• BMB Reports
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• 제37권4호
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• pp.507-514
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• 2004

Gamma irradiation ($\gamma$-IR) is reported to have diverse effects on immune cell apoptosis, survival and differentiation. In the present study, the immunomodulatory effect of a low dose $\gamma$-IR (5~10 Gy) was investigated, focusing on the role of NF-${\kappa}B$ in the induction of the B cell differentiation molecule, CD23/FceRII. In the human B cell line Ramos, $\gamma$-IR not only induced CD23 expression, but also augmented the IL-4-induced surface CD23 levels. While $\gamma$-IR did not cause STAT6 activation in these cells, it did induce both DNA binding and the transcriptional activity of NF-${\kappa}B$ in the $I{\kappa}B$ degradation-dependent manner. It was subsequently found that different NF-${\kappa}B$ regulating signals modulated the $\gamma$-IR-or IL-4-induced CD23 expression. Inhibitors of NF-${\kappa}B$ activation, such as PDTC and MG132, suppressed the $\gamma$-IR-mediated CD23 expression. In contrast, Ras, which potentiates $\gamma$-IR-induced NF-${\kappa}B$ activity in these cells, further augmented the $\gamma$-IR- or IL-4-induced CD23 levels, The induction of NF-${\kappa}B$ activation and the subsequent up-regulation of CD23 expression by $\gamma$-IR were also observed in monocytic cells. These results suggest that $\gamma$-IR, at specific dosages, can modulate immune cell differentiation through the activation of NF-${\kappa}B$, and this potentially affects the immune inflammatory response that is mediated by cytokines.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.709-717
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• 2017

Mucosal tissues are the initial site through which most pathogens invade. As such, vaccines and adjuvants that modulate mucosal immune functions have emerged as important agents for disease prevention. Herein, we investigated the immunomodulatory mechanisms of the B subunit of Escherichia coli heat-labile enterotoxin type IIa ($LT-IIa-B_5$), a potent non-toxic mucosal adjuvant. Alternations in gene expression in response to $LT-IIa-B_5$ were identified using a genome-wide transcriptional microarray that focused on dendritic cells (DC), a type of cell that broadly orchestrates adaptive and innate immune responses. We found that $LT-IIa-B_5$ enhanced the homing capacity of DC into the lymph nodes and selectively regulated transcription of pro-inflammatory cytokines, chemokines, and cytokine receptors. These data are consistent with a model in which directional activation and differentiation of immune cells by $LT-IIa-B_5$ serve as a critical mechanism whereby this potent adjuvant amplifies mucosal immunity to co-administered antigens.

• IMMUNE NETWORK
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• 제10권1호
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• pp.5-14
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• 2010

Background: There have been several reports describing the capability of ginseng extracts as an adjuvant. In this study, we tested if ginsan, a polysaccharide extracted from Panax ginseng, was effective in enhancing antibody response to orally delivered Salmonella antigen. Methods: Ginsan was treated before oral salmonella antigen administration. Salmonella specific antibody was determined by ELISA. mRNA expression was determined by RT-PCR. Cell migration was determined by confocal microscopy and flow cytometry. COX expression was detected by western blot. Results: Ginsan treatment before oral Salmonella antigen delivery significantly increased both secretory and serum antibody production. Ginsan increased the expression of COX in the Peyer's patches. Various genes were screened and we found that CCL3 mRNA expression was increased in the Peyer's patch. Ginsan increased dendritic cells in the Peyer's patch and newly migrated dendritic cells were mostly found in the subepithelial dome region. When COX inhibitors were treated, the expression of CCL3 was reduced. COX inhibitor also antagonized both the migration of dendritic cells and the humoral immune response against oral Salmonella antigen. Conclusion: Ginsan effectively enhances the humoral immune response to orally delivered antigen, mediated by CCL3 via COX. Ginsan may serve as a potent vaccine suppliment for oral immunization.

• IMMUNE NETWORK
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• 제23권2호
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• pp.19.1-19.10
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• 2023

Endemic human coronaviruses (HCoVs) have been evidenced to be cross-reactive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although a correlation exists between the immunological memory to HCoVs and coronavirus disease 2019 (COVID-19) severity, there is little experimental evidence for the effects of HCoV memory on the efficacy of COVID-19 vaccines. Here, we investigated the Ag-specific immune response to COVID-19 vaccines in the presence or absence of immunological memory against HCoV spike Ags in a mouse model. Pre-existing immunity against HCoV did not affect the COVID-19 vaccine-mediated humoral response with regard to Ag-specific total IgG and neutralizing Ab levels. The specific T cell response to the COVID-19 vaccine Ag was also unaltered, regardless of pre-exposure to HCoV spike Ags. Taken together, our data suggest that COVID-19 vaccines elicit comparable immunity regardless of immunological memory to spike of endemic HCoVs in a mouse model.

