• Title/Summary/Keyword: Surface Antigen

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Studies on the development of enzyme linked immuno-sorbent assay (ELISA) for hepatitis B surface antigen (HBsAg) by monoclonal antibodies of different affinity constants

  • Kim, Gye-Won;Hong, Sung-Youl;Shin, Soon-Cheon;Lee, Sung-Hee;Kim, Won-Bae
    • Archives of Pharmacal Research
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    • v.10 no.1
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    • pp.18-24
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    • 1987
  • Mouse monocolonal antibodies to Hepatitis B surface antien (HBsAg) were prepared and their functional capabilities tested by the method of solid phase enzyme linked immuno sorbent assay (ELISA). HBsAg binding studies inicated that one monoclonal antibody 6E-1-1 bound more HBsAg at a faster rate than the other monoclonal antibodies. Also, for the binding inhibition studies with the selected monoclonal antibody 6E-1-1, one monoclonal antibody 8D-3-6 didn't exhibit binding inhibition for HBsAg. Then, a simultaneous ELISA method was developed for the immunodiagnosis of HBsAg. Different combinations of two monoclonal antibodies as solid phase and horseradish peroxidase (HRPO) labeled phase were studied. The combination of monoclonal antibody of higher affinity constant (6E-1-1) immobilized in a solid phase and monoclonal antibody of lower affinity constant (8D-3-6) as a HRPO laeled phase was more sensitive when two monoclonal antibodies of different affinity constants for HBsAg were prepared.

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Development of Diagnostic kit for Hepatitis B Susrface Antigen using Immunochromatographic Assay Method (면역크로마토그래피법을 이용한 B형간염 진단용 kit의 개발)

  • 신형순;신광순;정홍근;허태련
    • KSBB Journal
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    • v.15 no.2
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    • pp.214-218
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    • 2000
  • A hepatitis B Surface Antigen(HBsAg)-screening kit using immunochromatographic assay(ICA) method was developed by e employing two kinds of antibodies. One is mouse monoclonal anti-HBs for tracer antibody and the other is goat p이yclonal a anti-HBs for capture antibody. This capture antibody was immobilized on the surface of nitroceliulose(NC) membrane and the t tracer antibody was conjugated with g미d particles. When serum sample was added to the sample well, the $\infty$njugates d deposited in a dry state on the surface of glass fiber filter were reconstituted and then combined with HBsAg in serum. In 5 5 min after adding, the assay result was visible through the window, that is, the complexes composed of HBsAg and the c conjugates appeared as maroon line on the lower part of the NC membrane. The detection limit of the ICA kit was 2 ng/ml w when being tested with the reference HBsAg.

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Development of serodiagnostic surface plasmon resonance imaging assay for the detection of antibodies to porcine circovirus type 2

  • Park, Chul;Kim, Bum-Seok;Kim, Yong-Hwan;Cho, Ho-Seong
    • Korean Journal of Veterinary Service
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    • v.34 no.1
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    • pp.1-4
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    • 2011
  • A surface plasmon resonance imaging (SPRI) assay was developed for measuring porcine circovirus type 2 (PCV2) antibody using a recombinant capsid protein as an antigen. The diagnostic potential of SPRI for detecting antibodies to the PCV2 capsid protein was compared with that of a conventional enzyme-linked immunosorbent assay (ELISA) using 70 pig serum samples taken from 6 pig farms. There was a strong positive correlation between the SPRI and ELISA (n = 70, r = 0.911, P<0.01). Therefore, this recombinant capsid protein can be used as an antigen for serological studies, and the SPRI, a label-free and high-throughput method, is expected to be a valuable tool in the serodiagnosis of PCV2 infection.

Optimization of Yeast Surface-Displayed cDNA Library Screening for Low Abundance Targets

  • Kim, Juhyung;Kim, Hyung Kyu;Jang, Hye Jeong;Kim, Eunkyung;Kim, Moon Kyu
    • Journal of Microbiology and Biotechnology
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    • v.25 no.4
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    • pp.547-553
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    • 2015
  • The yeast surface-displayed cDNA library has been used to identify unknown antigens. However, when unknown target antigens show moderate-to-low abundance, some modifications are needed in the screening process. In this study, a directional random-primed cDNA library was used to increase the number of candidates for the unknown antigen. To avoid the loss of target yeast clones that express proteins at a low frequency in the cDNA library, a comprehensive monitoring system based on magnetic-activated cell sorting, fluorescence-activated cell sorting, and immunofluorescence was established, and a small number of target yeast cells was successfully enriched. These results showed that our optimized method has potential application for identifying rare unknown antigens of the human monoclonal antibody.

