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)

Macrophages (M phi) are multifunctional cells that regulate humoral and cellular immune responses. Our studies of tumor-induced M phi-mediated dysfunction used M phi subsets which were defined by their Mac-1, Mac-2, and Mac-3 surface markers. To measure the accessory activity of M phi for T cell alloreactivity, thioglycollate-elicited peritoneal M phi from normal and tumor-bearing hosts (TBH) were labeled with anti-Mac-1, -2, or -3 antibodies and separated by flow cytofluorometry. The separated Mac-1+, -2+, and -3+ M phi were called sorted M phi, while unseparated M phi were designated unsorted M phi. Both M phi types were added to mixed lymphocyte reaction (MLR) cultures at concentrations ranging from a low of 2% M phi to a high of 20% M phi. The low concentration of unsorted normal host M phi caused a 31% suppression of alloreactivity. Suppression reached 68% when high concentrations of unsorted normal host M phi were added to the MLR cultures. Unsorted TBH M phi reduced alloreactivity by 64% and 86% at low and high concentrations, respectively. When separated into subpopulations, normal host Mac-1+ M phi reduced alloreactivity by 48% and 81% when added at low and high concentrations, respectively. TBH Mac-1+ reduced alloreactivity by 31% and 59% at low and high concentrations, respectively. There were no differences in the suppression caused by normal or TBH Mac-2+ M phi, and by normal or TBH Mac-3+ M phi. Indomethacin treatment did not effect the suppression caused by Mac-1+ M phi, suggesting that proataglandin E2 was not involved. Indomethacin treatment did reduce suppression mediated by Mac-2+, -3+, and unsorted M phi. Mac-2+ M phi dramatically enhanced alloreactivity at low concentrations with normal host Mac-2+ M phi providing greater enhancement of alloreactivity than TBH Mac-2+ M phi. The division of M phi into subpopulations on the basis of Mac antigens suggested that Mac-1+ and -3+ M phi played a major role in immunosuppression in the normal host, while Mac-3+ M phi were more active in TBH immunosuppression. Because no one population of sorted TBH M phi was more suppressive than sorted normal host M phi, we suggest that tumor-induced immunosuppression may involve a network of suppressor M phi.
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PMID:Modulation of alloreactivity by Mac-1+, -2+, and -3+ macrophages from normal and tumor-bearing hosts: flow cytofluorometrically separated macrophages. 215 12

The cytoplasmic tubulovesicular and canalicular membranes of gastric parietal cells are intimately involved in hydrochloric acid secretion. To characterise the glycoproteins of these membranes, we examined a panel of lectins for reactivity with parietal cells in paraffin sections of rat, dog and pig stomach. The poly-N-acetyllactosamine-specific lectin from Lycopersicon esculentum (tomato) and from Solanum tuberosum (potato), and the galactose-specific lectin Ricinus communis agglutinin (RCA120), showed strong cytoplasmic binding of parietal cells of all three species, with a pattern indicative of an intracellular membrane network. Binding to parietal cells was confirmed by double-labelling studies with parietal cell auto-antibodies from patients with autoimmune gastritis. Mucous cells and mucin also bound these lectins strongly. Other gastric cell types did not stain with either tomato or potato lectin, but stained weakly with RCA120. Electron-microscopic examination of lectin binding sites using biotinylated tomato lectin or RCA120 and streptavidin-gold, revealed specific binding to the luminal face of parietal cell tubulovesicular and canalicular membranes as well as the contents of mucous cell secretory granules. Tomato lectin and RCA120 reacted by lectin blotting with a major species of apparent molecular weight 60-90 X 10(3) Mr from rat, dog and pig gastric membranes. A tubulovesicular membrane fraction, enriched 10-fold for K(+)-dependent phosphatase activity, was also enriched three-fold for tomato lectin binding as assessed by a solid-phase lectin assay. The 60-90K (K = 10(3) Mr) component, in 125I-labelled detergent extracts of dog tubulovesicular membranes, bound to an affinity support of tomato lectin-Sepharose and was specifically eluted with N,N',N'-triacetylchitotriose. Digestion with N-glycanase collapsed the 60-90K component into a sharp 35K band. We conclude that: (1) a 60-90K membrane glycoprotein localised on the luminal face of tubulovesicles and canaliculi of parietal cells interacts strongly with tomato lectin and RCA120; and (2) the glycoprotein is composed of a 35K core protein glycosylated with N-glycans probably containing poly-N-acetyllactosamine sequences with terminal galactosyl residues. The properties of this 60-90K glycoprotein are identical to a major parietal cell autoantigen recognised by sera of patients with autoimmune gastritis.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Poly-N-acetyllactosamine-specific tomato lectin interacts with gastric parietal cells. Identification of a tomato-lectin binding 60-90 X 10(3) Mr membrane glycoprotein of tubulovesicles. 216 41

