• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.267-278
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• 1991

The natural killer (NK) cell activity of splenocytes and recycling capacity of NK cells were observed by combining the $^{51}Cr-release$ cytotoxicity assay and single cell cytotoxicity assay against YAC-1. The ICR mice were infected intranasally with Naegleria fewleri, that is a pathogenic free-living amoeba. The mice infected with $1{\times}10^5$ trophosoites showed mortality rate of 76.7% and mean survival time of 12. 9 days. The cytotoxic activity of NK cells in infected mice was significantly higher than that of non-infected mice during the period between 12 hours and day 3 after infection, and highest on day 1. The target-binding capacity of NK cells in infected mice was not different from that of non-infected ones. Maximal killing potential and maximal recycling capacity were remarkably increased in infected mice as compared with the control. The results obtained in this observation indicated that elevated NK cell activity in mice infected with N. fowieri was not due to target-binding capacity of NK cells but due to the increased activity of NK cells and increased recycling capacity of individual NK cells.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.117-124
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• 1986

The present study was undertaken to evaluate rosette formation and NK activity of splenic lymphocytes in 3-methylcholanthrene (MCA) treated mice. Mice were sensitized iv with 0.1ml of 1% sheep red blood cell (SRBC) suspension were treated with a single ip injection of olive oil alone or with different doses of MCA in oil at various time before or after sensitization, and were challenged at 4 days after SRBC. Rosette formation and NK activity of splenic lymphocytes were measured at 24 hours after challenge. Erythrocyte(E) rosette formation of splenic lymphocytes was significantly depressed in mouse treated with large dose of MCA (5~50mg) regardless of injecting time. But, there was no difference in the response between the treated with small dose of MCA (0.5mg). Whereas erythrocyte-antibody(EA) rosette or erythrocyte-antibody-complement(EAC) rosette forming cells were significantly depressed by MCA. Under small dose of MCA (0.5mg), any difference of NK activity was not observed in all course of injecting time. But, under large dose of MCA, the activity was markedly inhibited to about half the values seen in control and this suppression was transient, resulting that the normal level was reached again 19 days after MCA. These results, which conform with the predictions of immunosuppression hypothesis, suggest that MCA inhibits immunological responses including NK activity and thereby allows the outgrowth of antigenic neoplastic cells.

• The Journal of Korean Medicine
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• v.19 no.2
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• pp.313-325
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• 1998

The effect of Holotrichia on natural killer cell activity in normal mouse were studied. 1. The oral administration of Holotrichia increased spleen weight about 21.1% and also cell numbers of spleen compared to control mice group. 2. The cytotoxicity of effector cell was most effectively induced in a ratio of 50 : 1(effector/target cell). 3. Cytotoxicity of effector cells was. increased about 24% as compared with control group in in vivo test. 4. On the other hand, the administration of Holotrichia original solution showed significant increase the cytotoxicity. The cytotoxicity was increased concentration dependently. 5. The cytotoxicity by $^{3}H-thymidine$ incorporation assay showed similar effect with LDH enzyme method. 6. In the purified NK cells, the cytotoxicity was increased about 31% as compared with control group in in vivo system and the ratio of cytotoxicity was generally more increased than that of partially purified NK cell. 7. In vitro experimet of the purified NK cells, the cytotoxicity was increased 11.8% as compared with control group and the ratio of cytotoxicity was also more increased than that of partially purified NK cell. These results suggest that Holotrichia is administrated to mice with malignant tumors, the increase of NK cell activity may occur and affect tumor cells.

• IMMUNE NETWORK
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• v.23 no.3
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• pp.22.1-22.15
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• 2023