Functionalizing Liposomes with Dual Aptamers for Targeting of Breast Cancer Cells and Cancer Stem Cells

  • Park, Hee-Bin;You, Ji-Eun;Kim, Pyung-Hwan;Kim, Keun-Sik
    • Biomedical Science Letters
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    • v.27 no.1
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    • pp.1-11
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    • 2021
  • Cancer stem cells, which are known to drive tumor formation and maintenance, are a major obstacle in the effective treatment of various types of cancer. Trans-membrane glycoprotein mucin 1 antigen and cell surface glycogen CD44 antigen are well-known surface markers of breast cancer cells and breast cancer stem cells, respectively. To effectively treat cancer cells and cancer stem cells, we developed a new drug-encapsulating liposome conjugated with dual-DNA aptamers specific to the surface markers of breast cancer cells and their cancer stem cells. These two aptamer (Apt)-targeted liposomes, which were prepared to encapsulate doxorubicin (Dox), were named "Dual-Apt-Dox". Dual-Apt-Dox is significantly more cytotoxic to both cancer stem cells and cancer cells compared to liposomes lacking the aptamers. Furthermore, we demonstrated the inhibitory efficacy of Dual-Apt-Dox against the experimental lung metastasis of breast cancer stem cells and cancer cells in athymic nude mice. We also showed the potent antitumor effects of dual-aptamer-conjugated liposome systems by targeting cancer cells as well as cancer stem cells. Thus, our data indicate that dual-aptamer-conjugated liposome systems can prove to be effective drug delivery vehicles for breast cancer therapy.

A Study on the Trend of Changes in the Positive Rate of Hepatitis B Surface Antigens and Antibodies over the Last 9 Years in One Health Care Center

  • Kang-Sil Lee;Sang-Ha Kim;Young-Bin Yu;Young-Kwon Kim
    • Biomedical Science Letters
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    • v.29 no.4
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    • pp.314-320
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    • 2023
  • The purpose of this study was to provide basic data on hepatitis B infection control in the community through the results of the hepatitis B surface antigen and antibody tests conducted at the Cheongyang-County Health Medical Center. From 2012 to 2020, we retrospectively analyzed the HBsAg, HBsAb, HBeAg, HBeAb, and HBV DNA results of 7,329 hepatitis B-related testers. Among 7,329 subjects, the HBsAg positivity rate was 1.7%, and the positivity rate according to age was the highest at 4.4% in their 30s, 4.2% in their 40s, 4.1% in their 50s, 2.0% in their 60s, 1.9% in their 70s and over, and 10 it was shown in the order of 0.3% from less than large. The HBsAb positivity rate was 43.1% for men, 38.2% for men, and 46.7% for women (P<0.001). To summarize the above results, for infection control of hepatitis B in Cheongyang-County, hepatitis surface antigen proton management is required for those in their 30s or older, and it is thought that efforts to acquire immunity are necessary for those in their 20s or younger.

Enhancement of Proliferation and Antigen Presentation of Human B Cells in Vitro by K562 Cells Expressing CD40L (CD40L 발현 K562 세포주를 이용한 시험관내 B 세포 증식과 항원제공능 증가)

  • Park, Jung-Yong;Yoon, Sung-Hee;Kim, Eun-Kyung;Yun, Sun-Ok;Sohn, Hyun-Jung;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • v.7 no.2
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    • pp.80-86
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    • 2007
  • Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.

