• Molecules and Cells
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• v.24 no.1
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• pp.1-8
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• 2007

Natural killer (NK) cells play a crucial role in innate immune system and tumor surveillance. NK cells are derived from $CD34^+$hematopoietic stem cells and undergo differentiation via precursor NK cells in bone marrow (BM) through sequential acquisition of functional surface receptors. During differentiation of NK cells, many factors are involved including cytokines, membrane factors and transcription factors as well as microenvironment of BM. NK cells express their own repertoire of receptors including activating and inhibitory receptors that bind to major histocompatibility complex (MHC) class I or class I-related molecules. The balance between activating and inhibitory receptors determines the function of NK cells to kill targets. Binding of NK cell inhibitory receptors to their MHC class I-ligand renders the target cells to be protected from NK cell-mediated cytotoxicity. Thus, NK cells are able to discriminate self from non-self through MHC class I-binding inhibitory receptor. Using intrinsic properties of NK cells, NK cells are emerging to apply as therapeutic agents against many types of cancers. Recently, NK cell alloactivity has also been exploited in killer cell immunoglobulin-like receptor mismatched haploidentical stem cell transplantation to reduce the rate of relapse and graft versus host disease. In this review, we discuss the basic mechanisms of NK cell differentiation, diversity of NK cell receptors, and clinical applications of NK cells for anti-cancer immunotherapy.

• Biomolecules & Therapeutics
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• v.19 no.2
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• pp.206-210
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• 2011

Natural Killer (NK) cells are the lymphocytes that are derived from hematopoietic stem cells, developed in the bone marrow from hematopoietic stem cells (HSC) by sequential acquisition of functional surface receptors, and express the repertoire of inhibitory and activating receptors. Recently, Osteopontin (OPN) has been identified as a critical factor for differentiation of natural killer cells. However, the detailed mechanism of OPN-induced NK differentiation has been still to be elucidated. Here, we determined the signaling pathway and possible receptor for OPN in NK differentiation. OPN induced expression of Bcl-2 and activation of Erk kinase. Inhibition of Erk pathway decreased the effect of OPN on NK differentiation. In addition, the expression of integrin ${\alpha}9$ was significantly increased by OPN during NK differentiation, suggesting the possible role of a major signaling molecule for OPN- induced NK differentiation.

• BMB Reports
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• v.50 no.5
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• pp.263-268
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• 2017

${\beta}$-Agarase cleaves the ${\beta}$-1,4 linkages of agar to produce neoagarooligosaccharides (NAO), which are associated with various physiological functions. However, the immunological functions of NAO are still unclear. In this study, we demonstrated that ${\beta}$-agarase DagA-produced neoagarohexaose (DP6), an NAO product, promoted the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4). DP6 directly and indirectly enhanced the activation of natural killer (NK) cells in a TLR4-dependent manner in vitro and in vivo. Finally, the antitumor activity of DP6 against B16F1 melanoma cells was inhibited in NK cell-depletion systems by using NK-cell depleting antibodies in vivo. Collectively, the results indicated that DP6 augments antitumor immunity against B16F1 melanoma cells via the activation of DC-mediated NK cells in a TLR4-dependent manner. Thus, DP6 is a potential candidate adjuvant that acts as an immune cell modulator for the treatment of melanoma.

• IMMUNE NETWORK
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• v.8 no.2
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• pp.53-58
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• 2008

Background: Molecular mechanisms of natural killer (NK) cell development from hematopoietic stem cells (HSCs) have not been clearly elucidated, although the roles of some genes in NK cell development have been reported previously. Thus, searching for molecules and genes related NK cell developmental stage is important to understand the molecular events of NK cell development. Methods: From our previous SAGE data-base, Gpnmb (Glycoprotein non-metastatic melanoma protein B) was selected for further analysis. We confirmed the level of mRNA and protein of Gpnmb through RT-PCR, quantitative PCR, and FACS analysis. Then we performed cell-based ELISA and FACS analysis, to know whether there are some molecules which can bind to Gpnmb. Using neutralizing antibody, we blocked the interaction between NK cells and OP9 cells, and checked IFN-${\gamma}$ production by ELISA kit. Results: Gpnmb expression was elevated during in vitro developmental stage and bound to OP9 cells, but not to NK precursor cells. In addition, we confirmed that the levels of Gpnmb were increased at NK precursor stage in vivo. We confirmed syndecan4 as a candidate of Gpnmb's binding molecule. When the interaction between NK cells and OP9 cells were inhibited in vitro, IFN-${\gamma}$ production from NK cells were reduced. Conclusion: Based on these observations, it is concluded that Gpnmb has a potential role in NK cell development from HSCs.

• Molecules and Cells
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• v.44 no.8
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• pp.541-548
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• 2021

The discovery of human pluripotent stem cells (PSCs) at the turn of the century opened the door to a new generation of regenerative medicine research. Among PSCs, the donors available for induced pluripotent stem cells (iPSCs) are greatest, providing a potentially universal cell source for all types of cell therapies including cancer immunotherapies using natural killer (NK cells). Unlike primary NK cells, those prepared from iPSCs can be prepared with a homogeneous quality and are easily modified to exert a desired response to tumor cells. There already exist several protocols to genetically modify and differentiate iPSCs into NK cells, and each has its own advantages with regards to immunotherapies. In this short review, we detail the benefits of using iPSCs in NK cell immunotherapies and discuss the challenges that must be overcome before this approach becomes mainstream in the clinic.

