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

Langerhans cells (LCs) represent a subset of immature dendritic cells (DCs) specifically localized in the epidermis and other mucosal epithelia. As surrounding keratinocytes can produce interleukin (IL)-15, a cytokine that utilizes IL-2Rgamma chain, we analyzed whether IL-15 could skew monocyte differentiation into LCs. Monocytes cultured for 6 d with granulocyte/macrophage colony-stimulating factor (GM-CSF) and IL-15 differentiate into CD1a(+)HLA-DR(+)CD14(-)DCs (IL15-DCs). Agents such as lipopolysaccharide (LPS), tumor necrosis factor (TNF)alpha, and CD40L induce maturation of IL15-DCs to CD83(+), DC-LAMP(+) cells. IL15-DCs are potent antigen-presenting cells able to induce the primary (mixed lymphocyte reaction [MLR]) and secondary (recall responses to flu-matrix peptide) immune responses. As opposed to cultures made with GM-CSF/IL-4 (IL4-DCs), a proportion of IL15-DCs expresses LC markers: E-Cadherin, Langerin, and CC chemokine receptor (CCR)6. Accordingly, IL15-DCs, but not IL4-DCs, migrate in response to macrophage inflammatory protein (MIP)-3alpha/CCL20. However, IL15-DCs cannot be qualified as "genuine" Langerhans cells because, despite the presence of the 43-kD Langerin, they do not express bona fide Birbeck granules. Thus, our results demonstrate a novel pathway in monocyte differentiation into dendritic cells.
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PMID:Interleukin 15 skews monocyte differentiation into dendritic cells with features of Langerhans cells. 1158 22

Sarcoidosis, a chronic granulomatous disease of unknown etiology, is treated with immune suppressive drugs such as corticosteroids. Sarcoidosis patients have been reported to benefit clinically from treatment with thalidomide. We administered thalidomide for 16 weeks to eight patients with chronic skin sarcoidosis and evaluated the drug's effects before and with treatment. After thalidomide treatment, all skin biopsies showed decreases in granuloma size and reduction in epidermal thickness. We also observed extensive T cell recruitment into the granulomas, the appearance of multinucleated giant cells, and increased numbers of dermal Langerhans cells (CD1a(+)) and mature dendritic cells (CD83(+) or DC-LAMP(+)). Plasma IL-12 levels increased and remained elevated during the treatment period. We noted increased HLA-DR expression on peripheral blood lymphocytes and a corresponding drop in the naive T cell marker CD45RA. Our data suggest that thalidomide treatment of sarcoidosis results in granuloma differentiation to a Th1-type cellular immune response usually associated with protective immunity to tuberculosis and tuberculoid leprosy.
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PMID:Thalidomide induces granuloma differentiation in sarcoid skin lesions associated with disease improvement. 1189 Jul 9

Veiled cells (VC) present in afferent lymph transport antigen from the periphery to the draining lymph nodes. Although VC in lymph form a heterogeneous population, some of the cells clearly belong on morphological grounds to the Langerhans cell (LC)/ dendritic cell (DC) series. Here we show that culturing monocytes for 24 hrs while avoiding plastic adherence (polypropylene tubes) and avoiding the activation of NADPH oxidase (blocking agents) results in the generation of a population of veiled accessory cells. The generated VC were actively moving cells like lymph-borne VC in vivo. The monocyte (mo)-derived VC population existed of CD14(dim/-) and CD14(brighT) cells. Of these the CD14(dim/-) VC were as good in stimulating allogeneic T cell proliferation as immature DC (iDC) obtained after one week of adherent culture of monocytes in granulocyte-macrophage-colony stimulating factor (GM-CSF)/interleukin (IL)-4. This underscores the accessory cell function of the mo-derived CD14(dim/-) VC. Although the CD14(dim/-)VC had a modest expression of the DC-specific marker CD83 and were positive for S100, expression of the DC-specific markers CD1a, Langerin, DC-SIGN, and DC-LAMP were absent. This indicates that the here generated CD14(dim/-) VC can not be considered as classical LC/DC. It was also impossible to turn the CD14(dim/-) mo-derived VC population into typical DC by culture for one week in GM-CSF/IL-4 or LPS. In fact the cells died tinder such circumstances, gaining some macrophage characteristics before dying. The IL-12 production from mo-derived CD14(dim/-) VC was lower, whereas the production of IL-10 was higher as compared to iDC. Consequently the T cells that were stimulated by these mo-derived VC produced less IFN-gamma as compared with T cells stimulated by iDC. Our data indicate that it is possible to rapidly generate a population of CD14(dim/-) veiled accessory cells from monocytes. The marker pattern and cytokine production of these VC indicate that this population is not a classical DC population. The cells might earlier be related to the veiled macrophage-like cells also earlier described in afferent lymph.
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PMID:Accessory cells with a veiled morphology and movement pattern generated from monocytes after avoidance of plastic adherence and of NADPH oxidase activation. A comparison with GM-CSF/IL-4-induced monocyte-derived dendritic cells. 1218 52

