• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1204-1208
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• 2017

Natural killer (NK) cells have been reported to be dysfunctional in chronic hepatitis B (CHB) infection. However, the functional recovery of NK cells under antiviral therapeutic agents in CHB was not clearly understood. In this study, we investigated the phenotypic changes of NK(CD56+CD3-) cells in terms of their functional markers (CD16, NKG2A, NKG2D) during tenofovir therapy in CHB. The frequency of NK(CD56+CD3-) cells in CHB patients was significantly increased after 12 months of tenofovir therapy when compared with baseline. The expression levels of CD16+/CD56+CD3- and NKG2A+/CD56+CD3- cells were also affected by tenofovir treatment. In addition, there was a positive correlation between the proportion of NK(CD56+CD3-) cells and HBV DNA (log copies/ml) in CHB patients.

• Korean Journal of Pharmacognosy
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• v.21 no.4
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• pp.307-316
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• 1990

This study was undertaken to test the effects of Daturae Flos(DF) and Daturae Semen(DS) on the cellular and humoral immune responses, and the functions of the cells involved in immunoinflammation. Both extracts decreased the activity of superoxide dismutase, and the decrease was greater in the mouse group which was treated with DS. Both extracts decreased the phagocytic activity as measured by assessing the number of the latex particle within the phagocyte after incubation of peritoneal macrophages with fluorochrome-labelled latex particle and decreased natural killer cell activity as measured by enumerating the viable YAC-1 cells after treatment of target cells with splenic natural killer cells. Both extracts also decreased the cell-mediated immunity in vivo as assessed by measuring the ear thickness after sensitization and challenge with dinitrofluorobenzene, however, had no effects on the humoral immune responses as measured by checking hemolysin and hemagglutinin titers after immunization with sheep red blood cells(SRBC). Extracts of Semen caused decrease in the number of rosette forming cells between the splenic cells and SRBC. The results of this study suggested that both Daturae extracts could depress the immunoinflammation by affecting the various cell types involved in inflammation.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.181-187
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• 2010

Excessive alcohol consumption is one of the critical causative factors leading to alcoholic liver disease (ALD). ALD is characterized by a wide spectrum of liver damage, ranging from simple uncomplicated liver steatosis (fatty liver) to steatohepatitis and liver fibrosis/cirrhosis. It has been believed that the obvious underlying cause for ALD is due to hepatocyte death induced by alcohol itself. However, recent sparkling studies have shown that diverse immune responses contribute to ALD because liver is enriched with numerous immune cells. Especially, a line of evidence has suggested that innate immune cells such as Kupffer cells and natural killer (NK)/NKT cells are significantly involved in the pathogenesis of ALD via production of pro-inflammatory cytokines and other mediators. Indeed, more interestingly, hepatic stellate cells (HSCs), known as a major cell inducing liver steatosis and fibrosis, can be killed by liver NK cells, which could be suppressed by chronic alcohol consumption. In this review, with the view of liver as predominant innate immune organ, we describe the pathogenesis of ALD in which what roles of innate immune cells are and how they are interacting with HSCs.

• Journal of Ginseng Research
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• v.18 no.3
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• pp.151-159
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• 1994

To evaluate the anticarcinogenic effect and its mechanism of red ginseng, the mice were treated with red ginseng and received subcutaneous Bl6 melanoma cell line injection on the back. Tumor incidence was same (100%) both in water and red ginseng-treated groups, but tumor production was delayed in red ginseng-treated group. Survival time was somewhat longer in red ginseng-treated group. The histopathological findings were similar in both groups, but lymphocytic infiltration around the tumor and melanin production in the tumor cells were prominent in the red ginseng-treated group. Flow cytometric analysis on T lymphocytes and natural killer cells revealed increased $T_H$/$T_S$ ratio and increased NK cells in red ginseng-treated group. These results suggest that the anticarcinogenic effect of red ginseng may be exerted by the increased cell-mediated immunity and natural killer cell activity.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.193-197
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• 2008

The influence of alpha-fetoprotein (AFP) on the bone marrow (BM) natural suppressor (NS) cells of intact Ehrlich carcinoma -bearing CBA mice was studied. Bone marrow NS cells were fractionated into three fractions by isopycnic centrifugation on percoll gradients: NS1 (${\rho}$=1.080 g/ml), NS2 (${\rho}$=1.090 g/ml) and NS3 (1.100> ${\rho}$ > 1.090 g/ml). These fractions were highly different in their sensitivity to known NS cell inductors (interleukin (IL)-2, IL-3 or histamine). None of the NS fractions isolated from the intact mice spontaneously produced antiproliferative activity, however, they showed a high level of NS (antiproliferative and natural killer cell inhibitory) activity under the influence of AFP. A single injection of AFP to intact mice led to an increase of spontaneous NS activity and the inhibition of natural killer cell activity. NS activity, especially NS2, was increased in when tumor cells were subcutaneously inoculated three days after AFP injection. In the AFP-treated mice, the tumor mass at 14 days was 60% larger than that in the untreated mice. Our data confirmed that AFP is a tumor marker that can inhibit cancer immunity and plays a role in cancer pathogenesis.

