Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P17931 (galectin-3)
 2,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The demonstration of IgE-bearing epidermal Langerhans cells (LC) opened up new perspectives in the pathophysiology of atopic eczema. IgE receptors on LC have now been identified and characterized: all three IgE-binding structures so far known to be present in the human immune system have been demonstrated on LC, i.e. the low-affinity receptor for IgE (Fc epsilon RII/CD23), the so-called IgE-binding protein (epsilon BP) and the high-affinity receptor for IgE (Fc epsilon RI), which had hitherto been considered to be expressed exclusively on mast cells and basophils. Functionally, there is some evidence that these structures may be involved in the release of cytokines and/or IgE-mediated antigen focusing. Considering the specificity of IgE for environmental allergens and the particular place of LC in primary and secondary immune responses, it can be speculated that LC in the skin and mucosae play a major role in mechanisms of sensitization to such allergens and in the genesis of IgE-mediated diseases. Finally, IgE receptors on LC may provide targets for new therapeutic approaches in atopic diathesis.
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PMID:[IgE receptors in Langerhans cells. A link between the environment and the immune system?]. 147 69

We have recently demonstrated that normal human Langerhans cells are able to bind IgE. The study of IgE-binding molecules on normal LC led to the characterization of three distinct structures able to bind IgE, viz. the low affinity receptor for IgE, Fc epsilon R2/CD23, the so-called IgE-binding protein epsilon BP which is the human homologous of the murine Mac-2 antigen, and finally the high affinity receptor for IgE, Fc epsilon RI. In this review, we summarize the most recent data on these structures and their putative physiological relevance is discussed with regard to the atopic disease.
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PMID:IgE-binding molecules on human Langerhans cells. 147 37

Human epidermal Langerhans cells (LC) bearing IgE are found in disease states associated with hyperimmunoglobulinemia E. When studying the mechanism(s) underlying this phenomenon, immunohistology revealed that a majority of epidermal LC from normal skin of healthy individuals can specifically bind monomeric IgE. IgE binding to LC could neither be prevented by preincubation of the tissue with monoclonal antibodies (mAb) against either Fc epsilon RII/CD23 or Fc gamma RII/CD32, nor by the addition of lactose. However, binding could be entirely abrogated by preincubation with the anti-Fc epsilon RI alpha mAb 15-1, which interferes with IgE binding to Fc epsilon RI alpha gamma transfectants. These observations indicated that IgE binding to epidermal LC is mediated by Fc epsilon RI rather than by CD23, CD32, or the D-galactose-specific IgE-binding protein. This assumption gained support from our additional findings that: (a) the majority of LC exhibited distinct surface immunolabeling with the anti-Fc epsilon RI alpha mAbs 15-1 and 19-1, but not with any of eight different anti-Fc epsilon RII/CD23 mAbs; and (b) transcripts for the alpha, beta, and gamma chains of Fc epsilon RI could be amplified by polymerase chain reaction from RNA preparations of LC-enriched, but not of LC-depleted, epidermal cell suspensions. In view of the preeminent role of Fc epsilon RI crosslinking on mast cells and basophils in triggering the synthesis and release of mediators of allergic reactions, the demonstration of this receptor on epidermal LC may have important implications for our understanding of allergic reactions after epicutaneous contact with allergens.
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PMID:Epidermal Langerhans cells from normal human skin bind monomeric IgE via Fc epsilon RI. 153 43

Eosinophils display various receptors for immunoglobulin E (IgE) including the high affinity receptor for IgE (Fc epsilon RI), CD23 (Fc epsilon RII), and Mac-2/epsilon BP. We attempted here to clarify the role of these receptors in IgE-mediated activation of eosinophils from normal human bone marrow cultures. Pretreatment of eosinophils with IL-4 is required for IgE/anti-IgE-mediated stimulation of TNF-alpha and peroxydes production. TNF-alpha release from eosinophils was also induced following ligation of CD23 and to a lesser extent with anti-Mac-2, while Fc epsilon RI-ligation had no effect. IgE/anti-IgE effect dramatically decreased when eosinophils were pretreated with Fab fragments of CD23-mAb. In addition, this effect could also be reversed by inhibiting CD23-dependent nitric oxide pathway by NG-monomethyl-L-arginine. Nitric oxide chemical donor, SIN-1, induced TNF-alpha release from eosinophils. CD23 and nitric oxide pathway are thus involved in IgE-mediated stimulation of normodense human eosinophils.
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PMID:Involvement of Fc epsilon RII/CD23 and L-arginine dependent pathway in IgE-mediated activation of human eosinophils. 807 65

