Interleukin-4 regulates mRNA accumulation of macrophage-colony stimulating factor by fibroblasts: synergism with interleukin-1 beta

In vivo effects of IL-4, IL-10, and amifostine on cytokine production in patients with acute myelogenous leukemia

Both IL-4 and IL-10 have been shown in vitro to inhibit leukemia cell secretion of IL-1beta, GM-CSF, and TNFalpha, and increase leukemia cell release of IL-1ra. In this study, we have investigated the in vivo effects of IL-4, IL-10, and amifostine on cytokine production in patients with acute myelogenous leukemia (AML). Serum IL-1ra, IL-1beta, TNFalpha, GM-CSF, and SCF levels were measured in AML patients who received IL-4, IL-10, or amifostine. No significant changes in the serum levels of IL-1ra, IL-1beta, TNFalpha, GM-CSF, and SCF were found in AML patients who received amifostine. Both IL-4 and IL-10 were found to increase serum IL-1ra. This data is in accord with the in vitro studies. However, IL-4 increased serum GM-CSF levels and IL-10 increased serum IL-1beta and TNFalpha levels. These in vivo effects of the two cytokines differ from their in vitro effects. Despite the similar effects of IL-4 and IL-10 on cytokine production by AML cells in vitro, different effects were observed in AML patients in vivo. IL-4 increased serum SCF levels, whereas IL-10 decreased serum SCF levels. IL-4 increased serum GM-CSF levels, whereas IL-10 had no effect on them. Although IL-10 increased serum IL-1beta and TNFalpha levels, IL-4 had no effect on them. These findings indicate that the in vitro effects of IL-4 and IL-10 do not necessarily reflect their in vivo effects, and that the complex effects of the two cytokines on serum cytokine levels make it difficult to predict their therapeutic potential.

Effect of cytokines and growth factors on the macrophage colony-stimulating factor secretion by human bone marrow stromal cells

We have investigated the effect of growth factors, inflammatory and anti-inflammatory cytokines on the macrophage colony-stimulating factor (M-CSF) secretion by cultured human bone marrow stromal cells. Their production of M-CSF cultured in serum-free medium is enhanced in a time-dependent manner in response to tumour necrosis factor (TNF-)alpha and interleukin (IL-)4 but not to IL-1, IL-3, IL-6, IL-7, IL-10, SCF, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, bFGF and transforming growth factor (TGF-)beta. The co-addition of IL-4 and TNF-alpha has a greater than additive effect on the secretion of M-CSF suggesting that they act synergistically. The anti-inflammatory molecules IL-10 and TGF-beta have no effect on the TNF-alpha-induced M-CSF synthesis by marrow stromal cells. In conclusion TNF-alpha and IL-4 are potent stimulators of the M-CSF synthesis by human bone marrow stromal cells, a result of importance regarding the role of M-CSF in the proliferation/differentiation of mononuclear-phagocytic cells and the role of marrow stromal cells as regulators of marrow haematopoiesis.

A phase I and pharmacokinetic study of subcutaneously-administered recombinant human interleukin-4 (rhuIL-4) in patients with advanced cancer

PURPOSE

To investigate the pharmacokinetics and tolerability of recombinant human interleukin-4 (rhuIL-4), administered by daily subcutaneous injection, in patients with advanced cancer.

PATIENTS AND METHODS

Fourteen patients with advanced cancer treated with rhuIL-4 at escalating dose levels of 0.25, 1.0 and 5.0 microg/kg/day, on days 1, 8-17, and 28-57. The primary endpoints of the study were toxicity of rhuIL-4 and the determination of the pharmacokinetics of rhuIL-4 when given by subcutaneous injection. Secondary endpoints included effects on blood counts, hematopoietic cell precursors, and various immunologic parameters.

RESULTS

rhuIL-4 was well tolerated at all three dose levels. Detectable serum levels of IL-4 were found in patients at the 1.0 and 5.0 microg/kg/day dose levels. Peak serum IL-4 levels were achieved about 2 h after injection and IL-4 was still detectable 8 h after injection. No grade 4 toxicities were observed and grade 3 toxicities were confined to fever, headache and raised hepatic alkaline phosphatase. No consistent hematological or immunologic effects were observed. Although therapeutic efficacy was not an endpoint, one complete response (Hodgkin's disease) was observed. One patient with chronic lymphocytic leukemia progressed on therapy.

CONCLUSION

rhuIL-4 up to 5.0 microg/kg/day is well tolerated when given by subcutaneous injection. Biologically relevant serum IL-4 levels can be achieved and sustained for at least 8 h after a single injection.

