• IMMUNE NETWORK
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• v.3 no.4
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• pp.281-286
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• 2003

Background: Hepatitis B virus (HBV) infection is one of the worldwide public health problem affecting about 300 million people. The envelope protein of HBV consists of three components known as preS1, preS2, and S antigen. According to the recent study, anti-HBs Ab showed effective neutralization ability against HBV from chronic hepatitis B and liver transplant patients, suggesting the possible development of therapeutic antibody. Methods: Spleen cells immunized with S antigen of HBV were fused with myeloma cell line to obtain HBsAg specific monoclonal antibodies. High affinity antibodies against HBsAg (adr, ad and ay type) were selected by competitive ELISA method. Nucleotide sequence of the variable regions of monoclonal antibodies was analyzed by RT-PCR followed by conventional sequencing method. Results: We produced 14 murine monoclonal antibodies which recognize S antigen of HBV. Two of them, A9-11 and C6-9 showed the highest affinity. The sequence analysis of A9-11 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain I (B) and light chain lambda 1, respectively. Likewise, the sequence analysis of C6-9 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain II (B) and light chain kappa 1, respectively. Neutralization assay showed that A9-11 and C6-9 effectively neutralize the HBV infection. Conclusion: These results suggest that A9-11 and C6-9 mouse monoclonal antibodies can be used for the development of therapeutic antibody for HBV infection.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1376-1383
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• 2018

The hepatitis B virus (HBV) envelope contains small (S), middle (M), and large (L) proteins. PreS1 of the L protein contains a receptor-binding motif crucial for HBV infection. This motif is highly conserved among 10 HBV genotypes (A-J), making it a potential target for the prevention of HBV infection. In this study, we successfully generated a neutralizing human monoclonal antibody (mAb), 1A8 (IgG1), that recognizes the receptor-binding motif of preS1 using a phage-displayed human synthetic Fab library. Analysis of the antigen-binding activity of 1A8 for different genotypes indicated that it can specifically bind to the preS1 of major HBV genotypes (A-D). Based on Bio-Layer interferometry, the affinity ($K_D$) of 1A8 for the preS1 of genotype C was 3.55 nM. 1A8 immunoprecipitated the hepatitis B virions of genotypes C and D. In an in vitro neutralization assay using HepG2 cells overexpressing the cellular receptor sodium taurocholate cotransporting polypeptide, 1A8 effectively neutralized HBV infection with genotype D. Taken together, the results suggest that 1A8 may neutralize the four HBV genotypes. Considering that genotypes A-D are most prevalent, 1A8 may be a neutralizing human mAb with promising potential in the prevention and treatment of HBV infection.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.374-387
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• 1997

The purpose of this study was to examine the distribution of lymphocyte populations in normal, reversibly inflamed and irreversibly inflamed human dental pulp tissues using flow cytometry. Flow cytometry, with specific antibody and fluorochrome reagent allows us to know cellular properties of hematolymphoid cells by measuring fluorescence of stained cells. Before extirpation of pulps in routine endodontic treatment, the clinical diagnosis were performed by symptom. The extirpated pulp tissues were divided into normal pulp group (N=5), reversible pulpit is group(N=10) and irreversible pulpitis group(N=7). The specimen was placed into RPMI 1640 medium, minced into small pieces, and then digested in medium with collagenase. The cell suspension was resuspended in PBS for monoclonal antibody staining of T lymhocytes(CD3+), B lymphocytes (CD19+), T helper cell (CD4+) and T supressor cell (CD8+). The percentages of cells were counted by FACStar(BD) flow cytometer. Following results were obtained; 1. In the most normal and inflamed pulps, the percentages of T lymphocyte, B lymphocytes, T helper cell and T suppressor/cytotoxic cell were less than 1 % in total counted pulpal cells. 2. The higher percentages of T, B, T helper and T suppressor cells were observed in irreversible pulpitis group as compared with the normal pulp and reversible pulpitis group but the differences between groups were not statistically significant (p>0.05). 3. The percentages of T helper cells (CD4 + cells) were greater than that of T suppressor/cytotoxic cells (CD8 + cells) in the inflamed pulps.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.515-519
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• 2007

