• IMMUNE NETWORK
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• v.13 no.1
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• pp.25-29
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• 2013

Ribavirin is an antiviral drug used in combination with pegylated interferon-${\alpha}$ (IFN-${\alpha}$) for the treatment of hepatitis C virus (HCV) infection. Recently, ribavirin was reported to inhibit the suppressive activity of regulatory T (Treg) cells. In the present study, we re-evaluated the effect of ribavirin on $CD4^+$ $CD4^+$ $CD25^+$ Treg cells from normal donors. First, we examined the expression of CTLA-4 and CD39, which are known to play a role in the suppressive function of Treg cells. We found that ribavirin treatment did not modulate the expression of CTLA-4 and CD39 in Treg cells. We also studied the effect of ribavirin on Treg cells in the presence of IFN-${\alpha}$; however, the expression of CTLA-4 and CD39 in Treg cells was not changed by ribavirin in the presence of IFN-${\alpha}$. Next, we directly evaluated the effect of ribavirin on the suppressive activity of Treg cells in the standard Treg suppression assay, by co-culturing CFSE-labeled non-Treg $CD4^+$ T cells with purified Treg cells. We found that ribavirin did not attenuate the suppressive activity of Treg cells. Taken together, while ribavirin reversed Treg cell-mediated suppression of effector T cells in the previous study, we herein demonstrate that ribavirin does not impair the suppressive activity of Treg cells.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.385-390
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• 2012

In order to know the effect of pre-existing Trichinella spiralis infection on experimentally induced intestinal inflammation and immune responses, we induced colitis in T. spiralis-infected mice and observed the severity of colitis and the levels of Th1, Th2, and regulatory cytokines and recruitment of $CD4^+CD25^+Foxp3^+$ T (regulatory T; $T_{reg}$) cells. Female C57BL/6 mice were infected with 250 muscle larvae; after 4 weeks, induction of experimental colitis was performed using 3% dextran sulfate sodium (DSS). During the induction period, we observed severity of colitis, including weight loss and status of stool, and evaluated the disease activity index (DAI). A significantly low DAI and degree of weight loss were observed in infected mice, compared with uninfected mice. In addition, colon length in infected mice was not contracted, compared with uninfected mice. We also observed a significant increase in production of pro-inflammatory cytokines, IL-6 and IFN-${\gamma}$, in spleen lymphocytes treated with DSS; however, such an increase was not observed in infected mice treated with DSS. Of particular interest, production of regulatory cytokines, IL-10 and transforming growth factor (TGF)-${\beta}$, in spleen lymphocytes showed a significant increase in mice infected with T. spiralis. A similar result was observed in mesenteric lymph nodes (MLN). Subsets of the population of $T_{reg}$ cells in MLN and spleen showed significant increases in mice infected with T. spiralis. In conclusion, T. spiralis infection can inhibit the DSS-induced colitis in mice by enhancing the regulatory cytokine and $T_{reg}$ cells recruitment.

• Journal of Physiology & Pathology in Korean Medicine
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• v.38 no.1
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• pp.16-21
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• 2024

Haepyoijin-tang and its main components have been used for phlegm, cough and dyspnea. Using a respiratory inflammation model, we intend to reveal the anti-inflammatory effect and pharmacological mechanism of Haepyoijin-tang. We induced the respiratory inflammation model by Aspergillus oryzae protease and ovalbumin administration. Female Balb/c mice (8 weeks old) were classified into four groups as follows: saline control group, aspergillus oryzae protease and ovalbumin induced respiratory inflammation group (vehicle), inflammation with Haepyoijin-tang (200 mg/kg) administration group, inflammation with dexamethasone (5 mg/kg) administration group (n=7). To identify the anti-inflammatory effects of Haepyoijin-tang water extracts, we measured the inflammatory cell number in bronchoalveolar lavage fluid (BALF) and total live lung cell number. In addition, we checked eosinophil ratio and number in BALF. And Interleukin (IL)-5 level was also measured in lung cell culture supernatant. To confirm the mechanism of anti-inflammatory effects, we analyzed the activated helper T cell (CD4⁺CD25⁺ cell) and Th2 cell (CD4⁺GATA3⁺ cell) ratio and number in lung by using flow cytometry. Finally, we attempted to confirm the immune mechanism by measuring the ratio and number of regulatory T cells (CD4⁺Foxp3⁺ cell). Haepyoijin-tang extracts treatment diminished inflammatory cell, especially, eosinophil number in BALF and total live lung cell number. Moreover, IL-5 level was reduced in Haepyoijin-tang treated group. Surprisingly, Haepyoijin-tang extracts administration not only decreased the activated helper T cell but also Th2 cell population in lung. Additionally, regulatory T cell population was increased in Haepyoijin-tang administration group. Our findings proved that Haepyoijin-tang extract have anti-inflammatory efficacy by suppressing Th2 cell activation and promoting regulatory T cell population.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.304-312
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• 2018

