• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.293-300
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• 2022

Lipoteichoic acid (LTA) regulates the immune system, including inflammatory responses, through TLR2-mediated signaling pathways. LTA isolated from Staphylococcus aureus (aLTA) has been shown to induce apoptosis, but the detailed mechanism has not been identified. We found that aLTA induced apoptosis through an autocrine mechanism in the human monocyte-like cell line, THP-1. We observed that the expression level of the anti-apoptosis protein, Bcl2, was suppressed in LTA-treated THP-1 cells. In addition, the cytokines, TNF-α and IFN-γ, which have been shown to induce apoptosis in some cell lines, were involved in THP-1 cell death via the modulation of Bcl2. The suppression of Bcl2 by aLTA was recovered when the negative regulator, SOCS-1, was knocked down. Taken together, these results showed that aLTA induced apoptosis in THP-1 cells through an autocrine mechanism of cytokines and SOCS-1-mediated Bcl2 inhibition.

• IMMUNE NETWORK
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• v.23 no.1
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• pp.9.1-9.15
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• 2023

Cancer immunotherapies continue to face numerous obstacles in the successful treatment of solid malignancies. While immunotherapy has emerged as an extremely effective treatment option for hematologic malignancies, it is largely ineffective against solid tumors due in part to metabolic challenges present in the tumor microenvironment (TME). Tumor-infiltrating CD8⁺ T cells face fierce competition with cancer cells for limited nutrients. The strong metabolic suppression in the TME often leads to impaired T-cell recruitment to the tumor site and hyporesponsive effector functions via T-cell exhaustion. Growing evidence suggests that mitochondria play a key role in CD8⁺ T-cell activation, migration, effector functions, and persistence in tumors. Therefore, targeting the mitochondrial metabolism of adoptively transferred T cells has the potential to greatly improve the effectiveness of cancer immunotherapies in treating solid malignancies.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.31-38
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• 2007

Infection with virulent or attenuated Salmonella typhimuriumhas known to induce reduction in proliferative responses of spleen cells. We investigated a role of lipid A from S. typhimurium, a B cell mitogen, on proliferation of spleen cells by T cell mitogens such as concanavaline A and phytohemagglutinin under in vitro and ex vivo conditions. Lipid A alone induced proliferation of spleen cells in vitroin a dose-dependent manner. However, subsequent treatment of concanavaline A or phytohemagglutin in after lipid A treatment induced proliferation suppression of murine spleen cells in vitro and ex vivo. Removal of macrophages from spleen cells, which were obtained from a lipid A-injected mouse, restored proliferation by concanavaline A and phytohemagglutinin, indicating that macrophages appeared to play a role in lipid A-induced suppression. Secreted molecules from macrophages did not accounted for the suppression because suppressive effect was not achieved when the supernatant from macrophage-containing spleen cell culture was conditoned to macrophage-depleted spleen cell culture. Co-culture of spleen cells from lipid A-treated and - untreated mice showed proliferation suppression as increasing cell numbers of lipid A-treated mouse. These data suggested that the cell-to-cell contact of macrophage with splenic lymphocyte cells is responsible for immune responses against lipid A, which is applicable to the case of human S. typhi infection.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.49-55
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• 1981

