• Title/Summary/Keyword: Epitope

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Role of Citrullinated Fibrinogen Peptides in the Activation of CD4 T Cells from Patients with Rheumatoid Arthritis

  • Shin, Kihyuk;Hong, SeokChan;Choi, Eun-Hye;Lim, Mi-Kyoung;Shim, Seung-Cheol;Ju, Ji-Hyeon;Lee, Seung-Hyo
    • IMMUNE NETWORK
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    • v.13 no.4
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    • pp.116-122
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    • 2013
  • This study was conducted to determine whether CD4 T cell responses to citrullinated fibrinogen occur in patients with rheumatoid arthritis (RA), especially in HLA-DR4-positive subjects. Whole peripheral blood mononuclear cells (PBMCs) of RA patients and control subjects were stimulated with citrullinated fibrinogen peptides, and T-cell production of proliferation and proinflammatory cytokines, such as interferon-${\gamma}$(IFN-${\gamma}$) and interleukin-17A (IL-17A), were measured. In addition, CD4 T cells from RA patients were stimulated with the citrullinated fibrinogen peptide, $Fib-{\alpha}$ R84Cit, identified as a DRB1*0401-restricted T cell epitope in HLA-DR4 transgenic mice, and the degree of T cell activation was examined similarly. No proliferative responses to the citrullinated fibrinogen peptides were observed in whole PBMCs or CD4 T cells from RA patients. Furthermore, no increased production of IFN-${\gamma}$ or IL-17A was found in whole PBMCs or CD4 T cells stimulated with the citrullinated fibrinogen peptides, although these cells responded to recall antigen, a mixture of tetanus toxoid, purified protein derivative (PPD) from Mycobacterium tuberculosis, and Candida albicans. The results of this study indicate that anti-citrulline immunity in RA patients may be mediated by fibrinogen because there is no evidence of CD4 T cell-mediated immune responses to citrullinated fibrinogen peptides.

Production and Characterization of Monoclonal Antibodies against Human Ceruloplasmin

  • Eum, Won-Sik;Choi, Hee-Soon;Kim, Dae-Won;Jang, Sang-Ho;Choi, Soo-Hyun;Kim, So-Young;Park, Jin-Seu;Kang, Jung-Hoon;Cho, Sung-Woo;Kwon, Oh-Shin;Hwang, In-Koo;Yoo, Ki-Yeon;Kang, Tae-Cheon;Won, Moo-Ho;Choi, Soo-Young
    • BMB Reports
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    • v.38 no.1
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    • pp.71-76
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    • 2005
  • Ceruloplasmin (CP) is the major plasma antioxidant and copper transport protein. Monoclonal antibodies (mAbs) against human CP were produced and characterized. A total of five hybridoma cell lines were established (CP2, CP10, CP20, CP25, CP30). From the epitope mapping analysis, two subgroups of mAbs recognize different peptide fragments were identified. When the purified CP was incubated with the mAbs, the ferroxidase activity of CP was inhibited up to a maximum 57%. Immunoblotting with various tissue homogenates indicated that all the mAbs specifically recognize a single protein band of 130 kDa. They also appear to be extensively cross-reactive among different mammalian including human and avian sources. These results demonstrated that only one type of immunologically similar CP is present in all of the mammalian tissues including human. The CP mAbs could be of great benefit to design the diagnostic kit for CP-related diseases such as Wilson's disease.

Human Brain Pyridoxal-5'-phosphate Phosphatase: Production and Characterization of Monoclonal Antibodies

  • Kim, Dae-Won;Eum, Won-Sik;Choi, Hee-Soon;Kim, So-Young;An, Jae-Jin;Lee, Sun-Hwa;Sohn, Eun-Joung;Hwang, Seok-Il;Kwon, Oh-Shin;Kang, Tae-Cheon;Won, Moo-Ho;Cho, Sung-Woo;Lee, Kil-Soo;Park, Jin-Seu;Choi, Soo-Young
    • BMB Reports
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    • v.38 no.6
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    • pp.703-708
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    • 2005
  • We cloned and expressed human pyridoxal-5'-phosphate (PLP) phosphatase, the coenzymatically active form of vitamin $B_6$, in Escherichia coli using pET15b vector. Monoclonal antibodies (mAb) were generated against purified human brain PLP phosphatase in mice, and four antibodies recognizing different epitopes were obtained, one of which inhibited PLP phosphatase. The binding affinities of these four mAbs to PLP phosphatase, as determined using biosensor technology, showed that they had similar binding affinities. Using the anti-PLP phosphatase antibodies as probes, we investigated their cross-reactivities in various mammalian and human tissues and cell lines. The immunoreactive bands obtained on Western blots had molecular masses of ca. 33 kDa. Similarly fractionated extracts of several mammalian cell lines all produced a single band of molecular mass 33 kDa. We believe that these PLP phosphatase mAbs could be used as valuable immunodiagnostic reagents for the detection, identification, and characterization of various neurological diseases related to vitamin $B_6$ abnormalities.

