• Proceedings of the Korea Contents Association Conference
• /
• 2017.05a
• /
• pp.297-298
• /
• 2017

플라비바이러스(Flavivirus)는 모기와 같은 곤충을 매개로 하여 인체에 감염된다고 잘 알려져 있다. 그 대표적인 예로 지카 바이러스(Zika virus), 뎅기 바이러스(Dengue virus), 황열 바이러스(Yellow fever virus), 일본 뇌염 바이러스(Japanese encephalitis virus) 등을 들 수 있다. 본 연구에서는 생물정보학을 기반으로 인체 감염 주요 플라비바이러스인 지카 바이러스, 뎅기 바이러스. 황열 바이러스, 일본 뇌염 바이러스의 총 4종류 플라비바이러스에 공통적으로 적용 가능한 펩타이드 백신 후보를 제시하고자 한다. 먼저 UniProt (The Universal Protein Resource)의 유전자 서열정보를 이용하여 4종류의 바이러스가 가진 단백질 중 백신으로써 적합한 단백질을 선정하였다. 선정된 단백질의 아미노산 서열정보를 바탕으로 IEDB (Immune Epitope Database And Analysis Resource)를 활용한 에피토프(epitope) 분석을 통해 에피토프로 작용하는 4 종류 바이러스의 공통적인 서열을 도출하였다.

• BMB Reports
• /
• v.38 no.3
• /
• pp.290-293
• /
• 2005

In order to investigate the epitope of basic fibroblast growth factor (bFGF) and its immunogenicity, the epitopes of bFGF were screened from the phage display library with monoclonal antibody GF22, which can neutralize the bio-activity of bFGF. By three rounds of screening, the positive phage clones with bFGF epitopes were selected, which can effectively block the bFGF to bind with GF22. Sequence analysis showed that the epitopes shared a highly conservative sequence (Leu-Pro-Pro/Leu-Gly-His-Phe/Ile-Lys). The sequence of PPGHFK was located at 22-27 of the bFGF. The specific immuno-response of mouse could be highly induced by phage clones with the epitopes. And the anti-bFGF activity induced by LPGHFK was 3 times higher than the original sequence, which showed that the mimetic peptide LPLGHIK might be used as a tumor vaccine in the prevention and treatment of tumor.

• YAKHAK HOEJI
• /
• v.52 no.6
• /
• pp.494-499
• /
• 2008

The role of antibody in the fungal infections is controversial. However, our previous reports showed a certain epitope in Candida albicans cell wall (CACW) induces protective antibody. A major problem is that the epitope isolation requires tremendous time with high cost. This aspect led us to investigate a simple way inducing protective antibodies against C. albicans. In the present study, we determined if $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glabrae Radix (a family of Leguminosae) has immunoadjuvant activity. Data displayed that the $18{\beta}$-GA suppressed proliferations of both T- and Blymphocytes at high concentrations, whereas below 20 ${\mu}M$ concentration the compound supported the proliferations. These observations indicate that $18{\beta}$-GA has immunoregulatory activity. Based on this observation, an immunoadjuvant effect was examined at the low concentration. Results from animal experiments showed that CACW combined with or without $18{\beta}$-GA produced the anti-C. albicans antiserum in mice. Nevertheless, the CACW combined with $18{\beta}$-GA formula only protected mice against disseminated candidiasis (P<0.05). These data implicate that $18{\beta}$-GA has immunoadjuvant activity, which may provoke the CACW antigen to induce protective antibody. Currently, we are investigating possible mechanism of how the $18{\beta}$-GA provokes such protective immunity against the disseminated disease.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.4
• /
• pp.621-629
• /
• 2021

Shigella flexneri is a facultative intracellular pathogen that causes bacillary dysentery in humans. Infection with S. flexneri can result in more than a million deaths yearly and most of the victims are children in developing countries. Therefore, identifying novel and unique drug targets against this pathogen is instrumental to overcome the problem of drug resistance to the antibiotics given to patients as the current therapy. In this study, a comparative analysis of the metabolic pathways of the host and pathogen was performed to identify this pathogen's essential enzymes for the survival and propose potential drug targets. First, we extracted the metabolic pathways of the host, Homo sapiens, and pathogen, S. flexneri, from the KEGG database. Next, we manually compared the pathways to categorize those that were exclusive to the pathogen. Further, all enzymes for the 26 unique pathways were extracted and submitted to the Geptop tool to identify essential enzymes for further screening in determining the feasibility of the therapeutic targets that were predicted and analyzed using PPI network analysis, subcellular localization, druggability testing, gene ontology and epitope mapping. Using these various criteria, we narrowed it down to prioritize 5 novel drug targets against S. flexneri and one vaccine drug targets against all strains of Shigella. Hence, we suggest the identified enzymes as the best putative drug targets for the effective treatment of S. flexneri.

