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J W Coleman

Publications and source records attributed to J W Coleman.

At least 19 recordsLinked to original sources
PubMed1996

Selectivity of IgE responses, mast cell sensitization, and cytokine expression in the immune response of Brown Norway rats to chemical allergens.

Sensitizing chemicals can induce various types of allergic disease, including contact dermatitis and occupational asthma. In the present study we have examined the nature of the immune response induced in Brown Norway (BN) rats by oxazolone (OX), a potent contact allergen, and by trimellitic anhydride (TMA), a chemical known to cause sensitization of the respiratory tract and occupational asthma. BN rats were exposed topically to either OX or TMA at doses selected to achieve similar levels of proliferative activity by draining LNC. Both chemicals stimulated hapten-specific IgG antibody responses, but only TMA induced specific IgE antibody, an increase in total serum IgE and active sensitization of mast cells. Draining LNC from OX-treated rats expressed elevated IFN-gamma mRNA, whereas those from TMA-treated rats expressed elevated IL-5 mRNA compared to controls. Furthermore, Con A-activated draining LNC from rats exposed to TMA, but not OX, released significantly increased concentrations of IL-4. In conclusion, different chemical allergens can induce in the BN rat divergent patterns of IgE response and cytokine expression.

Allergens↗
PubMed1996

A comparative study of peritoneal mast cells from mutant IL-4 deficient and normal mice: evidence that IL-4 is not essential for mast cell development but enhances secretion via control of IgE binding and passive sensitization.

IL-4 enhances the growth and secretory function of mouse connective tissue type mast cells in vitro. To examine further the mast cell regulatory role of IL-4 we compared certain phenotypic and functional characteristics of peritoneal mast cells from mutant IL-4 deficient (IL-4(-/-)) or normal wildtype (IL-4(+/+)) mice. No differences were seen between mast cells from the two types of mouse in terms of numbers, histamine content, cell size, ultrastructure and number and size of granules. Mast cells from IL-4 deficient or wildtype mice responded equally to specific IgE/antigen and IL-4. However, Fc epsilon RI of IL-4(-/-) (in contrast to wildtype) mast cells were not pre-loaded with IgE, which would be expected to facilitate passive sensitization. Moreover, the in vitro total IgE binding capacity of mutant mast cells was significantly less than that of wildtype. Further in vitro experiments showed that IL-4 selectively enhanced IgE/antigen- rather than anti-IgE-induced degranulation from normal mast cells, and this effect was accompanied by an IL-4 induced increase in IgE binding capacity. In conclusion, IL-4 is not essential for peritoneal mast cell growth and exocytosis but regulates secretion via control of IgE binding and sensitization.

Animals↗
PubMed1996

Dexamethasone or cyclosporin A inhibits stem cell factor-dependent secretory responses of rat peritoneal mast cells in vitro.

Stem cell factor (SCF) is potent activator of degranulation of rat peritoneal mast cells in vitro and may promote mast cell activation under certain circumstances in vivo. In this study we report that the anti-inflammatory glucocorticoid dexamethasone (DEX) and the immunosuppressive cyclosporin A (CsA) are both effective inhibitors of SCF-induced degranulation of rat peritoneal mast cells in vitro, measured as release of serotonin (5-HT). Of the two drugs, DEX was the more potent with near maximal inhibition reached at 10(-8) M, whereas a graded inhibition was seen with CsA in the range 10(-8)-10(-6) M. DEX was equally effective in inhibiting the release of 5-HT induced by either SCF or anti-IgE, but was less effective in inhibiting release induced by compound 48/80 or calcium ionophore A23187. CsA produced a similar degree of inhibition of degranulation induced by SCF, anti-IgE or ionophore, but was without effect on the response to compound 48/80. Neither DEX nor CsA had any significant effect on mast cell surface expression of the SCF receptor or IgE antibody. We conclude that both DEX and CsA inhibit components of the secretion-coupling pathways that are triggered following either SCF receptor engagement or cross-linking of IgE, but that these drug differentially influence mast cell secretion induced by compound 48/80 or the calcium ionophore A23187.

Animals↗
PubMed1995

The effects of mercuric chloride on growth, cytokine and MHC class II gene expression in a human leukemic mast cell line.

