• IMMUNE NETWORK
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• 제3권3호
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• pp.235-241
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• 2003

Background: The protective immunity against tuberculosis (TB) involves both CD4+ T cells and CD8+ T cells. In our previous study, we defined four Mycobacterium tuberculosis derived peptide epitopes specific for HLA-$A^*0201$ restricted CD8+ T cells ($ThyA_{30-38}$, $RpoB_{127-135}$, $85B_{15-23}$, $PstA1_{75-83}$). In this study, we investigated the immune responses induced by these peptide specific CD8+ T cells in latently and chronically infected people with TB. Methods: We characterized these peptide specific CD8+ T cell population present in PBMC of both TB patients and PPD+healthy people using IFN-${\gamma}$elispot assay, intracellular staining and HLA-A2 dimer staining. Results: The frequency of peptide specific CD8+ T cell was in the range of 1 to 25 in $1.7{\times}10^5$ PBMC based on ex vivo IFN-${\gamma}$ elispot assay, demonstrating that these peptide specific CD8+ T cell responses are induced in both TB patients and PPD+ people. Short term cell lines (STCL) specific for these peptides proliferated in vitro and secreted IFN-${\gamma}$ upon antigenic stimulation in PPD+ donors. Lastly, HLA-$A^*0201$ dimer assays indicated that $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors is heterogeneous since approximately 25~33% of $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors produced IFN-${\gamma}$ upon peptide stimulation. Conclusion: Our results suggest that MHC class I restricted CD8+ T cell mediated immune responses to M. tuberculosis infection are induced in both TB patients and PPD + people; however, the CD8+ T cell population is functionally heterogeneous.

• Molecules and Cells
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• 제40권1호
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• pp.37-44
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• 2017

PDK1 is essential for T cell receptor (TCR)-mediated activation of $NF-{\kappa}B$, and PDK1-induced phosphorylation of $PKC{\theta}$ is important for TCR-induced $NF-{\kappa}B$ activation. However, inverse regulation of PDK1 by $PKC{\theta}$ during T cell activation has not been investigated. In this study, we found that $PKC{\theta}$ is involved in human PDK1 phosphorylation and that its kinase activity is crucial for human PDK1 phosphorylation. Mass spectrometry analysis of wild-type $PKC{\theta}$ or of kinase-inactive form of $PKC{\theta}$ revealed that $PKC{\theta}$ induced phosphorylation of human PDK1 at Ser-64. This $PKC{\theta}$-induced PDK1 phosphorylation positively regulated T cell activation and TCR-induced $NF-{\kappa}B$ activation. Moreover, phosphorylation of human PDK1 at Ser-64 increased the stability of human PDK1 protein. These results suggest that Ser-64 is an important phosphorylation site that is part of a positive feedback loop for human PDK1-$PKC{\theta}$-mediated T cell activation.

• Journal of Periodontal and Implant Science
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• 제33권3호
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• pp.499-518
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• 2003

The surface characteristics of titanium have been shown to have an important role in contact ossseointegration around the implant. Anodizing at high voltage produces microporous structure and increases thickness of surface titanium dioxide layer. The aim of present study was to analyse the response of rat calvarial osteoblast cell to commercially pure titanium and Ti-6A1-4V anodized in 0.06 mol/l ${\beta}$-glycerophosphate and 0.03 mol/l sodium acetate. In this study, rat calvarial osteoblasts were used to assay for cell viability and cell proliferation on the implant surface at 1,2,4,7 days. 1. Surface roughness was 1.256${\mu}m$ at 200V, and 1.745${\mu}m$ at 300V. 2. The thickness of titanium oxide layer was increased 1 ${\mu}m$ with the increase of 50V. 3. The proliferation rate of osteoblastic cells was increased with the increase of the surface roughness and the thickness of titanium oxide layer. 4. There was no difference in cell viability and cell proliferation between commercially pure titanium and Ti-6A1-4V anodized at the same condition. In conclusion, the titanium surface modified by anodizing was biocompatible, produced enhanced osteoblastic response. The reasons of enhanced osteoblast response might be due to reduced metal ion release by thickened and stabilized titanium dioxide layer and microporous rough structures.

