TNFα act synergistically to stimulate GM-CSF and G-CSF production by cultured marrow stromal cells. We further show that IL-1α and TNFα synergistically stimulate production of GM-CSF and G-CSF by a clonal stroma-derived cell strain. Although IL-1 and TNF share many of the same biological activities, we show that IL-1α and TNFα have an unequal ability to induce myeloid-CSF production by both cultures, with IL-1α being the more potent inducer. We found that induction by IL-1α and TNFα was independent of cell proliferation. The effect of IL-1α and TNFα on production of the two myeloid-CSFs by the clonal cells was significantly greater than the unfractionated passaged stromal cultures, having the greater effect on G-CSF production. The clonally derived stromal cells constitutively produced colony-stimulating activity, in particular GM-CSF, at levels easily detected by ELISA. These findings show that, in addition to the overlapping and additive activities of IL-1α and TNFα, they can interact synergistically. Our findings further suggest that a small subpopulation of stroma cells may be the major producer of G-CSF in the marrow microenvironment during immune response. © 1994 wiley-Liss, Inc.     

The induction of distinct cytokine cascades correlates with different effects of granulocyte-colony stimulating factor and granulocyte/macrophage-colony-stimulating factor on the lymphocyte compartment in the course of high-dose chemotherapy for breast cancer

The availability of the myeloid hemopoietic growth factors (HGF) granulocyte- and granulocyte/macrophage-colony stimulating factor (G-CSF and GM-CSF) has enhanced the therapeutic index of high-dose chemotherapeutic antitumoral regimens (HDCT), as well as the rate of severe damage to immune competence. We investigated some immune functions before, during and after one course of HDCT for poor-risk breast cancer and compared the effects of G-CSF and GM-CSF on the immune recovery. They exerted different influences on the functions we examined and showed distinctive patterns of both qualitative and quantitative in vivo activities on the immune system. The main findings were that (a) granulocyte and lymphocyte recovery rates were faster in the patients receiving G-CSF; (b) looking at the lymphocyte compartment, this difference was restricted to the CD3⁺/CD8⁺ and CD56⁺ lymphocyte subsets; (c) the reconstitution rate of CD19⁺ lymphocytes was slow in both groups; (d) at the end of follow-up HLA-DR expression by CD3⁺ lymphocytes was higher in the GM-CSF group; (e) the lymphocyte proliferative capacity was restored at a faster rate in the GM-CSF group, whereas cytotoxic activities recovered better in the G-CSF group; (f) the early repopulating phase was characterized by higher interleukin-6 serum levels in the GM-CSF group. Overall, GM-CSF seemed to exert an earlier effect on all T lymphocyte subsets, preventing them from a complete drop during the long-lasting “nadir” of the cell count, whereas G-CSF appeared to boost them strongly, though a few days later, hastening their final recovery. The distinct pattern of the cytokine cascade induced by each factor, consistent with the different functional changes, seemed to account for the peculiarities of their immune modulations. Received: 4 August 1998 / Accepted: 30 April 1999     

The differential inhibition of hemopoietic growth factor activity by cytotoxins and interferon-gamma

The effects of recombinant human tumor necrosis factor (TNF), lymphotoxin (LT), and interferon-gamma (IFN-gamma) on the growth of human hemopoietic progenitor cells in clonal culture have been examined. Colony growth was induced by using granulocyte colony-stimulating factor (G-CSF), or granulocyte-macrophage colony-stimulating factor (GM-CSF). A suppressive effect of TNF, LT, and IFN-gamma on the development of granulocyte, macrophage, and mixed granulocyte/macrophage colonies was shown. Suppression of colonies formed after stimulation with G-CSF was greater than that observed after stimulation with GM-CSF. In the presence of a monoclonal antibody to TNF, or polyclonal antibodies to either LT or IFN-gamma, the inhibitory effect of the molecule to which the antibody was directed was abrogated. These findings suggest that progenitor cells responsive to G-CSF or GM-CSF have different sensitivities to the effects of TNF, LT, and IFN-gamma. Defining the interactions of growth factors and inhibitors should increase understanding of mechanisms underlying diseases associated with suppression of normal hemopoiesis, and in predicting the effects in vivo of these bioregulatory molecules in clinical medicine.     