We have examined the effects of mercuric chloride (HgCl2) on growth and IL-4, IL-8, TNF-alpha and MHC class II gene expression in the HMC-1 human leukemic mast cell line. Proliferation, measured by [3H]thymidine incorporation or production of a formazan product (MTT assay), was substantially inhibited by HgCl2 at concentrations of 10(-6) M and above. Inspection of the DNA by agarose gel electrophoresis from HgCl2-treated cells revealed that it was intact, indicating inhibition of DNA synthesis, but not denaturation. HgCl2 inhibited expression of mRNA for IL-8, TNF-alpha and MHC class II at 4 x 10(-6) M and inhibited expression of IL-4 mRNA at 8 x 10(-6) M and above. At a concentration of 10(-5)M, HgCl2 almost completely blocked mRNA expression for IL-4, IL-8, TNF-alpha and MHC class II, but produced negligible inhibition of expression of mRNA encoding the housekeeping gene beta-actin, thus demonstrating selective toxicity for the cytokine and MHC class II genes studied. Pre-exposure of the cells to human recombinant IL-4 prior to treatment with HgCl2 had no effect on expression levels of any of the genes examined. The effects seen in this study are consistent with previous reports showing immunotoxic effects of HgCl2 on other cell types, therefore, the HMC-1 mast cell line may prove useful in further studies of mast cell cytokine gene expression and the mechanisms involved in cytokine gene toxicity.

Base Sequence↗
PubMed1995

Compounds that induce autoimmunity in the brown Norway rat sensitize mast cells for mediator release and interleukin-4 expression.

Brown Norway (BN) rats given mercuric chloride (HgCl2), gold (Au) salts or D-penicillamine develop a T helper 2 (Th2) cell-mediated autoimmune syndrome. The recent observation of tissue injury within 24 h of HgCl2 treatment suggested the involvement of a non-T cell. We therefore examined the effect of these compounds on rat mast cells in vitro. Incubation of BN rat peritoneal mast cells with HgCl2 enhanced the release of serotonin in response to IgE cross-linking agents. Mast cells from Lewis rats, a strain not susceptible to the autoimmune syndrome in vivo, were affected to a lesser extent. The effect was observed with purified BN mast cells, suggesting a direct action. Similar effects were seen with D-penicillamine in the presence of copper ions, a combination that produces hydrogen peroxide, and Au. HgCl2 caused significant induction of interleukin (IL)-4 mRNA in mast cells from BN, but not Lewis rats. The data demonstrate a novel enhancing effect of a number of compounds on mast cell mediator release, and an inducing effect of HgCl2 on mast cell IL-4, expression. These findings are consistent with our hypotheses that mast cells may contribute to early tissue injury, and also, via production of IL-4, may initiate and/or augment, the Th2 response in the BN rat model of chemical-induced autoimmunity.

Animals↗
PubMed1995

Activation and hapten inhibition of mast cells sensitized with monoclonal IgE anti-penicillin antibodies: evidence for two-site recognition of the penicillin derived determinant.

We utilized an in vitro mast cell activation assay and hapten inhibition of mediator release to characterize the fine specificity of two IgE anti-penicillin monoclonal antibodies (mAb). Cultured mouse mast cells were passively sensitized with IgE mAb anti-benzylpenicillin (BP) or anti-amoxicillin (AX) and challenged with a range of penicillin-human serum albumin (HSA) conjugates. Mast cells sensitized with IgE anti-BP degranulated in response to BP-HSA, but not to AX-HSA or ampicillin(AMP)-HSA, whereas mast cells sensitized with IgE anti-AX responded to AX-HSA but not to BP-HSA or AMP-HSA. Because BP, AX and AMP differ chemically only in the structure of their side chain, these results show that this part of the drug molecule is essential for recognition by IgE antibody. Unexpectedly, although IgE-sensitized mast cells responded to only one penicillin in protein-conjugated form, antigen-induced degranulation was inhibited by the monomeric derivative of more than one penicillin. Furthermore, antigen activation of IgE-sensitized cells was inhibited, although less potently, by haptens representative of the specific penicillin side chain or the binuclear portion of the drug molecule. These patterns of recognition and hapten inhibition were also seen in solid-phase enzyme-linked immunosorbent assay (ELISA), although all haptenic inhibitors were approximately 100 times less potent in the ELISA compared to the mast cell assay. To explain these findings we propose a model in which IgE binding to penicillin-protein antigen is dependent on recognition of two distinct epitopes on the drug molecule: the first comprising the side chain, and the second comprising the binuclear portion plus the proximal region of the side chain. This two-site hypothesis provides a generally applicable model of antibody recognition of penicillins and provides a rational basis for understanding the specificity and cross-reactivity of IgE-mediated allergic reactions to penicillins.