• BMB Reports
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• v.52 no.12
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• pp.718-727
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• 2019

Severe combined immunodeficiency (SCID) is a group of inherited disorders characterized by compromised T lymphocyte differentiation related to abnormal development of other lymphocytes [i.e., B and/or natural killer (NK) cells], leading to death early in life unless treated immediately with hematopoietic stem cell transplant. Functional NK cells may impact engraftment success of life-saving procedures such as bone marrow transplantation in human SCID patients. Therefore, in animal models, a T cell-/B cell-/NK cell+ environment provides a valuable tool for understanding the function of the innate immune system and for developing targeted NK therapies against human immune diseases. In this review, we focus on underlying mechanisms of human SCID, recent progress in the development of SCID animal models, and utilization of SCID pig model in biomedical sciences. Numerous physiologies in pig are comparable to those in human such as immune system, X-linked heritability, typical T-B+NK- cellular phenotype, and anatomy. Due to analogous features of pig to those of human, studies have found that immunodeficient pig is the most appropriate model for human SCID.

• BMB Reports
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• v.52 no.11
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• pp.625-634
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• 2019

Severe combined immunodeficiency (SCID) is a group of inherited disorders characterized by compromised T lymphocyte differentiation related to abnormal development of other lymphocytes [i.e., B and/or natural killer (NK) cells], leading to death early in life unless treated immediately with hematopoietic stem cell transplant. Functional NK cells may impact engraftment success of life-saving procedures such as bone marrow transplantation in human SCID patients. Therefore, in animal models, a T cell-/B cell-/NK cell＋ environment provides a valuable tool for understanding the function of the innate immune system and for developing targeted NK therapies against human immune diseases. In this review, we focus on underlying mechanisms of human SCID, recent progress in the development of SCID animal models, and utilization of SCID pig model in biomedical sciences. Numerous physiologies in pig are comparable to those in human such as immune system, X-linked heritability, typical T-B＋NK- cellular phenotype, and anatomy. Due to analogous features of pig to those of human, studies have found that immunodeficient pig is the most appropriate model for human SCID.

• BMB Reports
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• v.52 no.3
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• pp.165-174
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• 2019

Interleukin-32 (IL-32) was originally identified in natural killer (NK) cells activated by IL-2 in 1992. Thus, it was named NK cell transcript 4 (NK4) because of its unknown function at that time. The function of IL-32 has been elucidated over the last decade. IL-32 is primarily considered to be a booster of inflammatory reactions because it is induced by pro-inflammatory cytokines and stimulates the production of those cytokines and vice versa. Therefore, many studies have been devoted to studying the roles of IL-32 in inflammation-associated cancers, including gastric, colon cancer, and hepatocellular carcinoma. At the same time, roles of IL-32 have also been discovered in other cancers. Collectively, IL-32 fosters the tumor progression by nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$)-mediated cytokines and metalloproteinase production, as well as stimulation of differentiation into immunosuppressive cell types in some cancer types. However, it is also able to induce tumor cell apoptosis and enhance NK and cytotoxic T cell sensitivity in other cancer types. In this review, we will address the function of each IL-32 isoform in different cancer types studied to date, and suggest further strategies to comprehensively elucidate the roles of IL-32 in a context-dependent manner.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.306.1-306.1
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• 2002

Cefodizime has originally been developed for treating infections as antibiotics. However. according to some of recent studies. cefodizime. a third generation cephalosporin. may potentially have the capability of stimulating chemotactic activity of neutrophils and monocytes as well as the strong immuno-modulator. In this study. we studied to learn about the expressive effect of dentritic cells and macrophage. With this background. We have studied to see if cefodizime can be a potential substance inducing an immunological function in dendritic cells and peritoneal macrophages. IL-12 activates NK cell and macrophage, and shows antiviral effect by excreting INF-${\gamma}$. In vitro. total RNAs were extracted from murine dentritic cell at 4, 8, 12, 24hr after the application of 10, 50, 100${\gamma}g$/ml of cefodizime wighout other stimulators. And we analyzed IL-12 mRNA using RT-PCR method. In conclusion. IL-12 mRNA was increased. and the results suggest that cefodizime activate TH1 cell induction, CTL differentiation as well as accelerating the increase of NK. LAK cell.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.3
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• pp.167-174
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• 2012

Natural killer (NK) cells provide one of the initial barriers of cellular host defense against pathogens, in particular intracellular pathogens. Because bone marrow-derived hematopoietic stem cells (HSCs), lymphoid protenitors, can give rise to NK cells, NK ontogeny has been considered to be exclusively lymphoid. Here, we show that porcine c-$kit^+$ bone marrow cells (c-$kit^+$ BM cells) develop into NK cells in vitro in the presence of various cytokines [interleukin (IL)-2, IL-7, IL-15, IL-21, stem cell factor (SCF), and fms-like tyrosine kinase-3 ligand (FLT3L)]. Adding hydrocortisone (HDC) and stromal cells greatly increases the frequency of c-$kit^+$ BM cells that give rise to $CD2^+CD8^+$ NK cells. Also, intracellular levels of perforin, granzyme B, and NKG2D were determined by RT-PCR and western blotting analysis. It was found that of perforin, granzyme B, and NKG2D levels significantly were increased in cytokine-stimulated c-$kit^+$ BM cells than those of controls. And, we compared the ability of the cytotoxicity of $CD2^+CD8^+$ NK cells differentiated by cytokines from c-$kit^+$ BM cells against K562 target cells for 28 days. Cytokines-induced NK cells as effector cells were incubated with K562 cells as target in a ratio of 100 : 1 for 4 h once a week. In results, $CD2^+CD8^+$ NK cells induced by cytokines and stromal cells showed a significantly increased cytotoxicity 21 days later. Whereas, our results indicated that c-$kit^+$ BM cells not pretreated with cytokines have lower levels of cytotoxicity. Taken together, this study suggests that cytokines-induced NK cells from porcine c-$kit^+$ BM cells may be used as adoptive transfer therapy if the known obstacles to xenografting (e.g. immune and non-immune problems) were overcome in the future.