Selection of lineage-restricted cell lines immortalized at different stages of hematopoietic differentiation from the murine cell line 32D

Erythropoietin (Epo), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor- (G-CSF) dependent cell lines have been derived from the murine hematopoietic cell line 32D with a selection strategy involving the culture of the cells in FBS-deprived medium supplemented only with pure recombinant Epo, GM-CSF, or G-CSF. The cells retain the diploid karyotype of the original 32D clone, do not grow in the absence of exogenous growth factor, and do not induce tumors when injected into syngeneic recipients. The morphology of the Epo-dependent cell lines (32D Epo1, -2, and -3) was heterogeneous and evolved with passage. The percent of differentiated cells also was a function of the cell line investigated. Benzidine-positive cells ranged from 1-2% (32D Epo3) to 50-60% (32D Epo1). These erythroid cells expressed carbonic anhydrase I and/or globin mRNA but not carbonic anhydrase II. The GM-CSF- and G-CSF-dependent cell lines had predominantly the morphology of undifferentiated myeloblasts or metamyelocytes, respectively. The GM-CSF-dependent cell lines were sensitive to either GM-CSF or interleukin-3 (IL-3) but did not respond to G-CSF. The G-CSF-dependent cell lines grew to a limited extent in IL-3 but did not respond to GM-CSF. These results indicate that the cell line 32D, originally described as predominantly a basophil/mast cell line, has retained the capacity to give rise to cells which proliferate and differentiate in response to Epo, GM-CSF, and/or G-CSF. These cells represent the first nontransformed cell lines which can be maintained in growth factors other than IL-3 and which differentiate in the presence of physiologic signals. As such, they may represent a model to study the molecular mechanisms underlying the process of hematopoietic differentiation, as well as sensitive targets for bioassays of specific growth factors.     

Human articular cartilage and chondrocytes produce hemopoietic colony-stimulating factors in culture in response to IL-1.

The hemopoietic CSF, granulocyte-macrophage CSF (GM-CSF) and granulocyte CSF (G-CSF), are cytokines that mediate the clonal proliferation and differentiation of progenitor cells into mature macrophages and/or granulocytes. We have employed an all-human cell culture system, specific ELISA for GM-CSF and G-CSF, and Northern analysis to investigate whether chondrocytes are a potential source of CSF in rheumatoid disease. We report that human rIL-1 stimulated in a dose-dependent manner the production of GM-CSF and G-CSF by human articular cartilage and chondrocyte monolayers in organ and cell culture, respectively. Increased levels of the CSF Ag were detected after 2 to 8 h stimulation with IL-1, and the optimum dose of IL-1 was 10 to 100 U/ml (0.06 to 0.6 nM IL-1 alpha; 0.02 to 0.2 nM IL-1 beta); neither CSF was detectable in nonstimulated cultures nor in IL-1-stimulated cultures treated with actinomycin D or cycloheximide, indicating the requirement for de novo RNA and protein synthesis. The IL-1-mediated increase in GM-CSF could also be inhibited by the corticosteroid, dexamethasone, but not by the cyclo-oxygenase inhibitor, indomethacin. Although having little effect when tested alone, TNF-alpha and lymphotoxin (TNF-beta) could synergize with IL-1 for the production of GM-CSF. Basic fibroblast growth factor, platelet-derived growth factor, and IFN-alpha and IFN-gamma each had no effect on GM-CSF levels. Results obtained by Northern analysis of chondrocyte total RNA reflected those found for the CSF Ag, namely that CSF mRNA levels were elevated in response to IL-1, but not TNF, and that there was synergy between these two cytokines. We propose that chondrocyte CSF production in response to IL-1, and the concurrent destruction of cartilage by IL-1, could provide a mechanism for the chronic nature of rheumatoid disease.     

Proliferative effects of purified granulocyte colony-stimulating factor (G-CSF) on normal mouse hemopoietic cells

When granulocyte colony-stimulating factor (G-CSF), purified to homogeneity from mouse lung-conditioned medium, was added to agar cultures of mouse bone marrcw cells, it stimulated the formation of small numbers of granulocytic colonies. At high concentrations of G-CSF, a small proportion of macrophage and granulocyte-macrophage colonies also developed. G-CSF stimulated colony formation by highly enriched progenitor cell populations obtained by fractionation of mouse fetal liver cells using a fluorescence-activated cell sorter, indicating that G-CSF probably acts directly on target progenitor cells. Granulocytic colonies stimulated by G-CSF were small and uniform in size, and at 7 days of culture were composed of highly differentiated cells. Studies using clonal transfer and the delayed addition of other regulators showed that G-CSF could directly stimulate the initial proliferation of a large proportion of the granulocvte-macrophage progenitors in adult marrow and also the survival and/or proliferation of some multipotential, erythroid, and eosinophil progenitors in fetal liver. However, G-CSF was unable to sustain continued proliferation of these cells to result in colony formation. When G-CSF was mixed with purified granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF), the combination stimulated the formation by adult marrow cells of more granulocyte-macrophage colonies than either stimulus alone and an overall size increase in all colonies. G-CSF behaves as a predominantly granulopoietic stimulating factor but has some capacity to stimulate the initial proliferation of the same wide range of progenitor cells as that stimulated by GM-CSF.     

