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)

Previous studies have analyzed the lymphoid and myeloid foci within the gingival mucosa in health and chronic periodontitis (CP); however, the principal APCs responsible for the formation and organizational structure of these foci in CP have not been defined. We show that in human CP tissues, CD1a(+) immature Langerhans cells predominantly infiltrate the gingival epithelium, whereas CD83(+) mature dendritic cells (DCs) specifically infiltrate the CD4(+) lymphoid-rich lamina propria. In vivo evidence shows that exacerbation of CP results in increased levels of proinflammatory cytokines that mediate DC activation/maturation, but also of counterregulatory cytokines that may prevent a Th-polarized response. Consistently, in vitro-generated monocyte-derived DCs pulsed with Porphyromonas gingivalis strain 381 or its LPS undergo maturation, up-regulate accessory molecules, and release proinflammatory (IL-1beta, PGE(2)) and Th (IL-10, IL-12) cytokines. Interestingly, the IL-10:IL-12 ratio elicited from P. gingivalis-pulsed DCs was 3-fold higher than that from Escherichia coli-pulsed DCs. This may account for the significantly (p < 0.05) lower proliferation of autologous CD4(+) T cells and reduced release of IFN-gamma elicited by P. gingivalis-pulsed DCs. Taken together, these findings suggest a previously unreported mechanism for the pathophysiology of CP, involving the activation and in situ maturation of DCs by the oral pathogen P. gingivalis, leading to release of counterregulatory cytokines and the formation of T cell-DC foci.
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PMID:Mature dendritic cells infiltrate the T cell-rich region of oral mucosa in chronic periodontitis: in situ, in vivo, and in vitro studies. 1159

Chemokines are mediators of innate and acquired immunity. CCL18, also designated pulmonary and activation-regulated chemokine (PARC), dendritic cell-derived CC chemokine-1 (DC-CK1), alternative macrophage activation-associated CC chemokine-1 (AMAC-1) and macrophage inflammatory protein-4 (MIP-4), was for the first time isolated from peripheral blood mononuclear cells (PBMC) and biochemically characterized. We found that CCL18/PARC protein is spontaneously secreted by PBMC and is selectively induced in PBMC by staphylococcal enterotoxins (SEA, SEB) and IL-4, but not by IFN-gamma and the CXCL8/IL-8 inducers lipopolysaccharide (LPS) or Concanavalin A. Human fibroblasts, chondrocytes and endothelial cells did not produce CCL18/PARC in response to inflammatory mediators such as measles virus, double-stranded RNA, LPS or IL-1beta, whereas up to 150 ng/ml of CCL2/MCP-1 was induced under these conditions. In synovial fluids from septic and rheumatoid arthritis patients, fourfold-enhanced CCL18/PARC levels (150 ng/ml) were detected compared to those in crystal-induced arthritis and osteoarthritis. In septic arthritis, the synovial levels of CCL18/PARC were fivefold higher than those of CXCL8/IL-8. Immunochemistry revealed CD68(+) monocytes/macrophages as the main CCL18/PARC-producing cell type in both PBMC and arthritic synovial tissue. In addition, CD1a(+) blood dendritic cells expressed CCL18/PARC. These findings suggest that monocytic cells respond to Gram-positive bacterial infection by the production of CCL18/PARC in the synovial cavity.
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PMID:Selective induction of CCL18/PARC by staphylococcal enterotoxins in mononuclear cells and enhanced levels in septic and rheumatoid arthritis. 1174 96

Reciprocal regulation of opposing functions characterizes biological systems. We now show that adenovirus-infected plasmacytoid dendritic cells (PDC) inhibit monocyte to myeloid dendritic cell (MDC) differentiation and function, and that adenovirus-infected monocytes inhibit PDC type I interferon secretion. Adenovirus-infected PDC secreted IFN-alpha, beta and omega in an 86:2:1 ratio. PDC type I interferons inhibited MDC differentiation and function (reduced IL-12 secretion, IFN-gamma induction, MLR and CD40 expression, and increased CD1a(+)CD14(+) cells). Type I interferon receptor blocking antibody reversed all PDC effects, and recombinant IFN-alpha, beta or omega replicated all effects, except reduced CD40. Adenovirus-infected monocytes suppressed PDC type I interferon secretion, which was reversed with anti-IL-10 neutralizing antibodies. Exogenous IL-10 suppressed PDC type I interferon secretion without reducing PDC viability. Therefore, monocyte IL-10 regulates PDC type I interferon secretion, and PDC type I interferons inhibit MDC differentiation and function. Such reciprocal regulation of potentially opposing influences may help modulate anti-pathogen immunity.
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PMID:Reciprocal regulation of plasmacytoid dendritic cells and monocytes during viral infection. 1174 5

