• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.63-69
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• 2006

The methanolic (MeOH) extract of A. fruticosa bark, which showed immune-regulatory activities, was separated to purify an active compared by means of a multi-stage column chromatography. This resulted in the isolation and characterization of an isoflavone glycoside named 4', $6-Dimethoxyisoflavone-7-O-{\beta}-D-glucopyranoside$. Immuno-regulatory activities of the crude extract of Amorpha fruticosa LINNE bark were compared with that of an isoflavone glycoside (4', $6-dimethoxyisoflavone-7-O-{\beta}-D-glucopyranoside$). The crude methanolic extract of A. fruticosa and purified single compound showed 16% of relatively low cytotoxicity at a maximum concentration of 1.0 g/L in cultivated normal human lung cell line (HEL299). Cell growth of human T cells was increased up to 15%, 0.5 g/L of the crude extract added group. This was higher than a single compound added one. On the other hand, specific production rates of IL-6 and $TNF-{\alpha}$ from T cell were higher in the purified compound treat group ($0.82{\times}10^{-4}\;pg/cell$ and $1.08{\times}10^{-4}\;pg/cell$, respectively), compared to 0.5 g/L of the crude extract added group ($0.65{\times}10^{-4}\;pg/cell$ and $0.84{\times}10^{-4}\;pg/cell$, respectively). In addition, the growth of NK-92MI cells incubated with the crude extract was higher up to 56% over the cells grown with a single compound (0.5 g/L). In overall, the crude extract showed relatively higher immuno-regulatory activities compared with a single compound, probably due to the synergic effect given by other substances existed in the crude extract. Even though the siolated compound stimulated higher secretion of cytokines from human T cells.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.482-485
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• 2013

This case report describes the increment of regulatory T cells in thyroid carcinoma of a mixed breed dog compared with normal dogs. A mixed breed dog was referred for a submandibular mass and hyperthermia. Right cervical mass was detected during the physical examination and radiography identified right cervical mass suspected thyroid gland. Accurate location and size of mass was confirmed using computed tomography and 3D reconstructed images. After confirmation of mass, surgical resection was performed and evaluation of regulatory T cells in blood of this patient was performed using flow cytometric assay. The percentage of regulatory T cells was 38.28% of all CD4 (+)/CD25 (+) T cells. This result was higher than median percentage of regulatory T cells of healthy 8 beagles ($7.66{\pm}1.65%$ (p<0.01) of all CD4 (+)/CD25 (+) T cells). And masses were confirmed as giant cell thyroid carcinoma based on histopathologic examination. After surgical resection of cervical mass was performed, the owner didn't want chemotherapy. Seven days later, cervical mass came out again. And CBC showed severe leukocytosis (WBC $47.6{\times}10^3/{\mu}L$) and non-regenerative anemia (PCV 21%). Suspected pulmonic metastasis regions became more severe. Finally the dog died of severe anemia and respiratory disorder.

• BMB Reports
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• v.44 no.4
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• pp.217-231
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• 2011

T cell exhaustion develops under conditions of antigen-persistence caused by infection with various chronic pathogens, such as human immunodeficiency virus (HIV) and myco-bacterium tuberculosis (TB), or by the development of cancer. T cell exhaustion is characterized by stepwise and progressive loss of T cell function, which is probably the main reason for the failed immunological control of chronic pathogens and cancers. Recent observations have detailed some of the intrinsic and extrinsic factors that influence the severity of T cell exhaustion. Duration and magnitude of antigenic activation of T cells might be associated with up-regulation of inhibitory receptors, which is a major intrinsic factor of T cell exhaustion. Extrinsic factors might include the production of suppressive cytokines, T cell priming by either non-professional antigenpresenting cells (APCs) or tolerogenic dendritic cells (DCs), and alteration of regulatory T (Treg) cells. Further investigation of the cellular and molecular processes behind the development of T cell exhaustion can reveal therapeutic targets and strategies for the treatment of chronic infections and cancers. Here, we report the properties and the mechanisms of T cell exhaustion in a chronic environment.

