• Korean Journal of Plant Resources
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• v.25 no.3
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• pp.317-322
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• 2012

In this study we investigated the effects of supplementation with fucoidan from brown alga on the function of natural-killer (NK) cells to evaluate the possibility as an immunomodulator in ovariectomized (OVX) rats. A total of 18 female Wistar rats (six weeks) were used this study and 12 rats were OVX, and the rest of rats were sham-operated. The sham and one OVX group were fed standard diet, and the remaining OVX group received fucoidan (0.05% supplemented diet). After 12 weeks of supplementation, rats were sacrificed to assess the tumoricidal activity of the NK cells and the NO-iNOS regulation from splenocytes. The mass of body and the immune organs such as spleen and thymus were also studied. In OVX rats, body and thymus weights increased, however fucoidan supplementation did not change the body mass and organs weight compared to OVX group. Fucoidan supplementation increased NK cell activity and reduced NO-iNOS production in OVX rats. Ex vivo treatment of fucoidan increased NK cell activity in splenocytes from shame and OVX rats. Ex vivo, we confirmed that fucoidan partially reduced the NK cell activity in the presence of iNOS inhibitors in OVX-splenocytes. These results indicate fucoidan supplementation has a NK cell tumoricidal activity, which are regulated by the iNOS production in OVX rats. This suggests that fucoidan is useful for potential therapeutic strategies as a nutrient in regulating the NK cells in postmenopausal osteoporosis patients.

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.356-381
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• 2023

Although immunotherapy has been broadly successful in the treatment of hematologic malignancies and a subset of solid tumors, its clinical outcomes for glioblastoma are still inadequate. The results could be due to neuroanatomical structures such as the blood-brain-barrier, antigenic heterogeneity, and the highly immunosuppressive microenvironment of glioblastomas. The antitumor efficacy of endogenously activated effector cells induced by peptide or dendritic cell vaccines in particular has been insufficient to control tumors. Effector cells, such as T cells and natural killer (NK) cells can be expanded rapidly ex vivo and transferred to patients. The identification of neoantigens derived from tumor-specific mutations is expanding the list of tumor-specific antigens for glioblastoma. Moreover, recent advances in gene-editing technologies enable the effector cells to not only have multiple biological functionalities, such as cytokine production, multiple antigen recognition, and increased cell trafficking, but also relieve the immunosuppressive nature of the glioblastoma microenvironment by blocking immune inhibitory molecules, which together improve their cytotoxicity, persistence, and safety. Allogeneic chimeric antigen receptor (CAR) T cells edited to reduce graft-versus-host disease and allorejection, or induced pluripotent stem cell-derived NK cells expressing CARs that use NK-specific signaling domain can be a good candidate for off-the-shelf products of glioblastoma immunotherapy. We here discuss current progress and future directions for T cell and NK cell therapy in glioblastoma.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.107-115
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• 2024

Various vaccines were rapidly developed during the COVID-19 pandemic to prevent and treat infections but global infections continue, and concerns about new mutations and infectious diseases persist. Thus, active research focuses on developing, producing, and supplying vaccines and treatments for various infectious diseases and potential pandemics. Natural killer(NK) cells, as innate immune cells, can recognize and eliminate abnormal cells like virus-infected and cancer cells. Hence, their development as anticancer and antiviral treatments is rapidly advancing. In this study, optimal short-term culture conditions were identified for allogeneic NK cells by simplifying the culture process through the isolation of NK cells(referred to as NKi cells) and eliminating CD3+ cells(referred to as CD3- cells). NK cells demonstrated reduced viral titer in injection of NK cells into SARS-CoV-2 infected ACE-tg mice increased survival. The study's findings could form the basis for an antiviral treatment platform that swiftly responds to new viral disease pandemics.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.119-129
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• 2008

