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)

We have addressed the differential regulatory properties that IFN-gamma and IL-4 exert on macrophage (M phi) subpopulations. For this purpose, Thyoglicolate-, Peptone-, and Con A-elicited M phi, as well as bone marrow-derived M phi and P388D1 cells, were cultured in the presence of either IFN-gamma or IL-4. The expression of LFA-1, Mac-1, and Mac-2 after this treatment was studied by FACS analysis. We have found that these surface molecules are differentially modulated by the two lymphokines, depending on the M phi subpopulation studied. Mac-1 is upregulated only in Thyoglicolate-elicited cells after treatment with IFN-gamma, while no change in the expression of Mac-2 was observed in any of the groups. LFA-1 is upregulated by IFN-gamma in Thyoglicolate- and bone marrow-derived M phi and P388D1 cells, while IL-4 does not induce LFA-1 on these cells. Interestingly, however, we have observed the reverse situation on Con A-elicited M phi, where a strong induction of LFA-1 is achieved by treatment of the cells with IL-4, while IFN-gamma does not modify the expression of this antigen. Our results obtained with the lymphokine-stimulated M phi are interpreted in the context of functionally induced M phi subpopulations, which might be regulated by either Th1 or Th2 CD4+ T cells. Thyoglicolate-elicited M phi may represent the in vitro equivalent of a M phi subpopulation regulated in vivo by Th1 cells while Con A-elicited M phi could be the equivalent of a subpopulation regulated by Th2 cells.
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PMID:Regulation of macrophage activation markers by IL-4 and IFN-gamma is subpopulation-specific. 190 20

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

The aim of the present work was to further characterize immunological defects in osteopetrosis. The op/op mutant mouse is of particular interest since a marrow cavity develops spontaneously in older animals. The interleukin production (IL-1, IL-2, IL-3, IL-4, IL-6), the presence of macrophage differentiation antigens and the evolution of the bone lesions were studied in osteopetrotic and normal mice. Low levels of IL-1, IL-3 and IL-4 were observed at the age of 6 weeks in the op/op mice. However, at 22 weeks of age, the level of IL-1 and IL-4 returned to normal value in these op/op mice whereas the level of IL-3 remained partially decreased at the same age. Furthermore, macrophage expression of MAC-2 antigen, reduced at 12 weeks of age was found to be normal 10 weeks later. These immunological defects and their recovery seems to be concomitant with the healing of the bone lesions.
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PMID:Immune cell defects affect bone remodelling in osteopetrotic op/op mice. 814 72

The mechanisms contributing to the proliferation and differentiation of antigen-presenting cell (APC) precursors upon antigen stimulation or tissue injury are poorly understood. Herein, we report the induction of a population of dendritic cell-like cells (DLC) with potent antigen-presentation function from unfractionated spleen cells by means of repetitive allostimulation in long-term mixed leucocyte cultures (LT-MLC). Initially, only a few adherent DLC were observed. By 4-6 weeks, however, there were large numbers of DLC which survived persistently. Features of these DLC are closely related to dendritic cells (DC), including (1) dendritic, veiled or spiny-processed morphology; (2) expression of a wide array of leucocyte surface markers including DC-associated or restricted antigens: 33D1, NLDC-145, CD11c (N418), heat-stable antigen (HSA), CD44, B7-1 and B7-2; (3) ability to migrate to draining lymph nodes and white pulp area of spleen; (4) expression of high level of major histocompatability complex (MHC) class II molecules and (5) more potent mixed leucocyte reaction (MLR)-stimulating capacity than peritoneal macrophages and APC-enriched spleen cells. DLC-stimulated MLR was inhibited by monoclonal antibodies (mAbs) to B7-1, B7-2, intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), leucocyte-function associated antigen-1 (LFA-1) or very-late activation antigen-4 (VLA-4) by 30-55%. When maintained for more than 2 months, the DLC did not lose their MLR-stimulating activity, but many surface markers were down-regulated except for Mac-2 and VCAM-1, which remained stable or were up-regulated, respectively. In short-term culture, the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin (IL)-2 enhanced proliferation of DLC, while tumour necrosis factor-alpha (TNF-alpha) and IL-4 did not. IL-4 suppressed not only 'spontaneous', but also GM-CSF-enhanced proliferation, suggesting that cytokines play a differential role in DLC proliferation. These results confirm that professional APC can proliferate in response to repetitive antigen stimulation, and their proliferation is differentially regulated by cytokines. A comparison study of DLC with typical DC is being carried out in our laboratory.
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PMID:Generation of dendritic cell-like antigen-presenting cells in long-term mixed leucocyte culture: phenotypic and functional studies. 920 77

