• Genomics & Informatics
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• 제21권2호
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• pp.18.1-18.11
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• 2023

Immunologists have activated T cells in vitro using various stimulation methods, including phorbol myristate acetate (PMA)/ionomycin and αCD3/αCD28 agonistic antibodies. PMA stimulates protein kinase C, activating nuclear factor-κB, and ionomycin increases intracellular calcium levels, resulting in activation of nuclear factor of activated T cell. In contrast, αCD3/αCD28 agonistic antibodies activate T cells through ZAP-70, which phosphorylates linker for activation of T cell and SH2-domain-containing leukocyte protein of 76 kD. However, despite the use of these two different in vitro T cell activation methods for decades, the differential effects of chemical-based and antibody-based activation of primary human T cells have not yet been comprehensively described. Using single-cell RNA sequencing (scRNA-seq) technologies to analyze gene expression unbiasedly at the single-cell level, we compared the transcriptomic profiles of the non-physiological and physiological activation methods on human peripheral blood mononuclear cell-derived T cells from four independent donors. Remarkable transcriptomic differences in the expression of cytokines and their respective receptors were identified. We also identified activated CD4 T cell subsets (CD55⁺) enriched specifically by PMA/ionomycin activation. We believe this activated human T cell transcriptome atlas derived from two different activation methods will enhance our understanding, highlight the optimal use of these two in vitro T cell activation assays, and be applied as a reference standard when analyzing activated specific disease-originated T cells through scRNA-seq.

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.255-258
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• 1993

Molecular dynamics (MD) calculations were carried out in order to investigate the effect of MD cell size to predict the melting phenomena of A-type zeolite. We studied two model systems: a pseudocell of $(T_2O_4Na)_n$, (L= 12.264 $^{\AA}$, N= 84) and a true-cell of (SiAlO$_4Na)_n$. (L= 24.528 $^{\AA}$, N= 672), where T is Si or Al. The radial and bond angle distribution functions of T(Si, Al)-O-T(Si, Al) and diffusion coefficients of T and O were reported at various temperatures. For the true-cell model, the melting temperature is below 1500 K and probably around 1000 K, which is about 600-700 K lower than the pseudocell model. Although it took more time (about 30 times longer) to obtain the molecular trajectories of the true-cell model than those of the pseudocell model, the true-cell model gave more realistic structural transition for the A-type zeolite, which agrees with experiment.

• Korean Journal of Plant Resources
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• 제27권5호
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• pp.567-575
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• 2014

Resveratrol is a naturally occurring stilbene which is safe and well-described compound with a potent anti-inflammatory activity. Recent studies suggested that resveratrol suppressed various inflammation mediated diseases such as asthma, chronic colitis, rheumatoid arthritis, and type 1 diabetes. These studies indicated that resveratrol might directly modulate $CD4^+$ helper T cells (Th cells)-mediated immune responses. However, it is not fully elucidated whether resveratrol directly regulates $CD4^+$ Th cell activation and differentiation. In the present study, $CD4^+$ Th cells were purified from C57BL/6 and treated with various concentrations of resveratrol. We found that resveratrol directly suppressed $CD4^+$ Th cells activation, leading to a defect in T cell proliferation. When $CD4^+$ Th cells were treated with resveratrol, cytokine production was also significantly reduced in a dose dependent manner. In accordance with these results, resveratrol even inhibited $CD4^+$ Th cells differentiation into Th1, Th2 or Th17, which produces IFN-${\gamma}$, IL-4 or IL-17 respectively. We also found that resveratrol could induce apoptosis of $CD4^+$ T cells at a high concentration. Our data demonstrated that resveratrol inhibited directly $CD4^+$ Th cells activation and differentiation. It suggests that resveratrol could be an efficient therapeutic strategy for autoimmune diseases in which $CD4^+$ Th cells play a critical role.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.374-387
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• 1997

The purpose of this study was to examine the distribution of lymphocyte populations in normal, reversibly inflamed and irreversibly inflamed human dental pulp tissues using flow cytometry. Flow cytometry, with specific antibody and fluorochrome reagent allows us to know cellular properties of hematolymphoid cells by measuring fluorescence of stained cells. Before extirpation of pulps in routine endodontic treatment, the clinical diagnosis were performed by symptom. The extirpated pulp tissues were divided into normal pulp group (N=5), reversible pulpit is group(N=10) and irreversible pulpitis group(N=7). The specimen was placed into RPMI 1640 medium, minced into small pieces, and then digested in medium with collagenase. The cell suspension was resuspended in PBS for monoclonal antibody staining of T lymhocytes(CD3+), B lymphocytes (CD19+), T helper cell (CD4+) and T supressor cell (CD8+). The percentages of cells were counted by FACStar(BD) flow cytometer. Following results were obtained; 1. In the most normal and inflamed pulps, the percentages of T lymphocyte, B lymphocytes, T helper cell and T suppressor/cytotoxic cell were less than 1 % in total counted pulpal cells. 2. The higher percentages of T, B, T helper and T suppressor cells were observed in irreversible pulpitis group as compared with the normal pulp and reversible pulpitis group but the differences between groups were not statistically significant (p>0.05). 3. The percentages of T helper cells (CD4 + cells) were greater than that of T suppressor/cytotoxic cells (CD8 + cells) in the inflamed pulps.

