• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.732-736
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• 2020

Theobroma cacao L., a fruit of cacao trees, is a perennial plant, which belongs to Sterculiaceae, and is native to the Amazon in South Africa. It also has been known for its various biologically active effects, such as anti-oxidation, anti-cancer, and anti-bacterial. The spleen cell proliferations of mice were measured at 48 hours after treatment of Theobroma cacao L. water extracts in seven concentrations(0, 5, 10, 50, 100, 250, 500 and 1,000 ㎍/mL) an ELISA assay. The production of cytokine (IL-1β, TNF-α, IFN-γ), is secreted by macrophages stimulated with LPS, was detected by ELISA assay using the cytokine kit. From the results of in vitro study, both splenocytes and cytokine production activated by peritoneal macrophages have increased when water extracts were supplemented in the range between 250 and 500 ㎍/mL concentration. Notably, splenocytes production has a signigicant proliferation at 500 ㎍/mL concentration. The result from this research suggests that supplementation with Theobroma cacao L. water extracts may enhance the immune function by stimulating the splenocyte proliferation and improving the cytokine production activating macrophage in vitro.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.622-626
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• 2020

Recent studies have suggested that Canavalia gladiate, a dietary food and traditional folk medicine, has promising pharmaceutical potential, but the effects have mostly been demonstrated using its organo-soluble extract. To date, its immunomodulatory effect depending on the extraction method is unclear. Here, the immune responses of macrophages to C. gladiate and the underlying mechanisms were studied. C. gladiate hot water extract (CGW) induced cytokine production in bone marrow-derived macrophages (BMDMs) in a dose-dependent manner, whereas its ethanolic extract (CGE) did not. Immunoblotting analysis also showed that CGW activated nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs). Moreover, an inhibitor assay revealed the involvement of NF-κB, p38, and JNK, but not ERK, in CGW-induced cytokine production. CGE inhibited lipopolysaccharide-stimulated production of pro-inflammatory cytokines and activation of NF-κB and MAPKs in BMDMs. The results suggest that C. gladiate regulates the immune responses of macrophages differently depending on the extraction method.

• Molecules and Cells
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• v.40 no.1
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• pp.24-36
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• 2017

The stability of peptide-MHC complex (pMHC) is an important factor to shape the fate of peptide-specific T cell immune response, but how it influences on T cell activation process is poorly understood. To better understand that, we investigated various T cell activation events driven by $L^d$ MHCI loaded with graded concentrations of P2Ca and QL9 peptides, respectively, with 2C TCR Tg T cells; the binding strength of P2Ca for $L^d$ is measurably weaker than that of QL9, but either peptides in the context of $L^d$ interact with 2C TCR with a similar strength. When their concentrations required for early T cell activation events, which occur within several minutes to an hour, were concerned, $EC_{50}s$ of QL9 were about 100 folds lower than those of P2Ca, which was expected from their association constants for $L^d$. When $EC_{50}s$ for late activation events, which takes over several hours to occur, were concerned, the differences grew even larger (> 300 folds), suggesting that, due to weak binding, $L^d/P2Ca$ dissociate from each other more easily to lose its antigenicity in a short time. Accordingly, fixation of $L^d/P2Ca$ with paraformaldehyde resulted in a significant improvement in its immunogenicity. These results imply that binding strength of a peptide for a MHC is a critical factor to determine the duration of pMHC-mediated T cell activation and thus the attainment of productive T cell activation. It is also suggested that paraformaldehyde fixation should be an effective tool to ameliorate the immunogenicity of pMHC with a poor stability.

• Korean Journal of Head & Neck Oncology
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• v.36 no.2
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• pp.55-59
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• 2020

Hemophagocytic lymphohistiocytosis (HLH) is a rare but life-threatening one syndrome of excessive immune activation. This immune dysregulation disorder is prominently associated with cytopenias and combinations of clinical signs and extreme inflammation symptoms. For survival, it is important to diagnose early and treat appropriately. We report a case of 10 years old boy who was admitted to the hospital with a month history of fever and cervical lymph node enlargement. There were signs of hemophagocytic histiocytosis in the lymph node and bone marrow. The etiology, diagnosis, and treatment of hemophagocytic lymphohistiocytosis are reviewed.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.95-103
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• 2001

