• IMMUNE NETWORK
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• v.5 no.1
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• pp.11-15
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• 2005

Background: Throughtout the last three decades, the therapy of leukemias and lymphoma has set the stage for curative cancer therapy in systemic malignant disease. This was the result of an integrated work of basic reaserch and clinical investigators leading to more aggressive albeit tolerable protocol of chemotherapy and radiotherapy. High dose therapy marks the most elaborated strategies in this field today. However, intensification of conventional therapeutic modalities as mentioned has to be based on new approaches and the exploration of new antineoplastic mechanisms. This insight has resulted in immune therapy of cancer. Among the cells of the immune system, natural killer (NK) cells and T cells are of major interest for the development of therapeutic strategies. Methods: Cytotoxicity to target cells was measured by LDH release method, Characterization of activated lymphocyte was measured by Flow cytometry analysis. Anti-CD3, 16, 56 monoclonal antibody and IL-2 were used for the activation of NK and T cell. The analysis of effect of activated lymphocyte, in vivo, were used by Balb/c nude mouse. Results and Conclusion: Cytotoxicity to K562 cells was significantly higher in the mixture group of NK and T cells than that of a group of activating T cells. The survivors and the rate of reduction of size of tumor craft of nude mouse group treatment with activated lymphocyte was higher than that of the group without treatment with activated lymphocyte. Therefore, this results are suggested that the activated lymphocytes by anti-CD3, CD16 and CD56 can reduce the malignancy effect of lymphoma.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.150-155
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• 2003

The nuclear factor of activated T cells (NFAT) protein induce transcription of cytokine genes required for T-cell activation, including the IL-2 gene. Activation of NFAT normally plays a significant role in inducing immune response. However, excessive activation provokes immunopathological reactions including autoimmunity, transplant rejection and inflammation. Thus, several natural products were screened on the inhibitory activity against the NFAT transcription factor. Among them, Euonymus sieboldiana showed strong inhibitory activity against the NFAT transcription factor without affecting cell viability.

• 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.

• International Journal of Oral Biology
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• v.38 no.1
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• pp.37-42
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• 2013

Receptor activator of NF-${\kappa}B$ ligand (RANKL) is an essential cytokine for osteoclast differentiation, activation and survival. T lymphocytes such as $T_{17}$ cells, a subset of T helper cells that produce IL-17, play an important role in rheumatoid arthritic bone resorption by producing inflammatory cytokines and RANKL. It has not yet been clearly elucidated how T cell activation induces RANKL expression. T cell receptor activation induces the activation of nuclear factor of activated T cell (NFAT) and expression of its target genes. In this study, we examined the role of NFAT in T cell activation-induced RANKL expression. EL-4, a murine T lymphocytic cell line, was used. When T cell activation was induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin, RANKL expression increased in a time-dependent manner. In the presence of cyclosporin, an inhibitor of NFAT activation, this PMA/ionomycin-induced RANKL expression was blocked. Overexpression of either NFATc1 or NFATc3 induced RANKL expression. Chromatin immunoprecipitation results demonstrated that PMA/ionomycin treatment induced the binding of NFATc1 and NFATc3 to the mouse RANKL gene promoter. These results suggest that NFATc1 and NFATc3 mediates T cell receptor activation-induced RANKL expression in T lymphocytes.

• Biomolecules & Therapeutics
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• v.30 no.5
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• pp.418-426
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• 2022

Chimeric antigen receptor T (CAR-T) cell therapy is one of the promising anticancer treatments. It shows a high overall response rate with complete response to blood cancer. However, there is a limitation to solid tumor treatment. Additionally, this currently approved therapy exhibits side effects such as cytokine release syndrome and neurotoxicity. Alternatively, bispecific antibody is an innovative therapeutic tool that simultaneously engages specific immune cells to disease-related target cells. Since programmed death ligand 1 (PD-L1) is an immune checkpoint molecule highly expressed in some cancer cells, in the current study, we generated αCD3xαPD-L1 bispecific antibody (BiTE) which can engage T cells to PD-L1⁺ cancer cells. We observed that the BiTE-bound OT-1 T cells effectively killed cancer cells in vitro and in vivo. They substantially increased the recruitment of effector memory CD8⁺ T cells having CD8⁺CD44⁺CD62L^low phenotype in tumor. Interestingly, we also observed that BiTE-bound polyclonal T cells showed highly efficacious tumor killing activity in vivo in comparison with the direct intravenous treatment of bispecific antibody, suggesting that PD-L1-directed migration and engagement of activated T cells might increase cancer cell killing. Additionally, BiTE-bound CAR-T cells which targets human Her-2/neu exhibited enhanced killing effect on Her-2-expressing cancer cells in vivo, suggesting that this could be a novel therapeutic regimen. Collectively, our results suggested that engaging activated T cells with cancer cells using αCD3xαPD-L1 BiTE could be an innovative next generation anticancer therapy which exerts simultaneous inhibitory functions on PD-L1 as well as increasing the infiltration of activated T cells having effector memory phenotype in tumor site.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.459-465
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• 2011

