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J Gauldie

Publications and source records attributed to J Gauldie.

At least 163 records · Page 9Linked to original sources
PubMed1991

Monocyte-macrophage differentiation induced by human upper airway epithelial cells.

We examined the ability of conditioned medium (CM) generated by human upper airway epithelial (Ep) cells from normal (NN) and inflamed, allergic rhinitis (AR) and nasal polyp (NP) tissues to induce monocytic differentiation of hemopoietic progenitors of the HL-60 myeloid leukemia cell line in vitro. In HL-60 cells cultured in RPMI with 10% FBS, there was differentiation to 0.4 +/- 0.4% monocytic cells. NN-, AR-, and NP-EpCM induced differentiation to 23 +/- 6%, 42 +/- 11%, and 71 +/- 10% monocytic cells, respectively. EpCM also induced isolated peripheral blood nonadherent mononuclear cells to express monocyte/macrophage-specific antigens as detected by immunohistochemistry using FMC-32 monoclonal antibodies (anti-CD14). We also examined the cytokine content of these EpCMs and found that they contained granulocyte/macrophage colony-stimulating factor (GM-CSF): 126 +/- 35, 198 +/- 22, and 489 +/- 118 pg/ml for NN-, AR-, and NP-EpCM, respectively. These CMs also contained granulocyte-CSF (G-CSF) and interleukin-6 (IL-6), but there were no significant differences between normal and inflamed tissue-derived cell supernatants. No macrophage-CSF (M-CSF) was detected in these EpCMs. Recombinant human GM-CSF, G-CSF, and IL-6, alone and in combinations, at doses similar to or greater than those found in the EpCMs, did not induce comparable monocytic differentiation of HL-60 cells. Preincubation of the EpCM with neutralizing anti-GM-CSF, anti-G-CSF, or anti-IL-6 antibodies did not significantly inhibit the monocytic differentiation induced by the EpCM.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Differentiation↗
PubMed1991

Promotion of eosinophil survival by human bronchial epithelial cells and its modulation by steroids.

Accumulation of eosinophils in the bronchial tissue occurs in a variety of inflammatory disorders of the human airway. We asked whether airway epithelial cells released factors that could influence eosinophil survival and thus contribute to accumulation of these cells in the tissues. Using conditioned medium (CM) generated from cultured human bronchial epithelial cells (HBEC), we examined the in vitro survival of eosinophils isolated from human peripheral blood. When cultured in control medium, more than 90% of the eosinophils were dead by day 4. In contrast, culture in HBEC-CM resulted in dose-dependent survival at day 6 of 69 +/- 9.4%, 40.5 +/- 5.9%, and 25 +/- 2% viability with 2, 0.5, and 0.1% HBEC-CM, respectively (n = 4). Granulocyte/macrophage colony-stimulating factor (GM-CSF) was detected in the HBEC-CM by enzyme-linked immunosorbent assay at levels of 22 to 48 pg/ml. Furthermore, preincubation of the HBEC-CM with a neutralizing monoclonal antibody to human GM-CSF completely inhibited this increased survival of eosinophils. Because corticosteroids are potent eosinopenic agents, we also examined the effects of the synthetic steroid budesonide on this system. Budesonide inhibited both spontaneous and interleukin-1 (IL-1)-induced GM-CSF production by cultured HBEC. In addition, preincubation of eosinophils with budesonide caused marked abrogation of the survival induced subsequently with either HBEC-CM or recombinant human GM-CSF. In summary, HBEC can support eosinophil survival via the elaboration of GM-CSF and thus may contribute to the local control of inflammatory cell accumulation. Steroids may modulate this process both by inhibiting cytokine production from HBEC and by a direct effect on eosinophils, preventing their response to cytokines.

Antibodies↗
PubMed1991

Granulocyte/macrophage colony-stimulating factor (GM-CSF) gene expression by eosinophils in nasal polyposis.

