• IMMUNE NETWORK
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• v.11 no.6
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• pp.399-405
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• 2011

Background: Endogenous uveitis is a chronic inflammatory eye disease of human, which frequently leads to blindness. Experimental autoimmune uveoretinitis (EAU) is an animal disease model of human endogenous uveitis and can be induced in susceptible animals by immunization with retinal antigens. EAU resembles the key immunological characteristics of human disease in that both are $CD4^+$ T-cell mediated diseases. Dendritic cells (DCs) are specialized antigen-presenting cells that are uniquely capable of activating naive T cells. Regulation of immune responses through modulation of DCs has thus been tried extensively. Recently our group reported that donor strain-derived immature DC pretreatment successfully controlled the adverse immune response during allogeneic transplantation. Methods: EAU was induced by immunization with human interphotoreceptor retinoid-binding protein (IRBP) $peptide_{1-20}$. Dendritic cells were differentiated from bone marrow in the presence of recombinant GM-CSF. Results: In this study, we used paraformaldehyde-fixed bone marrow-derived DCs to maintain them in an immature state. Pretreatment with fixed immature DCs, but not fixed mature DCs, ameliorated the disease progression of EAU by inhibiting uveitogenic $CD4^+$ T cell activation and differentiation. Conclusion: Application of iBMDC prepared according to the protocol of this study would provide an important treatment modality for the autoimmune diseases and transplantation rejection.

• IMMUNE NETWORK
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• v.19 no.1
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• pp.6.1-6.14
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• 2019

Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.

• IMMUNE NETWORK
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• v.11 no.5
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• pp.299-306
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• 2011

Background: $CD4^+Fop3^+$ regulatory T cells (Tregs) are needed to maintain peripheral tolerance, but their role in the development of autoimmune arthritis is still debated. The present study was undertaken to investigate the mechanism by which Tregs influence autoimmune arthritis, using a mouse model entitled K/BxN. Methods: We generated Treg-deficient K/BxNsf mice by congenically crossing K/BxN mice with Foxp3 mutant scurfy mice. The arthritic symptoms of the mice were clinically and histopathologically examined. The proportions and activation of $CD4^+$ T cells and/or dendritic cells were assessed in the spleens, draining lymph nodes and synovial tissue of these mice. Results: K/BxNsf mice exhibited earlier onset and more aggressive progression of arthritis than their K/BxN littermates. In particular, bone destruction associated with the influx of numerous RANKL+ cells into synovia was very prominent. They also contained more memory phenotype $CD4^+$ T cells, more Th1 and Th2 cells, and fewer Th17 cells than their control counterparts. Plasmacytoid dendritic cells expressing high levels of CD86 and CD40 were elevated in the K/BxNsf synovia. Conclusion: We conclude that Tregs oppose the progression of arthritis by inhibiting the development of $RANKL^+$ cells, homeostatically proliferating $CD4^+$ T cells, Th1, Th2 and mature plasmacytoid dendritic cells, and by inhibiting their influx into joints.

• IMMUNE NETWORK
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• v.12 no.6
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• pp.277-283
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• 2012

Vitamin C is an essential water-soluble nutrient which primarily exerts its effect on host defense mechanisms and immune homeostasis, but the mechanism related to immune-potentiation is poorly understood. Since dendritic cells (DCs) are known as a potent antigen presenting cell (APC) that could enhance the antigen specific immune responses, we investigate the effects of vitamin C on activation of DCs and its related mechanism by using dendritic cell lines, DC-1. First, we found that there was no damage on DC-1 by 2.5 mM of vitamin C. In the presence of vitamin C, the expression of CD80, CD86, and MHC molecules was increased, but it was decreased by the pre-treatment of SB203580, p38 MAPK-specific inhibitor. We confirmed the phosphorylation of p38 MAPK was increased by the treatment of vitamin C. Taken together, these results suggest that vitamin C could enhance the activity of dendritic cells via the up-regulation of the expression of CD80, CD86, and MHC molecules and the activation of p38 MAPK is related to this process.

• 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.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.508-513
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• 1994

For Pb-20wt%Cu alloys, severe macrosegregation due to density difference of the resulting phases in normal directional solidification has been minimized and a uniformly aligned dendritic structure has been produced by axially rotating the sample of 5mm diameter in conjunction with horizontal directional solidification. Under the constant growth velocity of $20{\mu}m/sec$, increasing the rotation rate from 0.18 to 12rpm results in a transition from an aligned columnar to an equiaxed Cu-dendritic structure. With a constant rotation rate of 0.18rpm, increasing the growth velocity from 10 to $50{\mu}m/sec$ also has promoted a transition from columnar to equiaxed structure.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.4
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• pp.451-462
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• 1996

In this study, which focuses on ice storage, a fundamental study in cooling and solidification was performed, including the interesting phenomena of density inversion, supercooling and dendritic ice. A numerical study was performed for natural convection and ice formation considering existence of subcooling and dendritic ice were analyzed numerically by using finite difference method and boundary fixing method. In the mesh, the solid fraction was introduced with adding as a term to the energy conservation equation. A flow in the dendrite was modelled as a flow in a porous medium, and the momentum conservation equation was modified to incorporate resistance forces involved in flows through porous media. A numerical solution of the time dependencies of dendrite area and dense ice front was successfully obtained, and the numerical results were good agreement with experimental results. Based on this methodology, a discussion was made of phenomena and characteristics of cooling and freezing processes under various conditions.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.105-109
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• 2005

Background: Dendritic cells (DCs) are the most potent APCs (antigen-presenting cells) and playa critical role in immune responses. Galectin-3 is a biological lectin with a beta-galactoside binding affinity. Recently, proteomic analysis revealed the presence of galectin-3 in the exosome of mature DCs. However, the expression and function of galectin-3 in DCs remains unclear yet. Methods: We used bone marrow-derived DCs of mouse and showed the expression of galectin-3 in DCs by using flow cytometry analysis and Western blot analysis. Results: Galectin-3 was determined as single band of 35 kDa in Western blot analysis. Flow cytometry analysis showed the major growth factor for DCs, granulocyte-macrophage colony stimulating factor (GM-CSF) and maturing agents, anti-CD40 monoclonal antibody (mAb) and lipopolysaccharide (LPS) consistently increased the intracellular expression of galectin-3 in DCs compared to medium alone. In addition, DCs treated with maturing agents did marginally express galectin-3 on their surface. Conclusion: This study suggests that galectin-3 in DCs may be regulated by critical factors for DC function.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.71-78
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• 2002

Since the early 1980's the use of zinc-aluminum alloy-coated steel sheet(Galvalume) for vehicular corrosion protection has increased drastically. It is consisting of 55%Al-43.4% Zn-1.6%Si. Galvalume has a good corrosion resistance, heat reflectivity and shiny appearance, which has a dendritic structure of alloy layer. It has a good corrosion resistance due to dendritic structure. But, this also has a weak point against moisture during long period of transportation as sheeted and or coiled without any relation of chromating on the surface of steel sheet or not because of high humidity and temperature. Here, We studied the corrosion mechanism by the moisture.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1234_1235
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• 2009

The Langmuir-Blodgett (LB) method has been one of the most suitable techniques for fabricating organic thin films with well-controlled structures, compositions and thickness at the molecular level. We investigated the surface activity of dendrimer films at air-water interface by $\pi$-A isotherm. Also, we attempted to fabricate a G3-9Ph dendritic silsequioxane LB films. And their surface morphologies were observed by atomic force microscopy (AFM).