• Korean Journal of Microbiology
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• v.47 no.4
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• pp.342-347
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• 2011

T cells play a key role in viral infection. However, in patients with chronic hepatitis C virus (HCV) infection, HCV-specific T cells are dysfunctional and impaired in the liver, which is the primary site for HCV replication. There are multiple potential mechanisms for HCV-specific T cell dysfunction including induction of immune inhibitory pathways (program death-1; PD-1, cytotoxic t lymphocyte associated antigen-4; CTLA-4) and immune tolerance induced specific for the liver. However, the interaction between hepatocytes and HCV-specific CD8 T cells has not clearly established. In this study, we confirmed huh (human hepatoma) 7.5 cells expressing HLA (human leukocyte antigen) A2 presented antigen to activate HCV-specific CD8 T cells in HLA A2-restricted manner and expression of PD-L (program death ligand) 1 on huh7.5 cells reduced HCV-specific CD8 T cell activation, suggesting an immune modulatory activity. Loss of HCV-specific tetramer responses following antigenic stimulation correlated with increased caspase-3 activity. In addition, PD-L1 on huh7.5 cells rescued HCV-specific CD8 T cells from apoptosis. Our results suggest that the interaction between PD-L1 and PD-1 can recover the function of HCV-specific CD8 T cells in the liver, which could be applied in therapy of HCV chronic infection.

• Pediatric Infection and Vaccine
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• v.4 no.1
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• pp.106-115
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• 1997

Objective : To evaluate the immunogenicity and safety afforded by the HG-II$^{(R)}$ recombinant hepatitis B vaccine given to healthy neonates and children and to find the influence of preceding BCG vaccination on immunogenicity. Methods : Three doses of recombinant hepatitis B vaccine with a dose of $10{\mu}g$ were given at birth, 1 and 6 months of age. This study was conducted in three hospitals (Gyeongsang National University Hospital(Group A), Kangnam General Hospital(Group B) and Younsei University Hospital(Group C)) from April, 1995 to June, 1996. Group A and Group B received 2nd dose of hepatitis B vaccine at 1 week after and before BCG vaccine, respectively. Antibidy levels, at 1 month after the 3rd dose of hepatitis B vaccine were determined by a radioimmunoassay. Results : 1) One hundred four infants and ten children were enrolled : 55 infants and 43 infants received 2nd dose of hepatitis B vaccine at 1 week after( After BCG Group) and before BCG vaccine(Before BCG Group), respectively. 2) The seropositive rate was 99.1%, and geometric mean anti-HBs titer was 131.2mIU/ml. 3) The geometric mean titers were 105.5mIU/ml and 162.8mIU/ml in After BCG and Before BCG Group, respectively(p<0.025). 4) Among 359 episodes of vaccination, the occurrence of systemic and local side reaction were reported in 7.8% and 1.4%, respectively. Conclusion : Recombinant hepatitis B vaccine(HG-II$^{(R)}$))was highly immunogenic and safe. The significantly lower geometric mean antibody titer in the BCG preceding group was observed. Well-designed controlled study with the large number of sample size will be required to show the influence of preceding BCG vaccination.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.261-266
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• 2018

To determine the clinical utility of an immunoblot test and RT-PCR-hybridization test, 160 samples from patients with a chronic HCV infection were analyzed by two tests. A total of 133 samples out of 150 positive samples were positive by RT-PCR-hybridization. The true positive rate of the immunoblot tests and the concordance rate of the two tests was 88.6% and 89.3%, respectively. Serotyping and genotyping were performed to evaluate the distribution of the HCV subtype in Korean isolates. HCV serotypes 1 and 2, and genotypes 1b and 2a were the most common sources of HCV infections in this group. In 49 cases studied with the serotypes and genotypes, serotypes 1 and 2 were 57.1% and 42.9%, respectively. Genotypes 1b, 1b/2b, 2a, 2a/2c, and 2b were 51.0%, 2.0%, 34.7%, 8.2%, and 4.1%, respectively. This study shows that immunoblot tests are more useful for screening HCV infections. The RT-PCR-hybridization test confirmed the HCV infection in patients with positive immunoblot test results. The serotype test is preferred over the genotype test for monitoring the progression or response to treatment. On the other hand, there were no significant differences in the response to an ${\alpha}$-interferon treatment of HCV infection with serotype type 1 or type 2 in Korea.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.321-326
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• 1994