The nuclear factor of activated T cells (NFAT) protein induces transcriptions of cytokine genes including IL-2 for T-cell activation. Normally activation of NFAT is important to induce immune responses but excessive NFAT activation provokes immunopathological reactions such as autoimmunity, transplant rejection, and inflammation. Thus, for the treatment of autoimmune diseases drugs repressing the activation of NFAT have been searched. In this study, immnunosuppressive effects of Rosa chinensis Jacq. extracts identified as a potent NFAT inhibitor from a natural product library were examined. NFAT reporter assay, MTS assay, real time PCR, IL-2 ELISA, MLR, and FACS (Fluorescent Activated Cell Sorting) were used to measure inhibitory immunocyte activities of Rosa chinensis Jacq. The variety of natural products have been screened and some were found to show inhibitory activities against the NFAT transcription factor. Among them, extract of Rosa chinensis Jacq. showed an strong inhibitory effect on the activation of NFAT without affecting cell viability. Levels of IL-2 transcripts as well as IL-2 protein were decreased with treatment of Rosa chinensis Jacq. extract. In addition, immunosuppressive activity of Rosa chinensis Jacq. extract was exhibited in the mixed leukocytes reaction. The increasement of CD4+CD25+ (Treg) immunocyte was also detected in the analysis using FACS after applying Rosa chinensis Jacq. extract. Immunosuppressive effects of the Rosa chinensis Jacq. extracts were clearly demonstrated in the present study. In addition, Rosa chinensis Jacq. extract also positively affected regulatory T cell induction. Further investigations in particular on purification of single substance responsible for the immunosuppressive effects from the extract and analysis on possible actions of the extract in interfering cell signaling and cytokine production will be needed.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.136-145
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• 2010

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

• Molecules and Cells
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• v.45 no.8
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• pp.513-521
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• 2022

Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an immune checkpoint molecule that is mainly expressed on activated T cells and regulatory T (Treg) cells that inhibits T-cell activation and regulates immune homeostasis. Due to the crucial functions of CTLA-4 in T-cell biology, CTLA-4-targeted immunotherapies have been developed for autoimmune disease as well as cancers. CTLA-4 is known to compete with CD28 to interact with B7, but some studies have revealed that its downstream signaling is independent of its ligand interaction. As a signaling domain of CTLA-4, the tyrosine motif plays a role in inhibiting T-cell activation. Recently, the lysine motif has been shown to be required for the function of Treg cells, emphasizing the importance of CTLA-4 signaling. In this review, we summarize the current understanding of CTLA-4 biology and molecular signaling events and discuss strategies to target CTLA-4 signaling for immune modulation and disease therapy.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.199-205
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• 2019

Yeast two-hybrid (Y2H) technique has been used to study protein-protein interactions, but its application particularly to a large-scale analysis of protein interaction networks, is limited by the fact that the technique is labor-intensive, based on scoring colonies on plate. Here, we develop a new reporter for the measurement of the protein-protein interactions by flow cytometry. The yeast harboring interacting proteins can also be enriched by fluorescence-activated cell sorting (FACS) or magnetic-activated cell sorting (MACS). When two interacting proteins are present in the same yeast cell, a reporter protein containing 10 tandem repeats of c-myc epitope becomes localized on the surface of the cell wall, without affecting cell growth. We successful measured the surface display of c-myc epitope upon interacting p53 with SV40 T antigen by flow cytometry. Thus, the newly developed Y2H assay based on the display of c-myc repeat on yeast cell wall could be used to the simultaneous analysis of multiple protein-protein interactions without laborious counting colonies on plate.

• Tuberculosis and Respiratory Diseases
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• v.86 no.4
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• pp.304-318
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• 2023

Background: Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment and significantly contribute to immune evasion. We investigated the effects of CAFs on the immune function of CD4+ and CD8+ T cells in non-small cell lung cancer (NSCLC). Methods: We isolated CAFs and normal fibroblasts (NFs) from tumors and normal lung tissues of NSCLC patients, respectively. CAFs were co-cultured with activated T cells to evaluate their immune regulatory function. We investigated the effect of CAF conditioned medium (CAF-CM) on the cytotoxicity of T cells. CAFs were also co-cultured with activated peripheral blood mononuclear cells and further incubated with cyclooxygenase-2 (COX2) inhibitors to investigate the potential role of COX2 in immune evasion. Results: CAFs and NFs were isolated from the lung tissues (n=8) and lymph nodes (n=3) of NSCLC patients. Immune suppressive markers, such as COX2 and programmed death-ligand 1 (PD-L1), were increased in CAFs after co-culture with activated T cells. Interestingly, CAFs promoted the expression of programmed death-1 in CD4+ and CD8+ T cells, and strongly inhibited T cell proliferation in allogenic and autologous pairs of CAFs and T cells. CAF-CM decreased the cytotoxicity of T cells. COX2 inhibitors partially restored the proliferation of CD4+ and CD8+ T cells, and downregulated the expression of COX2, prostaglandin E synthase, prostaglandin E2, and PD-L1 in CAFs. Conclusion: CAFs promote immune evasion by suppressing the function of CD4+ and CD8+ T cells via their effects on COX2 and PD-L1 in NSCLC. The immunosuppressive function of CAFs could be alleviated by COX2 inhibitors.