Reduction of Allergenicity of Wheat Flour by Enzyme Hydrolysis (효소 분해에 의한 밀가루의 항원성 저감화)

  • Park, Ju-Yeon;Ahn, Jeung-Yeub;Hong, Hee-Ok;Hahn, Young-Sook
    • Korean Journal of Food Science and Technology
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    • v.36 no.1
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    • pp.152-157
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    • 2004
  • Gluten was extracted from domestic wheat flour using UTH buffer (4 M urea in 0.1 M Tris-HCl, pH 8.6) and validated by SDS-PAGE analysis for production of wheat flour products with reduced gluten content.. Anti-gluten polyclonal antibody was made by administering extracted gluten fraction on animal model. Anti-gluten serum titer of extracted gluten fraction was evaluated by ELISA, and that of antibody titer according to administration period. Anti-gluten sera were used for ELISA and immunoblot analysis before and after hydrolysis of gluten fraction at optimal pH and temperature condition for each protease. Gluten fraction separated by SDS-PAGE showed several bands covering 75 to 10 kDa, in which anti-gluten sera were 25, 34, and 45 kDa. Enzyme hydrolysis of gluten fraction revealed protein band sizes to be lower than 15 kDa. Content of pretense from bovine pancreas (b.p. protease) for gluten hydrolysis was estimated as 1 mg in 10 mL gluten fraction extracted for 4 hr.

Pharmacokinetics and Lymphatic Delivery of Oligopeptide after Intramuscular Injection of Oligopeptide-bearing Liposomes to Rats (흰쥐에서 올리고펩타이드 함유 리포솜의 근육주사후 체내동태 및 임파이행)

  • Shin, Dae-Hwan;Cho, Byung-Suk;Choi, Kyu-Seok;Song, Suk-Gil;Lee, Chong-Kil;Chung, Youn-Bok
    • Journal of Pharmaceutical Investigation
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    • v.38 no.3
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    • pp.191-197
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    • 2008
  • The purpose of the present study was to examine the pharmacokinetics and lymphatic delivery of the oligopeptide, a model peptide of X antigen epitope peptides, after the intramuscular administration of the peptide-bearing liposomes in rats. $^{14}C$-labelled peptide was used as a tracer to analyze the peptide levels in plasma, bile, urine, tissue homogenates, and lymph nodes (superior cervical nodes, brachial nodes and superior mesenteric nodes). Model peptide rapidly disappeared from the plasma by 30 min (${\alpha}$ phase) after i.v. administration, which was followed by the late disappearance. The apparent plasma half-lives ($t_{1/2({\alpha}),app}$) of the peptide at the ${\alpha}$ phase when administered at a dose of 0.2-1.0 mg/kg were about 5 min. The maximum plasma concentration ($C_{max}$) was $1.52\;{\mu}g/mL$, after the i.m. administration of the peptide at a dose of 1.0 mg/kg. The bioavailability, which was calculated from the time zero to last quantitative time, of the i.m. administered peptide was over 60%. Of the various tissues tested, the peptide was mainly distributed in the kidney after the i.m. administration. The peptide levels in the kidney 3 hr after the i.m. administration were higher than those of maximum plasma concentration ($C_{max}$). The cumulative amounts of the peptide found in the urine 72 hr after the administration of 1.0 mg/kg were 2-folder higher than those in the bile, suggesting that the peptide is mostly excreted in the urine. Moreover, the concentrations of the peptide in the lymph nodes were as high as that of the plasma and the tissues. In conclusion, the peptide concentration in the lymph nodes was maintained by 24 hr after the i.m. administration of the peptide-bearing liposomes.