Mast cells and basophils, which are activated by immunoglobulin E (IgE) and allergen, play a prominent role in anaphylaxis. However, they express at least three types of IgE receptor, including the high affinity IgE receptor (Fc epsilon RI). The relative contribution of these IgE receptors, and possibly other receptors such as Fc epsilon RII/CD23 and Mac-2, to the genesis of in vivo anaphylaxis is still unclear. To address this question, we have generated Fc epsilon RI-deficient mice. These mice appear normal and express a normal number of mast cells, but they are resistant to cutaneous and systemic anaphylaxis. These data demonstrate that Fc epsilon RI is necessary for the initiation of IgE-dependent anaphylactic reactions. Therefore, interfering with its function should be an effective means of treating allergy, regardless of the allergen specificity.
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PMID:Abolition of anaphylaxis by targeted disruption of the high affinity immunoglobulin E receptor alpha chain gene. 825 32

A better understanding of the pathophysiological role of Langerhans cells (LC) in atopic diseases is dictated by the characterization of the structures involved in immunoglobulin (IgE)-binding on their cell surface. We previously reported that human LC express the high affinity receptor for IgE (Fc epsilon RI), as well as the low affinity receptor for IgE (Fc epsilon RII/CD23). In the present study, we document the presence of a third IgE-binding structure on human LC, the IgE-binding protein (epsilon BP), an endogenous soluble beta-galactoside binding lectin. Immunohistochemical studies performed on normal human skin revealed an anti-epsilon BP reactivity in the cytoplasm of keratinocytes and in that of acinous cells of eccrine sweat glands. epsilon BP was also found on the cell surface of LC, as shown by anti-epsilon BP/anti-CD1a double labeling and flow cytometric analysis. Anti-epsilon BP binding to the surface of LC was completely abolished by preincubation with lactose and restored by addition of recombinant human epsilon BP, indicating that epsilon BP binds to LC surface by virtue of its lectin property. Immunoblot analysis of anti-epsilon BP-reactive material in keratinocytes and purified LC disclosed a protein with an apparent molecular weight of 33,000 consistent with epsilon BP. Interestingly, mRNA transcripts for epsilon BP were detected only in keratinocytes but not in purified LC isolated from normal skin. epsilon BP was found to be released in culture supernatants of keratinocytes. Incubation of LC with these supernatants resulted in epsilon BP-binding to LC surface via protein-carbohydrate interaction. Most importantly, we could show that binding of human myeloma IgE to LC was inhibited by epsilon BP. In contrast, neuraminidase-treated human myeloma IgE binds to LC only in the presence of epsilon BP. In situ binding studies revealed that keratinocytes, although containing epsilon BP intracytoplasmatically, failed to exhibit any IgE-binding properties. Collectively, our results suggest that human keratinocytes produce the beta-galactoside-binding lectin epsilon BP, which subsequently binds to the surface of LC where it is functional in modulating their binding capacity for IgE glycoforms.
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PMID:Human keratinocytes release the endogenous beta-galactoside-binding soluble lectin immunoglobulin E (IgE-binding protein) which binds to Langerhans cells where it modulates their binding capacity for IgE glycoforms. 835 53

It has been suggested that neutrophils may be involved in the late-phase reaction of immunoglobulin E (IgE)-dependent hypersensitivity states. However, the identity of neutrophil-associated molecules inducing the release of mediators remains unclear. In this report, we demonstrate that human neutrophils from normal donors or from patients with inflammatory disorders could bind myeloma IgE proteins, especially after desialylation. Northern blot, immunoprecipitation, and flow cytometry analyses revealed that neutrophils did not express Fc epsilon RII/CD23, but rather Mac-2/epsilon binding protein (BP), belonging to the S-type lectin family. Similarly to IgA used as positive control, myeloma IgE proteins, as well as polyclonal IgE antibodies with or without antibody specificity, were both capable of inducing a neutrophil respiratory burst. Anti-Mac-2 but not anti-CD23 mAb strongly decreased the IgE-dependent activation of neutrophils, induced either by the specific antigen or by anti-IgE antibodies. These findings open new perspectives on the functional role of neutrophils in IgE-associated diseases including allergic states or parasitic infections.
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PMID:Human neutrophils express immunoglobulin E (IgE)-binding proteins (Mac-2/epsilon BP) of the S-type lectin family: role in IgE-dependent activation. 841 6

