• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.47-59
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• 2023

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4⁺ and CD8⁺ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4⁺ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8⁺ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4⁺ T-cell early priming.

• The Journal of Korean Society of Virology
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• v.27 no.2
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• pp.105-113
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• 1997

The truncated $E1_{192-283}$ and $E2_{384-649}$ genes of hepatitis C virus (HCV) linked to the gene for glutathione S-transferase (GST) were constructed and their expressions were analyzed. The $GST-E1_{192-283}$ fusion gene overexpressed the fusion protein in E. coli as a soluble form, while the $GST-E1_{192-383}$ plasmid did not express expected fusion protein. The purified $GST-E1_{192-283}$ fusion protein was efficiently cleaved by thrombin. More than 90% pure, HCV $E1_{192-283}$ protein was obtained by GST-agarose chromatography. The truncated $GST-E2_{384-649}$ fusion gene expressed the fusion protein mainly as an insoluble form, whereas the $GST-E2_{384-740}$ did not express the fusion protein. The truncated $GST-E1_{182-283}$ and $GST-E2_{384-649}$ fusion proteins reacted specifically with an HCV patient serum. In addition, mice immunized with either the purified $E1_{192-283}$ or $GST-E2_{384-649}$ proteins generated specific antibodies to each antigen. The results suggested that hydrophobic carboxyl portions of the E1 and E2 proteins might affect expression levels as well as the solubility of each fusion protein in bacteria. Also, the truncated E1 protein with Tyr-192 to Ser-283 contained antigenic epitope(s) which could be specifically recognized by an HCV patient serum.

• Animal cells and systems
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• v.5 no.3
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• pp.195-198
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• 2001

Hepatitis B virus (HBV) polymerase, which possesses the activities of terminal binding, DNA polymerase, reverse transcriptase and RNaseH, has been shown to accomplish viral DNA replication through a pregenomic intermediate. Because the HBV polymerase has not been purified, the expression of HBV polymerase was examined in an E. coli expression system that is under the regulation of arabinose operon. The expressed individual domain containing terminal binding protein, polymerase, or RNaseH turned out to be insoluble. The activities of those domains were not able to be recovered by denaturation and renaturation using urea or guanidine-HCI. The expressed reverse transcriptase containing the polymerase and RNaseH domains became extensively degraded, whereas the proteolysis was reduced in a Ion- mutant. These results indicate that Lon protease proteolyzes the HBV reverse transcriptase expressed in E. coli.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1769-1771
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• 2010

The envelope glycoprotein E2 of hepatitis C virus (HCV) binds to various cell surface receptors for viral infection. We performed biopanning against this protein and selected peptides from phage display peptide libraries. Two short peptides, pep7-1 and pep12-1, were selected and their ability to inhibit the infection process was investigated. When pep7-1 was present, the infectivity of HCV particles in cell culture was notably decreased. This decrease was demonstrated by Western blot analysis, immunofluorescence assay, and reverse transcription PCR assay. However, pep12-1 showed little inhibitory effect on HCV infection.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.304-304
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• 1999

• The Korean Nurse
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• v.15 no.4 s.84
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• pp.49-52
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• 1976

• Safe Food
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• v.3 no.2
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• pp.17-22
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• 2008

• Journal of Preventive Veterinary Medicine
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• v.41 no.3
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• pp.121-123
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• 2017

The hepatitis E virus (HEV) is a leading causative agent of acute hepatitis in humans. Zoonotic HEV strains have been isolated from several animal species, including pigs. New HEV variants have been recently isolated from camels in the Middle East. In the present study, fecal samples from fallow deer, formosan deer, alpaca, and guanaco were analyzed for the detection of HEV. One HEV strain was detected from guanaco, a species of camelids. The nucleotide sequence of guanaco HEV was identical to those of deer HEV-3 strains, which implied the cross-species transmission of HEV-3 from deer to guanaco.

• Annals of Clinical Neurophysiology
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• v.19 no.1
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• pp.50-53
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• 2017

An infection is less likely to elicit chronic inflammatory demyelinating polyneuropathy (CIDP) than Guillain-$Barr{\acute{e}}$ syndrome. We here report a case of acute-onset CIDP following hepatitis A virus infection and briefly comment on the potential mechanisms regarding the induction and chronicity of autoimmunity after a viral infection.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.41-46
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• 2014

Purpose: The spontaneous seroconversion rate of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) virus infection in children is lower than that in adults. However, few studies have investigated the rate of transition from the immune-tolerant to the early immune-clearance phase in children. Methods: From February 2000 to August 2011, we enrolled 133 children aged <18 years who had visited the Department of Pediatrics, Kyungpook National University Hospital. All subjects were in the immune-tolerant phase of HBeAg-positive CHB virus infection. The estimated transition rate into the early immune-clearance phase was calculated using the Kaplan-Meier method. Results: Among the 133 enrolled pediatric CHB virus infection patients in the HBeAg-positive immune-tolerant phase, only 21 children (15.8%) had converted to the early immune-clearance phase. The average age at entry into active hepatitis was $10.6{\pm}4.8$ years. The incidence of transition from the immune-tolerant to the early immune-clearance phase in these children was 1.7 episodes/100 patient-years. When analyzed by age, the estimated transition rate was 4.6%, 7.1%, and 28.0% for patients aged <6, 6-12, >12 years, respectively. Conclusion: In children with CHB virus infection, the estimated rate of entry into the early immune-clearance phase was 28.0% for patients aged 12-18 years, which was significantly higher than that observed for children aged <12 years (11.7%; p=0.001).