The diagnosis of pulmonary Langerhans cell histiocytosis might be refined by demonstrating reliability of a new cell marker, i.e., Langerin (CD207), used on bronchoalveolar lavage fluid. For this purpose, we collected material from patients with this disease and also with sarcoidosis and idiopathic pulmonary fibrosis as controls. In addition to the immunocytochemical detection of Langerin, we examined the expression profiles of CD1a and the macrophage tandem-repeat mannose receptor (CD206). To test accessibility of Langerin, a C-type lectin, for mannosides, we employed reverse lectin histochemistry using mannose-containing neoglycoproteins. The analysis revealed a significantly increased percentage of CD1a- and Langerin-positive cells in pulmonary Langerhans cell histiocytosis in comparison with both other studied diseases. No expression of the 175-kDa mannose-binding lectin (CD206) in Langerhans cells was observed. Evidently, binding sites on the cells were not accessible for the mannose-containing neoglycoligand. These results provide evidence for the usefulness of Langerin-directed immuno- and glycohistochemical monitoring of bronchoalveolar lavage fluid in the diagnosis of pulmonary Langerhans cell histiocytosis.

• MeSH
• Antigens, CD1 biosynthesis   MeSH
• Antigens, Surface metabolism   MeSH
• Bronchoalveolar Lavage Fluid cytology   MeSH
• Antigens, CD MeSH
• Diagnosis, Differential MeSH
• Adult MeSH
• Microscopy, Fluorescence MeSH
• Histiocytosis, Langerhans-Cell diagnosis   MeSH
• Immunohistochemistry MeSH
• Lectins, C-Type biosynthesis   metabolism   MeSH
• Mannose-Binding Lectins biosynthesis   metabolism   MeSH
• Middle Aged MeSH
• Humans MeSH
• Pulmonary Fibrosis diagnosis   MeSH
• Sarcoidosis, Pulmonary diagnosis   MeSH
• Mannose Receptor MeSH
• Receptors, Cell Surface biosynthesis   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Antigens, CD1 MeSH
• Antigens, Surface MeSH
• Antigens, CD MeSH
• CD1a antigen MeSH Browser
• CD207 protein, human MeSH Browser
• Lectins, C-Type MeSH
• Mannose-Binding Lectins MeSH
• Mannose Receptor MeSH
• Receptors, Cell Surface MeSH

Tandem-repeat C-type lectins (pattern-recognition receptors) with specificity for mannosides are intimately involved in antigen recognition, uptake, routing and presentation in macrophages and dendritic cells. In Langerhans cells, Langerin (CD207), a type-II transmembrane protein with a single C-type carbohydrate recognition domain attached to a heptad repeat in the neck region, which is likely to establish oligomers with an alpha-coiled-coil stalk, has been implicated in endocytosis and the formation of Birbeck granules. The structure of Langerin harbours essential motifs for Ca2+-binding and sugar accommodation. Lectin activity has previously been inferred by diminished antibody binding to cells in the presence of the glycan ligand mannan. In view of the complexity of the C-type lectin/lectin-like network, it is unclear what role Langerin plays for Langerhans cells in binding mannosides. In order to reveal in frozen tissue sections to what extent mannose-binding activity co-localizes with Langerin, we have used a synthetic marker, i.e. a neoglycoprotein carrying mannose maxiclusters, as a histochemical ligand, and computer-assisted fluorescence monitoring in a double-labelling procedure. Mannoside-binding capacity was detected in normal epithelial cells. Double labelling ensured the unambiguous assessment of the binding of the neoglycoprotein in Langerhans cells. Light-microscopically, its localization profile resembled the pattern of immunohistochemical detection of Langerin. This result has implications for suggesting rigorous controls in histochemical analysis of this cell type, because binding of kit reagents, i.e. mannose-rich glycoproteins horseradish peroxidase or avidin, to Langerin (or a spatially closely associated lectin) could yield false-positive signals. To show that recognition of carbohydrate ligands in dendritic cells is not restricted to mannose clusters, we have also documented binding of carrier-immobilized histo-blood group A trisaccharide, a ligand of galectin-3, which was not affected by the presence of a blocking antibody to Langerin. Remarkably, access to the carbohydrate recognition domain of Langerin appeared to be impaired in proliferatively active environments (malignancies, hair follicles), indicating presence of an endogenous ligand with high affinity to saturate the C-type lectin under these conditions.

• MeSH
• Antigens, Surface immunology   metabolism   MeSH
• Antigens, CD MeSH
• Epidermal Cells MeSH
• Epidermis chemistry   metabolism   MeSH
• Carcinoma metabolism   secondary   MeSH
• Langerhans Cells immunology   metabolism   pathology   MeSH
• Lectins, C-Type chemistry   immunology   metabolism   MeSH
• Mannose-Binding Lectins * MeSH
• Humans MeSH
• Mannosides immunology   metabolism   MeSH
• Neoplasms metabolism   pathology   MeSH
• Image Processing, Computer-Assisted MeSH
• Mouth Mucosa cytology   metabolism   MeSH
• Binding Sites, Antibody MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens, Surface MeSH
• Antigens, CD MeSH
• CD207 protein, human MeSH Browser
• Lectins, C-Type MeSH
• Mannose-Binding Lectins * MeSH
• Mannosides MeSH

BACKGROUND/AIM: Components of the tear fluid contribute to the biochemical defence system of the eye. To reveal whether the immune mediator and lipopolysaccharide binding galectin-3 is present in tears, tear samples were collected from eyes in healthy and pathological states. Investigation of expression of galectin-3 and galectin-3 reactive glycoligands in normal human conjunctival and corneal epithelia was also initiated as a step to understand the role of galectin-3 in ocular surface pathology. METHODS: Immunoblot analysis using either a rabbit polyclonal or a mouse monoclonal antibody against galectin-3 was employed to detect galectin-3 in tear fluid. Galectin-3 expression in tissue specimens was detected by immunocytochemistry employing A1D6 mouse monoclonal antibody, and galectin-3 reactive glycoligands were visualised by lectin histochemistry using labelled galectin-3. RESULTS: Galectin-3 was found only in tears from patients with ocular surface disorders. It was expressed in normal corneal and conjunctival epithelia but not in lacrimal glands. Inflammatory leucocytes and goblet cells found in galectin-3 containing tear fluid also expressed galectin-3. Galectin-3 binding sites were detected on the surface of conjunctival and corneal epithelial cells co-localising with desmoglein. CONCLUSIONS: This study revealed expression of galectin-3 in tear fluid obtained from patients with eye diseases. The role of this endogenous lectin (produced by inflammatory as well as epithelial cells) in antimicrobial action and inflammation modulation could be expected.

• MeSH
• Antigens, Differentiation analysis   MeSH
• Electrophoresis, Polyacrylamide Gel MeSH
• Fluorescent Antibody Technique MeSH
• Galectin 3 MeSH
• Immunoblotting MeSH
• Conjunctiva metabolism   MeSH
• Leukocytes metabolism   MeSH
• Humans MeSH
• Luminescent Measurements MeSH
• Eye Diseases metabolism   MeSH
• Goblet Cells metabolism   MeSH
• Epithelium, Corneal metabolism   MeSH
• Tears chemistry   MeSH
• Blotting, Western MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antigens, Differentiation MeSH
• Galectin 3 MeSH