Recent studies have demonstrated that histamine could have a modulatory influence on the immune response in vitro and in vivo. However, the effect of histamine on immune response in mice has not been extensivley analyzed. In the present study the regulatory effects of cimetidine, a histamine-2-receptor antagonist(H2 blocker) and histamine on the immune response to sheep red blood cells(SRBC) were evaluated in mice. Mice pretreated with daily intraperitoneal injection of varying concentrations of cimetidine for 14 days were immunized intraperitoneally with various concentrations of SRBC($10^6,\;10^7,\;and\;10^8$ cells) and challenged 4 days post immunization. The cellular immune response was determined by measuring the footpad swelling reaction. Footpad swelling reaction of each mouse was measured at 3hr(Arthus) reaction) and 24 or 48 hr(delayed reactions) after challenge. The humoral immune response was determined by measuring hemagglutinins to SRBC. Histamine in varying concentrations($10^{-1},\;10^{-3}\;and\;10^{-5}M$(was added in SRBC suspension at the time of antigen challenge into footpad, and 24-hr delayed type hypersensitivity(DTH) was measured. Cimetidine in varying concentrations(10, 50, 250, 1250 and 6250${\mu}g$) enhanced 24-hr DTH and this enhancement of DTH was more pronounced at 250${\mu}g$ of cimetidine. However, there were no significant differences between the cimetidine-pretreated groups and controls in Arthus reaction and hemagglutinin titers. Histamine suppressed the DTH in the dose-dependent fashion. This suppression was more pronounced at lower concentration of immunizing antigen($10^7\;and\;10^6$ SRBC). However, histamine did not diminish the DTH at higher concentration of antigen($10^8$ SRBC). These results present the evidences which strongly suggest that cimetidine enhances the cell-mediated immune response but not significantlly influences the humoral immune response and that exogenous and endogenous histamine is involved in the modulation of cellular immune response as well as immediate hypersensitivity.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.292-311
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• 2017

Purpose: Beyond the limited scope of non-specific polyclonal regulatory T cell (Treg)-based immunotherapy, which depends largely on serendipity, the present study explored a target Treg subset appropriate for the delivery of a novel epitope spreader Pep19 antigen as part of a sophisticated form of immunotherapy with defined antigen specificity that induces immune tolerance. Methods: Human polyclonal $CD4^+CD25^+CD127^{lo-}$ Tregs (127-Tregs) and $na\ddot{i}ve$ $CD4^+CD25^+CD45RA^+$ Tregs (45RA-Tregs) were isolated and were stimulated with target peptide 19 (Pep19)-pulsed dendritic cells in a tolerogenic milieu followed by ex vivo expansion. Low-dose interleukin-2 (IL-2) and rapamycin were added to selectively exclude the outgrowth of contaminating effector T cells (Teffs). The following parameters were investigated in the expanded antigen-specific Tregs: the distinct expression of the immunosuppressive Treg marker Foxp3, epigenetic stability (demethylation in the Treg-specific demethylated region), the suppression of Teffs, expression of the homing receptors CD62L/CCR7, and CD95L-mediated apoptosis. The expanded Tregs were adoptively transferred into an $NOD/scid/IL-2R{\gamma}^{-/-}$ mouse model of collagen-induced arthritis. Results: Epitope-spreader Pep19 targeting by 45RA-Tregs led to an outstanding in vitro suppressive T cell fate characterized by robust ex vivo expansion, the salient expression of Foxp3, high epigenetic stability, enhanced T cell suppression, modest expression of CD62L/CCR7, and higher resistance to CD95L-mediated apoptosis. After adoptive transfer, the distinct fate of these T cells demonstrated a potent in vivo immunotherapeutic capability, as indicated by the complete elimination of footpad swelling, prolonged survival, minimal histopathological changes, and preferential localization of $CD4^+CD25^+$ Tregs at the articular joints in a mechanistic and orchestrated way. Conclusions: We propose human $na\ddot{i}ve$ $CD4^+CD25^+CD45RA^+$ Tregs and the epitope spreader Pep19 as cellular and molecular targets for a novel antigen-specific Treg-based vaccination against collagen-induced arthritis.

• Journal of Korean Traditional Oncology
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• v.23 no.1
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• pp.1-14
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• 2018

Objectives: This study was conducted towards developing guidelines of herbal medicine treatment for gastric cancer. Methods: We performed a systematic review and meta-analysis designed to investigate the efficacy of herbal medicine treatment for gastric cancer on four cancer questions; survival rate, metastasis, immune function, and quality of life. Based on the findings, we utilized a two-round delphi process with panel of 22 experts for their level of agreement. Results: Combined therapy group, herbal medicine treated with chemotherapy, was significantly higher in the 1-year survival rate (RR=1.27, 95% CI: 1.14 to 1.40, P=0.005, $I^2=71%$) and 3-years survival rate (RR=1.41, 95% CI: 1.16 to 1.71, P=0.91, $I^2=0%$) than chemotherapy group. The suppression of metastasis was higher in the combined therapy group (RR=0.62, 95% CI: 0.45 to 0.84, P=0.09, $I^2=54%$). The immunology function was higher in the combined therapy group compared with the chemotherapy group (MD=16.43, 95% CI: 13.25 to 29.61, P<0.001, $I^2=99%$). The quality of life score was higher in the combined therapy group compared with the chemotherapy group (RR=1.55, 95% CI: 1.21 to 2.00, P<0.66, $I^2=0%$). Conclusions: Among the Randomized controlled trials (RCT) included, the levels of survival rates, suppression of metastasis, immune function, and quality of life of the group treated with chemotherapy were lower compared to those treated with herbal medicine in addition to chemotherapy.