Three major molecules have been recognized as IgE-binding structures on hematopoietic cells: the heterotrimeric high-affinity receptor for IgE (Fc epsilon RI), the low-affinity receptor for IgE (Fc epsilon RII/CD23) and the Mac-2/IgE-binding protein (epsilon BP). The latter has been shown to be expressed on polymorphonuclear neutrophils (PMN), where it regulates IgE-dependent activation. Experiments were undertaken to determine whether the IgE-binding capacity of PMN is mediated exclusively by this molecule. No detectable binding of human myeloma IgE to unstimulated PMN from normal volunteers could be evidenced. In contrast, PMN stimulated with granulocyte macrophage colony stimulating factor (GM-CSF) (500 U/ml) for 24 h displayed positive IgE binding. This binding was significantly inhibited in the presence of mAb directed against Mac-2/epsilon BP and also in the presence of anti-CD23 mAb, but not of anti-Fc epsilon RI mAb or isotype-matched controls. By flow cytometry, CD23 expression was detected on GM-CSF-primed PMN by several anti-CD23 mAb, including EBVCS-5, BB10 or Mab135, which recognize different epitopes. CD23 was also evidenced by immunocytochemistry in GM-CSF-primed PMN. By in situ hybridization, GM-CSF-treated PMN exhibited a hybridization signal for CD23 mRNA and the presence of the CD23b isoform-specific mRNA was detected by RT-PCR. These findings indicate that PMN can synthesize CD23 molecules under GM-CSF induction. This strong CD23 expression might be of physiopathological relevance in IgE-dependent activation during allergic processes.
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PMID:Granulocyte macrophage colony stimulating factor induces Fc epsilon RII/CD23 expression on normal human polymorphonuclear neutrophils. 872 38

Chronic infection with Schistosoma mansoni induces in humans and mice a Th2-dominant immune response in which eosinophils and IgE are conspicuously elevated. Human eosinophils express IgE receptors that participate in an IgE-dependent eosinophil-mediated ADCC reaction against Schistosomula larvae in vitro. To investigate the expression of IgE receptors on murine eosinophils, they were purified (>95% pure by Giemsa-stained cytospin preparations) from liver granulomas of Schistosoma-infected mice. Flow cytometric analysis showed the absence of the low-affinity IgE receptor Fc-epsilon RII (CD23) and Mac-2 and the absence of binding of murine IgE. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of granuloma eosinophil mRNA did not detect transcripts for Fc-epsilon RII or the alpha-chain of the high-affinity IgE receptor Fc-epsilon RI, but did detect transcripts that encode Mac-2 and the low-affinity IgG receptors Fc-gamma RIIb2, Fc-gamma RIII, and the FcR-associated gamma-chain. In vitro stimulation of granuloma eosinophils with interleukin-4 (IL-4) did not induce IgE binding, surface expression of Mac-2, or the transcription of Fc-epsilon receptors (Fc-epsilon RI, Fc-epsilon RII/CD23). To investigate normal murine eosinophils, we cultured normal mouse bone marrow cells with recombinant IL-3, recombinant IL-5, and recombinant granulocyte-macrophage colony-stimulating factor, conditions that promote eosinophil differentiation. Flow cytometric analysis of bone marrow-derived eosinophils failed to detect IgE binding or cell surface expression of Fc-epsilon RII and Mac-2, and RT-PCR analysis of fluorescence-activated cell sorted bone marrow-derived eosinophils failed to detect transcripts that encode Fc-epsilon RI or Fc-epsilon RII. These findings show that, in contrast to human eosinophils, murine eosinophils do not express cell surface receptors that bind IgE. However, because IgG receptors (Fc-gamma RIIb2, Fc-gamma RII) were present on eosinophils purified from granulomas, we investigated whether they might be involved in eosinophil activation. We found that an oxidative burst in eosinophils could be triggered through their IgG receptors.
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PMID:Lack of Fc-epsilon receptors on murine eosinophils: implications for the functional significance of elevated IgE and eosinophils in parasitic infections. 916 Jun 53

Polymorphonuclear neutrophils (PMNs) are important effector cells in host defense and the inflammatory response to antigen. The involvement of PMNs in inflammation is mediated mainly by the Fc receptor family, including IgE receptors. Recently, PMNs were shown to express two IgE receptors (CD23/Fc epsilon RII and galectin-3). In allergic diseases, the dominant role of IgE has been mainly ascribed to its high-affinity receptor, Fc epsilon RI. We have examined the expression of Fc epsilon RI by PMNS: mRNA and cell surface expression of Fc epsilon RI alpha chain was identified on PMNs from asthmatic subjects. Furthermore, preincubation with human IgE Fc fragment blocks completely the binding of anti-Fc epsilon RI alpha chain (mAb15--1) to human PMNS: Conversely, preincubation of PMNs with mAb15--1 inhibits significantly the binding of IgE Fc fragment to PMNs, indicating that IgE bound to the cell surface of PMNs mainly via the Fc epsilon RI. Peripheral blood and bronchoalveolar lavage (BAL) PMNs from asthmatic subjects also express intracellular Fc epsilon RI alpha and beta chain immunoreactivity. Engagement of Fc epsilon RI induces the release of IL-8 by PMNS: Collectively, these observations provide new evidence that PMNs express the Fc epsilon RI and suggest that these cells may play a role in allergic inflammation through an IgE-dependent activation mechanism.
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PMID:Human neutrophils express the high-affinity receptor for immunoglobulin E (Fc epsilon RI): role in asthma. 1129 54


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