• IMMUNE NETWORK
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• 제2권2호
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• pp.72-78
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• 2002

Background: The precise mechanism by which CTLA-4 regulates T cell immune responses is still not fully understood. Previously we proposed that CTLA-4 could downregulate T cell function by modulating a signaling cascade initiated from the T cell receptor complex. The evidence for this notion comes from our findings that CTLA-4 associated with the T cell receptor zeta (TCR zeta) chain, and hence regulated TCR zeta phosphorylation by co-associated SHP-2 tyrosine phosphatase (1). In this report, we investigated whether any other signaling molecules could be involved in the CTLA-4 signaling pathway. Methods: We have taken biochemical approaches, such as immunoprecipitation followed by autoradiography or immunoblotting, to identify the molecules associated with CTLA-4. To perform these assays, we used activated primary T cells and ectopically transfected 293 cells. Various truncation mutants of CTLA-4 were used to map the interaction site on CTLA-4. Results: We found that in addition to TCR zeta and SHP-2, a recently cloned small adaptor molecule, SAP (SLAM-associated protein), was also able to associate with CTLA-4. We identified the domain of SAP association in CTLA-4 being a motif involving GVYVKM. This motif has been previously found to bind SHP-2 through its phosphorylated tyrosine interaction with SH-2 domain of SHP-2. Indeed, co-expression of SAP and SHP-2 reduced their binding to CTLA-4 significantly, suggesting that SAP and SHP-2 compete for the common binding site, GVYVKM. Thus, by blocking SHP-2 recruitment SAP could function as a negative regulator of CTLA-4. Conclusion: Taken together, our data suggest the existence of complicate signaling cascade in regulating CTLA-4 function, and further provide evidence that SAP can act either as a positive or negative regulator depending on the nature of the associating receptors.

• IMMUNE NETWORK
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• 제15권2호
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• pp.100-109
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• 2015

Controlling balance between T-helper type 1 (Th1) and T-helper type 2 (Th2) plays a pivotal role in maintaining the biological rhythm of Th1/Th2 and circumventing diseases caused by Th1/Th2 imbalance. Interleukin 4 (IL-4) is a Th2-type cytokine and often associated with hypersensitivity-related diseases such as atopic dermatitis and allergies when overexpressed. In this study, we have tried to elucidate the function of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) as an essential modulator of Th1/Th2 balance. EC-18 has showed an inhibitory effect on the production of IL-4 in a dose-dependent manner. RT-PCR analysis has proved EC-18 affect the transcription of IL-4. By analyzing the phosphorylation status of Signal transducer and activator of transcription 6 (STAT6), which is a transcriptional activator of IL-4 expression, we discovered that EC-18 induced the decrease of STAT6 activity in several stimulated cell lines, which was also showed in STAT6 reporter analysis. Co-treatment of EC-18 significantly weakened atopy-like phenotypes in mice treated with an allergen. Collectively, our results suggest that EC-18 is a potent Th2 modulating factor by regulating the transcription of IL-4 via STAT6 modulation, and could be developed for immune-modulatory therapeutics.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.183-189
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• 2015

Foeniculum vulgare Mill. (fennel) is used to flavor food, in cosmetics, as an antioxidant, and to treat microbial, diabetic and common inflammation. No study to date, however, has assessed the anti-inflammatory effects of fennel in experimental models of inflammation. The aims of this study were to investigate the anti-inflammatory effects of fennel in model of lipopolysaccharide (LPS)-induced acute lung injury. Mice were randomly assigned to seven groups (n=7~10). In five groups, the mice were intraperitoneally injected with 1% Tween 80-saline (vehicle), fennel (125, 250, $500{\mu}l/kg$), or dexamethasone (1 mg/kg), followed 1 h later by intratracheal instillation of LPS (1.5 mg/kg). In two groups, the mice were intraperitoneally injected with vehicle or fennel ($250{\mu}l/kg$), followed 1 h later by intratracheal instillation of sterile saline. Mice were sacrificed 4 h later, and bronchoalveolar lavage fluid (BALF) and lung tissues were obtained. Fennel significantly and dose-dependently reduced LDH activity and immune cell numbers in LPS treated mice. In addition fennel effectively suppressed the LPS-induced increases in the production of the inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, with $500{\mu}l/kg$ fennel showing maximal reduction. Fennel also significantly and dose-dependently reduced the activity of the proinflammatory mediator matrix metalloproteinase 9 and the immune modulator nitric oxide (NO). Assessments of the involvement of the MAPK signaling pathway showed that fennel significantly decreased the LPS-induced phosphorylation of ERK. Fennel effectively blocked the inflammatory processes induced by LPS, by regulating pro-inflammatory cytokine production, transcription factors, and NO.