Neutrophils in cystic fibrosis display a distinct gene expression pattern

We compared gene expression in blood neutrophils (polymorphonuclear leukocytes, or PMNs) collected from healthy subjects with those of cystic fibrosis (CF) patients devoid of bacterial colonization. Macroarray analysis of 1050 genes revealed upregulation of 62 genes and downregulation expression of 27 genes in CF blood PMNs. Among upregulated genes were those coding for vitronectin, some chemokines (particularly CCL17 and CCL18), some interleukin (IL) receptors (IL-3, IL-8, IL-10, IL-12), all three colony-stimulating factors (G-, M-, GM-CSF), numerous genes coding for molecules involved in signal transduction, and a few genes under the control of gamma-interferon. In contrast, none of the genes coding for adhesion molecules were modulated. The upregulation of six genes in CF PMNs (coding for thrombospondin-1, G-CSF, CXCL10, CCL17, IKKvarepsilon, IL-10Ra) was further confirmed by qPCR. In addition, the increased presence of G-CSF, CCL17, and CXCL10 was confirmed by ELISA in supernatants of neutrophils from CF patients. When comparison was performed between blood and airway PMNs of CF patients, there was a limited difference in terms of gene expression. Only the mRNA expression of amphiregulin and tumor necrosis factor (TNF) receptor p55 were significantly higher in airway PMNs. The presence of amphiregulin was confirmed by ELISA in the sputum of CF patients, suggesting for the first time a role of amphiregulin in cystic fibrosis. Altogether, this study clearly demonstrates that blood PMNs from CF patients display a profound modification of gene expression profile associated with the disease, suggesting a state of activation of these cells.     

Phorbol ester-treated human acute myeloid leukemia cells secrete G-CSF, GM-CSF and erythroid differentiation factor into serum-free media in primary culture.

Upon treatment with the phorbol ester, tetradecanoylphorbol 13-acetate (PMA), peripheral mononuclear blood cells from patients with acute myeloid leukemia secrete into serum-free cell-conditioned media (PMA-CCM) at least three distinct nondialysable 'hematopoietic' factors: granulocyte-colony-stimulating factor (G-CSF), granulocyte/macrophage-colony-stimulating factor (GM-CSF) and erythroid differentiation factor (EDF, activin A). G-CSF was identified by its stimulation of [3H]thymidine incorporation into a G-CSF-responsive cell line, NSF-60, and the inhibition of its stimulation by a G-CSF-specific monoclonal antibody (MAB). GM-CSF was identified by its stimulation of [3H]thymidine incorporation into a GM-CSF-responsive line, TALL-101, and the inhibition of its stimulation by a GM-CSF-specific MAB. EDF was identified by its ability to stimulate erythroid differentiation in mouse erythroleukemia cell lines, its identical retention times to those of authentic EDF on three successive reverse-phase HPLC columns and characterization of its penultimate N-terminal residue as leucine which is the same as that of authentic EDF. Both authentic EDF and the erythroid-stimulating activity in PMA-CCM were found to act synergistically with a suboptimal inducing concentration of a well-studied inducing agent, dimethyl sulfoxide, in inducing erythroid differentiation. In addition, a fourth activity was observed in PMA-CCM: normal human fetal bone marrow cell-proliferation stimulating activity (FBMC-PSA). FBMC-PSA was identified by its ability to stimulate the growth of granulocytes and macrophages in FBMC suspension cultures, which neither recombinant G-CSF or GM-CSF were found to do.     