Transcription and translation of CSF-1 in the dental follicle

The dental follicle, a loose connective tissue sac which surrounds the unerupted tooth, is required for eruption to occur. Injection of colony-stimulating factor-1 (CSF-1) will accelerate molar eruption in rats, as well as stimulate tooth eruption in osteopetrotic rats. Utilizing in situ hybridization and reverse- transcription polymerase chain-reaction techniques, we show here that CSF-1 mRNA is present in vivo in the dental follicle of the first mandibular molar of the rat. Analysis of the molars from day 0 through day 10 post-natally demonstrates that the maximal expression of CSF-1 mRNA is at day 3 post-natally. Immunostaining also reveals that the CSF-1 mRNA is translated, with immunostaining for the CSF-1 itself, being heavy in early post-natal days and absent by day 9 postnatally. In view of the fact that there is a maximal influx of mononuclear cells (monocytes) into the dental follicle at day 3 post-natally--an influx which increases the numbers of osteoclasts needed to form a tooth eruption pathway--it is probable that the maximal expression of CSF-1 mRNA by day 3 post-natally contributes to this monocyte influx. Thus, this study establishes a relationship among a molecule (CSF-1), cell (monocyte), and tissue (dental follicle) that appear to play a major role in tooth eruption.

Messenger RNA decay of macrophage colony-stimulating factor in human ovarian carcinomas in vitro

OBJECTIVE

Recently, the importance of the macrophage colony-stimulating factor (CSF-1) and its receptor (encoded by the c-fms proto-oncogene) in patients with epithelial ovarian cancer has been recognized. Overexpression of CSF-1 denotes poor prognosis. Macrophage colony-stimulating factor may be one of a group of inflammatory cytokines, whose 3' untranslated region (UTR) contains AU-rich stretches and whose expression may be largely dependent on mRNA decay. The purposes of this study were to investigate the effect of protein synthesis inhibition on CSF-1 transcript expression, to help determine whether there is a role for labile intermediary proteins in the regulation of CSF-1 expression, and to explore the transcriptional or post-transcriptional mechanisms that could underlie such overexpression of CSF-1 transcripts by protein synthesis inhibitors. Although regulation of CSF-1 gene expression has been investigated in hematopoietic cells, such studies have not been carried out in any epithelial cancer.

METHODS

Northern blot analyses for CSF-1 expression were performed on total cellular RNA extracted from primary and established ovarian cancer cell lines in the absence or presence of proteins synthesis inhibitors with different modes of action. The probe for the AU-rich exon 10 of CSF-1 was prepared by amplification of the terminal 143 bp of the 3' UTR of human CSF-1 by polymerase chain reaction. Transcription rates were assessed in the presence or absence of cycloheximide (CH) in nuclei of ovarian cancer cells by run-off analyses. The effect of CH on CSF-1 mRNA half-life was measured by actinomycin D chase experiments in SKOV3 cells.

RESULTS

We demonstrate that CSF-1 mRNA was expressed by all of a panel of primary and established ovarian cancer cell lines. There are at least three CSF-1 transcripts expressed by ovarian cancer cells; we demonstrate that the 4.2-kb CSF-1 transcript contains exon-6 sequences, which are spliced from the 3.4- and 1.9-kb transcripts, whereas both the 4.2- and 3.4-kb CSF-1 transcripts contain the 3' AU-rich exon 10. Treatment with several different protein synthesis inhibitors resulted in marked overexpression of CSF-1 transcript levels, suggesting a potential role for labile proteins in the regulation of CSF-1 expression. The predominant effect of CH is on the two CSF-1 transcripts that contain exon 10. Although CH does not change the rate of CSF-1 gene transcription, measurement of CSF-1 mRNA stability reveals a prolongation of CSF-1 transcript half-life by CH from 4.5 hours to significantly greater than 6 hours in ovarian cancer cells.

CONCLUSIONS

Augmented CSF-1 transcript stability underlies the marked overexpression of CSF-1 seen with protein synthesis inhibitors. Our results suggest the involvement of a labile regulatory protein that contributes to CSF-1 mRNA decay in ovarian cancer cells. Our data suggest further that exon 10 (not the spliced exon-6 sequences) of the CSF-1 transcript may contain an instability determinant.

Value of DNA analysis with multiple DNA probes for the detection of hemophilia A carriers

Detection of hemophilia carriers is an important issue and should be addressed with great care. The allelic frequencies of three intragenic probes (Bcl I for probe p114.12, Xba I for probe p482.6, and Bgl I for probe C) and one linked probe (Bgl II for probe DX 13) are reported, together with their diagnostic yield singly and in combination. In this series, 725 individuals (405 females) in 156 families were analyzed for restriction fragment-length polymorphisms. A total of 255 females (63%) were found to be informative for their carrier state with one or more probes. The most informative intragenic probe was p482.6 (useful in 49% of informative females). The most informative probe was DX 13 (useful in 59% of informative females), but this is a linked probe that carries a 5% risk of cross-over. By the use of probes p114.12, p482.6, and DX 13, almost 98% of all the informative females could be detected. In about 71% of families with a family history and a known carrier, prenatal diagnosis was feasible.