• 대한수의학회지
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• 제35권4호
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• pp.735-741
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• 1995

The present study was conducted to investigate the incidence of equine herpesvirus 1(EHV-1) infection in Korean horses by cell EUSA and serum neutralization test A significant level of antibodies to EHV-1 was detected from 539(82.8%) by cell EUSA and from 524 horses(80.5%) by SNT indicating that EHV-1 infection in Korean horses are widely spreaded throughout the country.

• Rapid Communication in Photoscience
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• 제1권2호
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• pp.35-37
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• 2012

Photoinduced electron-transfer process of 1,8-naphthalimide-linker-trimethylsilane (NI-O3-TMS, O3 = 3,6,9-trioxaundecyl) and NI-O3 has been investigated using the transient absorption measurements in $CH_3CN$ and $CH_3CN/H_2O$. The excitation of NI-O3-TMS in $CH_3CN$ produced the NI radical anion ($NI^{{\cdot}-}$) with a transient absorption band around 413 nm, via the intermolecular electron-transfer between NI moieties in the excited singlet state. In contrast, in a protic polar solvent mixture of $CH_3CN/H_2O$, a proton abstraction process occurred from $NI^{{\cdot}-}$ to generate the NI ketyl radical ($NIH^{\cdot}$), which showed a transient absorption band around 405 nm. The decay time constants of $NIH^{\cdot}$ were quite long compared to those of $NI^{{\cdot}-}$ in $CH_3CN$.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.431-436
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• 2009

The role of apurinic/apyrimidinic endonuclease1/redox factor-1 (Ref-1) on the lead (Pb)-induced cellular response was investigated in the cultured endothelial cells. Pb caused progressive cellular death in endothelial cells, which occurred in a concentration- and time-dependent manner. However, Ref-1 overexpression with AdRef-1 significantly inhibited Pb-induced cell death in the endothelial cells. Also the overexpression of Ref-1 significantly suppressed Pb-induced superoxide and hydrogen peroxide elevation in the endothelial cells. Pb exposure induced the downregulation of catalase, it was inhibited by the Ref-1 overexpression in the endothelial cells. Taken together, our data suggests that the overexpression of Ref-1 inhibited Pb-induced cell death via the upregulation of catalase in the cultured endothelial cells.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.43-43
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• 2003

This study was conducted to produce transgenic pig harboring human tissue plasminogene activator (tPA) gene. Two different tPA genes containing bovine $\beta$-casein promoter and mouse uroplakin promoter were prepared for microinjection and confirmed the expression level of tPA protein from the CHO (Chinese hamster ovary) cell lines by gene transfection. Concentration of tPA expression from the six cell lines (all of CHO cells) were average 212.4 ng/ml. Reconstructed DNA to used the CHO cell were microinjected into the pronuclei of in vivo embryos The total of 2,307 zygotes were collected from 95 donors and 1,851 embryos were in 1-cell stage which were visualized the pronuclei for DNA microinjection. The concentration of linear DNA was 2.0 ng per microliter and injected into zygotes with two pronuclei on an inverted Nikon microscope equipped with narishige micromanipulator and modulation contrast optics. The 541 embryos injected with bovine $\beta$-casein promoter-tPA were transferred to 22 recipients. The 1,154 embryos injected with mouse uroplakin promoter-tPA were transferred to 51 recipients. Sixty nine offspring from 9 delivered sows were produced. We analysed the transgenes with PCR methods from 69 offsprings, but could not detect the PCR product from piglet tails DNA.

