Preclinical and clinical evaluation of recombinant human macrophage colony-stimulating factor (rhM-CSF)

M-CSF improves protection against bacterial and fungal infections after hematopoietic stem/progenitor cell transplantation

Myeloablative treatment preceding hematopoietic stem cell (HSC) and progenitor cell (HS/PC) transplantation results in severe myeloid cytopenia and susceptibility to infections in the lag period before hematopoietic recovery. We have previously shown that macrophage colony-stimulating factor (CSF-1; M-CSF) directly instructed myeloid commitment in HSCs. In this study, we tested whether this effect had therapeutic benefit in improving protection against pathogens after HS/PC transplantation. M-CSF treatment resulted in an increased production of mature myeloid donor cells and an increased survival of recipient mice infected with lethal doses of clinically relevant opportunistic pathogens, namely the bacteria Pseudomonas aeruginosa and the fungus Aspergillus fumigatus M-CSF treatment during engraftment or after infection efficiently protected from these pathogens as early as 3 days after transplantation and was effective as a single dose. It was more efficient than granulocyte CSF (G-CSF), a common treatment of severe neutropenia, which showed no protective effect under the tested conditions. M-CSF treatment showed no adverse effect on long-term lineage contribution or stem cell activity and, unlike G-CSF, did not impede recovery of HS/PCs, thrombocyte numbers, or glucose metabolism. These results encourage potential clinical applications of M-CSF to prevent severe infections after HS/PC transplantation.

Wound healing after radiation therapy: review of the literature

Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

Transient Thrombocytopenia Produced by Administration of Macrophage Colony-Stimulating Factor: Investigations of the Mechanism

Administration of macrophage colony-stimulating factor (M-CSF) to mice (2 to 8 mg/kg/d × 5d) produced dose-dependent thrombocytopenia, which reached its nadir on days 4 to 5, followed by rapid recovery. Surprisingly, when administration of M-CSF was prolonged, the thrombocytopenia completely resolved, despite continued treatment. Splenectomy did not prevent the thrombocytopenia. Readministration of M-CSF after various intervals continued to produce the thrombocytopenic effect, even after 35 days. Measurements of Meg-CFC and megakaryocyte ploidy during the periods of M-CSF treatment and recovery of normal platelet levels showed no evidence of bone marrow suppression. Platelet survival was markedly decreased after 5 days of M-CSF (at the platelet count nadir) and after 9 days of continued M-CSF treatment, when the platelet count had returned to normal. Platelets from M-CSF–treated donors demonstrated normal survival when transfused into normal recipients. We concluded that thrombocytopenia produced by M-CSF was not due to suppression of thrombopoiesis, but to increased activity of the monocyte/macrophage system, which caused shortened platelet survival, and that subsequently, increased platelet production compensated for ongoing platelet destruction and resulted in normal platelet levels.

Transient Thrombocytopenia Produced by Administration of Macrophage Colony-Stimulating Factor: Investigations of the Mechanism

Administration of macrophage colony-stimulating factor (M-CSF) to mice (2 to 8 mg/kg/d × 5d) produced dose-dependent thrombocytopenia, which reached its nadir on days 4 to 5, followed by rapid recovery. Surprisingly, when administration of M-CSF was prolonged, the thrombocytopenia completely resolved, despite continued treatment. Splenectomy did not prevent the thrombocytopenia. Readministration of M-CSF after various intervals continued to produce the thrombocytopenic effect, even after 35 days. Measurements of Meg-CFC and megakaryocyte ploidy during the periods of M-CSF treatment and recovery of normal platelet levels showed no evidence of bone marrow suppression. Platelet survival was markedly decreased after 5 days of M-CSF (at the platelet count nadir) and after 9 days of continued M-CSF treatment, when the platelet count had returned to normal. Platelets from M-CSF–treated donors demonstrated normal survival when transfused into normal recipients. We concluded that thrombocytopenia produced by M-CSF was not due to suppression of thrombopoiesis, but to increased activity of the monocyte/macrophage system, which caused shortened platelet survival, and that subsequently, increased platelet production compensated for ongoing platelet destruction and resulted in normal platelet levels.

Increased serum levels of macrophage colony-stimulating factor (M-CSF) in alpha- and beta-thalassaemia syndromes: correlation with anaemia and monocyte activation

