• 제목/요약/키워드: Inhibitory B cell co-receptor

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CD72 is a Negative Regulator of B Cell Responses to Nuclear Lupus Self-antigens and Development of Systemic Lupus Erythematosus

  • Takeshi Tsubata
    • IMMUNE NETWORK
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    • v.19 no.1
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    • pp.1.1-1.13
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    • 2019
  • Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease characterized by production of autoantibodies to various nuclear antigens and overexpression of genes regulated by IFN-I called IFN signature. Genetic studies on SLE patients and mutational analyses of mouse models demonstrate crucial roles of nucleic acid (NA) sensors in development of SLE. Although NA sensors are involved in induction of antimicrobial immune responses by recognizing microbial NAs, recognition of self NAs by NA sensors induces production of autoantibodies to NAs in B cells and production of IFN-I in plasmacytoid dendritic cells. Among various NA sensors, the endosomal RNA sensor TLR7 plays an essential role in development of SLE at least in mouse models. CD72 is an inhibitory B cell co-receptor containing an immunoreceptor tyrosine-based inhibition motif (ITIM) in the cytoplasmic region and a C-type lectin like-domain (CTLD) in the extracellular region. CD72 is known to regulate development of SLE because CD72 polymorphisms associate with SLE in both human and mice and CD72-/- mice develop relatively severe lupus-like disease. CD72 specifically recognizes the RNA-containing endogenous TLR7 ligand Sm/RNP by its extracellular CTLD, and inhibits B cell responses to Sm/RNP by ITIM-mediated signal inhibition. These findings indicate that CD72 inhibits development of SLE by suppressing TLR7-dependent B cell response to self NAs. CD72 is thus involved in discrimination of self-NAs from microbial NAs by specifically suppressing autoimmune responses to self-NAs.

Emerging Co-signaling Networks in T Cell Immune Regulation

  • Jung, Keunok;Choi, Inhak
    • IMMUNE NETWORK
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    • v.13 no.5
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    • pp.184-193
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    • 2013
  • Co-signaling molecules are surface glycoproteins that positively or negatively regulate the T cell response to antigen. Co-signaling ligands and receptors crosstalk between the surfaces of antigen-presenting cells (APCs) and T cells, and modulate the ultimate magnitude and quality of T cell receptor (TCR) signaling. In the past 10 years, the field of co-signaling research has been advanced by the understanding of underlying mechanisms of the immune modulation led by newly identified co-signaling molecules and the successful preclinical and clinical trials targeting co-inhibitory molecules called immune checkpoints in the treatment of autoimmune diseases and cancers. In this review, we briefly describe the characteristics of well-known B7 co-signaling family members regarding the expression, functions and therapeutic implications and to introduce newly identified B7 members such as B7-H5, B7-H6, and B7-H7.

Synergistic Effect of Natural Killer Cells and Bee Venom on Inhibition of NCI-H157 Cell Growth

  • Sung, Hee Jin;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.33 no.1
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    • pp.47-56
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    • 2016
  • Objectives : This study examined the effects of Bee venom on apoptosis in NCI-H157 human lung cancer cells and for promoting the apoptosis effects of Natural killer cell. Methods : Bee venom and Natural killer-92 cells were cultured either separately from or together with NCI-H157 cells for 24 hours. To figure out whether Bee venom enhances the cytotoxic effect of Natural Killer-92 cells, a cell viability assay was conducted. To observe the changes in Death receptors, apoptotic regulatory proteins and Nuclear $Factor-{\kappa}B$, western blot analysis was conducted. To observe the effect of Bee venom through an extrinsic mechanism, a transfection assay was conducted. Results : 1. Natural killer-92 cells and Bee venom significantly inhibited the growth of NCI-H157 cells and co-culture had more inhibitory effect than the separate culture. 2. Expressions of Fas, DR3, DR6, Bax, caspase-3, caspase-8, cleaved caspase-3, cleaved caspase-8 were increased, and expressions of Bcl-2 and cIAP were decreased. More efficacy was observed in co-culture than in separate culture. 3. Nuclear $Factor-{\kappa}B$ activation was clearly decreased. And co-culture showed much less activation than separate culture. 4. As a result of treatment for DR-siRNA, the reduced cell viability of NCI-H157 cells and the activity of Nuclear $Factor-{\kappa}B$ were increased. With this, it can be seen that Bee venom and Natural killer-92 cells have an effect on the cancer cells through the extrinsic mechanism. Conclusion : Bee venom is effective in inhibiting the growth of human lung cancer cells. Furthermore Bee venom effectively enhances the functions of Natural killer cells.