Purified carbohydrate-binding protein 35 (CBP35) and extracts of mouse cells containing CBP35 were analyzed by two-dimensional gel electrophoresis. Such an analysis on recombinant CBP35, obtained by expression of a cDNA clone in Escherichia coli, yielded a pI value of 8.7. When extracts of mouse 3T3 cells were subjected to two-dimensional gel electrophoresis and immunoblotting, two spots were observed, corresponding to pI values of 8.7 and 8.2. The pI 8.2 species represents post-translational modification of the CBP35 polypeptide (pI 8.7) by the addition of a single phosphate group. This conclusion is based on the finding that purified CBP35 contained a pI 8.2 species that was labeled with 32PO4 and could be converted to the unlabeled pI 8.7 species by alkaline phosphatase treatment. The phosphorylated (pI 8.2) form of CBP35 is found in both the cytosolic and nuclear fractions, whereas the unphosphorylated (pI 8.7) species is found exclusively in the nuclei. Quiescent populations of 3T3 fibroblasts (confluent monolayers or serum-starved sparse cultures) are characterized by the predominance of phosphorylated CBP35. Stimulation of the same cells into the proliferative state resulted in an increase in the amount of the phosphorylated species; more dramatic, however, is the elevation of the level of the unphosphorylated form, which is barely detectable in quiescent cells.
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PMID:Carbohydrate-binding protein 35. Isoelectric points of the polypeptide and a phosphorylated derivative. 217 Mar 92

Pancreatic islets from SJL/J mice infected with the D variant of encephalomyocarditis virus (EMC-D virus) showed lymphocytic infiltration with moderate to severe destruction of beta cells. Immunohistochemical staining of the islet sections with several monoclonal antibodies, anti-Mac-1, anti-Mac-2, and F4/80 for macrophages, anti-L3T4 for helper/inducer T cells, and anti-Lyt2 for cytotoxic/suppressor T cells revealed that the major population of infiltrating cells at the early stage of viral infection was Mac-2-positive macrophages. In contrast, macrophages detected by anti-Mac-1 and F4/80 monoclonal antibodies were not found at the early stage of viral infection but were found at intermediate and late stages of viral infection. Helper/inducer T cells and cytotoxic/suppressor T cells also infiltrated the islets at intermediate and late stages of viral infection. Short-term treatment of mice with silica prior to viral infection resulted in an enhancement of beta-cell destruction, leading to the development of diabetes. In contrast, long-term treatment of mice with silica resulted in complete prevention of diabetes caused by a low dose of viral infection and a significant decrease in the incidence of diabetes caused by an intermediate or high dose of viral infection. Furthermore, depletion of macrophages by a specific monoclonal antibody (anti-Mac-2) resulted in a much greater decrease in the incidence of diabetes caused by an intermediate dose of viral infection. However, suppression of helper/inducer T cells and cytotoxic/suppressor T cells, by anti-L3T4 and anti-Lyt2 antibodies, respectively, did not alter the incidence of diabetes. On the basis of these data, it is concluded that macrophages, particularly Mac-2-positive macrophages, play a crucial role in the process of pancreatic beta-cell destruction at the early stage of encephalomyocarditis D virus infection in SJL/J mice.
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PMID:Role of macrophages in the pathogenesis of encephalomyocarditis virus-induced diabetes in mice. 217 63