The coordinated migration and maturation of dendritic cells (DCs) such as intraepithelial Langerhans cells (LCs) is considered critical for T cell priming in response to inflammation in the periphery. However, little is known about the role of inflammatory mediators for LC maturation and recruitment to lymph nodes in vivo. Here we show in human dermatopathic lymphadenitis (DL), which features an expanded population of LCs in one draining lymph node associated with inflammatory lesions in its tributary skin area, that the Langerin/CD207(+) LCs constitute a predominant population of immature DCs, which express CD1a, and CD68, but not CD83, CD86, and DC-lysosomal-associated membrane protein (LAMP)/CD208. Using LC-type cells generated in vitro in the presence of transforming growth factor (TGF)-beta1, we further found that tumor necrosis factor (TNF)-alpha, as a prototype proinflammatory factor, and a variety of inflammatory stimuli and bacterial products, increase Langerin expression and Langerin dependent Birbeck granules formation in cell which nevertheless lack costimulatory molecules, DC-LAMP/CD208 and potent T cell stimulatory activity but express CCR7 and respond to the lymph node homing chemokines CCL19 and CCL21. This indicates that LC migration and maturation can be independently regulated events. We suggest that during DL, inflammatory stimuli in the skin increase the migration of LCs to the lymph node but without associated maturation. Immature LCs might regulate immune responses during chronic inflammation.
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PMID:Accumulation of immature Langerhans cells in human lymph nodes draining chronically inflamed skin. 1218 34

Recruitment of monocytes into tissues and their differentiation into macrophages or dendritic cells (DCs) depend on the microenvironment of the inflammatory site. Although many factors affecting this process have been identified, the intracellular signaling pathways implicated are poorly understood. We found that cyclic nucleotides regulate certain steps of monocyte differentiation into DCs. Increased levels of the cyclic nucleotides, cAMP or cGMP, inhibit differentiation of CD14(+)/CD1a(low) monocytes into CD14(-)/CD1a(high) DCs. However, DC-specific ICAM-3-grabbing nonintegrin (CD209) up-regulation was not affected by cyclic nucleotides, indicating that DC development was not blocked at the monocyte stage. Interestingly, Ag-presenting function was increased by cyclic nucleotides, as measured by the higher expression of MHC class II, CD86, and an increased ability to stimulate CD4(+) T cell proliferation in allogeneic MLRs. Although cyclic nucleotides do not completely block DC differentiation, they do block the ability of DCs to be induced to mature by LPS. Treatment during DC differentiation with either cAMP or cGMP analogues hampered LPS-induced expression of CD83, DC-LAMP, and CCR7 and the ability of DCs to migrate toward CCL19/macrophage-inflammatory protein 3beta. Interestingly, the induction of a CD16(+) subpopulation of cells was also observed. Thus, signals causing an increase in either cAMP or cGMP levels during monocyte recruitment to inflammatory sites may restrain the activation of acquired immunity by blocking DC development and migration to lymph nodes. At the same time, these signals promote development of an active intermediate cell type having properties between those of macrophages and DCs, which might contribute to the innate immune response in the periphery.
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PMID:Cyclic nucleotides promote monocyte differentiation toward a DC-SIGN+ (CD209) intermediate cell and impair differentiation into dendritic cells. 1466 41

