• 제목/요약/키워드: Surface antigen

검색결과 401건 처리시간 0.029초

Characteristics of a Bimetal-Layer Chip of a Surface Plasmon Resonance Sensor in the Intensity Interrogation for Tumor Marker Detection

  • Kim, Hyungjin;Kim, Chang-duk;Sohn, Young-Soo
    • 센서학회지
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    • 제25권4호
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    • pp.243-246
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    • 2016
  • The characteristics of a bimetallic surface plasmon resonance (SPR) chip were investigated to detect a tumor biomarker, carcinoembryonic antigen (CEA). The linewidth and the tangential slope of the reflectance curve of the bimetallic SPR chip was compared with those of the reflectance curve of a conventional gold (Au) SPR chip. The changes in reflectance in response to the variation in CEA in the critical concentration range were analyzed at an angle where the tangential slope of the reflectance curve was maximum. From linear regression analysis, the sensitivity of the bimetallic SPR chip with respect to the CEA in critical concentration was obtained.

($Interferon{\gamma}$)로 자극된 치은섬유아세포와 치주인대섬유아세 포에서 항원제시기능과 관련된 세포 표면분자의 발현 (Expression of Antigen Presenting Function-Associated Surface Molecules on $Interferon{\gamma}$-Treated Gingival Fibroblasts and Periodontal Ligament Fibroblasts)

  • 서석란;류성훈;오귀옥;김형섭
    • Journal of Periodontal and Implant Science
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    • 제30권4호
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    • pp.895-913
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    • 2000
  • It is becoming increasingly clear that human gingival fibroblasts(HGF) may play a role in regulating immune responsiveness in inflammatory periodontal lesions. Stimulation of HGF with locally-secreted T cell cytokine $IFN_{\gamma}$ induces human leukocyte antigen class II(HLA II) expression on HGF, which is one of the characteristic feature of professional antigen presenting cells(pAPC). However, $IFN_{\gamma}$-treated HGF and other nonprofessional antigen presenting cells(npAPC) are known to be ineffective or less effective antigen presenter to resting T cells. This study, therefore, was undertaken in an effort to elucidate the differences in expression of cell surface molecules between npAPC in periodontal tissues, such as HGF and periodontal ligament fibroblasts(PDLF), and pAPC such as monocytes/macrophages. Using flow cytometry, the levels of cell surface expression of HLA-D, ICAM-1, LFA-3, and B7-1, which are involved in antigen presentation, were determined in HGF, PDLF and human myelomonocytic cell line THP-1. $IFN_{\gamma}$ clearly induced HLA-D expression on both of fibroblasts and monocytes dose dependently. However, expression level on monocytes were 4 to 5 times higher than that on fibroblasts, and induction rate was faster in monocytes than in fibroblasts. The levels of ICAM-1 expression on fibroblasts and monocytes were enhanced by $IFN_{\gamma}$ in a dose dependent manner. On the other hand, the expression of LFA-3 molecule, which could be detected in fibroblasts and monocytes without cytokine stimulation, was no more enhanced by addition of $IFN_{\gamma}$. B7-1, important costimulatory molecule in T cell activation and proliferation, was not detected on both of fibroblasts and monocytes even when stimulated with $IFN_{\gamma}$, except on monocytes fully differentiated by pretreatment of PMA and treated by $IFN_{\gamma}$. These results suggest that delayed expression of HLA-D and absence of B7-1 on $IFN_{\gamma}$ - treated fibroblasts may at least in part be involved in the ineffectiveness of fibroblasts as primary APC. And it is postulated that although periodontal fibroblasts may not serve as primary APC in normal periodontium, sustained expression of HLA II on ubiquitous fibroblasts in inflammatory lesions may perpetuate immune responses and produce chronic inflammation and tissue injury.

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Conformation of Group "a" Epitope in Hepatitis B Surface Antigen

  • Chun, Mun-Ho;Park, Won-Bong;Bok, Jin-Woo;Kim, Ha-Won;Choi, Eung-Chil;Kim, Byong-Kak
    • Archives of Pharmacal Research
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    • 제15권4호
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    • pp.347-355
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    • 1992
  • To elucidate structure of group "a" epitope, mouse antibodies that express idiotype monoclonal antibody and anti-idiotype monoclonal antibody against the group specific "a" determinant were purified by hydroxyapatite column. To obtain hepatitis B surface antigens (HBsAg). HBsAg positive blood was sequencially purified by ammonium sulfate precipitation, hydroxyapatite, sepharose 4B column chromatography and ultracentrifugation. The major protein (p25) and glycoprotein (gp30) of HBsAg were isolated by concanavalin-A-sepharose 4B. The ability of p25-gp30 among the HBsAg to inhibit the idiotype-anti-idiotype reaction was dependent on conformation, since reduced and alkylated p25-gp30 virtualy lost their inhibitory capacity when compared to native HBsAg. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of p25-gp30.