• Journal of Korean Biological Nursing Science
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• v.26 no.3
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• pp.185-194
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• 2024

Purpose: This study investigated changes in psychological and physiological indices in cancer survivors who participated in a forest therapy camp in Korea. Methods: A total of 37 cancer survivors (19 and 18 in the experimental and control groups, respectively) participated in this study. Over a 2-night and 3-day period, the participants in the experimental group took part in a forest therapy camp that included activities such as gymnastics, walking, five-senses experiences, and meditation. Both groups completed self-report questionnaires that measured their stress levels and profile of mood states, both before and after the forest therapy camp. Blood samples were collected to measure the levels of cortisol, serotonin, and natural killer (NK) cells. Results: After the forest therapy camp, the experimental group exhibited reduced stress levels (p = .031) and a significant improvement in total mood disturbance (p = . 047) when compared with the control group. The level of serotonin also significantly increased (p < .001). However, in contrast to the prediction, a significant increase in cortisol was noted in the experimental group relative to the control group (p = .016). Moreover, no significant difference in NK cells was noted between the two groups. Conclusion: Forest therapy can be easily applied to cancer survivors. The positive psychological effects of the forest therapy camp were confirmed by improvements in stress and mood states and the increased level of serotonin in forest therapy camp participants. However, there is a need for a follow-up evaluation of cortisol and NK cells due to the absence of significant between-group differences.

• 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.

• Biomolecules & Therapeutics
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• v.3 no.4
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• pp.273-278
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• 1995

The effect of methamphetamine on the pulmonary metastasis was investigated in C57BL/6 mice injected with Bl6 melanoma cells. Bl6 melanoma cells (2$\times$10$^{5}$ cells) were injected intravenously into 5~7 weeks old C57BL/6 mice. Mice were then treated intraperitoneally with methamphetamine either acutely (two times with one week interval) or subchronically (daily for 14 days). Degree of pulmonary metastasis was investigated and specific immunologic parameters such as natural killer cell cytotoxicity(NKCC), antibody-dependent cellular cytotoxicity(ADCC) and blastogenic responses of splenocytes were examined. Mice which had been subchronically treated with methamphetamine showed significant decreases in the number of pulmonary metastasis of Bl6 melanoma cells, NKCC and ADCC without a significant change in blastogenic responses. In the acutely-treated group, slight trends of decrease in the numbers of pulmonary metastasis, NKCC and ADCC were observed without statistical significances whereas there was a significant increase in blastogenic responses. The mechanism underlying the decrease in the degree of metastasis despite diminished NKCC and ADCC after methamphetamine treatment and the relationship between the degree of pulmonary metastasis and duration of methamphetamine treatment remain to be investigated.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.8.1-8.13
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• 2023

CD8⁺ T cells are activated by TCRs that recognize specific cognate Ags, while NK-cell activation is regulated by a balance between signals from germline-encoded activating and inhibitory NK receptors. Through these different processes of Ag recognition, CD8⁺ T cells and NK cells play distinct roles as adaptive and innate immune cells, respectively. However, some human CD8⁺ T cells have been found to express activating or inhibitory NK receptors. CD8⁺ T-cell populations expressing NK receptors straddle the innate-adaptive boundary with their innate-like features. Recent breakthrough technical advances in multi-omics analysis have enabled elucidation of the unique immunologic characteristics of these populations. However, studies have not yet fully clarified the heterogeneity and immunological characteristics of each CD8⁺ T-cell population expressing NK receptors. Here we aimed to review the current knowledge of various CD8⁺ T-cell populations expressing NK receptors, and to pave the way for delineating the landscape and identifying the various roles of these T-cell populations.

• IMMUNE NETWORK
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• v.4 no.2
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• pp.94-99
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• 2004

Background: We previously reported that ginsan, a polysaccharide extracted from Panax ginseng had an immunostimulatory activity such as mitogenic activity, activation of macrophages and killer cells, and production of a variety of cytokines which resulted in antitumor and antiseptic effects. We further purified $\alpha$-(1$\longrightarrow$6)-glucan and $\beta$-(2$\longrightarrow$6)-fructan from the ginsan with size exclusion and ion-exchange column chromatography successively. In this study, we performed the structure-based activity of ginsan by comparison with known polysacchrides such as $\beta$-glucan, curdlan, laminarin, levan, dextran, lentinan and OK-432. Methods: To investigate the immunostimulatory activity of several polysaccharide compounds, we investigated the stimulation of lymphocytes proliferation, the generation of activated killer cells and the secretion of nitrites from activated macrophages. Results: Of polysaccharides tested, curdlan and ginsan stimulated lymphocyte proliferation, suggesting that the molecular weight and composition of polysaccharide are dependent on the mitogenic activity. The production of nitric oxide was significantly increased in curdlan, levan, ginsan and its fraction, indicating that fructan has also capacity to activate macrophages and may devote to kill pathogens. In addition, the activation of macrophages was seemed to be independent of molecular weight of polysaccharide. The generation of AK cells was exhibited in order of curdlan, OK-432> F1, ginsan, F3> levan> etc. The AK activity may be dependent on molecular weight and composition of polysaccharides. Conclusion: Unfortunately, purified polysaccharide from ginsan were less active on immunostimulatory activity than mixed compounds of polysaccharides. From the viewpoint of structure and activity relationships, we found several characteristic features.