• Korean Journal of Veterinary Research
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• 제34권3호
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• pp.441-446
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• 1994

The responsiveness of $CD8^+$ T-cell subpopulation according to serum-containing and serum-free conditions were investigated. Cells are freshly isolated from spleen of mature adult BALB/C mice between 13-20 weeks of age. $CD8^+$ T cells in serum-free conditions produce small amounts of IL-2, while significant amounts of IFNr following activation when compared the results of serum-containing conditions. These data indicate that serum-derived factors may play an important role in the alternations of $CD8^+$ T cell responsiveness.

• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1066-1076
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• 2012

Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

• IMMUNE NETWORK
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• 제8권4호
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• pp.107-123
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• 2008

It has now been well documented in a variety of models that T regulatory T cells (Treg cells) play a pivotal role in the maintenance of self-tolerance, T cell homeostasis, tumor, allergy, autoimmunity, allograft transplantation and control of microbial infection. Recently, Treg cell are isolated and can be expanded in vitro and in vivo, and their role is the subject of intensive investigation, particularly on the possible Treg cell therapy for various immune-mediated diseases. A growing body of evidence has demonstrated that Treg cells can prevent or even cure a wide range of diseases, including tumor, allergic and autoimmune diseases, transplant rejection, graft-versus-host disease. Currently, a large body of data in the literature has been emerging and provided evidence that clear understanding of Treg cell work will present definite opportunities for successful Treg cell immunotherapy for the treatment of a broad spectrum of diseases. In this Review, I briefly discuss the biology of Treg cells, and summarize efforts to exploit Treg cell therapy for autoimmune diseases. This article also explores recent observations on pharmaceutical agents that abrogate or enhance the function of Treg cells for manipulation of Treg cells for therapeutic purpose.

• BMB Reports
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• 제55권2호
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• pp.57-64
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• 2022

Autoimmune disease is known to be caused by unregulated self-antigen-specific T cells, causing tissue damage. Although antigen specificity is an important mechanism of the adaptive immune system, antigen non-related T cells have been found in the inflamed tissues in various conditions. Bystander T cell activation refers to the activation of T cells without antigen recognition. During an immune response to a pathogen, bystander activation of self-reactive T cells via inflammatory mediators such as cytokines can trigger autoimmune diseases. Other antigen-specific T cells can also be bystander-activated to induce innate immune response resulting in autoimmune disease pathogenesis along with self-antigen-specific T cells. In this review, we summarize previous studies investigating bystander activation of various T cell types (NKT, γδ T cells, MAIT cells, conventional CD4⁺, and CD8⁺ T cells) and discuss the role of innate-like T cell response in autoimmune diseases. In addition, we also review previous findings of bystander T cell function in infection and cancer. A better understanding of bystander-activated T cells versus antigen-stimulated T cells provides a novel insight to control autoimmune disease pathogenesis.

• Biomedical Science Letters
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• 제27권4호
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• pp.329-333
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• 2021

We previously identified that tumor cells genetically modified with a 4-1BBL co-stimulatory molecule had anticancer effects in a CT26 mouse colorectal tumor model. To identify the distinction between immune cells in a mouse tumor model treated with tumor cells genetically modified with 4-1BBL or β-gal, we examined the immune cells in CT26-WT, CT26-βgal, and CT26-4-1BBL tumor bearing mice 21 days after tumor cell administration. The CD8+ T cells population in mice treated with tumor cells genetically modified with 4-1BBL was significantly increased on day 21 compared to that of tumor cells genetically modified with β-gal in the spleen and tumor tissue. The CD4+ T cell population was not different between the two mice groups. The Foxp3+CD25^high CD4 T cell population decreased on day 21 in tumor tissues, but the decrease was not significant. We also found that CD8 T cells had pivotal roles in inhibiting tumor growth by treating mice with ant-CD4 and CD8 antibodies. These results suggest that tumor cells genetically modified with 4-1BBL could inhibit tumor growth by affecting on CD8 T lymphocytes.

• Korean Journal of Animal Reproduction
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• 제27권3호
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• pp.225-231
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• 2003

Transgenic mice containing Diphtheria Toxin-A (DT-A) gene fused to proximal lck promoter sequences was used for analysis of DT-A gene expression and thymocyte development. The diphtheria toxin gene was expressed in thymus, spleen and liver of transgenic mice confirmed by RT-PCR and Northern blotting. A FACS analysis with thymocyte cell surface antigens antibodies (CD4 and CD8) showed that the number of peripheral mature single positive thymocytes ($CD4^{+}\;and\;CD8^{+}$ cells) T-cells was severely reduced in transgenic mice compared to that in the non-transgenic littermates. A relative portion of $CD8^{+}$ single positive thymocytes was about 33.2% in transgenic peripheral T-cells while 50.6% in wild type. Reduction of $CD4^{+}$ cell numbers in transgenic mice was observed (5.9% in transgenic versus 10.3% in non-transgenic). The data from analysis of these transgenic mice indicate that the proximal lck promoter regulated the expression of DT-A gene at high level in developing thymocytes and the DT-A disrupted developing thymocytes in transgenic mice.