Inhibitory Mechanism on NF-${\kappa}B$ Transactivation by Dexamethasone in Pulmonary Epithelial Cells (폐상피세포에서 Dexamethasone에 의한 NF-${\kappa}B$ Transactivation 억제기전에 관한 연구)

  • Lee, Kye-Young;Kim, Yoon-Seop;Ko, Mi-Hye;Park, Jae-Seok;Jee, Young-Koo;Kim, Keun-Youl;Kwak, Sahng-June
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.5
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    • pp.682-698
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    • 2000
  • Glucocorticoid receptor (GR) functions as a suppressor of inflammation by inhibiting the expression of many cytokine genes activated by NF-${\kappa}B$. The goal of this study is to investigate the mechanism by which GR repress NF-${\kappa}B$ activation in lung epithelial cells. We used A549 and BEAS-2B lung epithelia! cell lines. Using Ig$G{\kappa}$-NF-${\kappa}B$ luciferase reporter gene construct, we found that dexamethasone significantly suppressed TNF-$\alpha$-induced NF-${\kappa}B$ activation and the overexpression of GR showed dose-dependent reduction of TNF-$\alpha$-induced NF-${\kappa}B$ activity in both cell lines. However, DNA binding of NF-${\kappa}B$ induced by TNF-$\alpha$ in electromobility shift assay was not inhibited by dexamethasone. Super shift assay with anti-p65 antibody demonstrated the existence of p65 in NF-${\kappa}B$ complex induced by $\alpha$ Western blot showed that $I{\kappa}B{\alpha}$ degradation induced by TNF-$\alpha$ was not affected by dexamethasone and $I{\kappa}B{\kappa}$ was not induced by dexamethasone, neither. To evaluate p65 specific transactivation, we adopted co-transfection study of Gal4-p65TA1 or TA2 fusion protein expression system together with 5xGal4-luciferase vector. Co-transfection of GR with Gal4-p65TA1 or TA2 repressed luciferase activity profoundly to the level of 10-20% of p65TA1- or TA2-induced transcriptional activity. And this transrepressional effect was abolished by co-transfection of CBP of SRC-1 expression vectors. These results suggest that GR-mediated transrepression of NF-${\kappa}B$ in lung epithelial cells is through competing for binding to limiting amounts of transcriptional coactivators, CBP or SRC-1.

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Construction, and In Vitro and In Vivo Analyses of Tetravalent Immunoadhesins

  • Cho, Hoonsik;Chung, Yong-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.22 no.8
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    • pp.1066-1076
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    • 2012
  • Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

Effects of Dangkwisoo-San, Ginger and Curcumin on Transient Receptor Potential Melastatin 7 Channels (당귀수산, 생강, 커큐민의 대사성 질환과 관련된 일과성 수용체 전압 이온통로조절에 관한 연구)