T cells play a central role in the initiation and regulation of the immune response to foreign antigens. Full activation of T cells requires the engagement of T cell receptor complex (TCR) and the binding of a second costimulatory receptor to its ligand expressed on antigen presenting cells (APC). Among the molecules known to provide costimulatory function, CD28 has been the most dominant and potent costimulatory molecule. However, the function of CD28 is becoming more complex due to the recent discovery of its structural homologue, CTLA-4 and ICOS. This review summarizes the biology and physiologic function of each of these receptors, and further focuses on the biochemical mechanism underlying the function of these receptors. Complete understanding of the CD28/CTLA-4/ICOS costimulatory pathway will provide the basis for developing new therapeutic approaches for immunological dieseases.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1727-1735
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• 2017

Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

• BMB Reports
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• v.44 no.8
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• pp.497-505
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• 2011

Reactive oxygen species (ROS), which include superoxide anions and peroxides, induce oxidative stress, contributing to the initiation and progression of cardiovascular diseases involving atherosclerosis. The endogenous and exogenous factors hypercholesterolemia, hyperglycemia, hypertension, and shear stress induce various enzyme systems such as nicotinamide adenine dinucleotide (phosphate) oxidase, xanthine oxidase, and lipoxygenase in vascular and immune cells, which generate ROS. Besides inducing oxidative stress, ROS mediate signaling pathways involved in monocyte adhesion and infiltration, platelet activation, and smooth muscle cell migration. A number of antioxidant enzymes (e.g., superoxide dismutases, catalase, glutathione peroxidases, and peroxiredoxins) regulate ROS in vascular and immune cells. Atherosclerosis results from a local imbalance between ROS production and these antioxidant enzymes. In this review, we will discuss 1) oxidative stress and atherosclerosis, 2) ROS-dependent atherogenic signaling in endothelial cells, macrophages, and vascular smooth muscle cells, 3) roles of peroxidases in atherosclerosis, and 4) antioxidant drugs and therapeutic perspectives.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.99-104
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• 2014

Platycodon grandiflorum have been used as a traditional remedy and food source. This study was performed to investigate the immunomodulating effects of Platycodon grandiflorum in mouse, using ex vivo experiments. Six to seven-week old mice were fed ad libitum on a chow diet, and water extract of Platycodon grandiflorum was orally administrated at two different concentractions (50 and 500 mg/kg B.W./day) every other day for four weeks. In ex vivo experiments, the highest proliferation of splenocytes and levels of cytokine (IL-$1{\beta}$, IL-6, TNF-${\alpha}$) production were observed in 500 mg/kg BW/day supplementation group for all three cytokines stimulated by LPS. In conclusion, this study suggests that Platycodon grandiflorum extracts may enhance the immune function by regulating the splenocytes proliferation and cytokine production capacity by activating macrophages in mice.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.121-121
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• 2001

Thioacetamide has been known to cause immune suppression. In this report we studied the role of metabolic activation by flavin-containing monooxygenase in the thioacetamide-induced immune response. To determine whether the metabolites of thioacetamide produced by flavin-containing monooxygenase result in the immunosuppression, methimazole, a flavin-containing monooxygenase inhibitor, was used to block the flavin-containing monooxygenase pathway.(omitted)

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.332-336
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• 2008

Ginger is widely used as a traditional herbal medicine. Both ginger and its extracts have been used to treat many chronic inflammatory conditions via the inhibition of nuclear factor-kappa B (NF-${\kappa}B$) activation, which results in the suppression of cyclooxygenase-2 (COX-2) expression. However, the mechanisms as to how ginger extracts mediate their health effects are largely unknown. Toll-like receptors (TLRs) trigger anti-microbial innate immune responses, recognizing conserved microbial structural molecules that are known as pathogen-associated molecular patterns. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$. The activation of NF- ${\kappa}B$ leads to the induction of inflammatory gene products, including cytokines and COX-2. This study reports the biochemical evidence that 6-shogaol, an active compound in ginger, inhibits NF-${\kappa}B$ activation and COX-2 expression induced by TLR2, TLR3, and TLR4 agonists. Furthermore, 6-shogaol inhibited NF-${\kappa}B$ activation induced by the following downstream signaling components of the TLRs: MyD88, $IKK{\beta}$, and p65. These results imply that ginger can modulate immune responses that could potentially modify the risk of many chronic inflammatory diseases.