• IMMUNE NETWORK
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• v.13 no.5
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• pp.218-221
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• 2013

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ${\alpha}$-galactosylceramide (${\alpha}$-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-${\gamma}$ by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

• IMMUNE NETWORK
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• v.15 no.3
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• pp.111-120
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• 2015

Dendritic cells (DCs) play a significant role in establishing self-tolerance through their ability to present self-antigens to developing T cells in the thymus. DCs are predominantly localized in the medullary region of thymus and present a broad range of self-antigens, which include tissue-restricted antigens expressed and transferred from medullary thymic epithelial cells, circulating antigens directly captured by thymic DCs through coticomedullary junction blood vessels, and peripheral tissue antigens captured and transported by peripheral tissue DCs homing to the thymus. When antigen-presenting DCs make a high affinity interaction with antigen-specific thymocytes, this interaction drives the interacting thymocytes to death, a process often referred to as negative selection, which fundamentally blocks the self-reactive thymocytes from differentiating into mature T cells. Alternatively, the interacting thymocytes differentiate into the regulatory T (Treg) cells, a distinct T cell subset with potent immune suppressive activities. The specific mechanisms by which thymic DCs differentiate Treg cells have been proposed by several laboratories. Here, we review the literatures that elucidate the contribution of thymic DCs to negative selection and Treg cell differentiation, and discusses its potential mechanisms and future directions.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.364-367
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• 2011

Background: Prostaglandins (PGs) play pathogenic and protective roles in inflammatory diseases. The novel concept of PGs as immune modulators is being documented by several investigators. By establishing an in vitro experimental model containing human follicular dendritic cell-like cells, HK cells, we reported that HK cells produce prostaglandin $E_2$ ($PGE_2$) and prostaglandin $I_2$ ($PGI_2$) and that these PGs regulate biological functions of T and B cells. Methods: To investigate the respective contribution of cyclooxygenase-1 (COX-1) and COX-2 to $PGE_2$ and $PGI_2$ production in HK cells, we performed siRNA technology to knock down COX enzymes and examined the effect on PG production. Results: Both $PGE_2$ and $PGI_2$ productions were almost completely inhibited by the depletion of COX-2. In contrast, COX-1 knockdown did not significantly affect PG production induced by lipopolysaccharide (LPS). Conclusion: The current results suggest that mPGES-1 and PGIS are coupled with COX-2 but not with COX-1 in human follicular dendritic cell (FDC) and may help understand the potential effects of selective COX inhibitors on the humoral immunity.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.138.1-138
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• 1996

No Abstract, See Full Text

• Tuberculosis and Respiratory Diseases
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• v.60 no.5
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• pp.523-531
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• 2006

Background : Cervical tuberculous lymphadenopathy is a very common disease with a similar incidence to pulmonary tuberculosis. Dendritic cells play a role of initial antigen presentation of this illness. Nevertheless, the precise role of these antigen-presenting cells according to the clinical features in unclear. The aim of this study was to determine the clinical implication of dendritic cell infiltration in the cervical lymph nodes. Methods : A review of the clinical characteristics was carried out retrospectively based on the clinical records and radiography. Immunohistochemical staining was performed on the available histology specimens of 72 cases using the S-100b polyclonal antibody for dendritic cells. The number of dendritic cells with tuberculous granuloma were determined. A $X^2$ test, unpaired T test and multiple logistic regression analysis were performed. Results : Thirty percent of subjects had previous or concurrent pulmonary TB. Twenty one percent of cases showed a positive reaction on the AFB stain. Within a granuloma, the number of infiltrated dendritic cells was $113.0{\pm}7.0$. The incidence of fever and cough decreased with increasing infiltration of dendritic cells Multivariate regression analysis showed that the infiltration of dendritic cells could significantly contribute to fever. Conclusion : Overall, dendritic cells can control a Mycobacterium tuberculosis infection and modulate the immune response, as well as resolve the clinical manifestations of TB lymphadenopathy.