• 대한수의학회지
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• 제34권2호
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• pp.307-313
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• 1994

We have previously shown that crude water extract of Euonymus alatus (EA) had strong prophylactic effect against chemically induced-and tumor cell implanted-cancer, and that the mechanisms responsible for its antitumor effects were due to nonspecific enhancement of the NK cell activities and the cell mediated immunity. However, it was unknown that any components of crude extract did work so, since it consisted of several components. In this paper, we fractionated the crude watar EA-extract into several fraction such as hexane-, ethylether-, ethyl acetate-, n-butanol- and water soluble-fraction, and screened the immune regulating activities of each fraction by the evaluation of lymphokine production and activated lymphocyte proliferation. As a result of the component fraction of EA-extract, it was found that n-butanol fraction was a potent immunostimulator, and the remained water soluble fraction also contained some stimulator, But, other fraction did not showed any remarkable effect. It is therefore suggested that EA-glycosides in n-butanol fraction may be new one of the potent biological response modifiers. The present study was also undertaken in an efforts to investigate the effects of elm-bark(EB, Ulmus clavidiana var japonica), which has been used for curing ulcer and inflammation as a folk medicine without any kind of experimental evidence to support this, on the cellular- and humoral-immune responses, lymphocyte function and NK cell activities in mice. Regardless of time and duration of EB-treatment, Arthus reaction and antibody response to SRBC were not modified by EB, but delayed hypersensitivity to SRBC was significantly enhanced only when EB was treated prior to SRBC-sensitization. EB slightly inhibited the proliferation responses of splenocytes to PHA-stimulation, but it significantly augmented the responses of these cells to S aureus Cowan 1 and Con A-activation, and these effects were manifested only when EB was added at culture initiation. EB did not influence Ig secretion of spleen cells but it significantly augmented the Con A-induced 1L 2 and MIF production of splenocytes. NK cell activities of splenocytes were markedly riled when effector cells were pretreated with EB and this augmentation was dine to the increase of binding affinity of effector cells to target cells and the target cell lytic activities of effector cells. These results led to the conclusion that EB triggers increase of cellular immune responses, such as delayed hypersensitivitiy, lymphokine production and NK cell activities. Also these results suggested that EB contains potent immune stimulants, which may provide the rational basis for their therapeutic use as one of the new biological response modifiers.

• BMB Reports
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• 제53권11호
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• pp.576-581
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• 2020

Dimethylation of the histone H3 protein at lysine residue 9 (H3K9) is mediated by euchromatin histone methyltransferase II (EHMT2) and results in transcriptional repression of target genes. Recently, chemical inhibition of EHMT2 was shown to induce various physiological outcomes, including endoplasmic reticulum stress-associated genes transcription in cancer cells. To identify genes that are transcriptionally repressed by EHMT2 during apoptosis, and cell stress responses, we screened genes that are upregulated by BIX-01294, a chemical inhibitor of EHMT2. RNA sequencing analyses revealed 77 genes that were upregulated by BIX-01294 in all four hepatic cell carcinoma (HCC) cell lines. These included genes that have been implicated in apoptosis, the unfolded protein response (UPR), and others. Among these genes, the one encoding the stress-response protein Ras-related GTPase C (RRAGC) was upregulated in all BIX-01294-treated HCC cell lines. We confirmed the regulatory roles of EHMT2 in RRAGC expression in HCC cell lines using proteomic analyses, chromatin immune precipitation (ChIP) assay, and small guide RNA-mediated loss-of-function experiments. Upregulation of RRAGC was limited by the reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC), suggesting that ROS are involved in EHMT2-mediated transcriptional regulation of stress-response genes in HCC cells. Finally, combined treatment of cells with BIX-01294 and 5-Aza-cytidine induced greater upregulation of RRAGC protein expression. These findings suggest that EHMT2 suppresses expression of the RRAGC gene in a ROS-dependent manner and imply that EHMT2 is a key regulator of stress-responsive gene expression in liver cancer cells.

• 대한한방종양학회지
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• 제4권1호
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• pp.71-87
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• 1998

Even though appropriate immune response is necessary for the survival of the individual, excessive or insufficient immune Response might cause autoimmune or allergic disease. So the immune response must be controlled to the degree that is beneficial for the well being of the individual. This study was undertaken to know the effects of Gunleetang Gagambang on the immune system of the mouse. Gunleetang Gagambang has been used for cure of tumor as a traditional medicine without any experimental evidence to support the rational basis for its clinical use. This study was carried out to evaluate the possible therapeutic or antitumoral effects of Gunleetang Gagambang extract against tumor, and to carry out some mechanisms responsible for its effect. Some kinds of tumor were induced by the typical application of 3-methylcholanthrene(MCA) or by the implantation(s.c) of malignant tumor cells such as leukemia cells(3LL cells) or sarcoma cells(S180 cells). Treatment of the Gunleetang Gagambang on water-extract(dailly 1mg/mouse, i. p.) was continued for 7 days prior to tumor induction and after that the treatment was lasted for 20 days. Against squamous cell carcinoma induced by MCA, Gunleetang Gagambang decreased not only the frequency of tumor production but also the number and the weight of tumors per tumor bearing mice(TBM). Gunleetang Gagambang on also significantly suppressed the development of 3LL cell and S180 cell-implanted tumors in occurrence-frequency and their size. and some developed tumors were regressed by the continuous treatment of Gunleetang Gagambang extract into TBM. In vitro, treatment of Gunleetang Gagambang extract had no effect on the growth of some kinds of cell line such as FsaII, A431 strain but significantly inhibited the proliferation of 3LL, S180 cells and augmented the DNA synthesis of mitogen-activated lymphocytes. Gunleetang Gagambang also stimulated the migrative ability of leukocyte, the MIF and IL-2 production of T lymphocytes, but not IL 6 production of B cells. Gunleetang Gagambang administration to mice enhanced NK cells activities. These results demonstrated that Gunleetang Gagambang extract exhibited a significant prophylactic benefits against tumors and its antitumor activity was manifested depending on the type of tumor cells. And these results also suggested that effect of Gunleetang Gagambang might be chiefly due to nonspecitie enhancement of NK cell activities and cell-mediated immune responses.

