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)

Critical to the function of Ag-presenting dendritic cells (DCs) is their capacity to migrate to lymphoid organs and to sites of inflammation. A final stage of development, termed maturation, yields DCs that are strong stimulators of T cell-mediated immunity and is associated with a remodeling of the cell surface that includes a change in the levels of expression of many molecules, including chemokine receptors. We show in this study that CCR3, a chemokine receptor initially discovered on eosinophils, is also expressed by human DCs that differentiate from blood monocytes, DCs that emigrate from skin (epidermal and dermal DCs), and DCs derived from CD34+ hemopoietic precursors in bone marrow, umbilical cord blood, and cytokine-elicited peripheral blood leukapheresis. Unlike other chemokine receptors, such as CCR5 and CCR7, the expression of CCR3 is not dependent on the state of maturation. All DC subsets contain a large intracellular pool of CCR3. The surface expression of CCR3 is not modulated following uptake of particulate substances such as zymosan or latex beads. CCR3 mediates in vitro chemotactic responses to the known ligands, eotaxin and eotaxin-2, because the DC response to these chemokines is inhibited by CCR3-specific mAbs. We postulate that expression of CCR3 may underlie situations where both DCs and eosinophils accumulate in vivo, such as the lesions of patients with Langerhans cell granulomatosis.
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PMID:Expression of a functional eotaxin (CC chemokine ligand 11) receptor CCR3 by human dendritic cells. 1221 6

Langerhans cell histiocytosis (LCH) is characterized by a clonal proliferation and retention of cells with a Langerhans cell (LC)-like phenotype at various sites within the body. The present study set out to elucidate whether aberrant expression of chemokine receptors or dysregulation of chemokine production in LCH lesions could explain abnormal retention of these cells. Immunohistochemical analysis on 13 LCH biopsies of bone, skin, and lymph node all expressed the immature dendritic cell (DC) marker CCR6 on the lesional LCs and absence of the mature DC marker CCR7. Furthermore, regardless of the tissue site, LCH lesions markedly overexpressed CCL20/MIP-3alpha, the ligand for CCR6. The lesional LCs appeared to be the source of this CCL20/MIP-3alpha production as well as other inflammatory chemokines such as CCL5/RANTES and CXCL11/I-TAC. These may explain the recruitment of eosinophils and CD4+CD45RO+ T cells commonly found in LCH lesions. The findings of this study emphasize that, despite abundant TNF-alpha, lesional LCs remain in an immature state and are induced to produce chemokines, which via autocrine and paracrine mechanisms cause not only the retention of the lesional LCs but also the recruitment and retention of other lesional cells. We postulate that the lesional LCs themselves control the persistence and progression of LCH.
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PMID:Aberrant chemokine receptor expression and chemokine production by Langerhans cells underlies the pathogenesis of Langerhans cell histiocytosis. 1274 70

Accumulating data have shown that the microenvironment of dendritic cells modulates subtype differentiation and CD1 expression, but the mechanisms by which exogenous factors confer these effects are poorly understood. Here we describe the dependence of CD1a- monocyte-derived dendritic cell (moDC) development on lipids associated with the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma). We also show the consecutive differentiation of immature CD1a-PPARgamma+ moDCs to CD1a+PPARgamma- cells limited by serum lipoproteins and terminated by proinflammatory cytokines. Immature CD1a- moDCs possess higher internalizing capacity than CD1a+ cells, whereas both activated subtypes have similar migratory potential but differ in their cytokine and chemokine profiles, which translates to distinct T-lymphocyte-polarizing capacities. CD1a+ moDCs stand out by their capability to secrete high amounts of IL-12p70 and CCL1. As lipoproteins skew moDC differentiation toward the generation of CD1a-PPARgamma+ cells and inhibit the development of CD1a+PPARgamma- cells, we suggest that the uptake of lipids results in endogenous PPARgamma agonists that induce a cascade of gene transcription coordinating lipid metabolism, the expression of lipid-presenting CD1 molecules, subtype dichotomy, and function. The presence of CD1a-PPARgamma+ and CD1a+PPARgamma- DCs in lymph nodes and in pulmonary Langerhans cell histiocytosis confirms the functional relevance of these DC subsets in vivo.
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PMID:Differentiation of CD1a- and CD1a+ monocyte-derived dendritic cells is biased by lipid environment and PPARgamma. 1696 96

Osteopontin (OPN) acts as an osteoclast activator, a proinflammatory cytokine, and a chemokine attracting histiocytes/monocytes and is abundantly expressed in Langerhans cell histiocytosis (LCH). We investigated whether serum OPN levels are related to disease types in LCH. Fifty-eight newly diagnosed LCH patients were studied; eight with risk organ (liver, spleen and/or hematopoietic) involvements positive multisystem (MS+) disease, 27 with risk organ involvement negative multisystem (MS-) disease and 23 with single system (SS) disease. Pediatric patients with non-inflammatory disease (n=27) were used as controls. All of patients with MS+ disease were younger than 3 years. Serum OPN levels and 44 kinds of humoral factors were measured by ELISA and Bio-Plex suspension array system, respectively. In the patients younger than 3 years, the median serum OPN level (interquartile range) was 240.3 ng/ml (137.6-456.0) in MS+ (n=8); 92.7 ng/ml (62.0-213.8) in MS- (n=14) and 72.5 ng/ml (55.6-94.0) in SS (n=9) and 74.4 ng/ml (42.2-100.0) in control (n=12). The OPN values were significantly higher in the MS+ group than the MS-, SS and control groups (p=0.044, p=0.001 and p=0.002, respectively), but not different between the MS-, SS and control groups. In the patients older than 3 years, the median level of serum OPN (IQR) was 56.2 ng/ml (22.9-77.5) in MS- (n=13), 58.9 ng/ml (31.0-78.7) in SS (n=14) and 41.9 (28.9-54.1) in control (n=15). These values did not differ significantly between each group. The serum OPN levels were positively correlated with the serum IL-6, CCL2, IL-18, IL-8 and IL-2 receptor concentration. OPN may be involved in risk organ dissemination and poor prognosis of LCH through the function as inflammatory cytokine/chemokine.
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PMID:High serum osteopontin levels in pediatric patients with high risk Langerhans cell histiocytosis. 2508 62