• 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)

• Biomolecules & Therapeutics
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• v.20 no.2
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• pp.171-176
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• 2012

HaCaT cells are the immortalized human keratinocytes and have been extensively used to study the epidermal homeostasis and its pathophysiology. T helper cells play a role in various chronic dermatological conditions and they can affect skin barrier homeostasis. To evaluate whether HaCaT cells can be used as a model cell system to study abnormal skin barrier development in various dermatologic diseases, we analyzed the gene expression profile of epidermal differentiation markers of HaCaT cells in response to major T helper (Th) cell cytokines, such as $IFN{\gamma}$, IL-4, IL-17A and IL-22. The gene transcriptional profile of cornified envelope-associated proteins, such as filaggrin, loricrin, involucrin and keratin 10 (KRT10), in HaCaT cells was generally different from that in normal human keratinocytes (NHKs). This suggests that HaCaT cells have a limitation as a model system to study the pathophysiological mechanism associated with the Th cell cytokine-dependent changes in cornified envelope-associated proteins which are essential for normal skin barrier development. In contrast, the gene transcription profile change of human ${\beta}2$-defensin (HBD2) in response to $IFN{\gamma}$, IL-4 or IL-17A in HaCaT cells was consistent with the expression pattern of NHKs. $IFN{\gamma}$ also up-regulated transglutaminase 2 (TGM2) gene transcription in both HaCaT cells and NHKs. As an alternative cell culture system for NHKs, HaCaT cells can be used to study molecular mechanisms associated with abnormal HBD2 and TGM2 expression in response to $IFN{\gamma}$, IL-4 or IL-17A.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.231-237
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• 2001

To examine the effects of feed additives on the expression of perpheral blood cell surface molecules, phagocytosis and antigen specific antibody formation, broilers were randomly assigned to $T_{1}$ , $T_{2}$ , $T_{3}$ , and $T_{4}$ groups. $T_{1}$ group was fed diet without any additives for 13 weeks, $T_{2}$ was fed diet with full fat flax, $T_{3}$ was fed diet with full fat flax containing $\alpha$-tocopherol, and $T_{4}$ was fed diet with full- fat flax containing $\alpha$-tocopherol and selenium. Since 5 weeks feeding the data were examined by flow cytometry using a panel of monoclonal antibodies. The expression of monocyte in all treated groups was significantly increased, in which the ratio of expression in $T_{3}$ group was especially evident. B cell expression of all treated groups was increased more than 2 fold. The expression of CD4+(helper T cell) cell and CD8+(cytotox$ic^pressor T cell) cell of all treated groups also was increased.ed.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.231-237
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• 2010

Objective: To evaluate whether T helper 1 (Th1) immune response is predominant in women with reproductive failures (recurrent spontaneous abortion and recurrent implantation failure) and the activation of T cell is related to Th1 propensity. Methods: Women with a history of recurrent implantation failure or recurrent spontaneous abortion comprise the study group (n=37). Controls are normal fertile women without a history of infertility or pregnancy losses (n=11). Th1/Th2 ratios of interferon (INF)-$\gamma$/interleukin (IL)-10 and tumor necrosis factor (TNF)-$\alpha$/IL-10 expression on $CD3^+/4^+$ cells, CD154, and CD69 expression on T cells are measured by flow cytometric analysis. Results: The ratios of TNF-$\alpha$ to IL-10 expressing on $CD3^+/4^+$ cells (Th1/Th2 cell ratios) are significantly higher in study group ($42.1{\pm}2.3$) as compared with that of controls ($28.7{\pm}2.7$) (p=0.002). The overall trend of CD154 and CD69 expression on T cells are elevated in study group than those of controls. The proportion (%) of $CD3^+/4^+/154^+$ cells ($1.7{\pm}0.5$ vs. $0.3{\pm}0.2$, p=0.038) and the % of $CD3^+/8^+/154^+$ cells ($0.6{\pm}0.2$ vs. $0.1{\pm}0.0$, p=0.024) are significantly higher in study group. The % of $CD3^+/69^+$ cells ($5.6{\pm}1.9$ vs. $1.3{\pm}5.4$, p=0.046) and % of $CD3^+/8^+/69^+$ cells ($4.8{\pm}1.3$ vs. $1.8{\pm}0.2$, p=0.035) among $CD3^+/8^+$ cells are significantly increased in study group. Conclusion: Women with reproductive failures have Th1 propensity with increased T cell activation. These finding means that activated T cell has a harmful effect on early pregnancy and implantation by induction of Th1 immunity.

• 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.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.

