• 제목/요약/키워드: T cell activation

검색결과 727건 처리시간 0.022초

눈꽃동충하초 (Paecilomyces tenipes DGUM 32001) 균사배양물로부터 분리한 단백다당체 PJ-4의 in vitro 면역활성 (Flow Cytometrical Investigation on in vitro Immunomodulating Activity of PJ-4, a Protein-polysaccharide from Culture Flitrate of Insects-born Fungus Paecilomyces Tenuipes DGUM 32001)

  • 정경수;이지선;김용해;한영환;이만형
    • 약학회지
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    • 제46권3호
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    • pp.213-218
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    • 2002
  • In the previous report, we described the in vivo antitumor activity of PJ-4, a protein-polysaccharide fraction prepared from the culture filtrate of an insect-born fungus, Paecilomyces tenuipes DGUM 32001. In the present study, we elucidated the immunomodulating activity of PJ-4 on the BALB/c mouse splenic lymphocytes using flow cytometrical techniques. As a result, PJ-4 was found to stimulate the lymphocytes not only to form lymphoblasts but also to express CD25 (IL-2 receptor $\alpha$ chain) molecule, which is well known as a T cell activation marker. More interestingly, its T cell stimulatory activity was more strongly exerted on CD8$^{+}$ T cells than on CD4$^{+}$ T cells. All these data suggest that PJ-4 exerts its antitumor activity at least partly through stimulation of T cells which play major roles in the cell-mediated immune system.tem.

p-Coumaric acid에 의해 유도되는 인체 Jurkat T 세포의 에폽토시스 기전 (Activation of Pro-Apoptotic Multidomain Bcl-2 Family Member Bak and Mitochondria-Dependent Caspase Cascade are Involved in p-Coumaric Acid-Induced Apoptosis in Human Jurkat T Cells)

  • 이제원;김영호
    • 생명과학회지
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    • 제21권12호
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    • pp.1678-1688
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    • 2011
  • 다양한 식용식물에 함유되어 있는 것으로 알려진 phenolic acids의 일종인 p-coumaric acid의 항암활성을 규명하고자, 인체 급성백혈병 T 세포주인 Jurkat T 세포에 대한 p-coumaric acid의 에폽토시스 유도기전을 조사하였다. Jurkat T 세포를 p-coumaric acid (50-$150{\mu}M$)로 처리한 결과, 세포독성, 에폽토시스-관련 DNA fragmentation, 및 pro-apoptotic multidomain Bcl-2 family member인 Bak의 활성화, ${\Delta}{\psi}m$ loss, caspase-9, -3, -7, 및 -8의 활성화, 그리고 PARP 분해 등의 여러 에폽토시스-관련 생화학적 현상들이 농도의존적으로 나타났다. 그러나 이러한 에폽토시스-관련 생화학적 현상들은 Jurkat T 세포에 anti-apoptotic Bcl-2 단백질을 과발현할 경우에는 나타나지 않았다. 또한 p-coumaric acid처리에 의해 유도되는 Jurkat T 세포의 에폽토시스에는 necrosis가 수반되지 않는 것으로 확인되었다. Jurkat T 세포를 pan-caspase inhibitor인 z-VAD-fmk를 전처리할 경우, p-coumaric acid 처리에 의해 유도되는 apoptotic sub-$G_1$ peak는 차단되어 나타나지 않았으나 ${\Delta}{\psi}m$ loss는 여전히 나타났는데, 이는 p-coumaric acid처리에 의한 에폽토시스의 유도에 caspase cascade 활성화가 필수적이며 ${\Delta}{\psi}m$ loss의 downstream 현상임을 나타낸다. 한편, FADD 및 caspase-8을 함께 발현하는 Jurkat T 세포주 A3, FADD-결손 Jurkat T 세포주 I2.1, 그리고 caspase-8-결손 Jurkat T 세포주 I9.2의 p-coumaric acid의 세포독성에 대한 감수성은 서로 유사하게 나타났는데, 이는 p-coumaric acid처리에 의한 에폽토시스의 유도가 Fas와 FasL간의 상호작용에 의해 개시되지 않음을 시사한다. p-Coumaric acid의 세포독성은 Jurkat T 세포에 비해 인체 정상 말초혈액 T 세포에서 훨씬 낮게 나타났다. 이러한 결과들은 p-coumaric acid 처리에 의해 유도되는 Jurkat T 세포의 에폽토시스가 Bak 활성화, ${\Delta}{\psi}m$ loss, caspase-9, -3, -7, 및 -8로 이루어진 caspase cascade의 활성화, 그리고 PARP 분해에 의해 유도되며, 또한 anti-apoptotic 단백질인 Bcl-2의 과발현에 의해서 음성적으로 조절됨을 나타낸다.