Synergistic effects of purified recombinant human and murine B cell growth factor-1/IL-4 on colony formation in vitro by hematopoietic progenitor cells. Multiple actions

Purified recombinant human B cell growth factor-1/IL-4 was evaluated, alone and in combination, with purified preparations of recombinant human (rhu) CSF or erythropoietin (Epo) for effects on colony formation by human bone marrow CFU-GM progenitor cells (GM) and burst forming unit-E progenitor cells. rhu IL-4 synergized with rhu G-CSF to enhance granulocyte colony formation, but had no effect on CFU-GM colony formation stimulated by rhu GM-CSF, rhu IL-3, or rhu CSF-1. Rhu IL-4 synergized with Epo to enhance BFU-E colony formation equal to that of Epo plus either rhu IL-3, rhu GM-CSF, or rhu G-CSF. Removal of adherent cells and T lymphocytes did not influence the synergistic activities of rhu IL-4. Rmu IL-4, synergized with rhu G-CSF, but not with rmu GM-CSF, rmu IL-3, or natural mu CSF-1, to enhance CFU-GM (mainly granulocyte) colony numbers by a greater than 90% pure preparation of murine CFU-GM. Also, rhu IL-4 at low concentrations enhanced release of CSF and at higher concentrations the release also of suppressor molecules from human monocytes and PHA-stimulated human T lymphocytes. Use of specific CSF antibodies suggested that rhu IL-4 was enhancing the release of G-CSF and CSF-1 from monocytes and the release of GM-CSF and possibly G-CSF from PHA-stimulated T lymphocytes. Use of antibodies for TNF-alpha, IFN-gamma, or TNF-beta as well as measurement of TNF and IFN titers suggested that the suppressor molecule(s) released from monocytes were acting with TNF-alpha and those released from PHA-stimulated T lymphocytes were acting with IFN-gamma. These results implicate B cell growth factor-1/IL-4 as a synergistic activity for hematopoietic progenitors and suggest that the actions can be on both progenitor and accessory cells.     

Resolution and purification of three distinct factors produced by Krebs ascites cells which have differentiation-inducing activity on murine myeloid leukemic cell lines

The use of different myeloid leukemic cell lines (WEHI-3B D+ and M1) and different sources of factors has led to discrepancies concerning the identity of factors capable of inducing differentiation in leukemic cells. We have biochemically fractionated medium conditioned by one such source (Krebs II ascites cells) and assayed fractions for their bone marrow colony-stimulating activity as well as their differentiation-inducing activity for WEHI-3B D+ and M1 cells. This resulted in the resolution of four distinct molecular species with differentiation-inducing activity. One activity was purified to homogeneity and shown by a variety of biochemical, biological, and receptor-binding criteria to be authentic granulocyte colony-stimulating factor (G-CSF). A second activity was identified as granulocyte-macrophage colony-stimulating factor (GM-CSF). Two other activities termed LIF-A and LIF-B (leukemia inhibitory factor) were shown to probably be different glycosylation variants of the same protein and one of these (LIF-A) was purified 12,000-fold to homogeneity. G-CSF induced differentiation in both WEHI-3B D+ and at higher concentrations M1 cells while GM-CSF weakly induced differentiation in WEHI-3B D+ cells. LIF-A had no colony-stimulating activity and induced differentiation in and inhibited the proliferation of only M1 cells. Each factor bound to a unique cell surface receptor with no evidence of direct cross-reactivity.     

Clinicopathological study of involvement of granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor in non-lymphohematopoietic malignant tumors accompanied by leukocytosis

Involvement of granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF) in non-lymphohematopoietic malignant tumors accompanied by leukocytosis was clinicopathologically investigated. Among 1,778 autopsy cases in the last 20 years, 485 lesions of 439 cases with non-lymphohematopoietic malignant tumors accompanied by leukocytosis with a white blood cell count of 10,000/mm3 or greater during the course were immunohistologically examined for G-CSF and GM-CSF. Three (0.7%) and two cases (0.5%) were G-CSF- and GM-CSF-positive, respectively. GM-CSF mRNA was confirmed by using non-fixed cryopreserved tumor tissues in one case positive for GM-CSF. G-CSF-positive cases were large cell carcinoma of the lung, adenocarcinoma of the colon, and adenocarcinoma of the stomach, and GM-CSF-positive cases were spindle cell carcinoma of the lung and malignant thymoma. In the case with stomach carcinoma, the primary lesion showing moderately differentiated adenocarcinoma was negative, but the lung metastatic lesion showing less differentiated adenocarcinoma was G-CSF-positive. The survival period was six months or less in four out of five positive cases. The highest white blood cell count in five CSF-positive cases was markedly elevated: 29,400-103,500/mm3 (mean: 59,700/mm3). In four cases, excluding one case which may have been markedly affected by chemotherapy, the bone marrow showed hyperplasia, and the number of the granulocyte series cells significantly increased. There were three cases (0.7%) negative for both G-CSF and GM-CSF, although they showed marked leukocytosis (60,000/mm3 or higher) which were higher than the mean count of CSF-positive cases and was not observed in autopsy cases with non-tumorous diseases. Other stimulating factors may be involved in the development of leukocytosis in such cases.