Animals↗
PubMed1995

Rat connective tissue-type mast cells express MHC class II: up-regulation by IFN-gamma.

We studied MHC class II gene expression and its regulation by IFN-gamma in purified rat peritoneal connective tissue-type mast cells. Mast cells were cultured with or without recombinant rat IFN-gamma (70 ng/ml) for 48 hr and analyzed by RT-PCR for expression of mRNA encoding MHC class II and by fluorescence flow cytometry for surface expression of MHC class II protein product. Levels of MHC class II mRNA and cell-surface protein product in untreated mast cells remained constant throughout the culture period but increased progressively after treatment with IFN-gamma such that by 48 hr levels were significantly greater than those in untreated cells. Dual labeling confirmed that MHC class II product was coexpressed with IgE (a mast cell marker). To conclude, rat connective tissue-type mast cells express mRNA and surface product for the MHC class II gene which can be up-regulated by IFN-gamma.

Animals↗
PubMed1995

An analysis of beta-lactam-derived antigens on spleen cell and serum proteins by ELISA and Western blotting.

Penicillins and related beta-lactam antibiotics are known to conjugate to proteins to generate potentially antigenic (haptenic) determinants. In the present study, we used a rabbit polyclonal antibody raised against benzylpenicillin (BP) to investigate the capacity of six penicillins and one cephalosporin to generate haptenic groups in vitro on cultured mouse spleen cells and on serum proteins in the culture medium. All of the drugs tested, namely, BP, amoxicillin (AMX), ampicillin (AMP), cephalothin (CEP), cloxacillin (CLX), flucloxacillin (FLX), and phenoxymethylpenicillin (PMP) generated antigens in a concentration-dependent manner on cell and serum proteins, which could be detected by ELISA, although antigens generated by BP, CEP, FLX, or PMP in either cell- or serum-conjugated form were more readily detected than those generated by AMX, AMP, or CLX. Western blot analysis revealed that BP-derived antigens were generated relatively slowly on cell proteins (maximum binding was not yet reached after 8 h), compared to serum proteins (maximum binding within 1 h). BP, CEP, and PMP all generated similar distinctive patterns of immunostaining of electrophoresed cell or serum proteins which did not reflect the relative abundance of different proteins as revealed by Coomassie brilliant blue staining. FLX, CLX, AMP, and AMX did not generate antigens that could be detected on Western blots. In conclusion, we have shown that various beta-lactam antibiotics generate antigens on cell and serum proteins that can be detected and characterized immunochemically with polyclonal antiserum. Further application of these methods may offer potential for further identification of immunologically relevant cellular and serum antigens generated by these drugs.

Animals↗
PubMed1995

Induced expression of mRNA for IL-5, IL-6, TNF-alpha, MIP-2 and IFN-gamma in immunologically activated rat peritoneal mast cells: inhibition by dexamethasone and cyclosporin A.

We examined the capacity of purified rat peritoneal connective tissue-type mast cells (PMC) to express mRNA for several cytokines. Stimulation of PMC with anti-IgE for 4 hr induced the expression of mRNA encoding interleukin-5 (IL-5), IL-6, tumour necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2) and interferon-gamma (IFN-gamma). Unstimulated PMC expressed detectable mRNA for TNF-alpha but not for the other four cytokines. Incubation of PMC with cyclosporin A (CsA) or dexamethasone (DEX), each at 10(-6) M for 24 hr, significantly inhibited the induced expression of mRNA for each of the five cytokines, and also inhibited release of biologically active TNF-alpha. Throughout these experiments mRNA levels of the housekeeping gene G3PDH were not altered by stimulation with anti-IgE or incubation with CsA or DEX. We conclude that immunological activation of rat PMC induces gene expression of several cytokines and that expression of these genes can be inhibited by immunosuppressive drugs.