Serum levels of M-CSF were determined by an ELISA method in 29 and 34 patients with HbH disease (alpha 1/alpha 2 or alpha 2/HbCS) or beta zero-thal/HbE, respectively, in 28 haematologically normal subjects and in five patients with anaemia due to iron deficiency or myelodysplasia. In HbH disease and beta zero-thal/HbE, M-CSF concentrations were significantly higher than those in the normal subjects [986 +/- 138 and 1385 +/- 133, respectively, vs. 500 +/- 33 pg/ml (mean +/- SEM); p < 0.01, and p < 0.001, respectively]. By contrast, in patients with anaemia due to iron deficiency, M-CSF levels were within the normal range. In HbH disease and in beta zero-thal/HbE, M-CSF levels correlated inversely with mean basal Hb values (r = -0.39, p = 0.05 and r = -0.60, p < 0.001, respectively). In addition, in some of the HbH and beta zero-thal/HbE patients, monocyte ADCC activities towards red cells were tested and found to be approximately twice as high as those in normal controls [38.3 +/- 5.7 and 30.7 +/- 4.6 vs. 17.8 +/- 1.8% specific lysis (mean +/- SEM), respectively; p < 0.01 and p < 0.02, respectively]. When thalassaemic patients and normal controls were considered together there was a significant correlation between M-CSF levels and monocyte ADCC activities (r = 0.51, p < 0.02). The results suggest that in HbH disease and in beta zero-thal/HbE, raised serum M-CSF contributes to the anaemia by enhancing the effector function of mononuclear phagocytes towards red cells.

Abnormal gamma IFN and alpha TNF secretion in purified CD2+ cells from autoimmune thrombocytopenic purpura (ATP) patients: their implication in the clinical course of the disease

Gamma inferferon (gamma IFN), alpha tumor necrosis factor (alpha TNF), and interleukin 6 (IL-60) are cytokines produced by a wide variety of cells, including T lymphocytes and NK cells. These cytokines affect B-cell proliferation and differentiation into immunoglobulin secreting cells. In addition, gamma IFN and alpha TNF also enhance the function of macrophages, upregulating the expression of their IgG receptors. Abnormalities in the production of these cytokines may be involved in the clinical course of autoimmune thrombocytopenic purpura (ATP). This paper describes the production of these cytokines in PHA-stimulated peripheral blood CD2+ cells from ATP patients. Both gamma IFN and alpha TNF were significantly increased in PHA-stimulated CD2+ cells from therapy-dependent ATP patients (platelet counts < 50,000/microliter), as compared to ATP patients with stable disease (sustained platelet counts < 50,000/microliter without need treatment) (P < 0.05). No significant differences were found in gamma IFN production by PHA-stimulated CD2+ cells between therapy-dependent ATP patients and healthy controls (P < 0.05). However, the production of alpha TNF by PHA-stimulated CD2+ cells from therapy-dependent ATP patients was significantly higher compared to that found in healthy controls (P < 0.05). There were no significant differences in IL-6 production by PHA-stimulated CD2+ cells from ATP patients and healthy controls (P < 0.05). These findings demonstrate abnormal gamma IFN and alpha TNF secretion in purified CD2 cells from ATP patients. The clinical severity of the disease is associated with the altered secretion of these lymphokines by CD2 cells.

Colony-stimulating factors: a new step in clinical practice. Part II

Clinical application of colony-stimulating factors (CSFs) such as recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) are advancing rapidly now that these factors are approved as indicated therapy in patients with chemotherapy-induced neutropenia, patients undergoing autologous bone marrow transplantation (BMT) and patients who develop graft failure after BMT. Novel CSFs are also being explored for potential clinical application in situations not as significantly affected by rhG-CSF or rhGM-CSF. Studies determining unique effects of novel factors, combinations of factors and combinations with peripheral blood progenitor cell fusions which may lead to future clinical applications of CSFs will be reviewed.

Immunobiology of hematopoietic colony-stimulating factors: potential application to disease prevention in the bovine

Colony-stimulating factors are a family of glycoproteins instrumental in regulation of hematopoiesis and inflammation. Clinical effects of various colony-stimulating factors have been reported in murine and human hosts. This review summarizes findings from some clinical trial evaluations of macrophage colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, interleukin-1, interleukin-3, interleukin-4, interleukin-5, interleukin-6, and interleukin-7 administration to other species. These factors stimulate clonal expansion of progenitor cells in the bone marrow, induce differentiation of various cell lineages to a mature phenotype, and, in some cases, enhance the effector activities of immune cells. Each colony-stimulating factor has distinct lineages of bone marrow cells upon which they act, although there is some overlap in lineage activity and synergy between colony-stimulating factors. The close relationship in biological activity among different colony-stimulating factors is also reflected at the genomic level at which genes for some hematopoietic growth factors have been mapped to a region of human chromosome 5. Recently, colony-stimulating factor administration to cattle and its potential application to disease control in bovine preventive medicine programs has been investigated. Data from recent hematological, immunological, and intramammary bacterial (Staphylococcus aureus and Klebsiella pneumoniae) challenge studies in dairy cows are reviewed. These studies, with limited numbers of cows, found that rate of new infections, as well as duration and severity of infection, were reduced by pretreatment of cows with granulocyte-colony stimulating factor. The dose-dependent hematological and immunomodulatory effects of granulocyte colony-stimulating factor administration may explain reduced severity and incidence of mastitis in dairy cows given granulocyte colony-stimulating factor.