Objective: The purpose of this study was to quantify decidual $CD56^+$ and $CD16^+$ NK cell subtype population and to evaluate the correlation between decidual NK cell expression and peripheral $CD56^+$ NK cell expression in women with a history of recurrent abortion and increased peripheral NK cells. Methods: Twenty-nine women with recurrent abortion and elevated peripheral $CD56^+$ NK cell percentage who had chromosomally normal conceptus were included in this study. Thirty-two women with recurrent abortion who had chromosomally abnormal conceptus were used as controls. Distribution of $CD56^+$ and $CD16^+$ NK cells in decidual tissues including implantation sites was examined by immunohistochemical staining. The degree of immunohistochemical staining was interpreted by score and percentage. Results: There was a significant difference in decidual $CD56^+$ NK cell score ($43.6{\pm}24.5$ vs. $23.9{\pm}16.3$ P =0.001) and $CD56^+$ NK cell percentage ($42.1{\pm}11.7$ vs. $33.9{\pm}15.8$ P =0.027) between increased peripheral NK cell group and control group. However, there was no statistically significant difference in decidual $CD16^+$ NK cell score ($18.7{\pm}9.5$ vs. $13.2{\pm}39.4$ P =0.108) and $CD16^+$ NK cell percentage ($24.7{\pm}5.9$ vs. $23.4{\pm}11.7$ P =0.599). There was no significant correlation between decidual NK cell score and peripheral NK cell percentage in increase peripheral NK cell group (peripheral $CD56^+$ NK cell percentage vs. decidual $CD56^+$ NK cell score, r=-0.016, P =0.932, peripheral $CD16^+$ NK cell percentage vs. decidual $CD16^+$ NK cell score, r=0.008, P =0.968). Conclusion: This study shows that $CD56^+$ decidual NK cells are increased in decidua of women exhibiting a history of recurrent abortion with increased $CD56^+$ peripheral NK cell. There was no significant correlation between decidual and peripheral NK cell increment in increase peripheral NK cell group. This study suggests the possibility that decidual NK cells may play an important role in the immune mechanism of recurrent abortion.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9667-9672
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• 2014

Background: Pancreatic adenocarcinoma is a malignant gastrointestinal cancer with significant morbidity and mortality. Despite severe side effects of chemotherapy, the use of immunotherapy combined with chemotherapy has emerged as a common clinical treatment. In this study, we investigated the efficacy of the combined doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) therapy on murine pancreatic cancer Panc02 cells in vitro and in vivo and underlying mechanisms. Materials and Methods: A Panc02-bearing mouse model was established to determine whether doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) could effectively inhibit tumor growth in vivo. Cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) was evaluated using a standard LDH release assay. To evaluate the relevance of NK cells and CD8 T cells to the combination therapy-mediated anti-tumor effects, they were depleted in tumor-bearing mice by injecting anti-asialo-GM-1 antibodies or anti-CD8 antibodies, respectively. Finally, the influence of doxorubicin+interferon-${\alpha}$ (IFN-${\alpha}$) on the ligands of NK and T cells was assessed by flow cytometry. Results: The combination therapy group demonstrated a significant inhibition of growth of Panc02 in vivo, resulting from activated cytotoxicity of NK cells and CTLs. Depleting CD8 T cells or NK cells reduced the anticancer effects mediated by immunochemotherapy. Furthermore, the doxorubicin+IFN-a treatment increased the expression of major histocompatibility complex class I (MHC I) and NKG2D ligands on Panc02 cells, suggesting that the combined therapy may be a potential strategy for enhancing immunogenicity of tumors. All these data indicate that the combination therapy using doxorubicin and interferon-${\alpha}$ (IFN-${\alpha}$) may be a potential strategy for treating pancreatic adenocarcinoma.