Nasal polyposis is a chronic inflammatory condition of the upper airways characterized by infiltration of activated inflammatory cells, particularly eosinophils. Granulocyte/macrophage colony-stimulating factor (GM-CSF) is a cytokine with powerful biologic effects including the regulation of survival, proliferation, and activation of granulocytes as well as differentiation of hemopoietic cells. To examine the potential role of GM-CSF in the pathogenesis of this condition, we investigated gene expression and production of GM-CSF in nasal polyp tissues as well as in the normal nasal mucosa. Immunoreactive GM-CSF was detected by enzyme-linked immunosorbent assay in the 24-h supernatant of nasal polyp tissues placed in culture. By Northern blot analysis and Southern blot analysis following a reverse-transcription polymerase chain reaction using a human GM-CSF cDNA probe, we detected GM-CSF mRNA in nasal polyp tissues, as well as in the tissue from a patient with allergic rhinitis, but not in the normal nasal mucosa. By in situ hybridization using the same probe, cells expressing mRNA specific for GM-CSF were observed in nasal polyp tissues and in the allergic nasal mucosa. In addition, by the combination of in situ hybridization and counterstaining with chromotrope 2R, we demonstrated that approximately 30% of eosinophils infiltrating the polyp tissue express the GM-CSF gene. These results suggest a novel mechanism by which eosinophils may contribute to the pathogenesis of chronic inflammatory diseases such as nasal polyposis, allergic rhinitis, and, by implication, asthma.

Base Sequence↗
PubMed1991

Effects of interleukin-6 and leukemia inhibitory factor on the acute phase response and DNA synthesis in cultured rat hepatocytes.

Human recombinant interleukin-6 (IL-6) and human recombinant leukemia inhibitory factor (LIF) similarly stimulate synthesis of typical acute-phase proteins in the primary rat hepatocyte cultures. LIF is, however, less effective in increasing uptake of alpha-aminoisobutyric acid than IL-6. Antiserum to human IL-6 abolishes induced protein synthesis and amino acid uptake elicited by hrIL-6 but has no effect on the acute-phase response of rat liver cells stimulated by LIF. Both IL-6 and LIF inhibit basal and epidermal growth factor-induced DNA synthesis in rat hepatocytes.

Acute-Phase Proteins↗
PubMed1991

Autocrine activity of interleukin 6 secreted by hepatocarcinoma cell lines.

Among several rat hepatoma cell lines known to secrete interleukin 6 (IL6), the HTC.JZ1 line stands out as a high-level producer. HTC.JZ1 cells were stimulated to secrete up to fourfold increased amounts of IL6 over 24 hours by treatment with lipopolysaccharides (LPS). Both functional IL6 levels, measured as hepatocyte stimulating factor (HSF) activity, and IL6 mRNA concentrations were increased proportionally by exposure to LPS. Similarly, IL6 mRNA was induced by LPS treatment in cultured primary rat hepatocytes. The induction of Il6 mRNA by LPS was inhibited both in primary hepatocyte and hepatoma cell cultures by treatment with the synthetic glucocorticoid dexamethasone, consistent with the known analogous repression of the IL6 gene by dexamethasone in macrophages, monocytes and fibroblasts. IL6 secreted by HTC.JZ1 cells was utilized as an autocrine inducer of endogenous acute phase gene expression: HTC cells expressed constitutive levels of alpha 2-macroglobulin (alpha 2M) mRNA specified by the major rat acute phase gene, the alpha 2M gene, which is known to be regulated by IL6. By contrast, normal rat liver biopsy material and a number of other rat hepatoma cell lines lacked endogenous IL6 production and showed very low to zero expression of endogenous alpha 2M mRNA. Expression of alpha 2M mRNA in HTC.JZ1 cells was inducible by treatment with LPS. The constitutive and the LPS-induced production of alpha 2M mRNA were significantly reduced (up to 50% inhibition) by addition of an anti IL6 serum to the culture medium and removal of the immune complexes. However, complete neutralization of the alpha 2M-inducing HSF activity could not be obtained with anti-IL6 serum alone, probably because HTC.JZ1 cells secrete comparable quantities of a second HSF activity. This activity, the cytokine leukemia inhibitory factor (LIF), is also known to stimulate transcription of the rat alpha 2M gene but was not reactive with anti-IL6 sera. The induction of IL6 mRNA in HTC cells by LPS was regulated at the transcriptional level, as demonstrated by a series of mutagenesis and transfection experiments. Progressive deletion of 5' flanking sequences from the IL6 gene promoter region reduced the basal level, and the LPS-induced promoter activity after transfection into HTC.JZ1 hepatoma cells. IL6 has been shown to act as an autocrine regulator of growth for certain B lymphoid cell lines derived from human multiple myelomas. The results presented here establish that IL6 secreted by certain hepatoma cell lines also acts in an autocrine fashion to induce expression of the endogenous acute phase alpha 2M gene.

