Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human epidermal Langerhans cells express two (CD1a and CD1c) of the three human thymic cell surface differentiation antigens (CD1a, CD1b, and CD1c). The first cluster of differentiation antigens (CD1) is defined by a group of monoclonal antibodies (MCA). All these MCA were obtained after immunization of mice or rats with human cortical thymocytes. OKT6 MCA (a CD1a MCA) was the first to be described as reactive with human epidermal Langerhans cells. We produced a murine MCA, called DMC1, after immunization with proliferating Langerhans cells of Eosinophilic Granuloma of the bone (Histiocytosis X). In tissues DMC1 MCA reacted with epidermal dendritic cells (Langerhans cells) in the skin and cortical thymocytes in the thymus as observed on indirect immunofluorescence. At the ultrastructural level, DMC1 MCA was specific for Birbeck granule-containing Langerhans cells and did not react with melanocyte and keratinocyte populations. The quantitative analysis of immunoelectron labeling and the cytofluorometric study showed that the intensity of labeling was inversely correlated with the concentration of trypsin used in the preparation of epidermal cell from skin samples. DMC1 MCA precipitated a protein with a relative mass of 49,000 (CD1a molecule) from lysates of iodinated epidermal Langerhans cells under reducing conditions. It recognized the original CD1a molecule (Mr 49,000) but not the membrane breakdown product of CD1a (Mr 27,000) brought about by trypsin.
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PMID:DMC1: a monoclonal antibody produced from histiocytosis X cells which reacts with the native CD1a molecule of human epidermal Langerhans cells. 246 37

Congenital self-healing histiocytosis (CSHH) is a rare primary histiocytic skin disorder. Only a few cases have been studied by ultrastructure and immunohistochemistry. Here we report a new case that was investigated using an electron microscope and a panel of monoclonal (MCA) and polyclonal (PCA) antibodies. CSHH cells were found to bear the immunohistochemical phenotype of normal epidermal Langerhans cells (LC) and histiocytosis X (HX) cells (CD1a/c+, CD1b-, CD4+/-, human leukocyte antigen [HLA]-DR/DQ+, S-100+). However, an electron microscope showed a paucity of Birbeck granule (BG)-containing cells. This contrasted with their immunophenotype. This finding, along with other ultrastructural characteristics of CSHH cells, suggests that histologic differences exist between CSHH and HX. However, because no absolute histologic criterion is known that allows unequivocally the differential diagnosis between the two diseases, this distinction currently has to rely on clinical criteria, mainly the regressive course observed within a few months in CSHH. The precise nosologic position of CSHH among other histiocytic syndromes remains unsettled.
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PMID:Congenital self-healing histiocytosis (Hashimoto-Pritzker). An ultrastructural and immunohistochemical study. 327 80

Langerhans' cell histiocytosis (LCH) is characterized by the presence of large mononucleated cells, associated with inflammatory cells. The Langerhans' cell (LC) lineage of the mononucleated cells is suggested by the presence of Birbeck granules and the expression of CD1a. We investigated the presence of 14 markers expressed by normal LCs in vitro. Nine skin and one lymph node frozen biopsies of LCH children were analysed by in situ immunohistochemistry. The data were compared with six skin and five lymph node frozen biopsies. LCH cells of the ten samples were positive for all 14 LC markers. We observed three different groups of markers, according to the respective staining of normal LCs and LCH cells. Group 1 included DR, DQ, CD1a, CD1c, and ICAM-3. Markers of group 1 were present on the majority of both normal LCs and LCH cells. Group 2 included CD1b, CD4, LFA-1, LFA-3, CD32, and CD68. Markers of group 2 were detected on the majority of LCH cells, but only on a fraction of normal LCs. Group 3 included CD11b, CD24, and B7/BB1. Markers of this group were detected on LCH cells, but not on normal LCs. This in situ immunohistochemical study confirms that LCH cells belong to the LC lineage. The different clinical LCH syndromes had the same immunohistochemical staining. The expression of some markers of groups 2 and 3 is known to be related to the activation of LCs in vitro. Our study suggests that LCH cells are activated LCs.
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PMID:Langerhans' cell histiocytosis cells are activated Langerhans' cells. 796 9

Macrophage-derived chemokine (MDC)/CCL22 is a CC chemokine active on dendritic cells (DC), NK cells and Th2 lymphocytes. The present study was aimed at comprehensively investigating MDC production in vitro and in vivo. DC were the most potent producers of MDC among leukocytes tested. Endothelial cells did not produce MDC under a variety of conditions. Signals that induce maturation (lipopolysaccharide, IL-1, TNF, CD40 ligand, recognition of bacteria and yeast) dramatically augmented MDC production, and dexamethasone and vitamin D3 blocked it. Prostaglandin E(2), which blocked the acquisition of IL-12 production and the capacity to promote Th1 generation, did not affect MDC production. Using mass spectrometry-based techniques, DC supernatants were found to contain N-terminally truncated forms of MDC [MDC(3-69), MDC(5-69) and MD(C7-69)] as well as the full-length molecule. In vivo, CD1a(+), CD83(+), MDC(+) DC were found in reactive lymph nodes, and in Langerhans' cell histiocytosis. Skin lesions of atopic dermatitis patients showed that CD1a(+) or CD1b(+) DC, and DC with a CD83(+) phenotype were responsible for MDC production in this Th2-oriented disorder. Thus, DC are the predominant source of MDC in vitro and in vivo under a variety of experimental and clinical conditions. Processing of MDC to MDC(3-69) and shorter forms which do not recognize CCR4 is likely to represent a feedback mechanism of negative regulation.
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PMID:Dendritic cells as a major source of macrophage-derived chemokine/CCL22 in vitro and in vivo. 1124 Dec 86