Sulforaphane Enhances MHC Class II-Restricted Presentation of Exogenous Antigens

  • Shin, Seul-Mee;Jung, Ki-Sung;Park, Yoon-Hee;Ko, Young-Wook;Lee, Chong-Kil;Cho, Kyung-Hae;Ha, Nam-Joo;Kim, Kyung-Jae
    • Biomolecules & Therapeutics
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    • v.19 no.1
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    • pp.77-83
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    • 2011
  • Sulforaphane is an isothiocyanate found in cruciferous vegetables that has been reported to be an effective cancer preventive agent inducing growth arrest and/or cell death in cancer cells of various organs. This paper reports that sulforaphane exerts immunomodulatory activity on the MHC-restricted antigen presenting function. Sulforaphane efficiently increased the class II-restricted presentation of an exogenous antigen, ovalbumin (OVA), in both dendritic cells (DCs) and peritoneal macrophages in vitro. The class II-restricted OVA presentation-enhancing activity of sulforaphane was also confirmed using mice that had been injected with sulforaphane followed by soluble OVA. On the other hand, sulforaphane did not affect the class I-restricted presentation of exogenous OVA at concentrations that increase the class II-restricted antigen presentation. At a high concentration ($20\;{\mu}M$), sulforaphane inhibited the class I-restricted presentation of exogenous OVA. Sulforaphane did not affect the phagocytic activity of the DCs, and the cell surface expression of total H-$2K^b$, B7-1, B7-2 and CD54 molecules, even though it increased the expression of I-$A^b$ molecules to a barely discernable level. These results show that sulforaphane increases the class II-restricted antigen presenting function preferentially, and might provide a novel insight into the mechanisms of the anti-cancer effects of sulforaphane.

Modulatory Effect of Kaempferitrin, a 3,7-Diglycosylflavone, on the LPS-Mediated Up-regulation of Surface Co-stimulatory Molecules and CD29-Mediated Cell-cell Adhesion in Monocytic- and Macrophage-like Cells (활성화된 단핵구 및 대식세포의 항원제시기능에 대한 Kaempferitrin의 조절 효과)

  • Kim, Byung-Hun;Cho, Dong-Ha;Cho, Jae-Youl
    • YAKHAK HOEJI
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    • v.51 no.6
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    • pp.482-489
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    • 2007
  • Kaempferitrin, isolated from Kenaf (Hibiscus cannabinus), was examined to evaluate its modulatory effects on antigen-presenting cell functions of macrophages/monocytes such as phagocytosis of foreign materials, up-regulation of costimulatory molecules (CD40, CD80 and CD86), adhesion molecule activation, and antigen processing and presentation. Kaempferitrin strongly blocked up-regulation of CD40, CD80 and CD86, but not pattern recognition receptor (PRR) (e.g., TLR2). It also suppressed functional activation of CD29 (${\beta}1$-integrins), as assessed by cell-cell adhesion assay, required for T cell-antigen-presenting cell (APC) interaction. Furthermore, this compound did not block a simple activation of CD29, as assessed by cell-fibronectin adhesion assay. However, the compound did not diminish phagocytic uptake, an initial step for antigen processing, and ROS generation in RAW264.7 cells. In particular, to understand molecular mechanism of kaempferitrin-mediated inhibition, the regulatory role of LPS-induced signaling events was examined using immunoblotting analysis. Interestingly, this compound dose dependently suppressed the phosphorylation of $I{\kappa}B{\alpha}$, Src, Akt and Syk, demonstrating that it can negatively modulate the activation of these signaling enzymes. Therefore, our data suggested that kaempferitrin may be involved in regulating APC function-relevant immune responses of macrophages and monocytes by regulating intracellular signaling.

ELISA detection of vivax malaria with recombinant multiple stage-specific antigens and its application to survey of residents in endemic areas

  • Kim, Sera;Ahn, Hye-Jin;Kim, Tong-Soo;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.41 no.4
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    • pp.203-207
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    • 2003
  • An ELISA was developed for the diagnosis of vivax malaria using multiple stage-specific recombinant antigens of Plasmodium vivax. The DNA from the whole blood of a malaria patient was used as template to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), merozoite surface protein (MSP-1), apical merozoite antigen (AMA-1), serine repeat antigen (SERA), and exported antigen (EXP-1). Each amplified DNA fragment was inserted into pQE30 plasmid to induce the expression of His-tagged protein in Escherichia coli (M15 strain) by IPTG. His-tagged proteins were purified by Ni-NTA metal-affinity chromatography and used as antigens for ELISA with patient sera that were confirmed previously by blood smear examinations. When applied to patient sera, 122 (80.3%) out of 152 vivax malaria cases reacted to at least one antigen, while no reactions were observed with 128 uninfected serum samples. We applied this ELISA to the screening of 3,262 civilian residents in endemic regions near the DMZ, which resulted in 236 positively detected (7.2%) cases. This method can be applied to serological diagnosis and mass screening in endemic regions, or can be used as a safety test for transfusion blood in endemic areas.