Production of macrophage colony-stimulating factor (M-CSF) by human articular cartilage and chondrocytes. Modulation by interleukin-1 and tumor necrosis factor alpha

A specific radioimmunoassay was employed to demonstrate that human articular cartilage and chondrocyte monolayers in organ and cell culture, respectively, produce macrophage colony-stimulating factor (M-CSF) in response to stimulation with interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor alpha (TNF alpha) and TNF beta. Optimum doses were 10-100 U/ml for IL-1 (0.06-0.6 nM IL-1 alpha; 0.02-0.2 nM IL-1 beta) and 1-10 nM for TNF alpha. Low levels of M-CSF were observed in the supernatants of nonstimulated cultures while increased levels of M-CSF in response to IL-1 alpha and TNF alpha were detected following 2 h exposure to the cytokines. IL-1 alpha and TNF alpha did not show synergy for the production of M-CSF when both cytokines were added to cultures. Actinomycin D and cycloheximide inhibited both the basal and IL-1 alpha-induced production of M-CSF, suggesting a requirement for de novo RNA and protein synthesis. Cytokine-induced M-CSF production was also inhibited by the antiinflammatory corticosteroid, dexamethasone, but not by the cyclooxygenase inhibitor, indomethacin. The cytokines IL-4, IL-6, platelet-derived growth factor, leukemia inhibitory factor, transforming growth factor-beta and interferons -alpha and -gamma, each had little or no effect on M-CSF levels, while basic fibroblast growth factor, lipopolysaccharide, and retinoic acid were each weak stimuli. We propose that chondrocyte M-CSF production in response to IL-1 and TNF alpha, and the concurrent destruction of cartilage by these cytokines, could provide a mechanism for the chronic nature of rheumatoid disease.

Human recombinant interleukin-4 induces proliferation and interleukin-6 production by cultured human skin fibroblasts

The effect of human recombinant interleukin-4 (hrIL-4) on normal human adult dermal fibroblasts in terms of proliferation and IL-6 production was studied. Fibroblasts were exposed to different concentrations of IL-4 for various periods of time. Proliferation was measured using a [3H]thymidine incorporation assay. IL-6 production was measured at the transcriptional, protein, and functional levels by Northern blot analysis, radioimmunoassay, and B9 bioassay, respectively. Our results show that hrIL-4 significantly stimulated (two- to fivefold) fibroblasts to increase the incorporation of [3H]thymidine in a dose- and time-dependent manner. However, hrIL-1, hrIL-2, hrIL-5, or hrTNF alpha, at the same concentration (100 U/ml) and for the same time period (4 days), did not. In addition, IL-4 significantly induced (four- to eightfold) the production of immunoreactive and biologically functional IL-6. However, IL-4 was not as potent an inducer of IL-6 as IL-1. The IL-4-induced IL-6 production was dose and time dependent and was due, at least in part, to a dramatic increase in the steady-state levels of IL-6 mRNA. This is the first report describing the ability of IL-4 to activate human dermal fibroblasts in terms of proliferation and IL-6 production.

Regulation of gene expression of macrophage-colony stimulating factor in human fibroblasts by the acute phase response mediators interleukin (IL)-1 beta, tumor necrosis factor-alpha and IL-6

Fibroblasts constitute a major element of the bone marrow stroma. They play a pivotal role in blood cell development by providing the scaffolding required for cellular organization and tissue cohesion and by producing soluble molecules including colony stimulating factors (CSFs) and various interleukins regulating hematopoiesis. Our data demonstrate that the acute phase response mediators interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha and IL-6 which are abundantly produced by activated monocytes, enhance levels of macrophage-colony stimulating factor (M-CSF) in fibroblasts by both transcriptional and post-transcriptional mechanisms. The action of these proteins to induce M-CSF transcript levels was dependent on synthesis of new proteins and was not mediated by protein kinase C (PKC) stimulation as depletion of cellular PKC pools by prolonged exposure of fibroblasts to phorbolester TPA did not prevent factor induced synthesis of M-CSF transcripts. However, blockade of PKC by the isoquinoline sulfonamide derivative H7 and thus inhibition of phosphorylation was associated with augmentation of the fibroblasts response to TNF-alpha and IL-6.