Animals↗
PubMed1990

Transforming growth factor-beta and epidermal growth factor modulate basal and interleukin-6-induced amino acid uptake and acute phase protein synthesis in cultured rat hepatocytes.

Rat hepatocytes cultured for 2 days with interleukin-6 show increased synthesis of acute phase proteins and enhanced accumulation of 14C-labelled alpha-aminoisobutyric acid. Transforming growth factor-beta 1 (0.1-10 ng/ml) inhibits whereas epidermal growth factor (1-100 ng/ml) enhances both basal and interleukin-6-induced amino acid uptake by rat hepatocytes with only a slight alteration of acute phase protein synthesis.

Acute-Phase Proteins↗
PubMed1990

IL-6 functions as an exocrine hormone in inflammation. Hepatocytes undergoing acute phase responses require exogenous IL-6.

We have previously shown that IL-6 is the major monocyte- and fibroblast-derived regulator of acute phase protein gene expression and synthesis in hepatocytes in inflammation. Recently, we and others have shown that rat and human hepatoma cells express IL-6 mRNA, and the question arose as to whether normal hepatocytes express IL-6 and whether any such expression occurs under normal physiologic conditions or is seen in inflammation. Poly A+ mRNA of liver from normal rats and from rats undergoing an acute phase response was not positive when probed with cDNA for rat IL-6 under conditions in which macrophage mRNA was strongly positive. We then compared poly A+ mRNA from purified hepatocytes freshly isolated from normal rats--from rats that were undergoing an acute inflammatory response and from freshly isolated normal hepatocytes that had been cultured for 24 h in the presence or absence of dexamethasone (microM). Only the mRNA from normal hepatocytes cultured for 24 h in the absence of any glucocorticoid was obviously positive for IL-6. The increased expression of gamma-fibrinogen mRNA indicated the presence of inflammation. These results confirm the identification of IL-6 as an exogenous hormone for regulating normal hepatic acute phase protein synthesis in inflammation and rules out an autocrine mechanism being active in the liver in normal homeostasis.

Acute-Phase Reaction↗
PubMed1990

Epidermal growth factor and transforming growth factor-beta differently modulate the acute phase response elicited by interleukin-6 in cultured liver cells from man, rat and mouse.

1. Complex effects of principal inflammatory cytokines (IL-6, IL-1, TNF, IFN-gamma) on acute phase protein synthesis and other metabolic processes in cultured liver cells are briefly reviewed. 2. Molecular properties and biological functions of transforming growth factor-beta and epidermal growth factor are compared. 3. The effects of these factors with respect to both amino acid uptake and acute phase protein synthesis are described in detail. The results are found to be different for rat or mouse hepatocytes and human hepatoma cells.

Acute-Phase Proteins↗
PubMed1990

Characterization of nonspecific esterase activity in macrophages and intestinal epithelium of the rat.

We determined the histochemical characteristics of nonspecific esterase in different populations of rat macrophages. The cells included alveolar and peritoneal macrophages recovered by lavage and a mixed cell population obtained by collagenase digestion of the small intestine. The histochemically localized enzyme activity of alveolar and peritoneal macrophages was cytoplasmic, diffuse, and inhibited by sodium fluoride. Both populations were effectively stained using alpha-naphthyl acetate and alpha-naphthyl butyrate as the esterase substrate. When the intestinal cells were examined for activity, a greater percentage of cells showed positive nonspecific esterase than would be predicted by differential counts for macrophages on the basis of morphological criteria. We confirmed, using cell smears and tissue sections, that rat intestinal epithelial cells, a prominent component of the isolated cell population, possessed esterases that react similarly to macrophage esterases with histochemical procedures.

Animals↗
PubMed1990

The acute-phase protein response in parasite infection. Nippostrongylus brasiliensis and Trichinella spiralis in the rat.