This study utilizes immunofluorescence to describe the distribution of several extracellular matrix molecules in the chick embryo during the process of limb outgrowth and the formation of precartilage condensations. A large chondroitin sulfate proteoglycan (PG-M) is detected at the wing level at Hamburger and Hamilton stage 14 in and under the dorsal ectoderm, and is associated with the basement membranes around the neural tube, notochord and pronephros, but not with other basement membranes. The galactose-specific lectin, peanut agglutinin (PNA), has a similar distribution except that it also binds to the dorsal side of the neural tube. PG-M is not detected in the limb mesenchyme until after stage 17, when it is present in the distal region, as is PNA-binding material. With further development of the wing bud, PG-M is present in the subectodermal mesenchyme, the mesenchyme at the distal tip and in the prechondrogenic core. After stage 22 PNA-binding material becomes localized in the prechondrogenic core, the basement membranes under the apical ectodermal ridge, and the ventral sulcus. The distribution of these components (PG-M and PNA binding material) overlaps, but differs from that of type I collagen and fibronectin and basement membrane components, such as laminin, basement membrane heparan sulfate proteoglycan, and type IV collagen. Tenascin, on the other hand, is not detected in the limb bud until stage 25, after the appearance of cartilage matrix components such as type II collagen and cartilage proteoglycan (PG-H). These results are considered in relation to the formation of precartilage aggregates, and indicate that PNA binds to components in precartilage aggregates other than PG-M or tenascin.
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PMID:The distribution of mesenchyme proteoglycan (PG-M) during wing bud outgrowth. 218 66

A hundred years of lectin research has led to the development of lectinology as an independent field of study. Although lectinology is in part related to immunology, fundamental differences exist. Lectins are important tools in biochemistry, histochemistry and clinical diagnosis. The essential in vivo function of lectins is to combine glycoconjugates. The function of lectins in microorganisms and in animals is partially known, whereas the function of lectins in plants is mostly unclear. Of special interest, now as before, are the toxic lectins of the ricin type consisting of an A-chain (N-glycosidase) and a B-chain (D-galactose-specific lectin).
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PMID:[100 years of lectin research--a balance]. 218 42

Tumor-bearing host (TBH) macrophages (M phi) exhibit immune dysfunction that is concomitant with phenotypic changes. We examined M phi subpopulations by changes in the expression of surface antigens Mac-1, -2, -3, and Ia on normal and TBH peritoneal and splenic M phi. M phi were double-labeled and analyzed by flow cytometry to observe multiple expression of surface antigens. Tumor growth alters the multiple expression of these M phi markers. Peritoneal and splenic M phi had different Mac+ and Mac+Ia+ population percentages. In TBH, peritoneal M phi had decreased percentages of Mac-1+2+, Mac-1+3+, Mac-2+3+, and Mac+Ia+ M phi. This decrease correlated with functional changes in TBH M phi. In contrast, there was an increase in Mac-2-Ia- TBH peritoneal M phi. Previously undiscovered Mac-1+2-3- and Mac-1-2-3+ populations were found. In contrast to peritoneal M phi, there was an increase in the percentage of Mac-1+2+, Mac-1+3+, and Mac-2+3+ splenic TBH M phi but, like peritoneal M phi, there was a decrease in the percentage of Mac+Ia+ M phi. Also, TBH splenic M phi showed a smaller but more uniform antigen density than normal host splenic M phi. Tumor growth modulated phenotypic alterations in peritoneal and splenic M phi subpopulations. Combined with earlier functional studies of M phi subpopulations, these data suggested a relationship between changes in M phi phenotype and tumor-induced dysfunction of M phi-modulated immune activity.
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PMID:Two-color flow cytometric analysis of the expression of MAC and MHC class II antigens on macrophages during tumor growth. 220 Jun 57