• IMMUNE NETWORK
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• v.3 no.3
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• pp.201-210
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• 2003

Objective: The role of prostaglandin $E_2$ (PGE2) in the etiopathogenesis of immune and inflammatory diseases has become the subject of recent debate. To determine the role of PGE2 in rheumatoid arthritis (RA), we tested the effect of exogenous PGE2 on the production of cyclooxygenase-2 (COX-2) by rheumatoid synoviocytes. Methods: Fibroblast-like synoviocytes (FLS) were prepared from the synovial tissues of RA patients, and cultured in the presence of PGE2. The COX-2 mRNA and protein expression levels were determined by RT-PCR and Western blot analysis, respectively. The PGE2 receptor subtypes in the FLS were analyzed by RT-PCR. Electrophoretic mobility shift assay (EMSA) was used to measure the NF-${\kappa}B$ binding activity for COX-2 transcription. The in vivoeffect of PGE2 on the development of arthritis was also tested in collagen induced arthritis (CIA) animals. Results: PGE2 ($10^{-11}$ to $10^{-5}M$) dose-dependently inhibited the expression of COX-2 mRNA and the COX-2 protein stimulated with IL-$1{\beta}$, but not COX-1 mRNA. NS-398, a selective COX-2 inhibitor, displayed an additive effect on PGE2-induced COX-2 downregulation. The FLS predominantly expressed the PGE2 receptor (EP) 2 and EP4, which mediated the COX-2 suppression by PGE2. Treatment with anti-IL-10 monoclonal antibodies partially reversed the PGE2-induced suppression of COX-2 mRNA, suggesting that IL-10 may be involved in modulating COX-2 by PGE2. Experiments using an inducer and an inhibitor of cyclic AMP (cAMP) suggest that cAMP is the major intracellular signal that mediates the regulatory effect of PGE2 on COX-2 expression. EMSA revealed that PGE2 inhibited the binding of NF-${\kappa}B$ in the COX-2 promoter via a cAMP dependent pathway. In addition, a subcutaneous injection of PGE2 twice daily for 2 weeks significantly reduced the incidence and severity of CIA as well as the production of IgG antibodies to type II collagen. Conclusion: Our data suggest that overproduced PGE2 in the RA joints may function as an autocrine regulator of its own synthesis by inhibiting COX-2 production and may, in part, play an anti-inflammatory role in the arthritic joints.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.332-336
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• 2008

Ginger is widely used as a traditional herbal medicine. Both ginger and its extracts have been used to treat many chronic inflammatory conditions via the inhibition of nuclear factor-kappa B (NF-${\kappa}B$) activation, which results in the suppression of cyclooxygenase-2 (COX-2) expression. However, the mechanisms as to how ginger extracts mediate their health effects are largely unknown. Toll-like receptors (TLRs) trigger anti-microbial innate immune responses, recognizing conserved microbial structural molecules that are known as pathogen-associated molecular patterns. All TLR signaling pathways culminate in the activation of NF-${\kappa}B$. The activation of NF- ${\kappa}B$ leads to the induction of inflammatory gene products, including cytokines and COX-2. This study reports the biochemical evidence that 6-shogaol, an active compound in ginger, inhibits NF-${\kappa}B$ activation and COX-2 expression induced by TLR2, TLR3, and TLR4 agonists. Furthermore, 6-shogaol inhibited NF-${\kappa}B$ activation induced by the following downstream signaling components of the TLRs: MyD88, $IKK{\beta}$, and p65. These results imply that ginger can modulate immune responses that could potentially modify the risk of many chronic inflammatory diseases.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.910-916
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• 2002