Regulatory T cells (Treg), known as immune-suppressors, may help modulate the immune response. In this study, we investigated the effect of Treg-derived $TGF-{\beta}1$ on pancreatic islet cell function in vitro and in vivo. One hundred eighty IEQ (islet equivalents) of pancreatic islets, the marginal amount to regulate blood glucose level after syngeneic islet transplantation in mouse type 1 diabetes (T1D) model, were co-cultured with $4{\times}10^6$ Treg cells for 48 hours. The changes in $TGF-{\beta}1$, interleukin-6 (IL-6), and insulin secretion levels were measured and analyzed among the Treg-only group, the islet-only group, and the Treg/islet co-cultured group. In the Treg/islet co-cultured group, IL-6 and insulin secretion levels were increased (P<0.0005, P<0.005) and islet viability was improved (P<0.005) compared with the islet-only group. Furthermore, after transplantation, the co-cultured islets regulated blood glucose levels efficiently in the T1D mouse model. These data suggest that Treg could improve islet functions and viability via the $TGF-{\beta}1$ secretion pathway (P<0.05~0.005), thus the use of Treg in islet transplantation should be explored further.

• Toxicological Research
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• v.11 no.1
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• pp.9-14
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• 1995

The immune system is partially under the control of the sympathetic and parasymphathetic nervous systems through the regulatory feedback loop. Methamphetamine (MA) is a neurotoxic chemical which affects the neurotransmitter system. The objective of this study was to investigate the immunotoxic effect of MA on the major immune target organ and lymphocyte proliferation to the various mitogens. Female Balb/C mice, 15 to 20 g, were injected subcutaneously with 0, 0.5, or 5 mg MA/kg for 14 consecutive days. In MA treated mice, the body weight gain and relative spleen and thymus weight were decreased in doserelated manner. Histopathologically, there was a paucity of lymphold follicles and germinal centers in the spleen, and thymic cortical atrophy with lymphophagocytosis was prominent. Apoptosis also occurred in germinal centers of spleen and thymic cortex. The threshold and peak of lymphocyte proliferation at various concentration of mitogens showed similar patterns. However, the response to lipopolysaccaride (LPS) and pokeweed mitogen (PWM) in the 5 mg MA/kg treated group showed threshold and peak proliferation at high concentration of mitogens (25${\mu}g$ LPS/ml for MA vs 15${\mu}g$ LPS/ml for control; 60${\mu}g$ PWM/ml for MA vs 45${\mu}g$ PWM/ml for control), which suggest that MA impairs T cell dependent-B cell function. This preliminary study indicated that MA affected the lymphold organs and immune function.

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.769-779
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• 1994

The root of Bupleurum falcatum L.(BF) has been widely used in oriental medicine as a major camponent in many prescriptions for chronic hepatitis, renal disease, tuberculosis and some other infectious diseases. Many attempts have done to investigate the therapeutic effects of these principles. However, any kinds of screenig on immune regulatory- and antitumor- effects of BF has not been reported. The present study, therefore, was undertaken to investigate the BF-effects on cellular- and humoral-immune responses, phagocytic activities of macrophages, lymphokine- and Immunoglobulin(Ig)-production of lymphocytes, tumorigenesis of implanted sarcoma 180 cells and B16 melanoma cells, and proliferations of some tumor cell lines(Fsa II, 3LL and EL4). BF increased phagocytic activities of mouse peritoneal macrophages in a dose- and time-dependent fashion. Arthus reaction and antibody responses to SRBC were slightly enhanced but delayed hypersensitivity was depresed when BF was injected before- and after-SRBC sensitization. BF inhibited the proliferative responses of human tonsillar lymphocytes to PHA- and Con A-stimulation but slightly augmented the response of these cells to Staphylococcus aureus Cowan 1(SAC)-activation. Ig secretion of human mononuclear cells activated with SAC was slightly increased by BF. BF significantly augmented the SAC-induced IL 6 production of human mononuclear cells but not influenced Con Ainduced IL 2 secretion. NK cell activities of mouse splenocytes were somewhat increased when BF was pretreated and this responses were due to the increment of binding affinities of effector cells to target cells and of lytic activities of effector cells against target cells. In vitro BF significantly inhibited the proliferations of cancer cells such as Fsa II, 3LL and EL4 strains. BF decreased not only the frequency of tumor induction but also the tumor size per sarcoma 180 or B16 cell-implanted mouse. Taken together, these results indicate that BF is one of the potential immunomodulator, and suggest its possibility to be used as a desirable antitumor agent.