Dendritic cells (DCs) play important roles in initiation and regulation of immune responses. DCs derived from human monocytes can be classified according to presence of CD1a molecules. Although CD1a+ DCs can be prepared from monocytes in media containing GM-CSF, IL-4, and FCS, it has been reported that CD1a+ DCs could not be easily obtained from monocytes using media containing human serum or plasma. In this study, we demonstrate for the first time that heparin can reliably induce differentiation of CD1a+ DCs from monocytes with or without autologous serum or plasma. The development of CD1a+ DCs is heparin concentration dependent (0-50 U/ml). Comparing with CD1a- DCs developed without heparin, CD1a+ DCs express higher CD40 and CD80 and lower CD86. Both CD1a+ and CD1a- DCs express similar levels of HLA-DR. CD80, CD86, HLA-DR, and CD40 are proportionally up-regulated when both types of DCs are stimulated with LPS or LPS plus IFN-gamma. The effect of heparin is neutralized by heparin-binding proteins, such as protamine sulfate, platelet factor-4, and beta-thromboglobulin. Functionally, heparin-treated DCs respond to LPS or LPS plus IFN-gamma with higher IL-10 and less IL-12 production than heparin-untreated DCs. Heparin-treated DCs are more potent in priming allogeneic and autologous CD4+ T cells to proliferate and to produce both type 1 and type 2 cytokines. The results of our study show that CD1a+ DCs can be prepared from monocytes ex vivo without using xenogeneic serum and may be used for immunotherapy.
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PMID:Heparin induces differentiation of CD1a+ dendritic cells from monocytes: phenotypic and functional characterization. 1180 47

P-glycoprotein (Pgp) and vaults are associated with multidrug resistance in tumor cells, but their physiological functions are not yet clear. Pgp, the prototypical transmembrane transporter molecule, may also facilitate the migration of skin dendritic cells (DC). Vaults--ribonucleoprotein cell organelles, frequently overexpressed in Pgp-negative drug-resistant tumor cells--have also been associated with intracellular transport processes. Given the pivotal role of DC in dealing with exposure to potentially harmful substances, the present study was set out to examine the expression of Pgp and vaults during differentiation and maturation of DC. DC were obtained from different sources, including blood-derived monocytes, CD34(+) mononuclear cells, and chronic myeloid leukemia cells. Whereas flow cytometric and immunocytochemical analyses showed slightly augmented levels of Pgp, up-regulation of vault expression during DC culturing was strong, readily confirmed by Western blotting, and independent of the source of DC. In further exploring the functional significance of vault expression, it was found that supplementing DC cultures with polyclonal or mAbs against the major vault protein led to lower viabilities of LPS- or TNF-alpha-matured monocytes-DC. Moreover, expression of critical differentiation, maturation, and costimulatory molecules, including CD1a and CD83, was reduced and their capacity to induce Ag-specific T cell proliferative and IFN-gamma release responses was impaired. These data point to a role for vaults in both DC survival and functioning as APC.
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PMID:Up-regulation of drug resistance-related vaults during dendritic cell development. 1182 84

The American cutaneous forms of leishmaniasis include immune-responder individuals with localised cutaneous leishmaniasis (LCL) and non-responder individuals with diffuse cutaneous leishmaniasis (DCL). Patients with intermediate or chronic cutaneous leishmaniasis (ICL) have increased morbidity due to the length of their illness, atypical forms and areas of compromise. In the present study, we evaluated the expression of the leukocyte antigens (CD4, CD8, CLA: cutaneous lymphocyte antigen, CD69, CD83 and CD1a) and cytokines (IFN-gamma, IL-4, IL-10 and TGF-beta 1) in the lesions of patients with ICL (n = 18) using an immunocytochemical procedure. ICL results were compared with the information for LCL (n = 19) and DCL (n = 4). The numbers of CD4+ and CD8+ T cells in ICL were similar to those of LCL lesions, but significantly different (P < or = 0.05) from DCL lesions. LCL lesions have about half the numbers of early activated CD69+ cells as ICL, but most are CLA+ skin homing memory T cells, whereas ICL lesions have the highest number of CD69+ T cells, but about one-third of these cells expressed CLA. This suggests that the granuloma of ICL patients contains many activated T cells that are unprimed to cutaneous-launched antigens, thus contributing to an aberrant immune response. In contrast, DCL granulomas presented the lowest numbers of activated CD69+ and CLA+ cells, associated with the characteristic tolerogenic state of these patients. The immunolocalisation of cytokines showed a mixed cytokine pattern in ICL lesions with many positive cells for IL-10, TGF-beta 1, IL-4 and IFN-gamma, with a preponderance of the first two, and different from the prevalent Th1 and Th2 responses associated with LCL and DCL lesions, respectively. CD1a+ Langerhans cells were decreased (P < or = 0.05) in both ICL (271 +/- 15 cells/mm2) and DCL (245 +/- 19 cells/mm2) as compared to LCL (527 +/- 54 cells/mm2) epidermis. The percentage of IL-10+ epidermal Langerhans cells in ICL (33.69), from the total CD1a+ population, was higher than in LCL (17.45). In addition, fewer CD83+ primed Langerhans cells were present in ICL epidermis. The diminished participation of epidermal Langerhans cells, causing a defective signalling by the epidermis, in ICL lesions may account for the tissue-damaging state observed in these patients.
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PMID:Intermediate or chronic cutaneous leishmaniasis: leukocyte immunophenotypes and cytokine characterisation of the lesion. 1195 26