Endotoxin tolerance reduces the capacity of monocytes to produce proinflammatory cytokines, results in cellular immune paralysis, and down-regulates the production of helper T (Th)1 type cytokines with a shift toward a Th2 cytokine response. Prostaglandin (PG)E$_2$ in the immune system also results in macrophage inactivation and the suppression of Th1 activation and the enhancement of Th2 activation. However, the inhibitory effects of PGE$_2$ on the altered polarization of the Th cell and macrophage interleukin (IL)-6 production characterized in part by cellular immune paralysis in a state of endotoxin tolerance is unclear. This study was undertaken, using indomethacin, to investigate the role of endogenous PGE$_2$ on the Th cytokines and macrophage IL-6 production in a state of endotoxin tolerance compared to those with endotoxemia mice, wherein, in this latter case, the increased production of proinflammatory cytokines and PGE$_2$ is exhibited. Endotoxemia was induced by injection of lipopolysaccharide (LPS; 10 mg/kg in saline) i.p. once in BALB/c mice, and endotoxin tolerance was induced by pretreatment with LPS (1 mg/kg in saline) injected i.p. daily for two consecutive days and then with LPS 10 mg/kg on day 4. Splenocytes or macrophages were obtained from endotoxemia and endotoxin tolerance models pretreated with indomethacin, and then cytokine production was induced by Con A-stimulated splenocytes for the Th cytokine assays and LPS-stimulated macrophages for the IL-6 assay. Our results showed that endotoxemia led to significantly reduced IL-2 and IL-4 production, to significantly increased IL-6 production, whereas interferon $(IFN)-{\gamma}$ production was not affected. Indomethacin in the case of endotoxemia markedly attenuated $IFN-{\gamma}$ and IL-6 production and didnt reverse IL-2 and IL-4 production. Endotoxin tolerance resulted in the significantly reduced production of IL-2 and $IFN-{\gamma}$ and the significantly increased production of IL-4 and IL-6. Indomethacin in endotoxin tolerance greatly augmented IL-2 production, significantly decreased IL-4 production, and slightly attenuated IL-6 production. These findings indicate that endogenous PGE$_2$ may mediate the suppressed Th1 type immune response, with a shift toward a Th2 cytokine response in a state of endotoxin tolerance, whereas endotoxemia may be regulated differentially. Also, endogenous PGE$_2$ may mediate macrophage IL-6 production in the case of endotoxemia to a greater extent than in the case of endotoxin tolerance.

• The Korean Journal of Pharmacology
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• v.25 no.1
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• pp.93-99
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• 1989

In our previous studies, it was found that activities of maternal peripheral lymphocytes and thymocytes were depressed during the implantation period in rats and rabbits. This study was therefore attempted to clarify further this immunosuppression locally by determining lymphocyte response in lymph nodes draining the uterus (DLN) and to elucidate the mechanism by which prostaglandin E (PGE) modulates immune response during the implantation process in rats. As compared with non-pregnant rats, the response of DLN lymphocytes to concanavalin A (Con A) was depressed during the implantation period in 100% of rats studied. The activity of DLN lymphocytes depressed on day 8 of pregnancy was, however, restored partially by the treatment of indomethacin (ID), indicating that prostaglandin (PG) might be one of factors responsible for immunomodulation during the process of implantation. DLN lymphocyte activity in non-pregnant rats was suppressed if PGE was pre-treated prior to Con A and this suppression was partially restored by the treatment of ID. Furthermore, DLN lymphocytes pre-treated with PGE produced PGE in vitro and this PGE production was blocked by the treatment of ID, suggesting that PGE induced PGE-producing cells. However, the pretreatment of estradiol, progesterone, and hCG at doses enough to suppress lymphocyte activity was ineffective in inducing PGE-producing cells. From these results, it is suggested that PGE induces PGE-producing suppressor cells, thereby increasing PGE concentration and PGE in turn depresses maternal local immune response as well as systemic immune response during the implantation period in rats.