The aim of this study was to compare the cellular composition and organization of rheumatoid (RA) synovium, which has several of the characteristics of lymphoid organs, with lymph nodes. To clarify further whether RA synovium can be classified as an ectopic lymphoid organ, paired RA synovium and lymph node (LN) tissues from 11 patients were compared in terms of T-cell-B-cell and germinal centre (GC) organization, dendritic cell (DC) subsets, and chemokine expression. Tonsil, a normal secondary lymphoid organ, was used as a tissue control. In paired RA LN and synovium, more follicular DC-positive GCs were observed in LN, but when observed in synovium, they shared the same T-cell-B-cell organization and mean GC size. In LN, a predominance of mature DC-LAMP-positive DCs of myeloid (CD11c-positive) or lymphoid (CD123-positive) origin was observed, whereas paired RA synovium was characterized by the relative accumulation of immature CD1a-positive DCs. In the same way, CCL19-CCL21/CCR7, a chemokine/chemokine receptor complex involved in mature DC migration, was more frequently seen in LN than in paired RA synovium. In synovium, such expression was associated with lymphoid follicle formation, with or without a GC. Conversely, CCL20, a chemokine involved in immature DC migration, was expressed in RA synovium and tonsils but not in paired LNs. In conclusion, although similarities were observed, this study, using paired samples, indicates that the RA synovium lacks some of the features that are characteristic of a lymphoid organ.
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PMID:Paired synovium and lymph nodes from rheumatoid arthritis patients differ in dendritic cell and chemokine expression. 1530 35

There is a burgeoning literature on the contrasting role of intratumoral dendritic cells (DCs) and tumor-associated macrophages, making reliable identification of both cell types in clinical and experimental tissue sections important. However, because these cell types are closely related and share several differentiation antigens, their absolute distinction in tissue sections is difficult. We differentiated DCs and macrophages from monocytes in vitro, prepared cytospins and paraffin-embedded sections of the various cell populations, and tested a variety of antibodies that purportedly recognize monocytes and DCs for their capacity to react and distinguish cells after conventional formalin fixation. Cultured DCs but not macrophages were detected by fascin, DC-LAMP, and CD83 with a predictable increase in staining that paralleled their maturation. Staining by CD1a was found on immature DCs but was weak and absent on mature DCs and macrophages, respectively. CD14 and CD163 were characteristic for macrophages and absent on DCs. CD68, HLA-DR, and S100 did not discriminate between DCs and macrophages. We conclude that antigens such as HLA-DR and S100 are not in themselves sufficient for identification of DCs in formalin-fixed tissue sections, but that additional macrophage-specific (CD14, CD163) and DC-specific (CD1a, CD83, fascin, DC-LAMP) antigens should be used to distinguish cell types from each other and to provide information on their state of maturation.
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PMID:A basis for distinguishing cultured dendritic cells and macrophages in cytospins and fixed sections. 1571 17

In multiple sclerosis (MS), dendritic cells (DCs) recruited to the central nervous system (CNS) are thought to be involved in the regulation of autoimmune responses directed against myelin antigens. To better understand the role of DCs in CNS inflammation, we performed a detailed immunohistochemical analysis of DC maturation markers and of DC relationship to CNS-infiltrating T cells in autopsy brain tissue of patients with MS. We also investigated the presence of DCs containing myelin debris in MS lesions. Myeloid DC subsets were identified using the following markers: CD1a for immature DCs; DC-SIGN for immature and mature DCs; and fascin, CD83, DC-LAMP, and CCR7 for mature DCs. The most common finding was the presence of cells expressing DC-SIGN and containing myelin components in the perivascular cuffs of early active and chronic (both active and inactive) MS lesions. Perivascular CD1a DCs were detected in active lesions in only one of 10 patients with MS who were examined. Although less numerous than DC-SIGN DCs, cells expressing mature DC markers were consistently detected in the inflamed meninges and perivascular cuffs of most active lesions examined. CCR7 immunostaining was predominantly confined to activated microglia at the lesion edges. Some perivascular DC-SIGN cells were found in close proximity to or contacting rare proliferating lymphocytes, most of which expressed the DC-SIGN ligand ICAM-3 and CD8. These data suggest that DCs recruited and maturing in MS lesions, where self-antigens are made available by continuous myelin destruction, may contribute to the local activation and expansion of presumably pathogenic T cells.
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PMID:Dendritic cells in multiple sclerosis lesions: maturation stage, myelin uptake, and interaction with proliferating T cells. 1646 4