명태(Theragra chalcogramma) 껍질 유래 젤라틴 가수분해물의 항 HIV-1 효능 (Anti-HIV-1 Activity of Gelatin Hydrolysate Derived from Alaska Pollack Theragra chalcogramma Skin)

  • 박선주
    • 한국수산과학회지
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    • 제49권5호
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    • pp.594-599
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    • 2016
  • Infection with HIV (Human immunodeficiency virus), over time, develops into acquired immunodeficiency syndrome (AIDS). The development of non-toxic and effective anti-HIV drugs is one of the most promising strategies for the treatment of AIDS. In this study, we investigated the anti-HIV-1 activity of gelatin hydrolysates from Alaska pollack skin. Gelatin hydrolysates were prepared using four enzymes (alcalase, flavourzyme, neutrase, and pronase E). Among these, the pronase E gelatin hydrolysate was found to inhibit HIV-1 infection in the human T cell-line MT4. It exhibited inhibitory activity on HIV-1IIIB-induced cell lysis, reverse transcriptase activity, and viral p24 production at noncytotoxic concentrations. Moreover, it decreased the activation of matrix metalloproteinase-2 (MMP-2) in vitro. Because HIV infection-induced activation of MMP-2 can accelerate collagen resolution and collapse of the immune system, pronase E gelatin hydrolysate might prevent the activation of MMP-2 in cells, resulting in collagen stabilization and immune cell homeostasis consistent with anti-HIV activation. These results suggest that pronase E gelatin hydrolysate could potentially be incorporated into a novel therapeutic agent for HIV/AIDS patients.

Deletion Analysis of the Major NF-${\kappa}B$ Activation Domain in Latent Membrane Protein 1 of Epstein-Barr Virus

  • Cho, Shin;Lee, Won-Keun
    • Journal of Microbiology
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    • 제37권4호
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    • pp.256-262
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    • 1999
  • Latent membrane protein 1 (LMP1) of the Epstein-Barr virus (EBV) is an integral membrane protein with six transmembrane domains, which is essential for EBV-induced B cell transformation. LMP1 functions as a constitutively active tumor necrosis factor receptor (TNFR) like membrane receptor, whose signaling requires recruitment of TNFR-associated factors (TRAFs) and leads to NF-${\kappa}B$ activation. NF-${\kappa}B$ activation by LMP1 is critical for B cell transformation and has been linked to many phenotypic changes associated with EBV-induced B cell transformation. Deletion analysis has identified two NF-${\kappa}B$ activation regions in the carboxy terminal cytoplasmic domains of LMP1, termed CTAR1 (residues 194-232) and CTAR2 (351-386). The membrane proximal C-terminal domain was precisely mapped to a PXQXT motif (residues 204-208) involved in TRAF binding as well as NF-${\kappa}B$ activation. In this study, we dissected the CTAR2 region, which is the major NF-${\kappa}B$ signaling effector of LMP1, to determine a minimal functional sequence. A series of LMP1 mutant constructs systematically deleted for the CTAR2 region were prepared, and NF-${\kappa}B$ activation activity of these mutants were assessed by transiently expressing them in 293 cells and Jurkat T cells. The NF-${\kappa}B$ activation domain of CTAR2 appears to reside in a stretch of 6 amino acids (residues 379-384) at the end of the carboxy terminus.

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Cytoprotective Effects of Docosyl Cafferate against tBHP-Induced Oxidative Stress in SH-SY5Y Human Neuroblastoma Cells