During acute inflammation, the mammalian liver responds with increased production and secretion of a series of plasma glycoproteins, collectively termed the acute-phase proteins, resulting from the release at the site of inflammation of polypeptide cytokines, including IL-1 and IL-6, which interact with receptors on hepatocytes and alter gene expression. This attribute of the systemic acute-phase response was studied throughout the course of infection with two nematode parasites in rats. Significant increases in serum haptoglobin, alpha 1-acid glycoprotein and alpha 1-cysteine protease inhibitor were detected coincident with episodes of skin, lung and intestinal pathology during Nippostrongylus brasiliensis, but were not seen during Trichinella spiralis, infection of the rat despite similar intestinal pathology. These changes were seen at both the protein and mRNA levels in the liver. Infection with T. spiralis was not anti-inflammatory, as macrophages from various sites could be induced in vitro to release inflammatory cytokines, and in vivo induction of inflammation by turpentine injection was similar in control and infected animals. However, macrophage populations recovered from animals infected with T. spiralis were not activated. Moreover, intestinal infection alone with intestinal stages of N. brasiliensis also failed to elicit the systemic acute-phase protein response, requiring an explanation involving skin and lung for the acute-phase response during gut inflammation in a primary infection with N. brasiliensis. Taken together, these data suggest that during the intestinal phase of nematode infection, with pathological changes to the gut, the systemic acute-phase response is not elicited through compromise or lack of stimulation of inflammatory cells in the intestine. The systemic parameters of the acute-phase response may not be a component of gastrointestinal pathology.

Acute-Phase Proteins↗
PubMed1990

Alpha 2-macroglobulin and serum preferentially counteract the mitoinhibitory effect of transforming growth factor-beta 2 in rat hepatocytes.

Transforming growth factors-beta 1 and beta 2 (TGF-beta 1 and TGF-beta 2) are potent, multifunctional modifiers of cellular proliferation and differentiation in many cell types. To evaluate factors which may alter the activity of the TGF-beta s during hepatocyte proliferation, we examined the influences of bovine serum and purified bovine or human alpha 2-macroglobulin (alpha 2M) on the mitoinhibitory effects of the TGF-beta in primary cultures of rat hepatocytes. The inhibitory activity of TGF-beta was evaluated by autoradiographic labeling index at 48 hours in hepatocyte cultures exposed to [3H]thymidine between hours 24 and 48 in culture. In the absence of serum or alpha 2M, TGF-beta 1 and TGF-beta 2 were equivalently potent in inhibiting S-phase DNA synthesis in hepatocytes cultured with or without epidermal growth factor. However, bovine serum and purified bovine or human alpha 2M consistently counteracted the mitoinhibitory effects of TGF-beta 2. S-phase DNA synthesis increased five- to six-fold when bovine serum (15%) or alpha 2M (200 micrograms/ml) were included with TGF-beta 2 (0.1 ng/ml) and epidermal growth factor (20 ng/ml). The mitoinhibitory effect of TGF-beta 1 was not influenced by the addition of purified bovine alpha 2M. Human alpha 2M or bovine serum counteracted inhibition by TGF-beta 1 to a lesser extent. [125I]TGF-beta 1 and 125I]TGF-beta 2 formed complexes with purified bovine alpha 2M and serum proteins migrating at identical positions to purified alpha 2M during nondenaturing polyacrylamide gel electrophoresis. However, [125I]TGF-beta 1 associated preferentially with the "fast" migrating form of alpha 2M, whereas [125I]TGF-beta 2 associated with both the "slow" and "fast" migrating forms. Inhibitory activity of TGF-beta 1 and TGF-beta 2 coeluted with alpha 2M in the high molecular weight fractions from a Sephacryl S-200 column. These results support the hypothesis that purified alpha 2M and alpha 2M in bovine serum binds both TGF-betas but preferentially counteracts the mitoinhibitory effect of TGF-beta 2 on rat hepatocytes.

Animals↗
PubMed1990

Regulation of hepatic acute phase plasma protein genes by hepatocyte stimulating factors and other mediators of inflammation.

The hepatic response to systemic injury is characterized by a co-ordinated increase in the expression of several, functionally essential plasma proteins. The factors responsible for initial hepatic stimulation have been identified and include the cytokines IL-1 (interleukin-1), tumor necrosis factor alpha (TNF alpha), IL-6 (interleukin-6), hepatocyte-stimulating factor-III (HSF-III) as well as corticosteroids. The absolute level of expression of the regulated proteins appears to be modulated by the pre-existing hepatic hormonal environment and changes to that environment that occur during acute phase reactions. The specific effects of glucocorticoids, IL-1 and activation of protein kinase C are addressed in this study. In order to predict the phenotype of liver response in acute phase, the hepatic activities of all inflammatory cytokines present must be established. Moreover, it must be recognized that the hepatic environment itself can modulate the anabolic response of the liver to these cytokines. The same considerations are needed when determining the changes seen during the progression to chronic inflammation.