As the most potent antigen presenting cells, dendritic cells (DCs) play key roles in the immune response against tumors. Their density in the tumor tissue has been associated with prognosis in patients with various cancers. However, few studies have been aimed at the presence and maturation state of DCs in cutaneous melanoma, with regard to their potential clinical correlates. In this study, the density of DCs expressing CD1a and the maturation marker DC-LAMP was determined by immunohistochemistry in primary tumor samples from 82 patients with cutaneous malignant melanoma. Intratumoral and peritumoral cell densities were analyzed in relation to tumor thickness and the subsequent development of metastases, as well as to patients' survival. CD1a(+) DCs were found both infiltrating melanoma cell nests and in the surrounding stroma, while DC-LAMP(+) mature DCs were generally confined to the peritumoral areas, associated with lymphocytic infiltrates. DC density values significantly correlated with the number of activated (CD25(+) or OX40(+)) T lymphocytes (p < 0.001). The degree of infiltration by CD1a(+) and DC-LAMP(+) DCs showed strong inverse correlation with the thickness of melanomas (p < 0.001). High peritumoral density of mature DCs was associated with significantly longer survival (p = 0.0195), while density of CD1a(+) cells had a prognostic impact of borderline significance (p = 0.0610). Moreover, combination of high peritumoral CD1a(+) or DC-LAMP(+) cell density with high number of CD25(+) or OX40(+) lymphocytes identified patient subgroups with more favorable survival compared to other subgroups. A multivariate survival analysis involving DC and activated T-cell densities alone and in combinations, as well as traditional prognostic factors, identified high DC-LAMP(+) cell/high OX40(+) cell density and Breslow index as independent predictors of good prognosis. These results suggest that the presence of CD1a(+) DCs primarily depends on the thickness of melanomas, without direct relationship with the patients' survival. On the other hand, the density of mature DCs, especially in association with that of activated T cells, proved of prognostic importance, suggesting that these parameters could be considered as signs of a functional immune response associated with better outcome of the disease.
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PMID:Density of DC-LAMP(+) mature dendritic cells in combination with activated T lymphocytes infiltrating primary cutaneous melanoma is a strong independent prognostic factor. 1727 13

The purpose of this study was to investigate with immunohistochemical methods antigen presenting cells and their relationship to blood and lymphatic vessels in human term placenta. Fetal placental antigen presenting cells, historically also known as Hofbauer cells, were located in the chorionic villi below the syncytiotrophoblast and in the vicinity of fetal capillaries. DC-SIGN/CD209 expression was observed on CD163+, CD68+, CD45+, HLA-A,B,C+, DC-LAMP/CD208-, CD86-, Langerin/CD207-, FXIIIa-, CD1a- cells consistent with the macrophage nature of these cells. These fetal DC-SIGN+ cells lack HLA-DR, -DP, -DQ expression. Moreover, we show for the first time that they co-express the hyaluronan receptor LYVE-1. In contrast, no LYVE-1+ vessel structures, i.e. lymphatic vessels, were detected. Human term decidua hosted a variety of CD45+ cells, further phenotyped as CD163+, DC-SIGN+, CD68+, HLA-DR+, HLA-A,B,C+. Mature dendritic cells were never observed in human term placenta. In summary, human term placenta is an immunoprivileged organ without lymphatic drainage and with numerous DC-SIGN+ macrophages within the chorionic villi. We hypothesize that these cells may fulfil a function in innate responses against pathogens as well as be involved in the homeostasis of hyaluronan metabolism in the rapidly differentiating placenta.
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PMID:DC-sign+ CD163+ macrophages expressing hyaluronan receptor LYVE-1 are located within chorion villi of the placenta. 1807 89


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