• Archives of Pharmacal Research
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• v.26 no.10
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• pp.861-867
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• 2003

Inhibitory effect of the lectins (KML-C) isolated from Korean mistletoe (KM; Viscum album coloratum) on tumor metastases produced by murine tumor cells (B16-BL6 melanoma, colon 26M3.1 carcinoma and L5178Y-ML25 lymphoma cells) was investigated in syngeneic mice. An intravenous (i.v.) administration of KML-C (20-50 ng/mouse) 2 days before tumor inoculation significantly inhibited lung metastases of both B16-BL6 and colon 26-M3.1 cells. The prophylactic effect of 50 ng/mouse of KML-C on lung metastasis was almost the same with that of 100 $\mu$ g/mouse of KM. Treatment with KML-C 1 day after tumor inoculation induced a significant inhibition of not only the experimental lung metastasis induced by B16-BL6 and colon 26M3.1 cells but also the liver and spleen metastasis of L5178Y-ML25 cells. Furthermore, multiple administration of KML-C given at 3 day-intervals after tumor inoculation led to a significant reduction of lung metastasis and suppression of the growth of B16-BL6 melanoma cells in a spontaneous metastasis model. In an assay for natural killer (NK) cell activity. i.v. administration of KML-C (50 ng/mouse) significantly augmented NK cytotoxicity against Yac-1 tumor cells 2 days after KML-C treatment. In addition, treatment with KML-C (50 ng/mouse) induced tumoricidal activity of peritoneal macrophages against B16-BL6 and 3LL cells. These results suggest that KML-C has an immunomodulating activity to enhance the host defense system against tumors, and that its prophylactic and therapeutic effect on tumor metastasis is associated with the activation of NK cells and macrophages.

• Biomedical Science Letters
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• v.29 no.3
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• pp.178-183
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• 2023

Natural killer (NK) cells are innate cytotoxic lymphoid cells that actively prevent neoplastic development, growth, and metastatic dissemination in a process called cancer immunosurveillance. Regulation of the cytotoxic activity of NK cells relies on integrated interactions between inhibitory receptors and numerous activating receptors that act in tandem to eliminate tumor cells efficiently. Conventional chemotherapy is designed to produce an anti-proliferative or cytotoxic effect on early tumor cell division. Therapies designed to kill cancer cells and simultaneously maintain host anti-tumor immunity are attractive strategies for controlling tumor growth. Depending on the drug and dose used, several chemotherapeutic agents cause DNA damage and cancer cell death through apoptosis, immunogenic cell death, or other forms of non-killing (i.e., mitotic catastrophe, senescence, autophagy). Among stress-induced immunostimulatory proteins, changes in the expression levels of NK cell activating and inhibitory ligands and tumor cell death receptors play an important role in the detection and elimination by innate immune effectors including NK cells. Therefore, we will address how these cytotoxic lymphocytes sense and respond to high and low concentrations of drug-induced stress to the drug cisplatin, among the various types of drugs that contribute to their anticancer activity.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.130-136
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• 2008

Background: Human cytomegalovirus UL18, a MHC class I homologue, has been considered a natural killer (NK) cell decoy. It ligates LIR-1/ILT2 (CD85j), an NK inhibitory receptor, to prevent lysis of infected target cells. However, precise role of UL18 to NK cell cytotoxicity is yet elusive. Difficulty in clarifying the function of UL18 lies in complication in detecting UL18 mainly due to low level expression of UL18 on the surface and gradual loss of its expression. Methods: To overcome this hurdle, cDNA of cytoplasmic tail-less UL18 was constructed and expressed in swine endothelial cell (SEC). The expression level and its stability in the cell surface were monitored with FACS analysis. Results: Surface expression of UL18 is up-regulated by removing cytoplasmic tail portion from UL18F (a full sequence of UL18). SECs transfected with a cDNA of UL18CY (a cytoplasmic tail-less UL18) stably expressed UL18 molecule on the surface without gradual loss of its expression during 6 week continuous cultures. In the NK cytotoxicity assay, UL18 functions either inhibiting or activating NK cell cytotoxicity according to the source of NK cells. We found that there is individual susceptibility in determining whether the engagement of NK cell and UL18 results in overall inhibiting or activating NK cell cytotoxicity. Conclusion: In this study, we found that cytoplasmic tail is closely related to the regulatory function for controlling surface expression of UL18. Furthermore, by constructing stable cell line in which UL18 expression is up-regulated and stable, we provided a useful tool to clarify exact functions of UL18 on various immune cells having ILT2 receptor.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.115-124
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• 2010