• 약학회지
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• 제51권4호
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• pp.270-276
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• 2007

Silybin is known to be a major active flavonoid component isolated from Silybum marianum, a hepatoprotective medicinal plant. In this study, we examined the immunomodulatory role of silybin on T cell and macrophage-mediated immune responses. To do this, the proliferation of splenic lymphocytes and CD8+ CTLL-2 cells under mitogenic stimulation with lipopolysaccharide (LPS), concanavalin (Con) A and interleukin (IL)-2 and the production of $TNF-{\alpha}$ and NO from LPS- and $IFN-{\gamma}$-activated macrophages was evaluated under silybin treatment. The mitogenic proliferation of splenic lymphocytes induced by LPS and Con A was strongly diminished by silybin in a dose-dependent manner. Moreover, the proliferation of CD8+ CTLL-2 cells was also negatively modulated by the compound. In contrast, silybin did not strongly suppress the proliferation of normal splenocytes and T cell line Sup-T1 cells, indicating that the inhibitory effect of silybin may be due to blocking only mitogenic responses of splenic lymphocytes. In addition, silybin inhibited $TNF-{\alpha}$ production in LPS-stimulated RAW264.7 cells. Effect of silybin however was distinct, according to NO-inducing stimuli. Thus, silybin only blocked NO production induced by $IFN-{\gamma}$ but not LPS and the inhibition was increased when PMA was co-treated with $IFN-{\gamma}$. Unlike NO inhibition, however, this compound protected the cytotoxic damage of RAW264.7 cells induced by both LPS and $IFN-{\gamma}$. Therefore, our data suggest that silybin may participate in host immune responses mediated by T cells and macrophages via regulating mitogenic proliferation, and the production of $TNF-{\alpha}$ and NO, depending on cellular stimuli.

• Journal of Nutrition and Health
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• 제37권1호
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• pp.23-30
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• 2004

Ginger (Zingiber officinale Roscoe) has been used as a raw material in many traditional preparations since the ancient time. As a component of traditional health products, Ginger is known to be effective as appetite enhancer, anticold and anti-inflammation. This study was performed to investigate the immunomodulative effects of Ginger in mouse, using in vitro and ex vivo experiments. In vitro experiment, the mice splenocytes proliferation and three kinds of cytokines (IL-1 $\beta$, IL-6, and TNF-$\alpha$) prodution by peritoneal macrophages cultured with ethanol and water extracts of Ginger were used to indicate the immunomodulative effect. In order to elucidate the immunomodulative effects of Ginger ex vivo, water extract of Ginger was orally administrated into mice, and isolated splencytes and macrophages were used as experimental model. Ex vivo experiment, six to seven week old mice were fed ad libitum on a chow diet, and water extract of finger was orally administrated every other day for four weeks at two different concentractions (50 and 500 mg/kg B.W./day). In vitro study, the splenocytes proliferation was increased when water extract was supplemented in the range of 50-500 $\mu$l/ml concentration. In case of cytokines production, IL-1 $\beta$, IL-6 and TNF-$\alpha$ released by activated peritoneal macrophages were augmented by the supplementation of water extract of the Ginger. Ex vivo experiment, the highest proliferation of splenocytes and production of cytokines by activated peritoneal macrophages were seen in the mice orally administrated at the concentration of 500 mg/kg B.W./day. In conclusion, this study suggests that Ginger extracts may enhance the immune function by regulating the splenocytes proliferation and enhancing the cytokine prodution capacity by activated macrophages in mice.

• BMB Reports
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• 제38권5호
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• pp.571-576
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• 2005

Cytokines are proteins produced by many different cells of the immune system and play a significant role in initiating and regulating the inflammatory process. In this research, an important cytokine, interleukin-10 (IL-10) gene, has been identified and characterized from zebrafish (Danio rerio) genome database. Zebrafish IL-10 is located within a 2690 bp fragment and contains five exons and four introns, sharing the same organization with mammalian IL-10 genes. An open reading frame of 543 bp was found to encode a putative 180 amino acid protein with a signal peptide of 22 amino acids, which shares 29.7-80.9% homology with amino acid sequences of other known IL-10. The signature motif of IL-10 is also conserved in zebrafish IL-10. The predicted transcript was finally confirmed by sequencing of cDNA clones. Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the tissue distribution and expression regulation of this gene in seven organs of normal and lipopolysaccharide (LPS) stimulation zebrafish. The results demonstrated that this gene was expressed slightly in normal kidney, gill and gut, no expression was detected in other four tissues. The expression was clearly upregulated after LPS stimulation. Using the ideal zebrafish model, further study of IL-10 characterization and function may provide insight on the understanding of the innate immune system.

• 한국식품영양학회지
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• 제27권4호
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• pp.603-608
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• 2014