• Hanyang Medical Reviews
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• v.33 no.1
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• pp.10-16
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• 2013

Follicular helper T cells (Tfh) play a significant role in providing T cell help to B cells during the germinal center reaction, where somatic hypermutation, affinity maturation, isotype class switching, and the differentiation of memory B cells and long-lived plasma cells occur. Antigen-specific T cells with IL-6 and IL-21 upregulate CXCR5, which is required for the migration of T cells into B cell follicles, where these T cells mature into Tfh. The surface markers including PD-1, ICOS, and CD40L play a significant role in providing T cell help to B cells. The upregulation of transcription factor Bcl-6 induces the expression of CXCR5, which is an important factor for Tfh differentiation, by inhibiting the expression of other lineage-specific transcription factors such as T-bet, GATA3, and RORγt. Surprisingly, recent evidence suggests that CD4 T cells already committed to Th1, Th2, and Th17 cells obtain flexibility in their differentiation programs by downregulating T-bet, GATA3, and RORγt, upregulating Bcl-6 and thus convert into Tfh. Limiting the numbers of Tfh within germinal centers is important in the regulation of the autoantibody production that is central to autoimmune diseases. Recently, it was revealed that the germinal center reaction and the size of the Tfh population are also regulated by thymus-derived follicular regulatory T cells (Tfr) expressing CXCR5 and Foxp3. Dysregulation of Tfh appears to be a pathogenic cause of autoimmune disease suggesting that tight regulation of Tfh and germinal center reaction by Tfr is essential for maintaining immune tolerance. Therefore, the balance between Tfh and Tfr appears to be a critical peripheral tolerance mechanism that can inhibit autoimmune disorders.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.675-687
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• 2000

Multiple periodontal pathogens sequentially colonize the subgingival niche during the conversion from gingivitis to destructive periodontal disease. An animal model of sequential immunization with key periodontal pathogens has been developed to determine whether T and B lymppocyte effector functions are skewed and fail to protect the host from pathogenic challenge. The present study was performed to evaluate immunomodulatory effect of exposure to Fusobacterium nucleatum(F. nucleatum) prior to Porphyromonas gingivalis(P. gingi - valis). Group 1(control) mice were immunized with phosphate-buffered saline, Group 2 were immunized with F. nucleatum prior to P. gingivalis, while Group 3 were immunized P. gingivalis alone. All the T cell clones derived from Group 2 demonstrated type 2 helper T cell clone(Th2 subsets), while those from Group 3 mice demonstrated Th1 subsets. Exposure of mice to F . nucleatum prior to P. gingivalis interfered with opsonophagocytosis function of sera against P. gingivalis. In adoptive T cell transfer experiments, in vivo protective capacity type 2 helper T cell clones(Th2) from Group 2 was significantly lower than type 1 helper T cell clones(Th1) from Group 3 against the lethal dose infection of P. gingivalis. Western blot analysis indicated the different pattern of recognition of P .gingivalis fimbrial proteins between sera from Group 2 and Group 3. In conclusion, these study suggest that colonization of the subgingival niche by F .nucleatum prior to the periodontal pathogen, P. gingivalis, modulates the host immune responses to P. gingivalis at humoral, cellular and molecular levels.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1021-1027
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• 2004

Panax ginseng has been used as a typical tonic medicine in Asian countries, such as Korea, China, and Japan. It has been reported that ginsenoside Rg1 in Panax ginseng increases the proportion of T helper cells in the whole T cells and promotes IL-2 gene expression in murine splenocytes. These studies imply that ginsenoside Rg1 increases the immune activity of CD4+ T cell, however the exact mechanism of ginsenoside Rg1 on helper T cell remains to be verified. The present study tried to elucidate the direct effect of Rg1 on helper T cell s activities and its Th1/Th2 lineage development. The results demonstrated that ginsenoside Rg1 had not mitogenic effects on the unstimulated CD4+ T cell, but augmented CD4+ T cell proliferation upon activating with anti-CD3/anti-CD28 antibodies in a dose dependent manner. Rg1 also enhanced the expression of cell surface protein CD69 on CD4+ T cell. In Th0 condition, ginsenoside Rg1 increases the expression of IL-2 mRNA, and enhances the expression of IL-4 mRNA on CD4+ T cells, suggesting Rg1 prefer to induce Th2 lineage development. In addition, ginsenoside Rg1 increases IL-4 secreting CD4+ T cell under Th2 skewed condition, while decreases IFN-γ secreting cell in Th1 polarizing condition. Thus, Rg1 enhances Th2 lineage development from naive CD4+ T cell both by increasing Th2 specific cytokine secretion and by repressing Th1 specific cytokine production. Therefore, these results suggest that ginsenoside Rg1 might be desirable agent for enhancing CD4+ T cell's activity, as well as the correction of Th1 dominant pathological disorders.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.5.1-5.28
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• 2023

Th cell lineage determination and functional specialization are tightly linked to the activation of lineage-determining transcription factors (TFs) that bind cis-regulatory elements. These lineage-determining TFs act in concert with multiple layers of transcriptional regulators to alter the epigenetic landscape, including DNA methylation, histone modification and threedimensional chromosome architecture, in order to facilitate the specific Th gene expression programs that allow for phenotypic diversification. Accumulating evidence indicates that Th cell differentiation is not as rigid as classically held; rather, extensive phenotypic plasticity is an inherent feature of T cell lineages. Recent studies have begun to uncover the epigenetic programs that mechanistically govern T cell subset specification and immunological memory. Advances in next generation sequencing technologies have allowed global transcriptomic and epigenomic interrogation of CD4+ Th cells that extends previous findings focusing on individual loci. In this review, we provide an overview of recent genome-wide insights into the transcriptional and epigenetic regulation of CD4+ T cell-mediated adaptive immunity and discuss the implications for disease as well as immunotherapies.