Acute-Phase Proteins↗
PubMed1990

Production of interleukin 6 by hepatoma cells.

Five rat hepatoma cell lines were shown to secrete hepatocyte-stimulating factors (HSFs) capable of inducing a characteristic spectrum of acute phase genes. Three of these lines, but not normal rat livers or livers from rats with an experimentally induced acute inflammation, produced interleukin 6 (IL6) mRNA. An anti-rat IL6 serum was prepared against synthetic peptides derived from the rat IL6 cDNA sequence. This antiserum cleared authentic rat IL6 and a fraction of the HSF activities secreted by the hepatoma cell lines. After concentration of culture supernatants from FTO2B hepatoma cells, IL6 was detected with the anti-IL6 serum by immuno-blot analysis. Biosynthesis of IL6 in the HTC line was demonstrated by metabolic labeling and immunoprecipitation. Secretion of HSF activities by hepatoma cells was increased by serum factors. These data suggest that different rat hepatoma lines each secrete different characteristic sets of HSF activities and establish unambiguously that IL6 is secreted by at least some of these lines.

Acute-Phase Proteins↗
PubMed1990

Characterization of Nippostrongylus brasiliensis infection in different strains of mice.

Five mouse strains, CBA/J, BALB/c, C3H/HeJ, A/J, and C57Bl/6J-bg-bg, all showed similar expulsion kinetics for Nippostrongylus brasiliensis (infective dose = 500 L3). Typically, parasite recovery was maximal on day 2 in the lungs and by day 4 in the small intestine. Few worms (less than 5% infective dose) were recovered on day 14 in all strains. These same mouse strains exhibited immune depression on day 5 of infection with mesenteric lymph node cells (MLN) showing reduced (10-30% normal) IgM, IgG, and IgA responses against heterologous antigen. The intestinal mast cell numbers and tissue histamine levels were examined in CBA/J mice. Mast cell numbers increased (normal = less than 1/villous crypt unit; VCU) from day 5 and peaked on day 12 (greater than 15/VCU). Intestinal histamine levels did not completely correlate with mast cell numbers with maximum concentrations (240 +/- 73 ng/g, 2-fold over normal) reached by day 8. Histamine concentrations in the intestine returned to normal levels by day 20.

Animals↗
PubMed1989

Polycarbonate membranes: a novel surface for solid-phase determinations with utility in field format serological assays.

A dipstick suitable for immunoassay procedures has been developed, and its utility demonstrated by the development of tests for the determination of immunoglobulin levels in newborn bovine blood, and for the detection of bovine antibodies against Brucella abortus. The dipstick is of simple design, consisting of three components: a polycarbonate membrane, an adhesive, and a support material. The polycarbonate membrane is a porous filter material upon which the immunoassay is undertaken. Biomolecules bind to the membrane with sufficient affinity to permit the development of useful immunoassay procedures; however, this membrane exhibits low non-specific binding of reagents. Collectively, these properties make polycarbonate a useful material for solid-phase immunoassay procedures.

Animals↗
PubMed1989

Different preparations of natural and recombinant human interleukin-6 (IFN-beta 2, BSF-2) similarly stimulate acute phase protein synthesis and uptake of alpha-aminoisobutyric acid by cultured rat hepatocytes.

1. Rat hepatocytes were cultured for 2 days in Williams E medium containing 1 microM insulin and dexamethasone. 2. Production of five plasma proteins was determined by electroimmunoassay in the media, and amino acid uptake was measured by [alpha-14C]aminoisobutyric acid accumulation in hepatocytes. 3. Supernatants from rat peritoneal macrophages and IL-6/IFN-beta 2/BSF-2 obtained from four different laboratories similarly stimulated synthesis of fibrinogen, alpha 1-cysteine proteinase inhibitor and alpha 2-macroglobulin, as well as [14C]-accumulation in cultured hepatocytes. 4. It is concluded that IL-6 is the principal hepatocyte stimulating factor responsible for typical features of the acute phase response of liver cells.

Acute-Phase Proteins↗