Rapid immunochromatographic assay (ICA) kits were developed using flagella-specific monoclonal antibodies (MAbs) and rabbit polyclonal antibodies for screening Listeria spp. in food. The establishment of different formats, MAb 2B1 as capture antibody and MAb 7A3 or rabbit polyclonal antibodies as detector antibody, was compared. The 2 formats of the ICA kit were shown to have specific reactions with Listeria and no cross-reactivity with any of the non-Listeria including Escherichia coli O157:H7 and Salmonella enteritidis. The detection limits of the ICA kit using the combination of gold-labeled MAb 7A3 and MAb 2B1 showed $1{\times}10^5$ and $1{\times}10^6\;CFU/0.1\;mL$ at 22 and $30^{\circ}C$, respectively. The other format of the ICA kit using the combination of gold-labeled rabbit polyclonal antibodies and MAb 2B1 showed $1{\times}10^6\;CFU/0.1\;mL$ at $22^{\circ}C$ but weak signal at 30 culture. The format utilizing MAb was more sensitive than the one using polyclonal antibodies for capture antibody. Samples contaminated with L. monocytogenes 4b culture (9-10, 5-6, and 1-2 CFU/mL) on pork and pasteurized milk were confirmed as positive results. Current data suggests that this ICA kit is a rapid, simple and effective tool to screen for Listeria spp. in food.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.719-727
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• 2011

Botulism is a neuroparalytic disease caused by Clostridium botulinum, which produces seven (A-G) antigenically diverse neurotoxins (BoNTs). BoNTs are the most poisonous substances known to humans, with a median lethal dose ($LD_{50}$) of approximately 1 ng/kg of body weight. Owing to their extreme potency and lethality, they have the potential to be used as a bioterrorism agent. The mouse bioassay is the gold standard for the detection of botulinum neurotoxins; however, it requires at least 3-4 days for completion. Attempts have been made to develop an ELISA-based detection system, which is potentially an easier and more rapid method of botulinum neurotoxin detection. The present study was designed using a synthetic gene approach. The synthetic gene encoding the catalytic domain of BoNT serotype B from amino acids 1-450 was constructed with PCR overlapping primers (BoNT/B LC), cloned in a pQE30 UA vector, and expressed in an E. coli M15 host system. Recombinant protein production was optimized at 0.5 mM IPTG final concentration, 4 h post induction, resulting in a maximum yield of recombinant proteins. The immunogenic nature of the recombinant BoNT/B LC protein was evaluated by ELISA. Antibodies were raised in BALB/c mice using various adjuvants. A significant rise in antibody titer (p<0.05) was observed in the Alum group, followed by the Titermax Classic group, Freund's adjuvant, and the Titermax Gold group. These developed high-titer antibodies may prove useful for the detection of botulinum neurotoxins in food and clinical samples.

• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.1-7
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• 1973

It was found that the diapause in the silkworm egg is induced by the action of the diapause hormone secreted from the suboesophageal ganglion, and "esterase A" affects protein metabolism in oocyte and egg. In this connection, some changes in protein metabolism of silkworm egg according to embryonic developments could give some information on the diapause, using Ouchterlony Test. Antigenicity of the protein of silkworm egg was detected through antigen-antibody interaction among the extracts of rabbit blood. Furthermore, existence of the specific antigen was also detected according to embryonic development, using the adsorption test. The results were obtained as follows: 1 Detection of antigenicity The antigenicity of silkworm egg was ascertained by inoculating it into a rabbit, but positive results were shown in most of the silkworm eggs tested, whereas the antibody specific to a certain antigen was not detected. 2. Detection of the common antigen It was demonstrated that most of the antigen could incite the common antibodies, but the specific antibody formation was not detected in a few antigens, even though the nonspecific antibody formation was displayed. 3. Detection of the specific antigen It is suggested that there are the specific antigens detectable in each treated eggs by the adsorption test.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.469-472
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• 2003

