• The Journal of Korean Medicine
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• 제19권2호
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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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• 제23권1호
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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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• 제4권4호
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• pp.205-215
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• 2004

In the early host defense system, effector function of natural killer (NK) cells results in natural killing against target cells such as microbe-infected, malignant, and certain allogenic cells without prior stimulation. NK cell cytotoxicity is selectively regulated by homeostatic prevalence between a repertoire of both activating and inhibitory receptors, and the discrimination of untransformed cells is achieved by recognition of major histocompatibility complex (MHC) class I alleles through inhibitory signals. Although it is well known that the bipotential T/NK progenitors are derived from the common precusor, functional mechanisms in terms of the development of NK cells remain to be further investigated. NK cells are mainly involved in innate immunity, but recent studies have been reported that they also play a critical role in adaptive immune responses through interaction with dendritic cells (DC). This interaction will provide effector functions and development of NK cells, and elucidation of its precise mechanism may lead to therapeutic strategies for effective treatment of several immune diseases.

• IMMUNE NETWORK
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• 제5권4호
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• pp.247-251
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• 2005

Background: Natural killer (NK) cells are CD3 (-) CD14 (-) CD56 (+) lymphocytes. They play an important role in the body's innate immune response. They can induce spontaneous killing of cancer cells or virus-infected cells via the Fas/Fas ligand or the granzyme/perforin systems. The corticotropin-releasing hormone (CRH) is an important regulator for the body's stress response. It promotes proliferation and migration of various cancer cells through the CRH type 1 receptor under stress, and also inhibits NK or T cell activity. However, the relationship of CRH and NK cell migration to the target has not been confirmed. Herein, we study the effect of CRH on NK cell migration. Methods: We used the human NK cell line, NK-92MI, and tested the expression of CRH receptor type 1 on NK-92MI by RT-PCR. This was to examine the effect of CRH on tumor and NK cell migration, thus NK cells (NK-92MI) were incubated with or without CRH and then each CRH treated cell's migration ability compared to that of the CRH untreated group. Results: We confirmed that CRH receptor type 1 is expressed in NK-92MI. CRH can decrease NK cell migration in a time-/dose-dependent manner. Conclusion: These data suggest CRH can inhibit NK cell migration to target cells.

• Clinical and Experimental Reproductive Medicine
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• 제32권2호
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• pp.165-170
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• 2005

Objective: The aim of present study was to evaluate the effectiveness of low-dose intravenous immunoglobulin (IVIg) therapy in women with recurrent spontaneous abortions (RSA) and elevated pre-conceptional peripheral blood CD56+Natural Killer (NK) cell percentage. Study Design: Retrospective case control study. Materials and Methods: Thirty three women with RSA and elevated pre-conceptional peripheral blood CD56+NK cell percentage who had received low-dose IVIg therapy (400 mg/kg per day, every 4 week, until 20 gestational weeks) were included in this study. Controls were nine women with RSA and elevated pre-conceptional peripheral blood CD56+ Natural Killer (NK) cell percentage who had not received IVIg therapy were included in this study. Medical records of study and control groups were retrospectively analyzed and we compared the successful pregnancy outcomes between two groups. Successful pregnancy outcome was defined as pregnancy ongoing beyond 25 gestational weeks. Results: Age, number of previous abortions, pre-conceptional CD56+NK cell percentage and type of RSA were not statistically different between two groups. Otherwise, twenty-five women who received IVIg therapy (25/33, 75.8%) but, only three women who had not received (3/9, 33.3%) had a successful pregnancy outcome and the rate difference between two groups was statistically significant. Conclusion: Based on our study, low-dose IVIg therapy have a effective role in treatment of RSA patients with elevated pre-conceptional peripheral blood CD56+ Natural Killer (NK) cell percentage, but more larger scaled prospective study is needed for available of conclusive evidence.

• IMMUNE NETWORK
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• 제8권2호
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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.

• The Korean Journal of Pain
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• 제31권1호
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• pp.43-49
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• 2018

Background: Chronic pain reportedly exerts complex effects on immune function. Natural killer (NK) cells are lymphocytes that play a critical role in cellular and innate immunity. This study examined changes in the subset populations and cytotoxic activity of peripheral blood NK cells in patients with chronic pain. Methods: Thirty patients with chronic moderate-to-severe pain (group P) and age-matched pain-free subjects (group NoP) were enrolled. Peripheral whole blood was analyzed for the percentage and expression of NK cell surface markers (CD56 and CD16) by flow cytometry. Cytotoxic activity was assayed by evaluating CD69 expression on $CD3^-/CD56^+NK$ cells. Results: The percentage of NK cells among total lymphocytes was not significantly different between groups P and NoP ($16.3{\pm}9.3$ vs. $20.2{\pm}10.5%$). Likewise, the percentages of two major NK cell subsets, $CD56^{bright}$ and $CD56^{dim}$, were also not significantly different between the two groups. However, the percentage of $CD56^{bright}/CD16^+$ subset, was slightly but significantly increased in group P ($1.0{\pm}0.9%$; P< 0.01) compared with group NoP ($0.5{\pm}0.6%$). The cytotoxicity of NK cells was not different between the two groups, showing similar CD69 expression (P vs. $NoP=29.2{\pm}15.2$ vs. $32.0{\pm}15.0%$). These findings were not influenced by pain intensity, opioid use, or disease causing pain in group P. Conclusions: NK cell cytotoxic activity and major subset populations, with the exception of an increased percentage of the $CD56^{bright}/CD16^+$ subset, are not significantly altered in patients with chronic severe pain.

