Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

With the aim of obtaining monospecific antibodies against the beta-galactoside-binding lectin of bovine heart muscle, spleen cells from Lou rats immunized with lectin were fused with the rat myeloma line Y3.Ag1.2.3. Two immunoglobulin M (IgM)-producing clones, designated NIBy 142-36/8 and NIBy 143-9/5, derived from separate fusions, were used to generate ascites containing high-titre binding activity against the 13kDa component in preparations of lectin. Direct evidence that haemagglutinating activity is associated with the 13kDa protein was obtained by the specific elution of 13kDa polypeptides with haemagglutinating activity from an immobilized antibody adsorbent. Solid-phase radiobinding assays and immunoblotting of isolated lectins and/or muscle homogenates confirmed the earlier indications with conventional antisera that the beta-galactoside-binding lectins of bovine, human and monkey muscle tissue are antigenically related.
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PMID:Production and characterization of monoclonal antibodies to beta-galactoside-binding lectin of bovine heart muscle. Direct evidence that haemagglutinating activity is associated with a 13kDa protein. 674 65

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