Objective: To testify whether the increased peripheral blood natural killer (pbNK) cells fraction and their cytolytic activity could coincide with patient's history of recurrent spontaneous abortion (RSA) and to evaluate these factors are can be valuable diagnostic markers in RSA. Methods: Women with a history of RSA comprised the patient group (n=35). Normal fertile women, who were experienced at least one healthy term birth without history of infertility or recurrent miscarriage, were included as the healthy control group (n=15). The pbNK cells of $CD3^-/CD56^+/CD16^+$ and their cytolytic activities against K562 cells were measured by flow cytometry and the values were compared between study and control groups. Results: Proportions of pbNK cells among peripheral blood monocytes (PBMC) ($14.2{\pm}5.2$ vs. $9.4{\pm}3.7%$, p=0.002, 95% confidence interval [CI], 1.8 to 7.8) was significantly higher in the patient group. The odds ratio of having RSA history was increased as 8.4 folds (59% of sensitivity, 80% of specificity, and 95% CI: 2.0 to 35.8) in patients who showed pbNK cells fraction above 12.1% which was determined as cut-off value by using ROC curve analysis. The cytolytic activities of pbNK cells which measured by three different ratio of effecter pbNK cells to target K562 cells and calculated by the percent of cytolytic K562 cells, were significantly higher in study group than that of control group (in 50:1 ratio, $48.3{\pm}19.0$ vs. $31.3{\pm}11.9%$, p=0.002; in 25:1 ratio, $37.0{\pm}18.1$ vs. $20.2{\pm}9.2%$, p<0.001; in 12.5:1 ratio, $23.5{\pm}12.7$ vs. $12.4{\pm}7.3%$, p=0.001). With the cut-off values of cytolytic activity of pbNK cells as 43.1% (50:1), 26.9% (25:1), and 17.4% (12.5:1) each, the risk of having RSA history was increased by 10.0, 11.4, and 15.0 folds in patients who had increased in each effector of pbNK to target of K562 cells ratio. Conclusion: The analysis of pbNK cells fraction and their cytolytic activity can be valuable diagnostic markers for RSA. We are going to planning the large scaled studies which include the data of obstetric outcomes in subsequent pregnancies to clarify our results of this study.

• The Korea Journal of Herbology
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• v.25 no.3
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• pp.35-41
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• 2010

Objectives : Allergy is an immune dysfunction caused by degranulation from mast cells in the early phase of allergic disease including allergic rhinitis (AR). The purpose of this study was to investigate the effects of Osterici Radix, roots of Ostericum koreanum Maximowicz in human mast cells and experimental allergic animal models. Methods : The anti-allergic effect of Osterici Radix water extract (NK-W) was investigated in human mast cell line, HMC-1 cells, and compound 48/80-induced systemic anaphylactic response in rats and ovalbumin (OVA)-induced AR in mice. Animals were orally administrated with NK-W (10 and 50 mg/kg) or anti-histamine drug, dosodium cromoglycate (50 mg/kg), and then intraperitoneally injected with compound 48/80 (8 mg/kg) or sensitized with 0.1% OVA into nasal. Animals were observed plasma histamine and histological changes of nasal mucosa. Also, mast cell degranulation and histamine production were determined in compound 48/80-stimulated HMC-1 cells. Results : NK-W inhibited compound 48/80-induced degranulation of mast cells and histamine releasing in HMC-1 cells. NK-W decreased mortality and serum histamine releasing in compound 48/80-induced anaphylatic rats in a dose-dependently manner. NK-W also inhibited serum histamine levels in OVA-induced AR mice and improved abnormal histological changes such as expansion of grandular cells and hypertrophy of epithelium in the nasal mucosa. These results indicate that Osterici Radix water extract suppress allergic response through downregulation of mast cell activation. Conclusions : This study suggests that a therapeutic potential of Osterici Radix as a source of anti-allergic agents for use in a number of allergic diseases.