  • Choi, Yong-Jun;Kwak, Eun-Bee;Lee, Jae-Won;Lee, Yong-Suk;Cheong, Il-Young;Lee, Hee-Jae;Kim, Sung-Soo;Kim, Myong-Jo;Kwon, Yong-Soo;Chun, Wan-Joo
    • Biomolecules & Therapeutics
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    • 제19권2호
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    • pp.195-200
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    • 2011
  • Neuronal cell death is a common characteristic feature of a variety of neurodegenerative disorders including Alzheimer's disease and Parkinson's disease. However, there have been no effective drugs to successfully prevent neuronal death in those diseases. In the present study, docosyl cafferate (DC), a derivative of caffeic acid, was isolated from Rhus verniciflua and its protective effects on tBHP-induced neuronal cell death were examined in SH-SY5Y human neuroblastoma cells. Pretreatment of DC significantly attenuated tBHP-induced neuronal cell death in a concentration-dependent manner. DC also significantly suppressed tBHP-induced caspase-3 activation. In addition, DC restored tBHP-induced depletion of intracellular Bcl-2, an anti-apoptotic member of the Bcl-2 family. Furthermore, DC significantly suppressed tBHP-induced degradation of IKB, which retains $NF-{\kappa}B$ in the cytoplasm, resulting in the suppression of nuclear translocation of $NF-{\kappa}B$ and its subsequent activation. Taken together, the results clearly demonstrate that DC exerts its neuroprotective activity against tBHP-induced oxidative stress through the suppression of nuclear translocation of $NF-{\kappa}B$.

건칠(乾漆)이 혈관신생관련 단백질 발현에 미치는 영향 (The Effect of Lacca Sinica Exsiccata on The Manifestation of Angiogenic Proteins)

  • 김성학;김경준
    • 한방안이비인후피부과학회지
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    • 제19권3호통권31호
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    • pp.1-12
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    • 2006
  • Objective : Angiogenesis is an essential process for metastasis of solid tumors and Psoriasis. Lots of Researches for anti-angiogenic effect to angiogenic factors have been carried out in the world. So this experiment was carried out for whether Lacca Sinica Exsiccata(LSE) extracts have an anti-angiogenic effect for angiogenic factors. Methods: To investigate the roles of the LSE extracts, we performed MIS assay, western blots using HaCaT cells and HepG2 cells. And then, HaCaT cells were treated with 10, 50, 100, 250, $500{\mu}g/ml$ LSE extracts. After 4hrs, HaCaT cells were theated with IGF-II protein for 1hr. HepG2 cells were treated with 1, 10, 25, 50, 100, 200 ${\mu}g/ml$ LSE extracts. After 4hrs, HepG2 cells were theated with $CoCl_2$ for 24hrs Results: 1. In $50{\mu}g/ml$ and $100{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by IGF-II in HaCaT cells. 2. In $50{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by $CoCl_2$ in HepG2 cells. 3. In $25{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to VEGF activation which was induced by $CoCl_2$ in HepG2 cells. Conclusion: The above-mentioned results proved that LSE extracts reduced $HIF-1{\alpha}$ protein level in the HaCaT cells and HepG2 cells. These results suggest that inhibition of HaCaT cell and HepG2 cell proliferation by LSE extracts contributes to the anti-angiogenic activities on the keratinocytes and hepatocellular carcinoma.

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DW2007 Ameliorates Colitis and Rheumatoid Arthritis in Mice by Correcting Th17/Treg Imbalance and Inhibiting NF-κB Activation

  • Lim, Su-Min;Lee, Sang-Yun;Jeong, Jin-Ju;Choi, Hyun Sik;Chang, Hwan Bong;Kim, Dong-Hyun
    • Biomolecules & Therapeutics
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    • 제24권6호
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    • pp.638-649
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    • 2016
  • In the previous study, the rhizome mixture of Anemarrhena asphodeloides and Coptis chinensis (DW2007), improved TNBS-, oxazolone-, or DSS-induced colitis in mice by regulating macrophage activation. Therefore, to understand the effect of DW2007 on the T cell differentiation involved in the adaptive immunity, we measured its effect on both Th17 and Treg cell differentiation in splenocytes, in the lamina propria of mice with DSS-induced colitis (DIC), and in the spleens of mice with collagen-induced arthritis (CIA). Results showed that DW2007 potently inhibited the differentiation of splenocytes into Th17 cells, but increased Treg cell differentiation in vitro. In the colon of wild type and $TLR4^{-/-}$ mice with DIC, DW2007 potently suppressed DSS-induced colon shortening and myeloperoxidase activity. DW2007 also suppressed collagen-induced paw thickening, clinical index, and myeloperoxidase activity in CIA mice. Overall, DW2007 potently suppressed Th17 cell differentiation in mice with CIA and DIC, but increased Treg cell differentiation. Moreover, DW2007 strongly inhibited the expression of TNF-${\alpha}$ and IL-$1{\beta}$, as well as the activation of NF-${\kappa}B$. Based on these findings, DW2007 may ameliorate inflammatory diseases by regulating the innate immunity via the inhibition of macrophage activation and the adaptive immunity via the correction of disturbed Th17/Treg cells.