• BMB Reports
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• v.48 no.5
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• pp.283-288
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• 2015

We found that resveratrol enhances interferon (IFN)-γ-induced tryptophanyl-tRNA-synthetase (TTS) expression in bone marrow-derived dendritic cells (BMDCs). Resveratrol-induced TTS expression is associated with glycogen synthase kinase-3β (GSK-3β) activity. In addition, we found that resveratrol regulates naive CD8⁺ T-cell polarization by modulating GSK-3β activity in IFN-γ-stimulated BMDCs, and that resveratol induces upregulation of TTS in CD8⁺ T-cells in the in vivo tumor environment. Taken together, resveratrol upregulates IFN-γ-induced TTS expression in a GSK-3β-dependent manner, and this TTS modulation is crucial for DC-mediated T-cell modulation. [BMB Reports 2015; 48(5): 283-288]

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.79-86
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• 2001

Recent clinical studies have shown that a high proportion of patients with acute promyelocytic leukemia (APL) achieve complete remission after treatment with all-trans retinoic acid (ATRA). However, most patients who receive continuous treatment with ATRA relapse and develop ATRA-resistant leukemia. Dendritic cells (DCs) are important antigen-presenting cells in the development of antileukemic T-cell responses. In this study, we investigated the strategies to overcome ATRA resistance of APL cells by inducing the differentiation of DCs from human leukemic cell lines for the developtment of adoptive immunotherapy. CD83 was used as a mature DC marker in this study and the expression of CD83 mRNA was determined by RT-PCR method. The promyelocytic leukemic cell line HL-60, B lymphoblast cell lines RPMI 7666 and NC-37 could be induced to dendritic cells in vitro. Treatment of HL-60 with phorbol 12-myristate 13-acetate (PMA) resulted in the expression of myeloid-related DC phenotypes, while treatment of RPMI 7666 with fms-like tyrosine kinase 3 ligand (Flt3-ligand, FL) and treatment of NC-37 with PMA and FL led to the expression of lymphoid-related DC phenotypes. In conclusion, myeloid-related DC phenotypes and lymphoid-related DC phenotypes could be generated from HL-60, NC-37 and RPMI 7666 cell lines, respectively. These DC phenotypes can potentially be used to generate antileukemic T cells in vitro for adoptive immunotherapy.

• BMB Reports
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• v.43 no.3
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• pp.188-192
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• 2010

Inflammatory reactology has become increasingly important in diabetic kidney disease. In this study, we estabilished STZ-induced diabetic rat model to investigate whether dendritic cells (DCs) mediated tubulointerstitial damages, and whether the effects by DCs were mediated by P-selectin expression and can be inhibited by atorvastatin. The study demonstrated that there was an accumulation of DCs in diabetic rats mediated by P-selectin. It also showed the accumulation of DCs and expression of P-selectin was closely correlated with the degree of renal tubulointerstitial injury. These effects were markedly attenuated by atorvastatin. Thus, DCs play a role in tubulointerstitial damages, atorvasttin can prevent renal tubulointerstitium from damage by inhibiting the P-selectin expression and DCs migration.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.132.1-132.1
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• 2014

Fluorescent-magnetic nanoclusters were synthesized for biomedical applications. The nanoclusters consisted of superparamagnetic core-nanoclusters, highly fluorescent shell of nanocrystals, and lipid A. Magnetic cores were used for both magnetic resonance imaging (MRI) and cell separation. Fluorescent shell was used for optical imaging. The lipid-A-loaded nanoclusters were up-taken by dendritic cells via phagocytosis, which successfully activated dendritic cells. The dendritic cells were migrated to lymph nodes and spleen of mice. The results showed that our novel nanoclusters can play a role as an efficient optical and magnetic imaging, a cell separating and a pathogen mimetic agent at the same time. Additionally, synthesis of wavelength conversion nanowires will be discussed, which may be used as an optical nanoprobe in biological studies.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.222-227
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• 2018

Mycobacterium tuberculosis (MTB)-originated lipid antigen is presented on the antigen-presenting cell surface with CD1b. When monocyte-derived dendritic cells phagocytosed MTB H37Rv (Multiplicity of infection 10, infectivity: 46.89%), the CD1b expression level decreased slowly. Since this was just a live MTB-mediated phenomenon, it was not detected from heat-killed MTB or mycolic acid, which is a unique antigen of MTB. We confirmed that the phosphorylation of CD1b molecules using 2D electrophoresis with staining could phosphorylate and induce the presentation of the lipid antigen using the phagocytosis assay.