  • Kim, Byung Joo
    • Journal of Korean Medicine for Obesity Research
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    • v.18 no.1
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    • pp.10-18
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    • 2018
  • Objectives: Metabolic syndrome is correlated with increased cardiovascular risk and characterized by several factors, including visceral obesity, hypertension, insulin resistance, and dyslipidemia. Several members of a large family of nonselective cation entry channels, e.g., transient receptor potential (TRP) melastatin 7 (TRPM7) channels have been associated with the development of cardiovascular diseases. The purpose of this study was to investigate the effects of Dangkwisoo-san, ginger and curcumin on TRPM7 channel. Methods: Human embryonic kidney (HEK) 293 cells stably transfected with the TRPM7 expression vectors were maintained in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% penicillin/streptomycin, $5{\mu}g/mL$ blasticidin, and 0.4 mg/mL zeocin in a humidified 20% $O_2$/10% $CO_2$ atmosphere at $37^{\circ}C$. Whole-cell patch clamp recordings were obtained using an Axopatch 700B amplifier and pClamp v.10.4 software, and signals were digitalized at 5 kHz using Digidata 1422A. Results: Dangkwisoo-san extract (100, 200, 300, 400, and $500{\mu}g/mL$) inhibited the outward and inward TRPM7 whole-cell currents at dose dependent manner and the half maximal inhibitory concentration $(IC)_{50}$ of Dangkwisoo-san was $218.3{\mu}g/mL$. Also, ginger extract (100, 200, 300, 400, and $500{\mu}g/mL$) inhibited the outward and inward of TRPM7 whole-cell currents in a dose dependent manner and the $IC_{50}$ of ginger was $877.2{\mu}g/mL$. However, curcumin had no effects on TRPM7 whole-cell currents. Conclusions: These results suggest that both Dangkwisoo-san and ginger have good roles to inhibit the TRPM7 channel, suggesting that Dangkwisoo-san and ginger are considered one of the candidate agents for the treatment of metabolic syndrome such as cardiovascular disease.

Effect of Co-administration of Aconiti Lateralis Preparata Radix and Cinnamomi Cortex on Osteoclast Differentiation (부자와 육계 병용투여 시 파골세포 분화 억제에 미치는 영향)

  • Jung, Gi-Eun;Kim, Jung Young;Kim, Ji-Hoon;Han, Sang-Yong;Kim, Yun-Kyung
    • The Korea Journal of Herbology
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    • v.29 no.2
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    • pp.61-67
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    • 2014
  • Objectives : Aconiti Lateralis Preparata Radix (Aconitum Carmichaeli, AC) and Cinnamomi Cortex (Cinnamomi Cortex, CC) have been treated to elderly for kidney yang enhancement in Korean traditional medicine. In this study, the effects of water extract of AC and CC on RANKL (Receptor Activator for Nuclear Factor ${\kappa}B$ Ligand)-induced osteoclast differentiation were evaluated in culture system. Methods : MTT assay was used to evaluate the potential cytotoxicity of AC and CC extracts in bone macrophage marrows (BMMs) stimulated with M-CSF. TRAP (tartrate-resistant acid phosphatase) staining and TRAP activity were performed to know the inhibitory effect on osteoclast differentiation. The protein expression levels of nuclear factors such as activated T cell(NFAT)c1, c-Fos, MAPKs and ${\beta}$-actin in cell lysates treated with AC and CC extracts were analysed by western blotting. Results : AC, CC extracts and their co-administration inhibited significantly RANKL-induced osteoclast differentiation in BMMs in a dose dependent manner without toxicity. Each AC and CC extracts inhibited the phosphorylation of p38. Also, AC and CC extracts, respectively, inhibited the protein expression of c-Fos and NFATc1 more than Co-administration of AC and CC even if all treatments did. It was observed that RANKL-induced degradation of I-${\kappa}B$ is significantly suppressed by all treatments. Conclusions : Taken together, It was concluded that AC and CC have beneficial effect on osteoporosis by inhibition of osteoclast differentiation. Thus, Atractylodis AC and CC could be a treatment option for osteoporosis.

