• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.406-413
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• 1993

This study was performed to produce monoclonal antibodies to the major polyhedral inclusion body (PIB) antigen of the occluded form of Hyphantria cunea nuclear polyhedrosis virus (HcNPV). PIB proteinS were purfied from the Spodoptera frugiperda cell infected with HcNPVs. Using the purified PIB protein, BALB/C mice were immunized 3 times with 2 weeks intervals. The spleen were removed and fused with Sp2/0-Ag14, mouse myeloma cells.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.490-496
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• 2017

Imatinib resistance has become a major clinical problem for chronic myeloid leukemia. The aim of the present study was to investigate the involvement of MEG3, a lncRNA, in imatinib resistance and demonstrate its underlying mechanisms. RNAs were extracted from CML patients' peripheral blood cells and human leukemic K562 cells, and the expression of MEG3 was measured by RT-qPCR. Cell proliferation and cell apoptosis were evaluated. Western blotting was used to measure the protein expression of several multidrug resistant transporters. Luciferase reporter assay was performed to determine the binding between MEG3 and miR-21. Our results showed that MEG3 was significantly decreased in imatinib-resistant CML patients and imatinib-resistant K562 cells. Overexpression of MEG3 in imatinib-resistant K562 cells markedly decreased cell proliferation, increased cell apoptosis, reversed imatinib resistance, and reduced the expression of MRP1, MDR1, and ABCG2. Interestingly, MEG3 binds to miR-21. MEG3 and miR-21 were negatively correlated in CML patients. In addition, miR-21 mimics reversed the phenotype of MEG3-overexpression in imatinib-resistant K562 cells. Taken together, MEG3 is involved in imatinib resistance in CML and possibly contributes to imatinib resistance through regulating miR-21, and subsequent cell proliferation, apoptosis and expression of multidrug resistant transporters.

• The Korean Journal of Cytopathology
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• v.11 no.2
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• pp.65-73
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• 2000

Cytologlc evaluation of cerebrospinal fluid(CSF) is an effective mean for diagnosing many disorders involving the central nervous systems(CNS). One of the most important reasons for cytologic examination of CSF is to detect metastatic or primary neoplasms of the CNS. We did a retrospective study of 1,438 CSF specimens obtained between 1992 and 1996. A total of 1,205 adult and 233 pediatric CSF specimens from 947 patients were accessed at the Department of Pathology of Seoul National University Hospital and Children's Hospital, respectively. Among 1,438 CSF cytology specimens, 169 cases(11.8%, 77 patients) including 135 adult cases(59 patients) and 34 pediatric cases(18 patients) were positive for malignant cells. Diagnoses included 50 metastatic carcinomas(adult, 60; pediatric, 0); 46 malignant lymphomas(adult, 44; pediatric, 2); 21 leukemias(adult, 20; pediatric, 1); 4 retinoblastomas(adult, 0; pediatric 4); 2 rhabdomyosarcomas(adult, 0; pediatric, 2); 1 multiple myeloma(adult, 1; pediatric, 0), and 35 primary CNS neoplasms(adult, 10; pediatric, 25). The most commonly identified metastatic carcinomas in adults were adenocarcinoma. Their primary sites were the lung, gastrointestinal tract, and breast in order of frequency. The most common primary CNS neoplasm in children was medulloblastoma.

• Korean Journal of Poultry Science
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• v.19 no.1
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• pp.13-16
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• 1992

Avian infectious bronchitis virus(IBV) was propagated in SPF eggs and purified by sucrose density gradient centrifugation in order to prepare the antigen. Several fusions were made between mouse myeloma cells and spleen cells from BALB/c mouse immunized with IBV antigen and two hybridoma clones producing specific monoclonal antibody(MCA) against the IBV were established. The MCAs were classified as IgG type and revealed no neutralizing and hemagglutination inhibition activity. Using the MCA IBV antigen was detected by IFA method in tracheal smears made from chickens infected with IBV during the experimental period of 10 days.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.93-93
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• 1997

Analysis of protein is often frustrated by the inability to isolate large amounts of purified protein from a native source. To overcome this problem, fusion protein expression systems such as pGEX system have been widely used. Using pGEX system, the desired protein could be easily obtained in a large amount in E. coli, and then the fusion protein could be used for the study of the function of the given protein. To analyze and purify the GST fusion protein, anti-GST antibody could be used as one of the system of choice. However, the production and characterization of monoclonal anti-GST antibody has not been studied extensively yet. To produce monoclonal anti-GST antibody, GST was purified from E. coli transformed with pGEX-cs, one of the pGEX system and was used as an antigen. The monoclonal antibody was produced by fusion of the immunized spleen cells with SP2-0 myeloma cells. The antibody was characterized by ELISA, western blotting, etc. The monoclonal antibody produced in this study (mAb-GSTA) showed strong and specific immunoreactivity against not only GST but also GST-fusion proteins. Also, mAb-GSTA was successfully used for the immunoaffinity purification of the GST ${\beta}$-Rc.-third intracellular-loop fusion protein. The results of the present study suggest that mAb-GSTA may be used for the identification and purification of GST fusion proteins.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.414-419
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• 1997