The Study of MHC class I Restricted CD8+ T Cell Mediated Immune Responses against Mycobacterium tuberculosis Infection: Evidence of M. tuberculosis S pecific CD8+ T Cells in TB Patients and PPD+ Healthy Individuals (MHC class I 분자들에 의해 제시되는 Epitope을 인지하는 CD8+ T 림프구의 결핵균 감염에 대한 면역반응의 연구: 결핵 환자와 PPD+ 건강개체에 존재하는 결핵균 항원에 특정한 CD8+ T세포)

  • Cho, Jang-Eun;Lee, Kyung Wha;Park, Seung Kyu;Cheon, Seon-Hee;Cho, Sang-Nae;Cho, Sungae
    • IMMUNE NETWORK
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    • v.3 no.3
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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.

The Significance of Caspase-Cleaved Cytokeratin 18 in Pleural Effusion

  • Lee, Keu Sung;Chung, Joo Yang;Jung, Yun Jung;Chung, Wou Young;Park, Joo Hun;Sheen, Seung Soo;Lee, Kyi Beom;Park, Kwang Joo
    • Tuberculosis and Respiratory Diseases
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    • v.76 no.1
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    • pp.15-22
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    • 2014
  • Background: Apoptosis plays a role in the development of pleural effusion. Caspase-cleaved cytokeratin 18, a marker for epithelial cell apoptosis, was evaluated in pleural effusion. Methods: A total of 79 patients with pleural effusion were enrolled. The underlying causes were lung cancer (n=24), parapneumonic effusion (n=15), tuberculous effusion (n=28), and transudates (n=12). The levels of M30, an epitope of caspase-cleaved cytokeratin 18, were measured in blood and pleural fluids using enzyme-linked immunosorbent assay along with routine cellular and biochemical parameters. The expression of M30 was evaluated in the pleural tissues using immunohistochemistry for M30. Results: The M30 levels in pleural fluid were significantly higher in patients with tuberculosis ($2,632.1{\pm}1,467.3U/mL$) than in patients with lung cancer ($956.5{\pm}618.5U/mL$), parapneumonic effusion ($689.9{\pm}413.6U/mL$), and transudates ($273.6{\pm}144.5U/mL$; all p<0.01). The serum levels were not significantly different among the disease groups. Based on receiver operating characteristics analysis, the area under the curve of M30 for differentiating tuberculous pleural effusion from all other effusions was 0.93. In the immunohistochemical analysis of M30, all pathologic types of cancer cells showed moderate to high expression, and the epithelioid cells in granulomas showed high expression in tuberculous pleural tissues. Conclusion: Caspase-cleaved cytokeratin 18 was most prominently observed in tuberculous pleural effusion and showed utility as a clinical marker. The main source of M30 was found to be the epithelioid cells of granulomas in tuberculous pleural tissues.

Human $CD103^+$ dendritic cells promote the differentiation of Porphyromonas gingivalis heat shock protein peptide-specific regulatory T cells

  • Kim, Myung-Jin;Jeong, Eui-Kyong;Kwon, Eun-Young;Joo, Ji-Young;Lee, Ju-Youn;Choi, Jeomil
    • Journal of Periodontal and Implant Science
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    • v.44 no.5
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    • pp.235-241
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    • 2014
  • Purpose: Regulatory T cells (Tregs), expressing CD4 and CD25 as well as Foxp3, are known to play a pivotal role in immunoregulatory function in autoimmune diseases, cancers, and graft rejection. Dendritic cells (DCs) are considered the major antigen-presenting cells (APCs) for initiating these T-cell immune responses, of which $CD103^+$ DCs are derived from precursor human peripheral blood mononuclear cells (PBMCs). The aim of the present study was to evaluate the capacity of these PBMC-derived $CD103^+$ DCs to promote the differentiation of antigen-specific Tregs. Methods: Monocyte-derived DCs were induced from $CD14^+$ monocytes from the PBMCs of 10 healthy subjects. Once the $CD103^+$ DCs were purified, the cell population was enriched by adding retinoic acid (RA). Peptide numbers 14 and 19 of Porphyromonas gingivalis heat shock protein 60 (HSP60) were synthesized to pulse $CD103^+$ DCs as a tool for presenting the peptide antigens to stimulate $CD3^+$ T cells that were isolated from human PBMC. Exogenous interleukin 2 was added as a coculture supplement. The antigen-specific T-cell lines established were phenotypically identified for their expression of CD4, CD25, or Foxp3. Results: When PBMCs were used as APCs, they demonstrated only a marginal capacity to stimulate peptide-specific Tregs, whereas $CD103^+$ DCs showed a potent antigen presenting capability to promote the peptide-specific Tregs, especially for peptide 14. RA enhanced the conversion of $CD103^+$ DCs, which paralleled the antigen-specific Treg-stimulating effect, though the differences failed to reach statistical significance. Conclusions: We demonstrated that $CD103^+$ DCs can promote antigen-specific Tregs from naive T cells, when used as APCs for an epitope peptide from P. gingivalis HSP60. RA was an effective reagent that induces mature DCs with the typical phenotypic expression of CD103 that demonstrated the functional capability to promote antigen-specific Tregs.