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Seroprevalence of Sarcocystis falcatula in Two Islands of Malaysia using Recombinant Surface Antigen 4

  • Nadzirah, Tengku-Idris Tengku Idzzan;Yik, Fong Mun;Ling, Lau Yee
    • Parasites, Hosts and Diseases
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    • 제58권1호
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    • pp.1-5
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    • 2020
  • Sarcocystosis was diagnosed worldwide by serodiagnostic tests utilising the whole parasite, for which the protozoa were maintained in vitro are more costly. In this study, antigenicity of Sarcocystis falcatula recombinant protein (rSfSAG4) was investigated towards the local communities of Pangkor and Tioman Islands and its seroprevalence was surveyed in these islands. A total of 348 human sera were tested using rSfSAG4 by Western blot and ELISA. High prevalence of sarcocystosis was observed in Tioman Island (80.6%) than in Pangkor Island (50.0%) by Western blot. In ELISA, the seroprevalence observed in Tioman Island was 45.9%, whereas in Pangkor Island 63.0%. In other parasitic infections, the prevalence was 34.0% by Western blot and 46.0% by ELISA. In healthy control group, 7% by Western blot and 8% by ELISA showed positivity to rSfSAG4. It is suggested SfSAG4 is a candidate antigen to measure seroprevalence of sarcocystosis.

이미지 엘립소미트리를 이용한 예시니아 검출용 바이오센서 개발 (Biosensor for Detection of Yersinia enterocolitica based on imaging ellipsometry)

  • Y. M. Bae;Park, K. W.;Park, J. W.;S. I. Cho
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2003년도 하계 학술대회 논문집
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    • pp.421-426
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    • 2003
  • The Immunosensor based on antigen-antibody binding have been developed for detecting several analytes including antigen, small molecules, and cell. This method can be rapid and show very good detection limits. For Implementation of immunosensor, technologies for immobilization of antibody onto solid surface and detection of protein-protein binding must be developed. (an ellipsis)

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단클론 항체를 이용하여 정제한 톡소포자충 30 kDa 항원의 면역학적 특성 (Immunological properties of the 30 kDa antigen of Toxoplasma gondii)

  • 이영화;노태진;신대환
    • Parasites, Hosts and Diseases
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    • 제35권1호
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    • pp.55-62
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    • 1997
  • 톡소포자충(ToxopLasmn gondii)은 다양한 항원을 가지고 있으며, 이들 항원의 분석은 세 포매개성 면역반응 및 톡소포자충증의 면역학적 진단방법의 연구에 매우 중요하다 본 연구는 톡소포자충의 여러 단백질중 대부분의 충주(strain)에 존재하는 분자량 30 kDa의 단백질을 단클론 항체를 이용하여 분리한 후. 30 kDa 항원의 면역학적 특성을 초음파 추출 조항원과 비교 평가하였다. 톡소포자충의 세포막 항원으로 면역한 마우스 비장세포와 마우스 Sp2/0-Agl4 골수종세포를 융합하여 8개의 단클론 항체를 Western blot으로 확인하였다 이들 단클론 항체는 높은 특이성을 보였으며, $IgG_{2b}가{\;}5개,{\;}IgG^{1}이{\;}2개,{\;}IgG_{2a}$가 1개였다. 간접형광항체법으로 충체내 위치를 관찰한 결과. 30 kDa 항원은 tachyzoite의 표면 세포막에 주로 분포하였다. 단클론 항체와 CNBr-activated Sepharose 4B를 coupling하여 만든 immunoafrnity chromatography를 이용 하여 30 kDa 항원을 분리하였다. 분리한 30 kDa 항원으로 자극시킨 마우스 복강대식세포의 $NO_2^{-}$ 생산량은 초음파 추출 조항원 사용군에 비해 유의하게 증가하였으나 대식세포의 탐식능은 유의한 차이가 없었다. 또한 ELISA로 톡소포자충증을 진단시, 톡소포자충 30 kDa 항원 사용군은 조항원 사용군에 비해 민감도의 변화는 없었으나 특이성은 증가하였다 이상으로 보아 톡소포자충 30 kDa 항원은 감염 방어 면역 효과가 있었으며 진단에 이용시 특이성을 더 높일 수 있었다.

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Double-Enhancement Strategy: A Practical Approach to a Femto-Molar Level Detection of Prostate Specific $Antigen-{\alpha}_1-Antichymotrypsin$ (PSA/ACT Complex) for SPR Immunosensing

  • Cao, Cuong;Sim, Sang-Jun
    • Journal of Microbiology and Biotechnology
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    • 제17권6호
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    • pp.1031-1035
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    • 2007
  • Prostate specific $antigen-{\alpha}_1-antichymotrypsin$ was detected by a double-enhancement strategy involving the exploitation of both colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation. The AuNPs were synthesized and conjugated with horse-radish peroxidase-PSA polyclonal antibody by physisorption. Using the protein-colloid for SPR-based detection of the PSPJACT complex showed their enhancement as being consistent with other previous studies with regard to AuNPs enhancement, while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the signal. The limit of detection was found at as low as 0.027 ng/ml of the PSA/ACT complex (or 300 fM), which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays.

SERS Immunoassay Using Microcontact Printing for Application of Sensitive Biosensors

  • Hong, Won-Jin;Seo, Hyeong-Kuyn;Jung, Young-Mee
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4281-4285
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    • 2011
  • We introduced a promising patterned substrate by using a microcontact printing method that can be used for SERS immunoassays based on antigen-antibody binding. SERS spectrum of the Raman reporter with antibody, which is rhodamine 6G (R6G) adsorbed on colloidal gold nanoparticles, was observed only for the surfaces in which prostate-specific antigen (PSA) is present on the substrate that is attached to an immobilized layer of antibody on the gold nanoparticles layer of the patterned substrate. Raman mapping images clearly showed that the antibodies on the Raman reporter were successfully and selectively conjugated with the antigen on the patterned substrate. This method could be potentially extended to multi-protein detections and ultrasensitive biosensors.