In order to develop an enzyme-linked immunosorbent assay (ELISA) for deoxynivalenol (DON) in com, we produced a specific monocl- onal antibody and established ELISA conditions. After the spleen cells from mice immunized with DON-bovine serum albumin conjugate were fused with S$_{p}$2/0 myeloma cells, a hybridoma cell 3G7 producing anti-DON antibody was screened by ELISA. From the standard curve of competitive direct ELISA (cdELISA) using 3G7 monoclonal antibody and DON-HRP conjugate, the detection range of DON showed 3-3,000 ng/ml (ppb). The monoclonal antibody showed some cross-reactivities against DON analogues such as 15 acetyl-DON (110%), nivalenol (5.0%), 3 acetyl-DON (1.7%), fusarenon-x (0.72%), and T-2 (0.59%). When the cdELISA was applied to the spiked coms after extracting with 60% methanol and diluting 5- fold with washing buffer, the assay recoveries of DON were 313, 163, 106, and 88.9% (av., 168%) in the levels of 200, 600, 2,000, and 6,000ng/g, respectively. For the quantitation of DON in coms, 30 samples kept under two different storage conditions of cold and room temperature were assayed by cdELISA. The mean detection concentrations were 595 (detection range, 0-2,750) and 2,448 (detection range, 0-4,500) ppb, respectively.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.446-446
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• 2000

Specific polyclonal and/or monoclonal antibodies (MAbs) to immunoglobulins (Igs) and their subunits have proved to be valuable tools in immunological research and in immunological assays. In this study, we developed and characterized MAbs against flounder serum Igs. To obtain the pure flounder serum Igs, mouse IgG (mIgG) was immunized to flounder. Flounder Igs were purified by using mIgG-agarose affinity column chromatography. The structure of purified flounder Ig was observed, on denatured SDS-PAGE, to be composed of two heavy chains (77 and 72 kd) and two light chains (28 and 26 kd). MAbs were produced by fusion of myeloma cells (SP2/0) with Balb/c mouse spleen cells previously primed with the flounder Igs. Finally, three hybridoma clones, FIM 511, FIM 519 and FIM 562 were established to recognize both 2 heavy chains, 26 kd of light chain and 28 kd of light chain, respectively. On the other hand, the flounder immune sera collected on the weekly basis were tested on ELISA and immunoblot analysis whether boosting effect is present in flounder humoral immune system. As a result, the secondary immune response in flounder was ascertained on ELISA, but not on immunoblot analysis. Further, we observed an alteration of serum protein levels following immunization. Our MAbs and basic information on flounder humoral immune system obtained in this study will be helpful to control and monitor the efficiency of fish vaccines and therapeutic process of flounder diseases.

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.71-80
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• 1996

The envelope of the rnannnalian oocyte plays crucial roles in sperm-oocyte interactions by providing sperm receptors, inducing acrosome reaction and preventing polyspermy. Understanding of properties of the zona pellucida (ZP) is essential for the artificial control of fertility in mammals. This study was carried out to produce and characterize monoclonal antibodies(MAbs) to porcine ZP proteins. Approximately 8,000 ZPs were obtained from follicular oocytes and dissolved in 40$\mu$l of double distilled water. Following immunization through foot-pad injections of Balb /c mice with a ZP solution, the popliteal lymph nodes were recovered at 2 weeks after the last injection. Hybridoma cell lines were established by fusing lymph node cells with P3X63 myeloma cells through selection using HAT medium and screening by immunofluorescence(IF) microscopy on the isolated ZP. Secreted MAbs were found to consist k chains and different heavy chains as evidenced by isotyping. Some of the MAbs demonstrated high specificity to the ZP in IF. The Mabs also showed positive cross reactivity with hamster and mouse eggs, while negative with bovine eggs. The results implicate that the MAbs can be used not only for identification of functional regions of the ZP, but also for elucidation of mechanisms involved in fertilization of mammals. The MAbs will provide basic information on biochemical anatomy of the ZP as well as can be candidates for the future contraceptive vaccines.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.205-214
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• 1993

The monoclonal antibody to chloramphenicol(CAP) was produced to develop an enzyme-linked immunosorbent assay(ELISA) for residual CAP. An immunogen(CAP-BSA) was prepared by immunogen, antibody titer was measured by indirect ELISA. Spleen cells form the immunized mouse were fused with SP2/OAg14 myeloma cells. Among hybridomas selected in HAT media, 6 clones shown high antibody titer to CAP were subjected to cloning by limit dilution, and all of the monoclonal antibodies(MCA1, 2, 3, 4, 5, 7 and 9) produced by each clone were identified as IgG1 by ELISA isotyping analysis. Competitive ELISA condition was established by using the purified monoclonal antibody MCA1 as primary antibody and CAP-HSA conjugate as coating antigen. Standard curve of CAP(n=28) showed that the lowest detection limit of CAP is 20ng/ml level. The cross-reactivities of the 6 monoclonal antibodies showed that CAP sodium succinate. CAP base, P-nitrophenol, and p-nitrobenzyl alcohol were 89∼178, 0.050∼2.237, 0.056∼0.794 and 0.013∼7.939%, respectively. No cross-reactivities were observed with phenylalanine, tyrosine, glutamine, thiamphenicol, neomycin, streptomycin, gentamicin, sulfamethazine, sulfathiazole, chlortetracycline and p-aminobenzoic acid.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1425-1428
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• 2013

The proteasome, which is highly evolutionarily conserved, is responsible for the degradation of most short-lived proteins in cells. Small-molecule inhibitors targeting the proteasome's degradative activity have been extensively developed as lead compounds for various human diseases. An exemplified molecule is bortezomib, which was approved by FDA in 2003 for the treatment of multiple myeloma. Here, using transiently and stably expressed N-end rule model substrates in mammalian cells, we evaluated and identified that salinosporamide A and salinosporamide B effectively inhibited the proteasomal degradation. Considering that a variety of proteasome substrates are implicated in the pathogenesis of many diseases, they have the potential to be clinically applicable as therapeutic agents.