Animals↗
PubMed1995

IL-4 enhances IL-3 and IL-8 gene expression in a human leukemic mast cell line.

We examined the capacity of interleukin (IL)-4 to induce or enhance the expression of certain cytokines in resting and activated cells of the HMC-1 human leukemic mast cell line. The HMC-1 mast cells were cultured with or without recombinant human IL-4 and then activated with the calcium ionophore ionomycin. Stimulation of non-IL-4-treated cells with ionomycin (10 microM) for periods of 30 min to 8 hr induced expression of mRNA encoding IL-3, IL-4 and IL-8 but was without effect on levels of mRNA for tumour necrosis factor (TNF)-alpha or beta-actin. Culture of the cells with IL-4 (100 ng/ml) for 24 hr led to a small increase in resting levels of mRNA for IL-3 and IL-8 but not for IL-4, TNF-alpha or beta-actin. More notably, the IL-4 treatment produced a pronounced elevation of mRNA for IL-3 and IL-8 when the cells were subsequently activated with ionomycin. The IL-4 treatment produced a negligible effect on IL-4 mRNA, and no effect on TNF-alpha or beta-actin mRNA levels in ionomycin-activated cells. Quantitation of cDNA by competitive polymerase chain reaction (PCR) revealed that the IL-4 treatment produced a sixfold increase in ionomycin-induced levels of cellular IL-3 mRNA, a fourfold increase in induced IL-8 mRNA and less than a twofold increase in induced IL-4 mRNA. The IL-4 treatment led to a 15- to 20-fold increase in ionomycin-induced secretion of IL-3 product and a doubling of induced IL-8 product. These effects of IL-4 were not associated with increased mast cell numbers. We conclude that IL-4 alone is a weak activator of IL-3 and IL-8 gene expression in mast cells, but is able to enhance activation signals in stimulated mast cells leading to transcription and secretion of these two cytokines.

Base Sequence↗
PubMed1995

Stem-cell factor, the kit ligand, induces direct degranulation of rat peritoneal mast cells in vitro and in vivo: dependence of the in vitro effect on period of culture and comparisons of stem-cell factor with other mast cell-activating agents.

We report that stem-cell factor (SCF), the ligand of the receptor encoded by the c-kit proto-oncogene, is a potent activator of degranulation of rat peritoneal mast cells in vitro and in vivo. Freshly isolated, purified mast cells were relatively unresponsive to SCF (4-500 ng/ml) but progressively acquired responsiveness to this agent, assessed as serotonin (5-HT) release, during 48 hr culture in vitro. The cells showed a similar kinetic pattern of acquisition of responsiveness to anti-IgE but responded fully to calcium ionophore A23187 or compound 48/80 regardless of time in culture. Acquisition of mast cell responsiveness to SCF or anti-IgE was not due to serum factors or to recovery from the Percoll purification procedure. During culture, mast cell expression of the SCF receptor (SCFR) increased, and this may explain in part the increased responsiveness to SCF. However, surface IgE expression remained constant, and the increased responses to anti-IgE therefore must reflect changes in components of the secretion-coupling pathway that are activated subsequent to IgE cross-linking. The unresponsiveness of freshly isolated peritoneal mast cells to SCF or anti-IgE does not reflect a state of in vivo unresponsiveness, as peritoneal mast cells degranulated in vivo in response to these agents. We conclude that in terms of their responsiveness to SCF or anti-IgE, cultured tissue mast cells may be more representative than freshly isolated mast cells of secretory function in vivo, and therefore may be more appropriate for physiological or pharmacological studies of SCF- or IgE-dependent secretory responses.

Animals↗
PubMed1994

Cytokine-mast cell interactions: relevance to IgE-mediated chemical allergy.

