In this study, three expression vectors encoding unmodified glycoproteins E1 and E2 from H77 (1a), Hebei (1b) and JFH1 (2a) strains were constructed to form pVRC-H77-E1E2, pVRC-HeBei-E1E2 and pVRC-JFH1-E1E2 expressing constructs. The protein expression was confirmed by immunofluorescene assay(IFA) and Western blot. The Lentiviral vector has the ability to package the cellular membrane into pseudo-particles. The plasmid expressing HCV E1-E2 glycoproteins in native form was co-transfected into 293FT cells with a lentiviral packaging plasmid (pHR'CMV delta R8.2)and a self-inactivated (SIN) transfer plasmid (pCS-CG) containing a reporter EGFP gene to produce infectious HCV pseudo-particles(pp). Flow cytometry assays showed that the HCVpp could infect Huh7 and Huh7-CD81, and the infectivity in Huh7-CD81 was about 2-3 times higher than that in Huh7 cells. Meanwhile, HCVpp could neither infect non-liver cells, for example, the 293 cells, nor HepG2 cell . Titration of HCVpp by p24 ELISA assay or infection assay showed that this HCVpp may contain 5-25 ng/mL p24 or 10(4)-10(5) TU (transducing unit)/ ml. An in vitro HCV neutralizing assays based on HCVpp (1a, 1b, 2a) were then established using AP33, a monoclone antibody with cross-neutralizing ability to different HCV strains. The neutralizing ability of the antibodies from HCV infected patients was further studied with this HCVpp system. In summary, three kinds of HCVpp (1a, 1b, 2a subtype) were successfully developed; In vitro HCV neutralizing assays based on HCVpp and SIN lentiviral system were established. This system paves a way for characterization of early steps of HCV infection (host tropisms, receptor binding, membrane fusion, et al. ) or screening anti-HCV drugs (such as inhibitor to virus entry). This system can be further applied to assess the human immune responses in HCV patients or evaluate HCV vaccine candidates.
Hepacivirus ; immunology ; Hepatitis C Antibodies ; immunology ; Hepatitis C, Chronic ; immunology ; Humans ; Neutralization Tests ; Viral Envelope Proteins ; immunology ; Virion ; immunology

In order to optimize the fabrication of SiO2 tubes immobilized with antibody for hepatitis C virus antigen (HCAg) detection, we formed the activated amino on the surface of SiO2 tubes by using the activation of aminosilane. Then we immobilized the hepatitis C virus (HCV) monoclonal antibody on the surface of SiO2 tubes by using glutaraldehyde as a chemical cross-linker, followed by detecting HCAg. Sequence tests showed that when the SiO2 tubes were treated in 10% (V/V) aminosilane solution and 3% (V/V) glutaraldehyde solution for 3 hours and 2 hours, respectively, the HCV monoclonal antibody had high immobilization efficiency and low nonspecificity, and the HCAg was detected to 1 ng/mL. This experiment can provide principle and experimental data for establishment of HCAg magnetic immunoassay system.
Antibodies, Immobilized ; immunology ; Antibodies, Monoclonal ; chemistry ; immunology ; Hepatitis C Antibodies ; chemistry ; immunology ; Hepatitis C Antigens ; analysis ; immunology ; Humans ; Silicon Dioxide ; chemistry

No abstract available.
Hepatitis A/prevention & control ; Hepatitis A Antibodies/*blood ; Hepatitis A Virus, Human/*immunology ; Humans ; Korea ; Seroepidemiologic Studies

No abstract available.
Hepatitis A/prevention & control ; Hepatitis A Antibodies/*blood ; Hepatitis A Virus, Human/*immunology ; Humans ; Korea ; Seroepidemiologic Studies

Hepatitis B virus (HBV) infection has been a major global cause of morbidity and mortality. The recognition of the problem led to a worldwide effort to reduce transmission of HBV through routine infant vaccination. HBV infection is the most common cause of chronic liver diseases and hepatocellular carcinoma in Korea. After hepatitis B vaccine era, seroprevalence of hepatits B surface antigen is decreasing, particularly in children. Hepatitis B vaccine is remarkably safe and shows high immunogenicity. Universal childhood immunization with three doses of hepatitis B vaccine in the first year of life is a highly effective method for prevention and control of hepatitis B.
Hepatitis B/*epidemiology/immunology/*prevention & control ; Hepatitis B Antibodies/blood/immunology ; Hepatitis B Vaccines/immunology/therapeutic use ; Hepatitis B virus/genetics/immunology ; Humans ; Vaccination

OBJECTIVEScreening and characterizing high affinity completely humanized single-chain antibody (ScFv) against PreS1 of hepatitis B virus.

METHODSA combinatorial library of phage-displayed human ScFv, genes of which were derived from peripheral blood lymphocytes immunized by PreS1 of Hepatitis B Virus in vitro, was constructed. The library contained 7 10(8) clones.

RESULTSAfter 3 rounds panning, a high affinity (K=10(7) to 10(8) mol/L) ScFv specific to PreS1 was obtained. The V(H) belonged to human V(H4) family, and V(1) to V(4) by sequence analysis.

CONCLUSIONThis study suggests that the method of antigen stimulation in vitro is an expeditious way for the source of human immune antibody. And the ScFv may provide a more satisfactory therapy.

Antibodies, Monoclonal ; biosynthesis ; Antibody Affinity ; Hepatitis B Antibodies ; biosynthesis ; Hepatitis B Surface Antigens ; immunology ; Humans ; Peptide Library ; Protein Precursors ; immunology

OBJECTIVETo observe the immunogenicity of combined hepatitis A and B vaccine (HAB).