인진(茵陳)분획물이 간세포활성, 세포주기 및 Fas-mediated Apoptosis에 미치는 영향 (The Effects of five kinds of Artemisia capillaris $T_{HUNB}$ fractions on Cell Viability, Cell Cycle Progression and Fas-mediated Apoptosis of HepG2 Cells)

  • 김영철;이장훈;우홍정;이종훈
    • 대한한방내과학회지
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    • 제21권3호
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    • pp.363-368
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    • 2000
  • Objective : This study was carried out to examine the effect of five fractions of an aqueous extract from Artemisia capillaris $T_{HUNB}$. Methods : The queous extract from Artemisia capillaris $T_{HUNB}$. was fractionized into 5 kinds of material. We observed the effect of each fractions on etoposide-induced apoptosis, cell viability, cell cycle progression and mRNA expression of apoptosis-related genes in human hepatocyte cell line HepG2. Results and Conclusions : The data shows that butanol fraction of Artemisia capillaris $T_{HUNB}$. has no relation with cell cycle, however, it inhibits apoptosis significantly and the action may be due to the suppression of Fas and Sax genes and activation of Bcl-2 gene.

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Transcriptional and Epigenetic Regulation of Context-Dependent Plasticity in T-Helper Lineages

  • Meyer J. Friedman;Haram Lee;June-Yong Lee;Soohwan Oh
    • IMMUNE NETWORK
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    • 제23권1호
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    • pp.5.1-5.28
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    • 2023
  • Th cell lineage determination and functional specialization are tightly linked to the activation of lineage-determining transcription factors (TFs) that bind cis-regulatory elements. These lineage-determining TFs act in concert with multiple layers of transcriptional regulators to alter the epigenetic landscape, including DNA methylation, histone modification and threedimensional chromosome architecture, in order to facilitate the specific Th gene expression programs that allow for phenotypic diversification. Accumulating evidence indicates that Th cell differentiation is not as rigid as classically held; rather, extensive phenotypic plasticity is an inherent feature of T cell lineages. Recent studies have begun to uncover the epigenetic programs that mechanistically govern T cell subset specification and immunological memory. Advances in next generation sequencing technologies have allowed global transcriptomic and epigenomic interrogation of CD4+ Th cells that extends previous findings focusing on individual loci. In this review, we provide an overview of recent genome-wide insights into the transcriptional and epigenetic regulation of CD4+ T cell-mediated adaptive immunity and discuss the implications for disease as well as immunotherapies.

The Role of PI3K/AKT Pathway and NADPH Oxidase 4 in Host ROS Manipulation by Toxoplasma gondii

  • Choi, Hei Gwon;Gao, Fei-Fei;Zhou, Wei;Sun, Pu-Reum;Yuk, Jae-Min;Lee, Young-Ha;Cha, Guang-Ho
    • Parasites, Hosts and Diseases
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    • 제58권3호
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    • pp.237-247
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    • 2020
  • Dendritic cell is one of the first innate immune cell to encounter T. gondii after the parasite crosses the host intestinal epithelium. T. gondii requires intact DC as a carrier to infiltrate into host central nervous system (CNS) without being detected or eliminated by host defense system. The mechanism by which T. gondii avoids innate immune defense of host cell, especially in the dendritic cell is unknown. Therefore, we examined the role of host PI3K/AKT signaling pathway activation by T. gondii in dendritic cell. T. gondii infection or T. gondii excretory/secretory antigen (TgESA) treatment to the murine dendritic cell line DC2.4 induced AKT phosphorylation, and treatment of PI3K inhibitors effectively suppressed the T. gondii proliferation but had no effect on infection rate or invasion rate. Furthermore, it is found that T. gondii or TgESA can reduce H2O2-induced intracellular reactive oxygen species (ROS) as well as host endogenous ROS via PI3K/AKT pathway activation. While searching for the main source of the ROS, we found that NADPH oxidase 4 (NOX4) expression was controlled by T. gondii infection or TgESA treatment, which is in correlation with previous observation of the ROS reduction by identical treatments. These findings suggest that the manipulation of the host PI3K/AKT signaling pathway and NOX4 expression is an essential mechanism for the down-regulation of ROS, and therefore, for the survival and the proliferation of T. gondii.