M. tuberculosis Somatic Antigen Specific CD8+T cell Responses in BCG-Vaccinated Subjects (BCG 예방접종을 받은 개체에서 유도되어 있는 결핵균 균체항원에 특정한 CD8+T 세포의 보호 면역반응)

  • Cho, Jang-Eun;Cho, Sang-Nae;Lee, Kyung Wha;Park, Seung Kyu;Cho, Sungae
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.3
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    • pp.272-278
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    • 2005
  • Background : The immune responses mediated by CD8+T cells are known to be significant in controlling M. tuberculosis infections. In order to determine the role of cytotoxic CD8+T cells in the protective immune mechanism in latently infected subjects, this study examined whether or not the cytotoxic immune responses of CD8+T cells specific to the M. tuberculosis somatic antigens are induced in BCG vaccinated healthy subjects. Methods : Cytotoxicity and $IFN-{\gamma}$ elispot assays were used to investigate the activities of CD8+T cells specific for the $thyA_{30-38}$ peptide epitope in circulating peripheral blood mononuclear cells (PBMC) from BCG-vaccinated HLA-A*0201 and A*0206 subjects. Results : The results indicate the cytotoxic and $IFN-{\gamma}$ immune responses of CD8+T cells specific for $thyA_{30-38}$ were induced in BCG vaccinated healthy subjects. Conclusion : The cytotoxic and $IFN-{\gamma}$ responses by CD8+T cells specific for the M. tuberculosis somatic antigens are induced in BCG-vaccinated subjects, and appear to be involved in the protective immune mechanism in latently infected people against a M. tuberculosis infection.

$RpoB_{127-135}$ Peptide Derived from Mycobacterium tuberculosis is Processed and Presented to HLA-$A^*0201$ Restricted CD8+ T Cells via an Alternate HLA-I Processing Pathway

  • Cho, Jang-Eun;Cho, Sang-Nae;Cho, Sungae
    • Biomedical Science Letters
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    • v.20 no.4
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    • pp.250-255
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    • 2014
  • Mycobacterium tuberculosis (MTB) resides and replicates inside macrophages. In our previous report, we reported that CD8+ T cell-mediated immune responses specific for the peptide derived from MTB RNA polymerase beta-subunit ($RpoB_{127-135}$) could be induced in TB patients expressing HLA-$A^*0201$ subtype. In order to examine whether $RpoB_{127-135}$ specific CD8+ T cells can recognize MTB infected macrophages in vitro, CD8+ T cell lines specific for $RpoB_{127-135}$ peptide were generated from peripheral blood mononuclear cells (PBMCs) of healthy HLA-$A^*0201$ subjects by in vitro immunization technique. In this study, we observed $RpoB_{127-135}$ specific CD8+ T cells could recognize and destroy macrophages infected with MTB for 2 to 4 days. $RpoB_{127-135}$ specific CD8+ T cell immune response was inducible from PBMC of healthy subjects expressing HLA-$A^*0206$ subtype, one of HLA-A2 supertype members. Next, we investigated the HLA-I processing mechanism of $RpoB_{127-135}$ peptide in MTB infected macrophages. As a result, the presentation of the MTB derived epitope peptide, $RpoB_{127-135}$, to CD8+ T cells was not inhibited by the treatment with brefeldin-A (ER-Golgi transport inhibitor) or lactacystin (proteasome inhibitor), which blocks the classical HLA-I processing pathway. However, $RpoB_{127-135}$ specific CD8+ T cell activity was blocked either by the blocking agent for the endocytosis (cytochalasin D) or by the blocking antibody (W6/32) for HLA-I molecules. Therefore, the $RpoB_{127-135}$ peptide may be processed by accessing the alternate HLA-I processing pathway. Understanding the processing and presentation mechanisms of the MTB derived proteins will help to improve the efficacy of vaccines and the efficiency of therapeutic agents for TB.