In vitro 실험을 통한 느타리버섯 물 추출물 첨가가 마우스의 면역세포 증식에 미치는 영향에 대한 연구 결과, 음의 대조군에 비해 느타리 물 추출물을 첨가한 모든 농도에서 비장세포 증식능이 증가하였으며, 특히 $100{\sim}1,000{\mu}g/mL$ 농도에서 유의적으로 증가하였다. 반면, 사이토카인 생성의 경우, IL-2, IFN-${\gamma}$, TNF-${\alpha}$ 사이토카인 생성량을 측정한 결과, 느타리버섯 물 추출물 $50{\sim}500{\mu}g/mL$ 농도에서 생성된 IL-2, IFN-${\gamma}$, TNF-${\alpha}$ 사이토카인은 대조군보다 높은 생성량을 보였다. IFN-${\gamma}$, TNF-${\alpha}$ 사이토카인 모두 50, 100, 250, $500{\mu}g/mL$의 농도에서 높은 생성량을 나타내었다. IL-2의 경우, 생성량이 유의적인 차이는 보이지 않았지만, $50{\mu}g/mL$ 이상에서 증가하는 경향을 보여주었다. 이상의 결과에 의하면 느타리버섯 물 추출물은 마우스 비장 세포를 증식시키고, 사이토카인 생성량에도 영향을 주어, 면역 기관의 주요 기능을 증진시킬 가능성이 있을 것으로 사료되며, 느타리버섯이 면역 증진 기능성 식품 개발의 소재로 활용될 가능성이 있을 것으로 기대된다.

• 약학회지
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• 제48권2호
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• pp.159-164
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• 2004

Primary pro-inflammatory cytokines are a trio: tumor necrosis- $\alpha$ (TNF-$\alpha$), interleukine-$\beta$ (IL-$\beta$), and interleukine-6 (IL-6). These cytokines initiate and regulate the acute-phase inflammatory response during infection, trauma, or stress and appear to play an important role in the immune process. Nitric oxide (NO) is a multi-functional mediator, which plays an important role in regulating various biological functions in vivo. NO production by inducible nitric oxide synthase (iNOS) in macrophages is essential for the defense mechanisms against microorganisms and tumor cells. However, over-expression of iNOS by various stimuli, resulting in over-production of NO, contributes to the pathogenesis of septic shock and some inflammatory and auto-immune disease. Solvent fractions of sage ( Salvia officinalis L.), which is cultivated in Jeju-Do, was assayed for their effects on TNF-$\alpha$ and IL-6 production in LPS-stimulated RAW 264.7 macrophages. Hexane and ethylacetate (EtOAc) fraction of sage inhibited the protein and mRNA expression of TNF-$\alpha$ and IL-6 in LPS stimulated RAW 264.7 cells at the concentration of 100 $\mu\textrm{g}$/$m\ell$. Also, incubation of RAW 264.7 cells with the fraction of hexane or EtOAc (50 $\mu\textrm{g}$/$m\ell$) inhibited the LPS induced nitrite accumulation and the LPS/IFN-${\gamma}$ induced iNOS protein. And this inhibition of iNOS protein is concordant with the inhibition of iNOS mRNA expression. Above results suggest that extract of sage may have anti-inflammatory activity through the inhibition of pro-inflammatory cytokines (TNF-$\alpha$, IL-1$\beta$, IL-6), iNOS and NO.

• 한국식품영양학회지
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• 제19권2호
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• pp.176-182
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• 2006

Sorghum bicolor L. Moench(Sorghum, Su-Su) is a major cereal food crop used in many parts of the world. It is used as a human food resource and folk medicines in Asia and Africa. The stem of sorghum has been used as a digestive aid and an anti-diarrheal agent. Sorghum hybrids contain high levels of diverse phenolic compounds that may provide health benefits. High levels of polyflavanols, anthocyanins, phenolic acids, and other antioxidant compounds have been reported in sorghums, which have also been shown to possess various biological activities such as anti-mutagenic, anti-carcinogenic, and HMG-CoA reductase inhibitory activities. In an in vitro experiment, we examined mice splenocyte proliferation and production of three types of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by peritoneal macrophages cultured with ethanol and water extracts of Sorghum bicolor L. Moench. A single cell suspension of splenocytes was prepared and the cell proliferation of the splenocytes was examined by MTT assay. The splenocyte proliferation was increased when water extracts of Sorghum bicolor L. Moench were used as supplements in all concentrations investigated. The production of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by activated peritoneal macrophage was detected by ELISA using the cytokine kit. $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ production by activated macrophages were increased by supplementation with Sorghum bicolor L. Moench water extracts. This study suggests that supplementation of with Sorghum bicolor L. Moench water extracts may enhance immune function by regulating the splenocyte proliferation and enhancing the cytokine production by activated macrophages in vitro.

• 대한한의학회지
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• 제28권4호
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• pp.27-41
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• 2007

Aim : This study aimed at elucidating the effects of Inonotus obliquus on anti-tumor effects in vivo and immune-based characterization of the mushroom as a potential candidate for cancer remedy. Methods : To investigate the immunomodulatory effects of Inonotus obliquus, we investigated macrophage functions and NK cell activities through the measurement of NO production of macrophage, NK cell cytotoxicity and expressions of cytokines and genes regulating immune responses, in addition to pulmonary metastasis model in vivo. Results : Inonotus obliquus showed general cytotoxicity at high concentrations over the 100 ${\mu}g/m{\ell}$ on the both of normal and cancer cell lines. Inonotus obliquus showed both inhibitory and promotive effects on pulmonary colonization of CT-26 cell depending on period or route of administration in vivo. Conclusion : From these results, it cannot be concluded that Inonotus obliquus has cancer-specific activity. Furthermore, Inonotus obliquus has the provability to show adverse effects differently according to the concentration and the method of administration.