Alcoholic liver cirrhosis (ALC) is caused by chronic alcohol overconsumption and might be linked to dysregulated immune responses in the gut-liver axis. However, there is a lack of comprehensive research on levels and functions of innate lymphocytes including mucosal-associated invariant T (MAIT) cells, NKT cells, and NK (NK) cells in ALC patients. Thus, the aim of this study was to examine the levels and function of these cells, evaluate their clinical relevance, and explore their immunologic roles in the pathogenesis of ALC. Peripheral blood samples from ALC patients (n = 31) and healthy controls (HCs, n = 31) were collected. MAIT cells, NKT cells, NK cells, cytokines, CD69, PD-1, and lymphocyte-activation gene 3 (LAG-3) levels were measured by flow cytometry. Percentages and numbers of circulating MAIT cells, NKT cells, and NK cells were significantly reduced in ALC patients than in HCs. MAIT cell exhibited increased production of IL-17 and expression levels of CD69, PD-1, and LAG-3. NKT cells displayed decreased production of IFN-γ and IL-4. NK cells showed elevated CD69 expression. Absolute MAIT cell levels were positively correlated with lymphocyte count but negatively correlated with C-reactive protein. In addition, NKT cell levels were negatively correlated with hemoglobin levels. Furthermore, log-transformed absolute MAIT cell levels were negatively correlated with the Age, Bilirubin, INR, and Creatinine score. This study demonstrates that circulating MAIT cells, NKT cells, and NK cells are numerically deficient in ALC patients, and the degree of cytokine production and activation status also changed. Besides, some of their deficiencies are related to several clinical parameters. These findings provide important information about immune responses of ALC patients.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.3
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• pp.139-153
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• 2012

Objectives : NK cells are spontaneously cytotoxic lymphocytes. These are not only important parts in the first line of defence against bacterial and viral infections of outside, but they may also play a critical role in chronic viral diseases. NK cells kill their targets spontaneously, without the need for prior sensitization and class I MHC restriction by the regulation of cytolytic functions and secretion of a variety of cytokines, such as interleukin-12(IL-12), MCP-1, IL-6, TNF-${\alpha}$, IFN-${\gamma}$. In addition, macrophage and NK cells cooperate through the production of cell mediates. These cooperation and modulation are one of major factors to prevent for evading immune surveillance of cancer. Hence, it could be assumed that if any candidate to enhance activities of macrophage and NK cell, it is considered as a potentially useful agents against cancer. Methods : In our study, to investigate effect of fermented soybean extracts by Lactic acid bacteria (SFE, soybean fermented extracts) work on intestinal immune cell to maintain general immune modulating and anti-cancer activity. We analyzed NK cytotoxicity assay and gene expressions of cytokine related with macrophage and NK cell activity. Results : In vitro experiment, SFE was verified as safety material for cell toxicicty to tumor cell strain without any toxicity of tumor growth inhibition and various cell strain. Effects of macrophage activity stimulating directly by SFE measured induced cytokine. The studies showed that IL-12 production by stimulation of SFE depended on concentration from 0.16mg/mL to 0.63mg/mL with non toxicity to cell, and it was the best activity at 0.63mg/mL. Besides, the effective concentration of SFE producing TNF-${\alpha}$ is similar to IL-12, but it was the best activity at 1.25mg/mL. The level of MCP-1, IL-6 and IFN-${\gamma}$ depended on concentration from 0.16mg/mL to 10mg/mL, IFN-${\gamma}$ showed the best activity at the effective concentration of 0.63mg/mL. With the result of NK cell activity measurement, the spleen cell of mouse injected SFE had 1.5 times higher killing effect than non injected cell. Conclusions : The result of this studies is that Soybean fermetated extracts(SFE) has possibility to immune aided material for the function not only inhibition of microbial infection to macrophage but also activity of adaption immune and cellular immune system.

• IMMUNE NETWORK
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• v.23 no.5
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• pp.39.1-39.15
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• 2023

Coronavirus disease 2019 (COVID-19) vaccination may non-specifically alter the host immune system. This study aimed to evaluate the effect of COVID-19 vaccination on hepatitis B surface Ag (HBsAg) titer and host immunity in chronic hepatitis B (CHB) patients. Consecutive 2,797 CHB patients who had serial HBsAg measurements during antiviral treatment were included in this study. Changes in the HBsAg levels after COVID-19 vaccination were analyzed. The dynamics of NK cells following COVID-19 vaccination were also examined using serial blood samples collected prospectively from 25 healthy volunteers. Vaccinated CHB patients (n=2,329) had significantly lower HBsAg levels 1-30 days post-vaccination compared to baseline (median, -21.4 IU/ml from baseline), but the levels reverted to baseline by 91-180 days (median, -3.8 IU/ml). The velocity of the HBsAg decline was transiently accelerated within 30 days after vaccination (median velocity: -0.06, -0.39, and -0.04 log₁₀ IU/ml/year in pre-vaccination period, days 1-30, and days 31-90, respectively). In contrast, unvaccinated patients (n=468) had no change in HBsAg levels. Flow cytometric analysis showed that the frequency of NK cells expressing NKG2A, an NK inhibitory receptor, significantly decreased within 7 days after the first dose of COVID-19 vaccine (median, -13.1% from baseline; p<0.001). The decrease in the frequency of NKG2A⁺ NK cells was observed in the CD56^dimCD16⁺ NK cell population regardless of type of COVID-19 vaccine. COVID-19 vaccination leads to a rapid, transient decline in HBsAg titer and a decrease in the frequency of NKG2A⁺ NK cells.

