Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Langerhans cells are dendritic antigen-presenting cells residing predominantly in the epidermis. Since endogenous galactoside-binding lectins with the jelly-roll motif (galectins) are known to trigger cellular responses, including mediator release, we investigated by lectin histochemistry the cells' capacity to bind two common members of this family, i.e. galectin-1 and -3. Actually, surrounding keratinocytes express a high level of galectin-3, and these cells can be considered as donors of this lectin to Langerhans cells. Employing biotinylated galectin-1 and -3, and concomitantly an antibody against CD1a as a second marker, to visualize the position of Langerhans cells in the human epidermis, the expression of galectin-3-reactive glycoligands in contrast to the lack of binding of galectin-1 was observed. Although the functional consequences of this selectivity are unclear, these results reveal an example for differential cellular reactivity towards two related endogenous lectins.
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PMID:Human epidermal Langerhans cells are selectively recognized by galectin-3 but not by galectin-1. 1105 99

In this study, the expression patterns of Galectin-3 (Gal-3) and the frequency of infiltrating CD1a positive dendritic cells (DCs) were determined in 82 cases of vulvar tissues, consisting of normal squamous epithelia (NE, N = 10), vulvar condylomas (VC, N = 24), high grade vulvar intraepithelial neoplasias (HG-VIN, N = 26) of common type, and invasive keratinizing squamous cell carcinomas (SCC, N = 22) by a standard immunohistochemical method using monoclonal antibodies to investigate their differential expression in vulvar squamous dysplasia and infiltrating carcinomas with an emphasis on neoplastic transformation and progression. Gal-3 expression was cytoplasmic, nuclear or membranous in NE, VCs, and HG-VINs, with negative or weak and occasionally moderate reactivities. In SCCs, exclusively cytoplasmic staining patterns with moderate or strong reactivity in 59% of cases were observed (p < 0.0001, chi-square test); Gal-3 expression was not related with stage, grade, and recurrence. The frequency of CD1a positive DCs increased from NE and VCs to highest numbers in HG-VINs, was lowest in SCCs (p < 0.0001, ANOVA), and was not related with stage and grade, but with recurrence in SCCs (p = 0,048, t-test). This study indicates that qualitative and quantitative changes of Gal-3 immunoexpression and infiltration by CD1a positive DCs in vulvar NE, VCs, and HG-VIN lesions, respectively, compared with SCCs play a role in the development of an infiltrative phenotype, and may provide adjunctive criteria in the diagnosis of invasion of vulvar squamous epithelia.
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PMID:Galectin-3 and CD1a-positive dendritic cells are involved in the development of an invasive phenotype in vulvar squamous lesions. 1630 81