• IMMUNE NETWORK
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• v.16 no.1
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• pp.13-25
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• 2016

Dendritic cells (DCs) are considered to play major roles during the induction of T cell immune responses as well as the maintenance of T cell tolerance. Naive CD4⁺ T cells have been shown to respond with high plasticity to signals inducing their polarization into effector/helper or regulatory T cells. Data obtained from in vitro generated bone-marrow (BM)-derived DCs as well as genetic mouse models revealed an important but not exclusive role of DCs in shaping CD4⁺ T cell responses. Besides the specialization of some conventional DC subsets for the induction of polarized immunity, also the maturation stage, activation of specialized transcription factors and the cytokine production of DCs have major impact on CD4⁺ T cells. Since in vitro generated BM-DCs show a high diversity to shape CD4⁺ T cells and their high similarity to monocyte-derived DCs in vivo, this review reports data mainly on BM-DCs in this process and only touches the roles of transcription factors or of DC subsets, which have been discussed elsewhere. Here, recent findings on 1) the conversion of naive into anergic and further into Foxp3^- regulatory T cells (Treg) by immature DCs, 2) the role of RelB in steady state migratory DCs (ssmDCs) for conversion of naive T cells into Foxp3⁺ Treg, 3) the DC maturation signature for polarized Th2 cell induction and 4) the DC source of IL-12 for Th1 induction are discussed.

• IMMUNE NETWORK
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• v.12 no.2
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• pp.48-57
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• 2012

Acute viral encephalitis caused by neurotrophic viruses, such as mosquito-borne flaviviruses, is an emerging and re-emerging disease that represents an immense global health problem. Considerable progression has been made in understanding the pathogenesis of acute viral encephalitis, but the immune-pathological processes occurring during the progression of encephalitis and the roles played by various molecules and cellular components of the innate and adaptive systems still remain undefined. Recent findings reveal the significant contribution of Toll-like receptors (TLRs) and regulatory $CD4^+$ T cells in the outcomes of infectious diseases caused by neurotrophic viruses. In this review, we discuss the ample evidence focused on the roles of TLRs and $CD4^+$ helper T cell subsets on the progression of acute viral encephalitis. Finally, we draw attention to the importance of these molecules and cellular components in defining the pathogenesis of acute viral encephalitis, thereby providing new therapeutic avenues for this disease.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.1-12
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• 2016

Th2 cell immunity is required for host defense against helminths, but it is detrimental in allergic diseases in humans. Unlike Th1 cell and Th17 cell subsets, the mechanism by which dendritic cells modulate Th2 cell responses has been obscure, in part because of the inability of dendritic cells to provide IL-4, which is indispensable for Th2 cell lineage commitment. In this regard, immune cells other than dendritic cells, such as basophils and innate lymphoid cells, have been suggested as Th2 cell inducers. More recently, multiple independent researchers have shown that specialized subsets of dendritic cells mediate Th2 cell responses. This review will discuss the current understanding related to the regulation of Th2 cell responses by dendritic cells and other immune cells.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.4.1-4.15
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• 2023

Th cells, which orchestrate immune responses to various pathogens, differentiate from naive CD4 T cells into several subsets that stimulate and regulate immune responses against various types of pathogens, as well as a variety of immune-related diseases. Decades of research have revealed that the fate decision processes are controlled by cytokines, cytokine receptor signaling, and master transcription factors that drive the differentiation programs. Since the Th1 and Th2 paradigm was proposed, many subsets have been added to the list. In this review, I will summarize these events, including the fate decision processes, subset functions, transcriptional regulation, metabolic regulation, and plasticity and heterogeneity. I will also introduce current topics of interest.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.62-63
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• 2003

The commitment of T helper (Th) cells to Thl or Th2 cells is of crucial importance with respective to susceptibility or resistance to particular infections, or to autoimmune diseases and allergic diseases. The nature of Thl or Th2 polarizing signals is not yet fully understood. However, the cytokines that are present in the environment of the $CD4^{+}$ T cell at the time it encounters the antigen significantly regulate the differentiation of Th cells into either Thl or Th2 subsets. (omitted)

• The Korea Journal of Herbology
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• v.24 no.1
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• pp.73-78
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• 2009

Objectives : In this study, we studied the effect of Pinellia Ternata (PT) on regulatory T cells and CD3+CCR3+ Th2 cells number in asthma model mice. Methods : All mice were immunized on two different days (21 days and 7 days before inhalational exposure) by i.p. injections of 0.2 $m\ell$ alum-precipitated Ag containing 100 ${\mu}g$ of OVA bound to 4 mg of aluminum hydroxide in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 min/day on 3 days/week for 12 weeks(at a flow rate of 250 L/min, 2.5％ ovalbumin in normal saline) and PT (400, 200 mg/kg) were orally administered 3 times a week for 8 weeks. After C57BL/6 mice were orally given of PT, the percentages, cell numbers, phenotype and function of CD4+CD25+Treg cells were determined by flow cytometry. Results : The cell numbers of CD4+CD25+Treg cell subsets were markedly increased in PT treated mice as reported. However, PT significantly reduced the CD3+CCR3+ Th2 cells in PBMC and lung of mice. Conclusions : These results indicate that PT has a deep inhibitory effect on asthma model mice by increase the number of regulatory T cells, and by reducing CD3+CCR3+ Th2 cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.580-585
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• 2004