• Journal of Haehwa Medicine
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• v.21 no.1
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• pp.87-96
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• 2012

Aim : Natural killer (NK) cells are cytotoxic lymphocytes that lyse certain tumor- and virus-infected cells without any prior stimulation or immunization. This article aims to review the significance of evaluating peripheral blood NK cells to predict anti-tumor immune function and prognosis in cancer patients. Methods : PubMed was used to create a database for this review. Search words of cancer, natural killer cell, prognosis were used to retrieve related articles. References of the collected articles were also reviewed. Results : Current evidence indicates that decreased or absent NK cell count or activity is mostly associated with the development or progression of cancer. In patients with various types of cancer, NK cell activity was mostly associated with the cancer prognosis and survival despite some conflicting results. Conclusion : The data shows the evaluation of anti-tumor immunity in cancer patients through natural killer cell measurement still remains a controversial matter. However, it is clear that the NK cell activity plays an important role in cancer and is associated with prevention of both early stage and metastatic cancer.

• Journal of Ginseng Research
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• v.46 no.2
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• pp.304-314
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• 2022

Background: Ginsenosides are biologically active components of ginseng and have various functions. In this study, we investigated the immunomodulatory activity of a ginseng product generated from ginseng powder (GP) via enzymatic bioconversion. This product, General Bio compound K-10 mg solution (GBCK10S), exhibited increased levels of minor ginsenosides, including ginsenoside-F1, compound K, and compound Y. Methods: The immunomodulatory properties of GBCK10S were confirmed using mice and a human natural killer (NK) cell line. We monitored the expression of molecules involved in immune responses via enzyme-linked immunosorbent assay, flow cytometry, NK cell-targeted cell destruction, quantitative reverse-transcription real-time polymerase chain reaction, and Western blot analyses. Results: Oral administration of GBCK10S significantly increased serum immunoglobulin M levels and primed splenocytes to express pro-inflammatory cytokines such as interleukin-6, tumor necrosis factor-α, and interferon-γ. Oral administration of GBCK10S also activated NK cells in mice. Furthermore, GBCK10S treatment stimulated a human NK cell line in vitro, thereby increasing granzyme B gene expression and activating STAT5. Conclusion: GBCK10S may have potent immunostimulatory properties and can activate immune responses mediated by B cells, Th1-type T cells, and NK cells.

• 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.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.69-75
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• 2010

Objectives : The root and rhizome of "Gangwhal" have been used as a traditional medicine for the treatment of cold, fever, headache, swelling, arthritis, rhinitis, and cardiovascular diseases in Korea and china. In china, Gangwhal is well known as a useful oriental medicinal plant that treats cardiovascular diseases such as stroke, headache and hypertension, but little research exists about the effect of O. koreanum on cardiovascular disease. Therefore we investigated the vasorelaxant effects of O. koreanum and compared the vasorelaxant effects of four species of Gangwhal. Methods : The vasorelaxant effects of the ethanol extracts of Ostericum koreanum (NK and BK), Notopterygium incisium (NI), and N. forbesii (NF) on phenyleprine ($1{\mu}M$) or KCl (60mM) pre-contracted rat thoracic aorta rings were compared. The vasorelaxant effects of the water extract and ethanol extract of NK on phenyleprine ($1{\mu}M$) or KCl (60mM) pre-contracted rat thoracic aorta rings were compared. And the vasorelaxant effects of chloroform, ethylacetate and water fraction of ethanol extract of NK on phenyleprine ($1{\mu}M$) or KCl (60mM) pre-contracted rat thoracic aorta rings were compared. Results : Ethanol extracts of NK, BK, NI and NF relaxed rat thoracic aorta rings with a concentration-dependent manner, and NK showed the greatest vasorelaxant effect. And ethanol extract of NK was much more effective than water extract of NK. Finally, chloroform, ethylacetate and water fraction of ethanol extract of NK also relaxed rat thoracic aorta rings, and chloroform fraction showed the greatest vasorelaxant effect.