A method that effectively precipitates capsular polysaccharide of Haemophilus influenzae type b (polyribosylribitol phosphate, PRP) conjugated to tetanus toxoid (TT), PRP TT in a liquid vaccine has been developed to measure free PRP present in TT-conjugate vaccine. The method involves adding anti-TT antibody and ammonium sulfate to precipitate PRP-TT conjugate and measuring free PRP in tile supernatant. This new method provides a complete precipitation of the total PRP-TT, and provides an accurate and reproducible measurements of free PRP. The accuracy of the assay was confirmed by spiking known amounts of unconjugated PRP to PRP-TT conjugate, and the new method was found to have no effect on free PRP while precipitating PRP-TT. The published acid precipitation method did not produce reproducible results due to incomplete precipitation of PRP-TT, especially when the vaccine is formulated in a salt-buffered solution.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.87-91
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• 1990

Development of a solid-phase chemiluminescence immunoassay for the detection of progesterone in serum extract was described. The chemiluminescence immunoassay was establised utilizing anti-progesterone monoclonal antibody that coated on polystyrene tubes and progesterone-ABEI conjugate as tracer. The light yield generated from antibody bound conjugate was counted on clinilumat luminometer by oxidation with microperoxidase and peroxide. The chemiluminescence immunoassay was high specific and accurate and detects as little as 3.9ng/ml of progesterone. The intra-assay CV ranged from 6% to 11.5% and inter-assay CV ranged from 13.6% to 18.7%. This assay system was good correlated with conventional kit radioimmunoassay system (r=0.98).

• YAKHAK HOEJI
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• v.31 no.5
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• pp.253-265
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• 1987

To develop hybridomas secreting monoclonal antibodies to be used as unlimited sources of reagents indispensable for the diagnosis and treatement of leukemic malignancy, a monoclonal antibody was generated to human pre-T leukemia cells (Jurkat). Hybridomas were produced against Jurkat cell line by fusing spleen cells from hyperimmunized mice with murine plasmacytoma cells (P3$\times$63Ag8. V653). One monoclonal antibody derived from this fusion, designated DMJ-2 was reactive with T-cell lines (Jurkat, Molt-4 and RPMI-8402) and normal peripheral E-rosette forming T cells, but unreactive with B-cell lines (Daudi, Nalm-6) and non-T, non-B cell line (K562). Conclusively DMJ-2 reactive with mature and immature T-lineage lymphoid cells.

• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.578-584
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• 2018

Background: Accurate, rapid, and cost-effective screening tests for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be useful in laboratories that cannot afford automated chemiluminescent immunoassays (CLIAs). We evaluated the diagnostic performance of a novel rapid automated fluorescent lateral flow immunoassay (LFIA). Methods: A fluorescent LFIA using a small bench-top fluorescence reader, Automated Fluorescent Immunoassay System (AFIAS; Boditech Med Inc., Chuncheon, Korea), was developed for qualitative detection of hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to HCV (anti-HCV) within 20 minutes. We compared the diagnostic performance of AFIAS with that of automated CLIAs-Elecsys (Roche Diagnostics GmbH, Penzberg, Germany) and ARCHITECT (Abbott Laboratories, Abbott Park, IL, USA)-using 20 seroconversion panels and 3,500 clinical serum samples. Results: Evaluation with the seroconversion panels demonstrated that AFIAS had adequate sensitivity for HBsAg and anti-HCV detection. From the clinical samples, AFIAS sensitivity and specificity were 99.8% and 99.3% for the HBsAg test, 100.0% and 100.0% for the anti-HBs test, and 98.8% and 99.1% for the anti-HCV test, respectively. Its agreement rates with the Elecsys HBsAg, anti-HBs, and anti-HCV detection assays were 99.4%, 100.0%, and 99.0%, respectively. AFIAS detected all samples with HBsAg genotypes A-F and H and anti-HCV genotypes 1, 1a, 1b, 2a, 2b, 4, and 6. Cross-reactivity with other infections was not observed. Conclusions: The AFIAS HBsAg, anti-HBs, and anti-HCV tests demonstrated diagnostic performance equivalent to current automated CLIAs. AFIAS could be used for a large-scale HBV or HCV screening in low-resource laboratories or low-to middle-income areas.