Effects of Leejung-tang, Rikkunshito, and Bojungikgi-tang on Transient Receptor Potential Vanilloid 4 Channels (이중탕, 육군자탕, 보중익기탕의 이상지질혈증 및 고혈압과 관련된 일과성 수용체 전압 바닐로이드 4 이온통로 조절에 관한 연구)

  • Kim, Byung Joo
    • Journal of Korean Medicine for Obesity Research
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    • v.18 no.2
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    • pp.57-63
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    • 2018
  • Objectives: Metabolic syndrome is defined by a cluster of major cardiovascular risk factors: obesity, insulin resistance, dyslipidemia, and arterial hypertension. Several members of a large family of nonselective cation entry channels, e.g., transient receptor potential vanilloid 4 (TRPV4) channels have been associated with the development of dyslipidemia and hypertension. The purpose of this study was to investigate the effects of Leejung-tang (Lizhong-tang), Rikkunshito, and Bojungikgi-tang (Buzhongyiqi-tang) on TRPV4 channel. Methods: Human embryonic kidney 293 cells stably transfected with the TRPV4 expression vectors were maintained in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 1% penicillin/streptomycin, $5{\mu}g/mL$ blasticidin, and 0.4 mg/mL zeocin in a humidified 20% $O_2/10%$ $CO_2$ atmosphere at $37^{\circ}C$. Whole-cell patch clamp recordings were obtained using an Axopatch 700B amplifier and pClamp v.10.4 software (Molecular Devices, San Jose, CA, USA), and signals were digitalized at 5 kHz using Digidata 1422A. Results: Leejung-tang and Rikkunshito (10, 30 and 50 mg/mL) had no effects on the TRPV4 whole-cell currents at dose dependent manner. However, Bojungikgi-tang (10, 30, and 50 mg/mL) inhibited the TRPV4 whole-cell currents in a dose dependent manner and the half maximal inhibitory concentration (IC50) of Bojungikgi-tang was 18.2 mg/mL. Conclusions: These results suggest that Bojungikgi-tang plays an important roles to inhibit the TRPV4 channel, suggesting that Bojungikgi-tang is considered one of the candidate agents for the treatment of metabolic syndrome such as dyslipidemia and hypertension.

CBT-SL5, a Bacteriocin from Enterococcus faecalis, Suppresses the Expression of Interleukin-8 Induced by Propionibacterium acnes in Cultured Human Keratinocytes

  • Lee, Ye-Jin;Choi, Hye-Jeong;Kang, Tae-Wook;Kim, Hyung-Ok;Chun, Myung-Jun;Park, Young-Min
    • Journal of Microbiology and Biotechnology
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    • v.18 no.7
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    • pp.1308-1316
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    • 2008
  • Propionibacterium acnes is known to playa pivotal role in the pathogenesis of acne vulgaris. CBT-SL5 is one of the antimicrobial peptides from Enterococcus faecalis SL5, and it has shown antimicrobial activity against P. acnes. The aim of this study was to investigate the anti-inflammatory effect of CBT-SL5 on the inflammation induced by P. acnes in cultured human keratinocyes. Cultured human keratinocytes derived from neonatal foreskin were treated with heat-killed P. acnes to induce inflammation, and then various concentrations of CBT-SL5 were added to the P. acnes-treated keratinocytes. The mRNA expression and protein secretion of interleukin (IL)-8, an inflammation marker, was analyzed by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. We also analyzed the nuclear factor-kappa B (NF-$\kappaB$) p65 translocation by performing immunofluorescent staining. P. acnes treatment up regulated the IL-8 mRNA expression in the keratinocytes, and this was brought about through both toll-like receptor (TLR)2 and TLR4. At the concentrations of 10, 50, and 100 ng/ml, CBT-SL5 significantly down regulated the P. acnes-induced IL-8 mRNA expression and protein production (p<0.05). At 6 hand 12 h of the treatment, CBT-SL5 significantly suppressed the P. acnes-induced IL-8 mRNA expression. Secretion of IL-8 protein was significantly reduced at 24 h. The functional inhibitory activity of CBT-SL5 was shown by CBT-SL5 suppressing the P. acnes-induced NF-$\kappaB$ translocation from the cytoplasm to the nucleus. These results demonstrated that CBT-SL5 suppressed the P. acnes-induced IL-8 expression in keratinocytes. Therefore, CBT-SL5 may be a novel anti-inflammatory treatment for acne.