• Journal of Acupuncture Research
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• 제34권1호
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• pp.1-9
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• 2017

Objectives : We investigated the synergistic effects of bee venom (BV) and natural killer (NK) cells on B16F10 melanoma cell apoptosis mediated by IL-4. Methods : We performed a cell viability assay to determine whether BV can enhance the inhibitory effect of NK-92MI cells on the growth of B16F10 melanoma cells, and western blot analysis to detect changes in the expression of IL-4, $IL-4R{\alpha}$, and other apoptosis-related proteins. EMSA was performed to observe the activity of STAT6. To confirm that the inhibitory effect of BV and NK cells was mediated by IL-4, the above tests were repeated after IL-4 silencing by siRNA (50 nM). Results : B16F10 melanoma cells co-cultured with NK-92MI cells and simultaneously treated by BV ($5{\mu}g/ml$) showed a higher degree of proliferation inhibition than when treated by BV ($5{\mu}g/ml$) alone or co-cultured with NK-92MI cells alone. Expression of IL-4, $IL-4R{\alpha}$, and that of other pro-apoptotic proteins was also enhanced after co-culture with NK-92MI cells and simultaneous treatment with BV ($5{\mu}g/ml$). Furthermore, the expression of anti-apoptotic bcl-2 decreased, and the activity of STAT6, as well as the expression of STAT6 and p-STAT6 were enhanced. IL-4 silencing siRNA (50 nM) in B16F10 cells, the effects of BV treatment and NK-92MI co-culture were reversed. Conclusion : These results suggest that BV could be an effective alternative therapy for malignant melanoma by enhancing the cytotoxic and apoptotic effect of NK cells through an IL-4-mediated pathway.

• Development and Reproduction
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• 제24권1호
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• pp.53-62
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• 2020

Natural killer (NK) cells are innate lymphocytes that play an essential role in preventing cancer development by performing immune surveillance to eradicate abnormal cells. Since ex vivo expanded NK cells have cytotoxic activity against various cancers, including breast cancers, their clinical potential as immune-oncogenic therapeutics has been widely investigated. Here, we report that the pyrazole chemical XRP44X, an inhibitor of Ras/ERK activation of ELK3, stimulates NK-92MI cells to enhance cytotoxic activity against breast cancer cells. Under XRP44X stimulation, NK cells did not show notable apoptosis or impaired cell cycle progression. We demonstrated that XRP44X enhanced interferon gamma expression in NK-92MI cells. We also elucidated that potentiation of the cytotoxic activity of NK-92MI cells by XRP44X is induced by activation of the c-JUN N-terminal kinase (JNK) signaling pathway. Our data provide insight into the evaluation of XRP44X as an immune stimulant and that XRP44X is a potential candidate compound for the therapeutic development of NK cells.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7857-7861
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• 2014

Natural killer (NK) cells play an important role in anti-tumor immunity. Interleukin (IL)-18 is an immunoregulatory cytokine that induces potent NK cell-dependent anti-tumor responses when administrated with other cytokines. In this study, we explored the effects of combining IL-18 and IL-2 on NK cytotoxicity as well as expression levels of the NK cell receptor NKG2D in vitro. Freshly isolated PBMCs were incubated for 48 h with IL-18 and IL-2, then CD107a expression on $CD3^-CD56^+$ NK cells was determined by three-colour flow cytometry to evaluate the cytotoxicity of NK cells against human erythroleukemia K562 cells and human colon carcinoma HT29 cells. Flow cytometric analysis was also employed to determine NKG2D expression on NK cells. The combined use of IL-18 and IL-2 significantly increased CD107a expression on NK cells compared with using IL-18 or IL-2 alone, suggesting that the combination of these two cytokines exerted synergistic enhancement of NK cytotoxicity. IL-18 also enhanced NKG2D expression on NK cells when administered with IL-2. In addition, blockade of NKG2D signaling with NKG2D-blocking antibody attenuated the up-regulatory effect of combining IL-18 and IL-2 on NK cytolysis. Our data revealed that IL-18 synergized with IL-2 to dramatically enhance the cytolytic activity of human NK cells in a NKG2D-dependent manner. The results appear encouraging for the use of combined IL-18 and IL-2 in tumor immunotherapy.