• 에너지공학
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• 제11권3호
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• pp.254-261
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• 2002

The fabrication method for the main components of the polymer electrolyte membrane fuel cell stack such as electrodes, membrane-electrode assemblies, and bipolar plates was established for the effective electrode area of 240 ㎠. A counter-flow type 100-cell stack was fabricated by using the above components and then a maximum power of 7.44 kW for H$_2$/O$_2$ and 5.56 kW for H$_2$/air could be obtained at 70$\^{C}$ and 1 atm. It was seen that the distribution of the OCV for unit cells in the stack was uniform but the voltage deviation increased as the load increased due to the IR drop and the electrode polarization. The stack was applied to the power source of the fuel cell/battery hybrid electric golf car. It produced about 1 kW at a room temperature operation during the test run, which occupied about 43% of the total power required by the 2.3 kW motor.

• 한국환경성돌연변이발암원학회지
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• 제24권3호
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• pp.113-120
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• 2004

Chromium compounds are known human and animal carcinogens. In this study, the effects of sodium chromate on apoptosis and cell cycle were investigated in order to unveil the elements of early cellular responses to the metal. Using Chinese hamster ovary cells(CHO-K1-BH4), we found taht chromium (VI) treatment induced apoptosis in these cells, as signified by nuclear fragmentation, DNA laddering on agarose gel electrophoresis, and an increased proportionof cells with hypodiploid DNA. Preceding these changes, chromium (VI) treatment increased caspase 3 pritease activity and also increased expression of p53 protein, while the level of bcl2 protein was not changed. Coincubation with caspase inhibitor, Z-DEVD-FMK, inhibited chromium-induced apoptosis. In the flow cytometric analysis using propidium iodide fluorescence, an increase of cell population in G2/M phase was shown in cells exposed to at least 160 $\mu\textrm{m}$ of sodium chromate for 72h, form 9.8% for 0$\mu\textrm{m}$ chromium (VI) to 26.4% for 320$\mu\textrm{m}$ chromium(VI). Taken together, these findings suggest that chromium(VI)-induced apoptosis is accompanied by G2/M cell cycle arrest, and that p53-mediated pathway may be involved in positive regulation of G2/M arrest and a concurred apoptosis in CHO cells.

• Journal of Ginseng Research
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• 제12권2호
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• pp.104-113
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• 1988

여러가지 농도의 cholesterol을 함유한 배지에서 배양한 CHO 세포내로 흡입된 cholesterol 양을 조사한 결과 흡입량이 배지의 cholesterol 농도에 비례하였으므로 cholesterol 흡입은 확산에 의한 것으로 생각된다. $^{125}I$으로 표지된 저밀도 지방단백질($^{125}I$-LDL)을 이용하여 여러가지 농도의 cholesterol을 함유한 배지에서 배양한 CHO 세포와 cholesterol이 없는 정상배지에서 배양한 CHO 세포에서의 LDL 수용체의 합성양상을 조사한 결과 배지에 가해준 cholesterol이 LDL 수용체 합성을 억제함을 확인하였다. Cholesterol의 LDL 수용체 생합성 억제작용에 미치는 ginsenoside의 영향을 조사하기 위해 ginsenoside와 cholesterol을 함께 함유한 배지에서 배양한 CHO 세포(시험군)과 cholesterol만을 포함한 배지에서 배양한 CHO 세포(대조군)에서의 LDL 수용체의 활성양상을 분석한 결과 대조군에 비해 시험군에서의 LDL 수용체 활성이 크게 증가하였다. RNA 및 단백질 합성도 시험군이 대조군보다 증가하였음을 관찰하였다. 그러나 이와 같은 실험조건하에서의 대조군과 시험군의 cholesterol농도를 측정한 결과 시험군의 cholesterol 농도가 대조군보다 훨씬 저하되고 있었다. Ginsenoside의 cholesterol농도 저하작용을 관찰하기 위해 CHO세포에서의 cholesterol의 steroid hormone(estradiol, progesterone)으로의 전환에 미치는 ginsenoside의 영향을 조사한 결과 ginsenoside는 cholesterol의 hormone으로의 전환을 촉진하였음이 확인되었다. 위와 같은 실험결과로 볼 때 ginsenoside는 CHO 세포내부에서의 cholesterol의 LDL 수용체 합성억제를 완화시켜 주는 것이라고 생각된다.