• Archives of Pharmacal Research
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• 제29권11호
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• pp.1042-1048
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• 2006

Plasmid DNA vaccines encoding the hepatitis B virus (HBV) surface and hepatitis C virus (HCV) envelope antigens, respectively, were constructed, and attempt were made to find the possibility of a divalent vaccine against HBV and HCV. The expression of each plasmid in Cos-1 cells was confirmed using immunocytochemistry. To measure the induced immune response by these plasmids in vivo, female BALB/c mice were immunized intramuscularly with $100\;{\mu}g$ of either both or just one of the plasmids. Anti-HBV and HCV-specific antibodies and related cytokines were evaluated to investigate the generation of both humoral and cellular immune responses. As a result, specific anti-HBV and anti-HCV serum antibodies from mice immunized with these plasmids were observed using immunoblot. The levels of IL-2 and RANTES showing a $Th_{1}$ immune response were significantly increased, but there was no change in the level of IL-4 ($Th_{1}$ immune response) in any of the immunized groups. Compared with each plasmid DNA vaccine, the combined vaccine elicited similar immune responses in both humoral and cell-mediated immunities. These results suggest that the combined DNA vaccine can induce not only comparable immunity experimentally without antigenic interference, but also humoral and $Th_{1}$ dominant cellular immune responses. Therefore, they could serve as candidates for a simultaneous bivalent vaccine against HBV and HCV infections.

• Journal of Veterinary Science
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• 제23권3호
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• pp.41.1-41.15
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• 2022

Background: Proliferative enteritis caused by Lawsonia intracellularis undermines the economic stability of the swine industry worldwide. The development of cost-effective animal models to study the pathophysiology of the disease will help develop strategies to counter this bacterium. Objectives: This study focused on establishing a model of gastrointestinal (GI) infection of L. intracellularis in C57BL/6 mice to evaluate the disease progression and lesions of proliferative enteropathy (PE) in murine GI tissue. Methods: We assessed the murine mucosal and cell-mediated immune responses generated in response to inoculation with L. intracellularis. Results: The mice developed characteristic lesions of the disease and shed L. intracellularis in the feces following oral inoculation with 5 × 10⁷ bacteria. An increase in L. intracellularis 16s rRNA and groEL copies in the intestine of infected mice indicated intestinal dissemination of the bacteria. The C57BL/6 mice appeared capable of modulating humoral and cell-mediated immune responses to L. intracellularis infection. Notably, the expression of genes for the vitamin B12 receptor and for secreted and membrane-bound mucins were downregulated in L. intracellularis -infected mice. Furthermore, L. intracellularis colonization of the mouse intestine was confirmed by the immunohistochemistry and western blot analyses. Conclusions: This is the first study demonstrating the contributions of bacterial chaperonin and host nutrient genes to PE using an immunocompetent mouse model. This mouse infection model may serve as a platform from which to study L. intracellularis infection and develop potential vaccination and therapeutic strategies to treat PE.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2665-2669
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• 2015

CD4+CD25+regulatory T cells (Tregs) play a key role in regulation of immnue response and maintenance of self-tolerance. Studies have found Tregs could suppress tumor-specific T cell-mediated immune response and promote cancer progression. Depletion of Tregs can enhance antitumor immunity. Dendritic cells (DCs) are professional antigen-presenting cells and capable of activating antigen-specific immune responses, which make them ideal candidate for cancer immunotherapy. Now various DC vaccines are considered as effective treatment for cancers. The aim of this study was to evaluate variation of Tregs in BALB/C mice with hepatocellular carcinoma and investigate the interaction between tumor-derived Tregs, effector T cells (Teff) and splenic DCs. We found the percentages of Tregs/CD4+ in the peripheral blood of tumor-bearing mice were higher than in normal mice. Tumor-derived Tregs diminished the up-regulation of costimulatory molecule expression on splenic DCs, even in the presence of Teff cells and simultaneously inhibited IL-12 and $TNF-{\alpha}$ secretion by DCs.