A major 18-kD IgE-binding protein from Aspergillus fumigatus (Asp fI) has been purified. Partial amino acid sequencing of Asp f I showed extensive sequence homology (95%) between Asp fI and a cytotoxin (mitogillin) produced by A. restrictus. Crossinhibition radioimmunoassay using murine monoclonal antibody and human IgG and IgE antibodies showed that Asp fI and mitogillin were antigenically indistinguishable. Furthermore, both proteins inhibited protein synthesis in vitro by greater than 90%. Asp fI was expressed in A. fumigatus but not in seven other Aspergillus species. The results suggest that Asp fI could play a dual role in the pathogenesis of A. fumigatus-related diseases by promoting colonization through cytotoxic activity and by causing inflammatory reactions involving IgE antibodies.
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PMID:Aspergillus fumigatus allergen I, a major IgE-binding protein, is a member of the mitogillin family of cytotoxins. 223 Jun 56

IgE-binding protein (epsilon BP) is a protein which has affinity for IgE and was originally identified in rat basophilic leukemia (RBL) cells. Subsequently, it was found to be the rat homolog of CBP35, a murine beta-galactoside-specific lectin. This protein is also designated as L-34 and RL-29 and studied independently by several laboratories. More recently, CBP35 (epsilon BP) was found to be equivalent to Mac-2, a surface marker on activated macrophages. Using rat epsilon BP cDNA, we have succeeded in expressing recombinant epsilon BP in Escherichia coli. Milligram quantities of homogeneous epsilon BP could be obtained from bacterial lysate in a one-step affinity purification procedure utilizing lactosyl-Sepharose 4B and elution with a lactose gradient. The recombinant epsilon BP (r epsilon BP) binds mouse IgE and retains reactivity to anti-peptide antibodies specific for a sequence within rat epsilon BP. The purified r epsilon BP exhibits binding activity to various saccharides, with affinity for N-acetyllactosamine greater than thiodigalactoside greater than lactose much greater than D-galactose greater than L-arabinose, an order identical to that exhibited by native epsilon BP isolated from RBL cells. The recombinant lectin displayed hemagglutination activity when tested with rabbit erythrocytes. Although epsilon BP shares sequence homology to other lectins containing S-type (thiol-dependent) carbohydrate-recognition domains, r epsilon BP is resistant to air oxidation and does not require reducing agents for maintaining its activity. Furthermore, the single cysteine residue appears to be unexposed and can be alkylated only when the protein is denatured in 5.6 M guanidinium hydrochloride. The availability of a source for a large quantity of epsilon BP should facilitate the analysis of biological function(s) and structure-activity relationships of this lectin.
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PMID:Expression of biologically active recombinant rat IgE-binding protein in Escherichia coli. 224 84

IgE-binding protein (epsilon BP) refers to a protein originally identified in rat basophilic leukemia cells by virtue of its affinity for IgE. It is now known to be a beta-galactoside-binding lectin equivalent to carbohydrate-binding protein 35 (CBP 35). More recently, its identity to Mac-2, a macrophage cell-surface protein, has been established. cDNA coding for human epsilon BP has been cloned from a human HeLa cell cDNA library and contains an open reading frame of 750 base pairs encoding a 250 amino acid protein. Like the rat and murine counterparts, the human epsilon BP amino acid sequence can be divided into two domains with the amino-terminal domain consisting of a highly conserved repetitive sequence (YPGXXXPGA) and the carboxyl-terminal domain containing sequences shared by other S-type lectins. The human epsilon BP sequence exhibits extensive homology to murine and rat epsilon BP with 84% and 82% identity, respectively. The homology is particularly striking in the carboxyl-terminal domain where 95% identity is found between human and murine sequences in a stretch of over 70 amino acids. A survey of epsilon BP mRNA expression from several lymphocyte cell lines revealed that the level of epsilon BP transcription may reflect a relationship between cell differentiation and epsilon BP expression. Finally, human epsilon BP was purified from several human cell lines and shown to possess lactose-binding characteristics and cross-species reactivity to murine IgE. Surprisingly, three different human myeloma IgE proteins did not show reactivity to human epsilon BP. However, after neuraminidase treatment of each human IgE, pronounced binding to epsilon BP was observed, thereby indicating that only specific IgE glycoforms can be recognized by epsilon BP.
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PMID:Human IgE-binding protein: a soluble lectin exhibiting a highly conserved interspecies sequence and differential recognition of IgE glycoforms. 226 64


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