Recent work has shown that certain cytokines (inducible secreted proteins) are potent regulators of mast cell development and secretory function. We know also that sensitization of mice to chemical allergens induces T cell-dependent immune responses in which cytokines play an important role. Combining these observations, we postulate that in vivo T cell responses might influence, via the production of cytokines, the behaviour of mast cells in situ. In support of this hypothesis we have found that mast cells isolated from chemical allergen-sensitized mice show enhanced responsiveness to IgE-dependent activation in vitro. This effect is seen with chemical allergens that are either contact or respiratory sensitizers in man. Although respiratory and contact allergens cannot be distinguished according to their ability to modulate mouse mast cell function in vivo, they can be separated on the basis of their differential ability to induce specific IgE-dependent mast cell sensitization. In conclusion, the mouse may offer a useful model for investigating and predicting the potential of chemicals to act as mast cell promoting agents and/or respiratory sensitizers.

Allergens↗
PubMed1994

A western blot approach to detection of human plasma protein conjugates derived from D-penicillamine.

OBJECTIVES: To develop and apply an immunochemical approach to the study of drug-plasma protein conjugates derived from the anti-arthritic drug D-penicillamine (DP). METHODS: An antiserum with specificity for protein-conjugated DP was raised in a rabbit. Plasma samples from patients receiving DP or from incubations of isolated normal plasma with DP were analysed for DP-derived conjugates by Western blotting using the anti-drug antibody. RESULTS: A single DP-positive protein band was detected in plasma samples from 15/16 patients with rheumatoid arthritis receiving DP but in none of 20 patients of similar disease status who had not taken DP. The positive band appeared in patients' plasma during the course of treatment with DP. It was seen under nonreducing but not reducing conditions indicating that the drug is disulphide linked to the protein. The drug-modified protein migrated to a position intermediate between the trailing edge of albumin and the leading edge of transferrin (both non-reduced) suggesting a molecular weight of between 66 and 77 kDa. Incubations of normal human plasma, but not purified albumin or transferrin, with low concentrations of DP generated the same distinct band plus several less intense DP-positive bands. CONCLUSIONS: Drug-plasma protein conjugates derived from DP in vivo and in vitro can be detected immunochemically by the Western blot method. Theories of DP immunotoxicity have implicated antigenicity of the drug, but this is the first immunochemical demonstration of a potential DP-derived antigen in human plasma. The method we describe may have application to studies of the relationship between DP antigenicity and toxicity.

Arthritis, Rheumatoid↗
PubMed1994

Mast cell recovery following chronic treatment with compound 48/80.

Histochemical and functional properties of mast cells (MC) in Brown Norway rats recovering from chronic treatment with the MC secretagogue compound 48/80 were examined. In the skin, treatment for 5 days with compound 48/80 resulted in a marked decrease in MC subpopulations defined by differential alcian blue/safranin staining. Both safranin-positive connective tissue MC and alcian blue staining MC were reduced in number. This was accompanied by significant decreases in skin histamine and rat MC serine protease I contents and a loss of specific IgE-mediated passive cutaneous anaphylaxis (PCA) activity. The PCA reaction did not return to normal before 2 months after stopping treatment and only when the numbers of safranin-positive connective tissue MC and skin histamine content reached pretreatment levels. The subepidermal alcian blue staining MC not eliminated by the compound 48/80 treatment were formalin resistant (unlike alcian blue staining mucosal MC of the intestine) and apparently played no role in the PCA response. MC numbers, histamine levels, and rat MC serine protease I content of the tongue were similarly decreased by compound 48/80. In contrast, mucosal MC of the gut were unaffected by the secretagogue treatment.

Alcian Blue↗
PubMed1994

Interactions of IFN-gamma with IL-3 and IL-4 in the regulation of serotonin and arachidonate release from mouse peritoneal mast cells.

We have examined the interactions between interferon-gamma (IFN-gamma), interleukin-3 (IL-3) and interleukin-4 (IL-4) in the regulation of IgE/antigen-induced secretory responses of mouse peritoneal mast cells. The cytokines were added either alone or in various combinations to cultured mast cells sensitized passively with IgE antibody. In experiments with unfractionated peritoneal cells (containing approx. 1% mast cells), IL-3 and IL-4 enhanced in an additive manner antigen-induced release of serotonin (5-HT), while IFN-gamma inhibited release regardless of whether IL-3 and/or IL-4 were present. In experiments employing mast cells purified to > 90%, IL-3 and IL-4 retained their enhancing activities whereas the inhibitory effect of IFN-gamma was considerably diminished. Nevertheless, IFN-gamma still inhibited significantly IL-4-enhanced secretion. The effects of IL-3 and IL-4 +/- IFN-gamma on arachidonate release were identical to those seen for 5-HT release, indicating that the secretion of both preformed mediators and newly synthesized eicosanoids is regulated in a similar way by these cytokines.