Korean isolate, porcine epidemic diarrhea virus (KPEDV-9) was adapted through serial passages in vero cell. The viral yield reached up to $10^{5-6}$ $TCID_{50}/ml$ at the passage level of 90th. The cell adapted virus was characterized through genetic and morphological examinations. The RNA extracted from virus infected cell revealed the presence of RNA band with molecular size of >20Kb. The electron microscopic examination on purified virus showed the pleomorphic appearance of enveloped particles with 5-10nm surface projections, which fit with the shape of coronavirus. The etiological survey on swine diarrhea by immunofluorescence test(FA) indicated 17.5% positive rate on the PEDV infection. In addition, the incidence were detected both in piglets within two weeks old as well as fattening pigs. Serological survey by ELISA revealed the overall 45% positive result, thus, indicating the PEDV infection are widespread throughout this country.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.169-177
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• 1999

Purpose: To evaluate the efficacy of interferon alpha therapy with or without prednisolone in children with chronic hepatitis B. Methods: Twenty-eight children (22 boys, 6 girls, mean age 130 months) had seropositive results for HBsAg, HBeAg and HBV DNA; 11 had chronic persistent hepatitis and 17 had chronic active hepatitis. The patients were divided into two groups depending upon their inflammatory activity on liver biopsy, pretreatment serum ALT levels and HBV DNA levels. Fourteen children (group 1: chronic active hepatitis, ALT ${\geq}$ 100 IU/L and HBV DNA ${\leq}$ 100 pg/$300\;{\mu}L$) received interferon alpha 2a 5 $MU/m^2$ of body surface three times weekly for 6 months. Fourteen children (group 2: chronic persistent hepatitis or chronic active hepatitis with ALT < 100 IU/L or HBV DNA > 100 pg/$300\;{\mu}L$) received prednisolone in decreasing daily doses of 60 mg/$m^2$, 40 mg/$m^2$, and 20 mg/$m^2$, each for 2 weeks, followed after 2 weeks by interferon alpha 2a on the same schedule. At the end of therapy, 3 end points were analyzed: HBeAg seroconversion, serum ALT normalization rate and clearance of serum HBV DNA. Results: At the end of treatment, HBe antigen-to antibody seroconversion was higher but not more significant in group 1 than group 2 (71.4% vs. 50.0%). Only one patient in group 2 who lost HBeAg, also cleared HBsAg. ALT normalization was similar in both groups (64.3% in group 1 vs. 55.6% in group 2). Clearance of serum HBV DNA was observed in 78.6% of patients in group 1 and 64.3% in group 2, but no significant differences. Complete response was similarly achieved in both groups (57.1% in group 1 vs. 50.0% in group 2). Interferon alpha therapy with prednisolone priming was well tolerated and all children finished therapy. Conclusion: The combined therapy with prednisolone followed by interferon alpha may be safe and effective in inducing a serological and biochemical remission of the disease in approximately 50% of children with chronic hepatitis B and with a high level of viral replication and less active disease. However, a controlled study should be performed to confirm these results.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.280-287
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• 2015

Probiotics are microbial food supplements or components of bacteria which have traditionally been added to dairy foods for extra health boost. Our aim was to evaluate the hepatoprotective effect of Bifidobacterium adolescentis SPM0212 as probiotics, which we previously found has potential anti-hepatitis B virus activity. The study was conducted using Wistar albino rats and probiotics were treated orally for 9 days consecutively and acute liver injury was induced by administration of carbon tetrachloride ($CCl_4$) on the 7th and 8th days. Liver damage was assessed by quantifying serum activities of glutamate oxaloacetate transaminase (SGOT) and glutamate pyruvate transaminase (SGPT), as well as by histopathological examination. B. adolescentis SPM0212 significantly prevented the elevation of SGOT and SGPT levels, and reduced the negative effect of $CCl_4$ on body and organ weights. Histopathological study revealed the livers of the carbon tetrachloride treated rats showed almost complete loss of normal hepatocyte architecture, but that rats treated with B. adolescentis SPM0212 showed minimal damage and normal hepatocyte architecture. Our results suggest that B. adolescentis SPM0212 be considered useful probiotics for protecting the liver from xenobiotics and hepatitis B virus, and as well as useful as a functional food for maintaining human health.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.45-53
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• 1999

We examined the hepatitis G virus infections among 227 Koreans who were healthy or were suspected of hepatitis and determined the phylogenetic relationship based on a part of the NS-5 region of 5 positive samples. Viral RNA was extracted from sera and cDNA was synthesized and subsequently amplified by RT-PCR (reverse transcription-polymerase chain reaction) or RT-nested PCR using random hexamer and NS-5 specific primers (470-20-1-77F, 470-20-1-211R, HGVNESTFO, HGVNESTRE). Five positives were found to belong to samples of patients showing symptoms of viral hepatitis. Primers used for PCR or nested PCR were derived from the NS-5 region. On the other hand, no amplification was detected using primers derived from the 5'-NCR (G-146F, G-401R). We performed TA cloning and sequencing of 5 amplified fragments, and their sequences were compared with those of foreign isolates of HGV. The phylogenetic analysis using MegAlign programme of DNAstar has shown that the Korean isolates are clustered on the phylogenetic tree. In summary, we confirmed the hepatitis G virus infection in 5 cases out of 12 patients showing the symptoms of viral hepatitis. The phylogenetic analysis of sequences of 5 amplified fragments showed that their relations to each other were closer than those to the foreign HGV isolates reported.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.269-275
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• 1993

Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained Tissue distribution of RHDV in rabbits were examined by immunofluorescence and ABC methods. Tissues including liver, spleen, kidneys, lungs and brain were frozen, cut in a crycut, and fixed in 10% buffered formalin, embedded in paraplast, and cut $5{\sim}7{\mu}m$ thickness. Sections were immunostained with primary antiserum and conjugated second antibodies as recommended by manufacturer. None of the cultures tested showed virus-induced phenomena. Immunoreactive products were commonly found in the liver, in some cases there were also positive staining in the spleen and kidneys. Other organs showed weak or insignificant immunoreactions. By ABC method on the formalin-fixed, paraffin-embedded liver tissues, strong immunoreactivity was found in the periportal triad lesions and peripheral lesions of the hepatic lobules. Immunoreactive products showed diffuse fine granular in the cytoplasm of hepatocytes and sinusoidal cells. In some cells, immunoproducts marginate at the periphery of the cells. The intensive staining of the cytoplasm of infected cells allowed their exact differentiation from surrounding uninfected cells. The positive area involved coincided with histopathological lesion on serial liver sections. In conclusion, liver was proved to be a consistent target organ in RHD, and the immunoperoxidase method in the section of formalin-fixed, paraffin-embedded hepatic tissue could be broadly used for the routine diagnosis of the disease.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.186-194
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• 2005

Purpose : Hepatitis A viral infections have been continued after re-emerging since mid 1990s in Korea. The incidence of this disease has been increased in young adults younger than 30 years of age since 2000. This study was performed to evaluate the prevalence of antibody to hepatitis A in Korea(two regions; Incheon and Changwon) in 2005, and was compared with the results of similar studies in mid 1990s. Methods : The study was conducted from January 2005 to June 2005, and consisted of 1,301 enrolled subjects, neonates to 50 years old, living in Incheon and Changwon in Korea. All sera were frozen and stored at $-70^{\circ}C$ until assayed. Anti-HAV IgG antibodies were measured by microparticle enzyme immunoassay(HAVAB, Abbott Lab., IL, USA). Results : The prevalence of anti-HAV IgG was 61.1% in infants younger than 1 year old, 30.5% in 1~5 years, 14.6% in 6~10 years, 1.7% in 11~15 years, 6.5% in 16~20 years, 36.6%in 21~30 years, 77.5% in 31~40 years, and 99.8% in 41~50 years. Statistical differences were not found between male and female, but there was statistical difference in 6~10 years old age group between the two areas. Conclusion : Our study indicate that the prevalence of antihepatitis A virus antibody has shifted from children to old adolescents and young adults. This result suggests that the risk of sudden outbreaks or increasing incidence of hepatitis A viral infections in young adults may be expected in our society. The preventive strategies of hepatitis A including vaccination should be prepared.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.8 no.2
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• pp.213-221
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• 2005

Purpose: Hemophagocytic syndrome (HPS) is characterized by persistent high fever, hepatosplenomegaly, cytopenias, hypertriglyceridemia, and/or hypofibrinogenemia. Hepatic manifestations including overt hepatic failure and fulminant hepatitis are common in HPS. Liver transplantation (LT) should be considered in a case of fulminant hepatitis by other than HPS, but LT is contraindicated and complete cure is possible by chemotherapy in HPS. Therefore, we conducted this study to define the characteristics of HPS presenting as severe acute hepatitis. Methods: Among the total of 23 patients diagnosed as HPS by bone marrow examination between 1994 and 2005 in Asan Medical Center, 11 cases presented as severe acute hepatitis were enrolled in this study. We analyzed the clinical features, laboratory findings and outcome retrospectively. Results: Seven (64%) of the 11 children with HPS and hepatitis were referred to pediatric gastroenterologist at first. The mean age of onset was 50 months. There was no case with family history of primary HPS. Epstein-Barr virus was positive in 4, and herpes Simplex virus was positive simultaneously in 1 case. As the presenting symptoms and signs, fever was present in 10, hepatosplenomagaly was noted in all and jaundice in 10. Anemia was observed in 10, thrombocytopenia in 10, leukopenia in 8, hypertriglyceridemia in 9, hypofibrinogenemia in 8 and hyperferritinemia in 7 cases, respectively. Nine children received chemotherapy including etopside. The overall mortality rate was 72% (8/11). Conclusion: HPS, which needs chemotherapy, should be considered as a cause of severe acute hepatitis especially when accompanied with prolonged high fever and cytopenias.