• Molecules and Cells
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• v.28 no.4
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• pp.365-368
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• 2009

Toll-like receptors (TLRs) play an important role in host defense by sensing invading microbial pathogens and initiating innate immune responses. The stimulation of TLRs by microbial components triggers the activation of myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-${\beta}$ (TRIF)-dependent downstream signaling pathways. Isoliquiritigenin (ILG), an active ingredient of Licorice, has been used for centuries to treat many chronic diseases. ILG inhibits the MyD88-dependent pathway by inhibiting the activity of inhibitor-${\kappa}B$ kinase. However, it is not known whether ILG inhibits the TRIF-dependent pathway. To evaluate the therapeutic potential of ILG, we examined its effect on signal transduction via the TRIF-dependent pathway of TLRs induced by several agonists. ILG inhibited nuclear factor-${\kappa}B$ and interferon regulatory factor 3 activation induced by lipopolysaccharide or polyinosinic-polycytidylic acid. ILG inhibited the lipopolysaccharide-induced phosphorylation of interferon regulatory factor 3 as well as interferon-inducible genes such as interferon inducible protein-10, and regulated activation of normal T-cell expressed and secreted (RANTES). These results suggest that ILG can modulate TRIF-dependent signaling pathways of TLRs, leading to decreased inflammatory gene expression.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.553-562
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• 1998

Food allergy is defined as an immunologically-mediated adverse reaction to food.The food allergy as a clinical entity has been recognized for many years, although there is yet no general consensus as to the incidence of this syndrome. One difficulty in studying food allergies has been the lock of a reasonable animal model in which reactions could be induced by orally administrating foods. It has been generally accepted that the initial target for an immediate reaction to food is the mast cells, within the gastronitestinal mucosa, and such cells are sensitize in vivo by food-specific immunoglobulin(Ig) E. Degranulation of these cells facilitates the entry of an antigenic epitope into the lymphatic system and blood stream, thereby causing further degranulation of the mast cells and basophils throughout the boy. Accordingly, the author attempted to develop an animal model that is indicative of evaluating IgE-mediated immediate hypersensitivity. It is also necessary to evaluate the effects of nutritional envioronments on dietary protein-dependent allergy and the regulatory mechanisms of dietary fats on IgE-mediated immune response. In this review, animal models to evaluate a food ingredient, effects of dietary fats and curcuminoids, milk whey protein hydrolysates on allergic reaction, and effect of dietary fat in splenic immune cells are presented.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1321-1323
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• 2015

Lactic acid bacteria (LAB) are microorganisms that are believed to provide health benefits. Here, we isolated LAB from Indian fermented foods, such as traditional Yogurt and Dosa. LAB from Yogurt most significantly induced TNF-α and IL-1β production, whereas LAB from Dosa induced mild cytokine production. After 16S rRNA gene sequencing and phylogenetic analysis, a Yogurt-borne lactic acid bacterium was identified and classified as Lactobacillus delbrueckii subsp. bulgaricus, and it was renamed L. delbrueckii K552 for the further studies. Our data suggest that the newly isolated L. delbrueckii can be used for the treatment of immune deficiency disorders.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.1036-1043
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• 2006

The present study was conducted to investigate the effect of Gamisamul-tang (GSMT) on atopic dermatitis (AD). AD was induced in NC/Nga mutant mice by DNCB treatment. GSMT administration reduced levels of skin severity scores. Serum levels of IgE, IgG, IgM, and inflammatory cytokines including IL-4, IL-4 and 1L-13 were significantly decreased by GSMT treatment. Levels of mRNA's encoding IL-4, IL-6, IL-13, $TNF-{\alpha}$, and $interferon-{\gamma}$ in the dermal tissue and draining lymph node (DLN) by real time RT-PCR analysis showed decrease by GSMT testament. Moreover, the number of CD4+ and CD8+ cells was significantly decreased in the spleen and DLN tissues. Histological examination showed that infiltration levels of immune cells in ear, skin, and DLN of AD-induced NC/Nga mice were much improved by GSMT treatment. The present data suggest that GSMT may play an important role in recovering AD symptoms by regulating immune reactivity.