Animals↗
PubMed1993

Regulation of mouse peritoneal mast cell secretory function by stem cell factor, IL-3 or IL-4.

We examined whether three cytokines that promote mouse mast cell development, the c-kit ligand stem cell factor (SCF), IL-3, or IL-4, also can directly stimulate or modulate mouse peritoneal mast cell (PMC) mediator release. Challenge of purified PMC with rat rSCF164 at 20 to 100 ng/ml for 30 min induced a modest release of serotonin (5-HT), whereas IL-3 or IL-4 did not directly stimulate 5-HT release. Experiments in which PMC were exposed to each cytokine for 15 min, and then to DNP-HSA Ag or anti-IgE antibody for a further 15 min, showed that SCF, but not IL-3 or IL-4, had an additive effect on the 5-HT release induced by either of the IgE cross-linking agents. In longer term experiments, SCF (0.16 to 500 ng/ml), IL-3 (2.5 to 100 ng/ml), or IL-4 (0.06 to 2.5 ng/ml) was added to peritoneal cell cultures for 48 h, during which the cells were passively sensitized with IgE anti-DNP antibody. Incubation of either unfractionated or highly purified PMC preparations with each of the three cytokines resulted in a concentration-related increase in 5-HT release upon subsequent challenge of the cells with DNP-HSA Ag. However, after pretreatment of peritoneal cells for 48 h with each cytokine, only IL-4 (10 ng/ml) enhanced release of 5-HT induced by calcium ionophore A23187 (0.25 microM); IL-3 (100 ng/ml) had no effect, whereas SCF (100 ng/ml) significantly inhibited ionophore-induced release. Although IL-3 or SCF up-regulate responsiveness to IgE-dependent stimuli, we detected no effect of these cytokines on the binding of [125I]IgE to PMC. This suggests that the enhancing effects of SCF or IL-3 on IgE-dependent 5-HT release did not simply reflect changes in the amount of IgE bound to the cells. In conclusion, we found that SCF, IL-3, or IL-4 each exerted a different spectrum of stimulatory, costimulatory, or regulatory effects on the secretory function of mouse PMC.

Animals↗
PubMed1993

Induction of an auto-anti-IgE response in rats. IV. Effects on mast cell degranulation.

Induction of an auto-anti-IgE (auto-aIgE) response in the rat inhibits both total and specific IgE production and alters the distribution of mast cell (MC) subpopulations identified by differential Alcian blue/safranin staining. We have extended these observations by characterizing the auto-aIgE antibodies and determining their effects on MC degranulation in vitro and in vivo. An auto-aIgE response was induced in bacillus Calmette-Guérin (BCG)-primed rats by injecting a conjugate of highly purified rat IgE myeloma (IR2) coupled to tuberculin-derived purified protein derivative (PPD). Anti-IgE autoantibodies were almost exclusively IgG2a. The intradermal injection of auto-aIgE into untreated rats induced local MC degranulation as shown by a strong immediate skin response. Histologically there was evidence of significant degranulation of safranin staining connective tissue MC (SMC) in the skin but not of the Alcian blue staining MC (ABMC) in the sub-epidermal region. The induced degranulation was epsilon-chain specific; immunopurified anti-idiotypic antibodies raised to the IgE IR2 myeloma had no MC degranulating activity. When administered locally, auto-aIgE inhibited a subsequent passive cutaneous anaphylaxis (PCA) response elicited by anti-ovalbumin IgE. In addition, the PCA response was significantly decreased in animals with an ongoing auto-aIgE response. Immunopurified auto-aIgE also induced histamine release in vitro from rat peritoneal MC. These results are discussed in the context of naturally occurring autoantibodies to IgE present in patients with allergic disease.

Animals↗