METHODSThe combined HAB vaccine was prepared and different concentrations of HAB were administered on mice in week 0, 4 and 24, and then we tested the antibodies to both hepatitis A virus and B virus. After the first injection, we tested the hepatitis A antigen-induced and hepatitis B surface antigen-induced stimulation indices in spleen monocyte as well as changes of CD4+ and CD8+ cell numbers.

RESULTSThe serum antibody positive rates were 100% in all three groups, and the antibody induced by HAB vaccine were earlier than by monovalent vaccine. The hepatitis A antibody and hepatitis B surface antibody titers after the combined vaccine inoculation were not significantly higher than those after the monovalent vaccine inoculation. On the other hand, after the first injection of the combined vaccine, the hepatitis A antigen-induced and hepatitis B surface antigen-induced stimulation indices in spleen monocyte were detected. The numbers of CD4+ and CD8+ cells increased.

CONCLUSIONSHAB vaccine has reliable immunogenicity.

Animals ; CD4-CD8 Ratio ; Hepatitis A ; prevention & control ; Hepatitis A Antibodies ; blood ; Hepatitis A Vaccines ; immunology ; Hepatitis B ; prevention & control ; Hepatitis B Antibodies ; blood ; Hepatitis B Vaccines ; immunology ; Leukocytes, Mononuclear ; immunology ; Mice ; Mice, Inbred BALB C ; Random Allocation ; Vaccination ; Vaccines, Combined ; immunology

Human antibodies generated by phage antibody technology have been widely used in the immunotherapy of various diseases. Among the characteristics of these therapeutic antibodies, affinity is one of the most important determinants of their biological efficacy. The binding of an antibody and its corresponding antigen could be disrupted by thiocyanate solution of different concentrations, depend upon the affinity of the antibody. This mechanism has been adopted to determine the relative affinity of monoclonal or polyclonal antibodies in routine immunological practice. Correlation between the elution method and other techniques that measure the affinity such as equilibrium dialysis and biospecific interaction analysis (BIA) has been established. Here we describe the applications of the thiocyanate elution method in the determination of the relative affinity index (RAI) of phage antibodies (Phabs). Five clone antibodies, including 3 clones of anti-keratin antibodies (AK1, AK2 and AK3) and 2 clones of anti-HBsAg antibodies (HB1 and HB2) were selected to express Phabs and Fabs, and the RAI were determined by ELISA after thiocyanate elution. A HRP-conjugated anti-M13 was used as secondary antibody for Phabs and HRP-goat-anti-human Fab was used for Fabs. The affinity ranks of the Phabs were compared with that of the Fab fragments. The results showed that all the Phabs tested were tolerant to thiocyanate treatment. The relative affinity rank of 5 Phabs coincided well with that of their corresponding Fabs. We conclude that the thiocyanate elution can be used as an easy and rapid method to measure and compare the relative affinity of Phabs.
Antibodies ; immunology ; Antibodies, Monoclonal ; immunology ; Antibodies, Viral ; immunology ; Antibody Affinity ; Cloning, Molecular ; Enzyme-Linked Immunosorbent Assay ; methods ; Hepatitis B Antibodies ; immunology ; Hepatitis B Surface Antigens ; immunology ; Keratins ; immunology ; Peptide Library ; Proteomics ; methods ; Thiocyanates ; chemistry ; Transfection

One of the major cause of recent acute viral hepatitis in Korean adults is hepatitis A virus (HAV) infection. Most of hepatitis A cases are young adults in their twenties or thirties, and the severity of the disease is related to the age of patients. The seroprevalence of HAV among the adolescents and young adults in their teens and twenties is about 10%, which suggests that a growing number of young adults are susceptible to HAV infection. Development of more adult cases with severe presentation is expected in the near future, and some preliminary data suggest the incidence rate of hepatitis A in Korea might be higher than 20/100,000 population. This clinical features and the epidemiological shift of HAV urge to promote childhood vaccination and consider catch-up vaccination for adolescents and young adults. More extensive evaluation on the nationwide epidemiology of HAV infection, cost-benefit analysis of HAV vaccination, and setting-up of guidelines for HAV vaccination are urgently warranted.
Adolescent ; Adult ; Child ; Hepatitis A/immunology/*prevention & control ; Hepatitis A Antibodies/immunology ; *Hepatitis A Vaccines ; Humans ; Immunization Schedule ; Korea ; Seroepidemiologic Studies ; Vaccines, Inactivated

OBJECTIVETo evaluate safety and immunogenicity of inactivated hepatitis A vaccine in HBsAg carriers and healthy children.

METHODSOne hundred and twenty-one healthy children and ten HBsAg carriers, aged 1-10 years HAV susceptible were enrolled in the study. The inactivated hepatitis A vaccine was produced by Tangshan Biogenetic Company. The dosage of the vaccine was 1000 U/Dosage and 500 U/Dosage. The vaccination schedule was six month apart for two injections. The serum anti-HAV level was detected with EIA at one month after first injection and at one and six month after the booster injection, respectively.

RESULTSThe anti-HAV appeared in all the children. One month after the booster injection, the serum anti-HAV level in children vaccinated 500 U/Dosage was 4684.9 mIU and 4535.6 mIU, respectively and in the children vaccinated 1000 U/Dosage, 5399.8 mIU and 7347.1 mIU, respectively. The anti-HAV level was not statistically different between the two groups of children. There was no adverse reaction after the vaccination. The anti-HAV level was still high one year after first injection.

CONCLUSIONSThe data indicated that the safety and immunogenicity of the domestic inactivated hepatitis A vaccine were excellent in both groups of children.

Child ; Child, Preschool ; Hepatitis A Antibodies ; blood ; Hepatitis A Vaccines ; immunology ; Hepatitis B Surface Antigens ; blood ; Humans ; Immunization ; Infant ; Vaccines, Inactivated ; immunology