• Proceedings of the PSK Conference
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• 2005.04a
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• pp.81-83
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• 2005

• Journal of Ginseng Research
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• v.36 no.4
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• pp.375-382
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• 2012

Ginsenoside Rp1 (G-Rp1) is a saponin derivate that provides anti-metastatic activities through inhibition of the NF-${\kappa}B$ pathway. In this study, we examined the effects of G-Rp1 on regulatory T cell (Treg) activation. After treatment of splenocytes with G-Rp1, Tregs exhibited upregulation of IL-10 expression, and along with dendritic cells (DCs), these Tregs showed increased cell number compared to other cell populations. The effect of G-Rp1 on Treg number was augmented in the presence of lipopolysaccharide (LPS), which mimics pathological changes that occur during inflammation. However, depletion of DCs prevented the increase in Treg number in the presence of G-Rp1 and/or LPS. In addition, G-Rp1 promoted the differentiation of the memory types of $CD4^+Foxp3^+CD62L^{low}$ Tregs rather than the generation of new Tregs. In vivo experiments also demonstrated that Tregs and DCs from mice that were fed G-Rp1 for 7 d and then injected with LPS exhibited increased activation compared with those from mice that were injected with LPS alone. Expression of TGF-${\beta}$ and CTLA4 in Tregs was increased, and upregulation of IL-2 and CD80/CD86 expression by DCs affected the suppressive function of Tregs through IL-2 receptors and CTLA4. These data demonstrate that G-Rp1 exerts anti-inflammatory effects by activating Tregs in vitro and in vivo.

• Molecules and Cells
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• v.44 no.5
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• pp.342-355
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• 2021

The microphthalmia-associated transcription factor family (MiT family) proteins are evolutionarily conserved transcription factors that perform many essential biological functions. In mammals, the MiT family consists of MITF (microphthalmia-associated transcription factor or melanocyte-inducing transcription factor), TFEB (transcription factor EB), TFE3 (transcription factor E3), and TFEC (transcription factor EC). These transcriptional factors belong to the basic helix-loop-helix-leucine zipper (bHLH-LZ) transcription factor family and bind the E-box DNA motifs in the promoter regions of target genes to enhance transcription. The best studied functions of MiT proteins include lysosome biogenesis and autophagy induction. In addition, they modulate cellular metabolism, mitochondria dynamics, and various stress responses. The control of nuclear localization via phosphorylation and dephosphorylation serves as the primary regulatory mechanism for MiT family proteins, and several kinases and phosphatases have been identified to directly determine the transcriptional activities of MiT proteins. In different immune cell types, each MiT family member is shown to play distinct or redundant roles and we expect that there is far more to learn about their functions and regulatory mechanisms in host defense and inflammatory responses.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.

• IMMUNE NETWORK
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• v.11 no.1
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• pp.11-41
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• 2011

The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA.

• Korean Journal of Transplantation
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• v.31 no.4
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• pp.157-169
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• 2017

Regulatory T cells (Treg) naturally rein in immune attacks, and they can inhibit rejection of transplanted organs and even reverse the progression of autoimmune diseases in mice. The initial safety trials of Treg against graft-versus-host disease (GVHD) provided evidence that the adoptive transfer of Treg is safe and capable of limiting disease progression. Supported by such evidence, numerous clinical trials have been actively investigating the efficacy of Treg targeting autoimmune diseases, type I diabetes, and organ transplant rejection, including kidney and liver. The limited quantity of Treg cells harvested from peripheral blood and subsequent in vitro culture have posed a great challenge to large-scale clinical application of Treg; nevertheless, the concept of CAR (chimeric antigen receptor)-Treg has emerged as a potential resolution to the problem. Recently, two CAR-T therapies, tisagenlecleucel and axicabtagene ciloleucel, were approved by the US FDA for the treatment of refractory or recurrent acute lymhoblastic leukemia. This approval could serve as a guideline for the production protocols for other genetically engineered T cells for clinical use as well. The phase I and II clinical trials of these agents has demonstrated that genetically engineered and antigen-targeting T cells are safe and efficacious in humans. In conclusion, both the promising results of Treg cell therapy from the clinical studies and the recent FDA approval of CAR-T therapies are paving the way for CAR-Treg therapy in clinical use.

• Biomedical Science Letters
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• v.21 no.4
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• pp.172-180
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• 2015

It is well reported that tumor cells can regulate host immune systems. To identify the detailed changes of immune cells between tumor bearing mice and normal mice, we evaluated the systemic immune cell phenotype of B16F10 tumor bearing mice in a time dependent manner. The lymphocytic population (CD4+ and CD8+ T cells) of tumor bearing mice significantly decreased compared to that of normal mice. We found that the Foxp3+CD25+ CD4 T cell decreased, but the Foxp3+$CD25^{high}$ CD4 T cell significantly increased. All subpopulations of CD8 T cells decreased, except the CD62L-CD44+ CD8 T cell subpopulation. The myeloid cell population (CD11b+ and Gr-1+ cells) of tumor bearing mice significantly increased. Specifically, Foxp3+$CD25^{high}$ CD4 T cell and CD11b+Gr-1+ cells significantly increased in early phase of tumor progression. These results are helpful to understand the change of the systemic immune cell subpopulation of tumor bearing mice in a time-dependent manner.