BJYGC is often clinically used as a treatment of allergic rhinitis. This study was aimed to find out the effect BJYGC would have on the helper T cell, and how it can promote the subsets of helper T cells to regain their balance that they lost due to immunological diseases. Splenocytes were prepared from BALB/c mice was cultured without stimulation in the presence of BJYGC for 48 hr. The viability of CD4 T cells from Balb/c mouse were measured at various concentrations of BJYGC using the MTS assay. It was somewhat increased up to concentration of 400 ㎍/ml, but did not show any significant difference. Proliferation was measured using the MTS assay, CD4 Th cells were stimulated with anti-CD3/28 in the presence of BJYGC for 48 hr. As evidence for rapid T cell activation, CD25 expression by flow cytometry was evaluated at 10, 50, 100 and 200 ㎍/㎖ of BJYGC. Th cell differentiation experiments were performed to examine whether BJYGC can affect the Th polarization process. CD4 T cells were activated in culture under neutral, Th1-polarized or Th2-polarized conditions in the presence of BJYGC at 10, 100 and 200 ㎍/㎖. Cytokine production was measured by ELISA. This experiment proved that BJYGC could inhibit the secretion of both IL-4 and IFN-γ in neutral condition and polarized condition, too. Considering that BJYGC shows an excellent effect on treating allergies, the author can conclude that its pharmacological action may be associated with decreased IL-4 and, it may also regulate IFN-γ depending the host's need. Also, it was discovered that Th1 cell was pathologic in chronic inflammatory tissue specific diseases, such as insulin dependent diabetes mellitus, multiple sclerosis, RA, and uveitis. We are counting on the BJYGC to be able to control the tendency of Th1 cell predominancy in an immune reaction.

• Molecules and Cells
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• v.24 no.1
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• pp.132-138
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• 2007

4-1BB (CD137), a member of the tumor necrosis factor receptor superfamily, is expressed on activated T-cells, and 4-1BB signaling due to interaction with 4-1BB ligand or ligation with anti-4-1BB monoclonal antibody (mAb) costimulates T cells. It has been shown that administration of anti-4-1BB mAb induces anti-tumor immunity in mice, but the nature of the cellular subsets responsible for this immunity is uncertain. In this study we found that anti-4-1BB mAb administration to B16F10 melanoma-bearing mice induced marked expansion of $CD11c^+CD8^+$ T-cells in parallel with suppression of pulmonary tumors. The mAb-treated mice produced higher levels of $IFN-{\gamma}$ in their tumor tissues, spleen and lymph nodes than mice exposed to control antibody. When the $CD11c^+CD8^+$ T-cells were purified and re-stimulated in vitro, they produced high levels of the Th1 cytokines, $IFN-{\gamma}$ and IL-2, but low levels of the Th2 cytokines, IL-4 and IL-10. Furthermore, they expressed high levels of 4-1BB and CD107a, a marker of activated cytotoxic T-lymphocytes. Our results suggest that $CD11c^+CD8^+$ T-cells play a role in the anti-tumor immunity induced by anti-4-1BB mAb.

• Molecules and Cells
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• v.44 no.5
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• pp.318-327
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• 2021

CD4+ T helper (Th) cells play a crucial role in the modulation of innate and adaptive immune responses through the differentiation of Th precursor cells into several subsets, including Th1, Th2, Th17, and regulatory T (Treg) cells. Effector Th and Treg cells are distinguished by the production of signature cytokines and are important for eliminating intracellular and extracellular pathogens and maintaining immune homeostasis. Stimulation of naive Th cells by T cell receptor and specific cytokines activates master transcription factors and induces lineage specification during the differentiation of Th cells. The master transcription factors directly activate the transcription of signature cytokine genes and also undergo post-translational modifications to fine-tune cytokine production and maintain immune balance through cross-regulation with each other. This review highlights the post-translational modifications of master transcription factors that control the differentiation of effector Th and Treg cells and provides additional insights on the immune regulation mediated by protein argininemodifying enzymes in effector Th cells.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.687-700
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• 2000

Antigen-specific T cell clones were obtained from mice immunized with Fusobacterium nucleatum ATCC 10953(F .nucleatum) and/or Porphyromonas gingi valis 381(P. gingivalis). 10 Balb/c mice per group were immunized with F. nucleatum followed by P. gingivalis, or with P. gingivalis alone by intraperitoneal injection of viable microorganisms. Spleen T cells were isolated and stimulated in vitro with viable P. gingivalis cells to establish P. gingivalisspecific T cell clones. T cell phenotypes and cytokine profiles were determined along with T cell responsiveness to F .nucleatum or P. gingivalis. Serum IgG antibody titers to F. nucleatum or P. gingivalis were also determined by ELISA. All the T cell clones derived from mice immunized with F. nucleatum followed by P. gingivalis demonstrated Th2 subsets, while those from mice immunized with P. gingivalis alone demonstrated Th1 subsets based on the flow cytometric analysis and cytokine profiles, All T cells clones from both groups were cross-reactive to both P. gingivalis and F. nucleatum antigens. Phenotypes of T cell clones were all positive for CD4. Mean post-immune serum IgG antibody levels to F. nucleatum or P . gingivalis were significantly higher than the pre-immune levels(p <0.01, respectively). There were no significant differences in the antibody titers between the two groups. It was concluded that P. gingivalis-specific T cells initially primed by cross-reactive F. nucleatum antigens were polarized to Th2 subsets, while T cells stimulated with P. gingivalis alone maintained the profile of Th1 subset.