A c-myc retrovirus-transformed myeloid leukemia line, MMB3.19, of C57BL/6 (B6) origin, was developed to investigate graft-versus-leukemia (GVL) activity in murine bone marrow transplantation (BMT) models. It was previously determined that both naive and leukemia-presensitized CD4+-enriched T cells are capable of mediating GVL activity to MMB3.19 challenge in both syngeneic (B6) and allogeneic (C3H.SW-->B6) strain combinations, with the latter coinciding with minimal graft-versus-host disease. In the present study, MMB3.19 and 2 other similarly derived, yet phenotypically diverse, B6 myeloid leukemia lines (MMB1.10 and MMB2.18) were investigated for potential shared tumor antigens in the syngeneic GVL model. Morphologically, all 3 tumor lines are blastic with high cytoplasmic:nuclear ratios, but MMB2.18 displays dendritic processes, whereas MMB1.10 and MMB3.19 have a more rounded appearance. Flow cytometric analysis of the 3 lines revealed constitutive surface molecule expression of Mac-1, Mac-2, F4/80, LFA-1, B7-1, B7-2, H2Kb, H2Db, and macrophage scavenger receptor, consistent with macrophage/monocyte lineages. Furthermore, each of the lines expresses H2I-Ab, but to varying degrees, with MMB2.18 cells having the lowest percentage (31.6%). In vitro 51Cr release assays using MMB3.19-primed T-cell effectors demonstrated equivalent specific lysis of all 3 leukemia-line target cells. In addition, enzyme-linked immunospot analysis of MMB3.19-primed CD4+ T cells revealed significantly increased frequencies of tumor-stimulated interleukin (IL)-2-, IL-4-, and interferon-gamma-secreting cells when restimulated with each of the 3 leukemia lines. Furthermore, when MMB3.19-primed CD4+ T cells were administered in a BMT setting, a protective GVL effect was seen in those mice challenged with MMB1.10, MMB2.18, or MMB3.19. Therefore, in vitro and in vivo experiments indicate that the 3 distinct myeloid leukemia lines share 1 or more common major histocompatibility complex class II-restricted tumor antigens that can elicit a cross-protective in vivo T-cell GVL response.
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PMID:Cross-protective murine graft-versus-leukemia responses to phenotypically distinct myeloid leukemia lines. 1107 Dec 59

A soluble beta-galactoside-binding lectin, galectin-3 has been shown to be involved in cell adhesion and activation of immune cells. Although galectin-3 is known to be expressed in various types of cells, it has not been shown whether galectin-3 is expressed in T lymphocytes. We present evidence here that galectin-3 is expressed in activated murine T lymphocytes including CD4+ and CD8+ T cells but not in resting T cells. Galectin-3 expression was induced by anti-CD3 mAb or mitogen and enhanced by common gamma-chain signaling cytokines, IL-2, IL-4, and IL-7, in activated T lymphocytes, whereas the inflammatory cytokines including TNF-alpha and IFN-gamma did not. Galectin-3 expression and proliferation were down-regulated by withdrawal of IL-2 and gamma irradiation. Antisense but not sense phosphorothioated oligonucleotides for galectin-3 inhibited galectin-3 expression and blocked proliferation of T cells significantly. This study suggests that up-regulation of galectin-3 plays an important role in proliferation of activated T lymphocytes.
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PMID:Expression and function of galectin-3, a beta-galactoside-binding protein in activated T lymphocytes. 1131 Aug 41

The pathophysiology of asthma involves an intricate network of molecular and cellular interactions. Elevated Th2 cytokines (interleukin [IL]-5 and IL-4) associated with eosinophilic inflammation characterize allergic diseases and provide potential targets for immunomodulation. Recent evidence has demonstrated that galectin-3 induces selective downregulation of IL-5 gene expression in several cell types (eosinophils, T cell lines, and antigen specific T cells). Accordingly, we sought to elucidate whether in vivo intratracheal instillation of plasmid DNA encoding galectin-3 would inhibit an experimental asthmatic reaction in a rat model with increased eosinophils and T cells in bronchoalveolar fluid and impaired pulmonary function. We found that instillation of galectin-3 gene in these rats led to normalization of the eosinophil and T cell count in bronchoalveolar lavage fluid and that there was a strong concomitant inhibition of IL-5 mRNA in the lungs. As a consequence, galectin-3-treated rats showed recovery of pulmonary functional parameters, such as pulmonary pressure and expiratory flows. These data emphasize the potential utility of galectin-3 as a novel therapeutic approach for treatment of allergic asthma.
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PMID:Gene therapy with galectin-3 inhibits bronchial obstruction and inflammation in antigen-challenged rats through interleukin-5 gene downregulation. 1220 73