Myeloid (CD11c+) dendritic cells (DC) are present in cerebrospinal fluid (CSF), as well as in the meninges and choroid plexus. Functional studies of these DC are hindered or impossible. To obviate this problem, we investigated the effects of CSF supernatants from patients with non-inflammatory neurological diseases (NIND), multiple sclerosis (MS), bacterial meningitis (BM) and Lyme meningoencephalitis (LM) on immature monocyte-derived DC (moDC) from healthy donors. CSF supernatants caused maturation of moDC (MS > LM > NIND > BM), as reflected by a decrease in CD1a, and an increase in HLA-DR, CD80 and CD86 expression. The maturation effect of MS CSF and LM CSF could be blocked by anti-TNF-alpha MoAb or recombinant human IL-10. moDC cultured with BM CSF either remained immature or turned into CD14+ macrophage-like cells and were relatively inefficient at inducing T cell responses in vitro. In contrast, moDC cultured with LM CSF induced strong Th1 responses. Both BM CSF and LM CSF contained IFN-gamma, a cytokine that augments IL-12 production by moDC and hence should confer an ability to induce a Th1 response. However, BM CSF also contained high levels of IL-10, which could antagonize the effects of IFN-gamma on moDC. moDC cultured with MS CSF induced a higher production of IFN-gamma from T cells compared to moDC cultured with NIND CSF or BM CSF. In summary, soluble factors present in the CSF may influence the phenotype and functions of meningeal, choroid plexus and CSF DC which, in turn, may have an impact on the character of intrathecal T cell responses.
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PMID:Cerebrospinal fluid affects phenotype and functions of myeloid dendritic cells. 1198 31

Dendritic cells (DC) derived from plasmacytoid precursors depend on IL-3 for survival and proliferation in culture, and they induce preferentially Th2 responses. Monocytes express not only GM-CSF receptors, but also IL-3Rs. Therefore, we examined whether IL-3 had an effect on the functional plasticity of human monocyte-derived DC generated in a cell culture system that is widely used in immunotherapy. DC were generated with IL-3 (instead of GM-CSF) and IL-4. Yields, maturation, phenotype (surface markers and Toll-like receptors), morphology, and immunostimulatory capacity were similar. Only CD1a was differentially expressed, being absent on IL-3-treated DC. In response to CD40 ligation DC generated in the presence of IL-3 secreted significantly less IL-12 p70 and more IL-10 compared with DC grown with GM-CSF. Coculture of naive allogeneic CD4(+) T cells with DC generated in the presence of IL-3 induced T cells to produce significantly more IL-5 and IL-4 and less IFN-gamma compared with stimulation with DC generated with GM-CSF. These data extend the evidence that different cytokine environments during differentiation of monocyte-derived DC can modify their Th cell-inducing properties. A hitherto unrecognized effect of IL-3 on DC was defined, namely suppression of IL-12 secretion and a resulting shift from Th1 toward Th2.
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PMID:A novel role for IL-3: human monocytes cultured in the presence of IL-3 and IL-4 differentiate into dendritic cells that produce less IL-12 and shift Th cell responses toward a Th2 cytokine pattern. 1205 33

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

We analyzed the role of CD8+ T cells on dendritic cells (DCs). Incubation of monocytes with activated but not resting CD8+ T cells induced their differentiation into DCs with a CD1a+ and CD14- phenotype. Activated CD8+ lymphocytes induced down-regulation of CD14 expression in interleukin (IL)-10-treated macrophages and resulted in the expression of DC-related CD1a and up-regulation of mRNA transcripts for RelB, IL-12p40, MCP-2, MIP-1alpha, and ELC. These DCs were potent stimulatory cells in mixed lymphocyte reaction and induced primary CTL responses. This interaction was independent of a direct cell-to-cell contact. Monoclonal antibodies against IFN-gamma completely abolished the CD1a induction on IL-10-treated antigen-presenting cells. These results demonstrate that CD8+ cells can provide stimulatory signals to antigen-presenting cells to induce their differentiation in DC and to increase their immunostimulatory capacity.
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PMID:Activated CD8+ T lymphocytes induce differentiation of monocytes to dendritic cells and restore the stimulatory capacity of interleukin 10-treated antigen-presenting cells. 1220 62


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