• Parasites, Hosts and Diseases
• /
• v.57 no.1
• /
• pp.61-67
• /
• 2019

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

• The Journal of the Korea Contents Association
• /
• v.18 no.4
• /
• pp.99-113
• /
• 2018

Recently, global warming has widened the habitat of mosquitoes and infection chances for mosquito-borne diseases are increasing. Flavivirus is a typical mosquito-borne virus. Flaviviruses with a relatively high frequency of infection in Asian countries include Zika, Dengue, and Japanese encephalitis viruses. Although distinctive diagnosis of flaviviruses is required because the symptoms and therapeutic method differ, there is no diagnostic method that can distinguish them accurately yet. In this study, we propose distinctive diagnosis method of flaviviruses using informations and analysis tools constructed in bioinformatic databases. The envelope protein and non-structural protein 1 which are useful protein for the immuno-diagnostics of three flaviviruses were selected. Their homology was analyzed by multiple sequence alignments and epitope candidates consisting of 10-15 amino acids were selected. Finally two epitopes were suggested to be most useful by immunogenicity analysis and 3D structure prediction. These approaches and results are expected to be great value in the distinctive diagnosis of three flaviviruses with a high frequency of infection in Asian countries.

• Korean Journal of Microbiology
• /
• v.28 no.1
• /
• pp.13-18
• /
• 1990

A DNA sequence encoding the adr subtype preS2 region of hepatitis B virus envelope protein was fused to 5' end of lacZ gene yielding a plasmid pTSZ, in order to produce a preS2-$\beta$-galactosidase fusion protein. Serial deletions from 3' and 5' end of preS2 were constructed in plasmids, which were expressed and their antigenicities were examined with the monoclonal antibody H8. Deletions from amino and carboxy terminal to certain points did not affect the antigenicity, but the longer deletions destroyed the antigenicity. End points of deleted preS2 sequence were determined by DNA sequencing. As a result, each end of preS2 epitope was located in the region of amino acid residue 130-132 and 140-142, respectively. Residue 143 may be supplementary for antigenic epitope since the deletion from carboxy terminal to residue 143 revealed partial defect of antigenicity. In the interval of antigenic epitope the amino acid differences between adr and adw2 subtype occurred ar residue 130, 132, and 141. This result indicated that one or more of the three residues are responsible for the binding specificity of monoclonal antibody H8 to adr subtype preS2 fusion protein.

• IMMUNE NETWORK
• /
• v.21 no.5
• /
• pp.34.1-34.16
• /
• 2021

Sjögren's syndrome (SS) is an autoimmune disease characterized by dryness of the mouth and eyes. The glandular dysfunction in SS involves not only T cell-mediated destruction of the glands but also autoantibodies against the type 3 muscarinic acetylcholine receptor or aquaporin 5 (AQP5) that interfere with the secretion process. Studies on the breakage of tolerance and induction of autoantibodies to these autoantigens could benefit SS patients. To break tolerance, we utilized a PmE-L peptide derived from the AQP5-homologous aquaporin of Prevotella melaninogenica (PmAqp) that contained both a B cell "E" epitope and a T cell epitope. Repeated subcutaneous immunization of C57BL/6 mice with the PmE-L peptide efficiently induced the production of Abs against the "E" epitope of mouse/human AQP5 (AQP5E), and we aimed to characterize the antigen specificity, the sequences of AQP5E-specific B cell receptors, and salivary gland phenotypes of these mice. Sera containing anti-AQP5E IgG not only stained mouse Aqp5 expressed in the submandibular glands but also detected PmApq and PmE-L by immunoblotting, suggesting molecular mimicry. Characterization of the AQP5E-specific autoantibodies selected from the screening of phage display Ab libraries and mapping of the B cell receptor repertoires revealed that the AQP5E-specific B cells acquired the ability to bind to the Ag through cumulative somatic hypermutation. Importantly, animals with anti-AQP5E Abs had decreased salivary flow rates without immune cell infiltration into the salivary glands. This model will be useful for investigating the role of anti-AQP5 autoantibodies in glandular dysfunction in SS and testing new therapeutics targeting autoantibody production.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2005.04a
• /
• pp.294-295
• /
• 2005

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.713-714
• /
• 2000

Six monoclonal antibodies to human cardiac troponin I (hcTnI) were produced to eventually develop an immunosensor for acute myocardial infarction (AMI). For the characterization of these antibodies, a set of 11 different peptides covering selected ranges of the complete amino acid sequence of hcTnI was prepared and used for epitope mapping. Such analysis allowed to select an appropriate pair of antibodies that can form a sandwich type of immune complexes and was consequently used for an immunoassay.