The role of transcription factors in B cell survival and differentiation has been delineated during the last years. However, little is known about the intermediate signals and the intracellular pathways that control these events. In this study, we provide evidence both in vitro and in vivo, showing that galectin-3 (Gal-3), a beta-galactoside-binding protein, is a critical mediator of B cell differentiation and survival. Although Gal-3 is not expressed in resting B cells from normal mice, its expression is markedly induced after activation with stimuli such as IL-4 and CD40 cross-linking. These signals promote survival and block the final differentiation of these cells, thus allowing the rising of a memory B cell phenotype. In addition, Gal-3 is expressed in B cells from Trypanosoma cruzi-infected mice, which received signals for activation and differentiation in vivo. By using an antisense strategy, we determined that Gal-3 is a critical signal mediating the effects of IL-4 on B cell fate. Blockade of intracellular Gal-3 in vitro abrogated IL-4-induced survival of activated B cells, favoring the differentiation toward a plasma cell pathway. Moreover, B cells with restrained endogenous Gal-3 expression failed to down-regulate the Blimp-1 transcription factor after IL-4 stimulation. Finally, inhibition of Gal-3 in vivo skewed the balance toward plasma cell differentiation, which resulted in increased Ig production and parasite clearance during T. cruzi infection. Thus, the present study provides evidence of a novel role for Gal-3 as an intracellular mediator of B cell survival and a checkpoint in IL-4-induced B cell commitment toward a memory phenotype.
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PMID:Galectin-3 mediates IL-4-induced survival and differentiation of B cells: functional cross-talk and implications during Trypanosoma cruzi infection. 1468 59

Galectin-3 is a member of the beta-galactoside-binding animal lectin family expressed in various cell types, including mast cells. To determine the role of galectin-3 in the function of mast cells, we studied bone marrow-derived mast cells (BMMC) from wild-type (gal3(+/+)) and galectin-3-deficient (gal3(-/-)) mice. Cells from the two genotypes showed comparable expression of IgE receptor and c-Kit. However, upon activation by FcepsilonRI cross-linkage, gal3(-/-) BMMC secreted a significantly lower amount of histamine as well as the cytokine IL-4, compared with gal3(+/+) BMMC. In addition, we found significantly reduced passive cutaneous anaphylaxis reactions in gal3(-/-) mice compared with gal3(+/+) mice. These results indicate that there is a defect in the response of mast cells in gal3(-/-) mice. Unexpectedly, we found that gal3(-/-) BMMC contained a dramatically lower basal level of JNK1 protein compared with gal3(+/+) BMMC, which is probably responsible for the lower IL-4 production. The decreased JNK1 level in gal3(-/-) BMMC is accompanied by a lower JNK1 mRNA level, suggesting that galectin-3 regulates the transcription of the JNK gene or processing of its RNA. All together, these results point to an important role of galectin-3 in mast cell biology.
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PMID:Role of galectin-3 in mast cell functions: galectin-3-deficient mast cells exhibit impaired mediator release and defective JNK expression. 1701 81

Antibodies directed against tumor-associated antigens are emerging as effective treatments for a number of cancers, although the mechanism(s) of action for some are unclear and still under investigation. We have previously examined a chimeric IgE antibody (MOv18 IgE), against the ovarian tumor-specific antigen, folate binding protein (FBP), and showed that it can direct human PBMC to kill ovarian cancer cells. We have developed a three-color flow cytometric assay to investigate the mechanism by which IgE receptors on U937 monocytes target and kill ovarian tumor cells. U937 monocytes express three IgE receptors, the high-affinity receptor, FcepsilonRI, the low-affinity receptor, CD23, and galectin-3, and mediate tumor cell killing in vitro by two mechanisms, cytotoxicity, and phagocytosis. Our results suggest that CD23 mediates phagocytosis, which is enhanced by upregulation of CD23 on U937 cells with IL-4, whereas FcepsilonRI mediates cytotoxicity. We show that effector : tumor cell bridging is associated with both activities. Galectin-3 does not appear to be involved in tumor cell killing. U937 cells and IgE exerted ovarian tumor cell killing in vivo in our xenograft model in nude mice. Harnessing IgE receptors to target tumor cells suggests the potential of tumor-specific IgE antibodies to activate effector cells in immunotherapy of ovarian cancer.
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PMID:Role of IgE receptors in IgE antibody-dependent cytotoxicity and phagocytosis of ovarian tumor cells by human monocytic cells. 1765 88


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