• Korean Journal of Microbiology
• /
• v.43 no.2
• /
• pp.137-141
• /
• 2007

The similarities among five strains of Streptomyces were measured by the serological methods. Antigens were prepared by dissolving cell envelope fractions in Tween 20 buffer and antisera were produced from the immunized rabbits. Immunodiffusion studies and ELISA results showed that the degree of antigen-antibody reaction was not exactly matched to the taxonomic distance; i. e. the strains of the cluster group A exhibited low level of cross-reactions each other, while relatively strong cross-reactions were observed between Streptomyces lavendulae of cluster group F and Streptomyces viridochromogenes of cluster group A.

• Laboratory Medicine and Quality Assurance
• /
• v.40 no.2
• /
• pp.51-69
• /
• 2018

As part of the immunoserology program of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of hepatitis viral markers in 2016 and 2017. The hepatitis viral antigens and antibodies program consisted of 10 test items. We delivered two and three types of pooled sera specimens to 965 and 965 institutions for the first and second trials of external proficiency testing in 2016, respectively. The number of participating laboratories was 915 (94.8%) and 913 (95.0%) in the first and second trials in 2016, respectively. We also delivered three kinds of pooled sera specimens to 936 and 1,015 institutions for the first and second trials of external proficiency testing in 2017, respectively. The number of participating laboratories was 920 (98.3%) and 996 (98.1%) in the first and second trials in 2017, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, anti-hepatitis C virus, hepatitis B envelope antigen, antibodies to hepatitis B envelope antigen, anti-hepatitis A virus and antibodies to hepatitis B core antigen. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay and the electrochemiluminescence immunoassay, but they yielded a few-false positive results due to the matrix effect. The immunochromatographic assay yielded false-negative results for anti-hepatitis A virus due to low sensitivity. Continuous improvement in the quality of viral hepatitis testing through participation in the survey seems necessary.

• The Korean Journal of Zoology
• /
• v.34 no.1
• /
• pp.44-53
• /
• 1991

Distribution of the antigens during the cell cycle of amoebae was followed by immunof-luorescence microscopy using a monoclonal antibody against the nucleus as a probe. While the cells were in the interphase, the antigen was localized on the nucleus membrane. But it was dispersed all over the cytoplasm during mitosis and cytokinesis. The molecular weights of the immunoreacted antigens were 210 KD and 190 KD as determined by SDS PAGE and western blotting of the purified nuclei. The antigens were not soluble in non-ionic detergent, but were released from the nucleus by incubation with 0.05 M sodium carbonate, pH 10.6 or with 8 M urea at serial chemical extraction. Thus the antigens appeared to be peripheral proteins of the nurBeus envelope. The isoelectic point of both antigens was 7.64 as determined by 2 D PAGE and transfer blotting. Considering the peiipherd association with the nucleus membrane and the dispersed distribution during mitosis, the antigens could be lamin like proteins. Hourever, it appears also possible that they are the component molecules of the unusually structured aurous lamina of amoeba nucleus since they have the large molecular weight and the basic pl.

• Archives of Pharmacal Research
• /
• v.29 no.11
• /
• pp.1042-1048
• /
• 2006

Plasmid DNA vaccines encoding the hepatitis B virus (HBV) surface and hepatitis C virus (HCV) envelope antigens, respectively, were constructed, and attempt were made to find the possibility of a divalent vaccine against HBV and HCV. The expression of each plasmid in Cos-1 cells was confirmed using immunocytochemistry. To measure the induced immune response by these plasmids in vivo, female BALB/c mice were immunized intramuscularly with $100\;{\mu}g$ of either both or just one of the plasmids. Anti-HBV and HCV-specific antibodies and related cytokines were evaluated to investigate the generation of both humoral and cellular immune responses. As a result, specific anti-HBV and anti-HCV serum antibodies from mice immunized with these plasmids were observed using immunoblot. The levels of IL-2 and RANTES showing a $Th_{1}$ immune response were significantly increased, but there was no change in the level of IL-4 ($Th_{1}$ immune response) in any of the immunized groups. Compared with each plasmid DNA vaccine, the combined vaccine elicited similar immune responses in both humoral and cell-mediated immunities. These results suggest that the combined DNA vaccine can induce not only comparable immunity experimentally without antigenic interference, but also humoral and $Th_{1}$ dominant cellular immune responses. Therefore, they could serve as candidates for a simultaneous bivalent vaccine against HBV and HCV infections.

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

• Korean Journal of Microbiology
• /
• v.43 no.4
• /
• pp.321-324
• /
• 2007

The changes in antigenicity during cultivation of streptomycetes were determined by immunodiffusion assay and indirect ELISA. New precipitin lines in immunodiffusion assay began to appear in the growth period of the soluble pigment production and became thickened thereafter. The increase in the antigenicity was also confirmed by ELISA. The antigenic development was relatively weak for S. lavendulae and S. viridochromogenes while that was strong for S. lavendulae and S. viridochromogenes. The results indicated that Streptomyces strains, even though not proved for some strains, changed the compositions of cell envelope during submerged growth and this could be estimated quantitatively by serological method.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.11
• /
• pp.5463-5467
• /
• 2012

Hepatitis B virus (HBV) infection is contagious with transmissiobn vertically or horizontally by blood products and body secretions. Over 50% of Iranian carriers contracted the infection prenatally, making this the most likely route of transmission of HBV in Iran. To evaluate the resistance to adefovir (ADV) therapy in patients with chronic hepatitis B infection, a study was conducted on 70 patients (63 males and 7 females), who had received in first line lamivudine and second line adefovir. All were tested for the presence of hepatitis B surface antigen (HBsAg), hepatitis B envelope antigen (HBeAg), serum alanine amino transferase (ALT) level and HBV DNA load before and after treatment with ADV. In all samples, resistance to lamivudine and ADV was tested with real time PCR. Among seventy patients with chronic hepatitis B infection, 18 (25.7%) were resistant to LAM and 8 (11.4%) were resistant to ADV. Only one patient was negative for the presence of HBS-Ag (5.6%) and two were negative for HBe-Ag (11.1%). In this study we used a new method (ALLGIO probe assay) that has high sensitivity in detection of adefovir resistance mutants, which we recommend to other researchers. Mutant strains of the YMDD motif of HBV polymerase can be found in some patients under treatment with lamivudine and ADV. ADV has been demonstrated to be efficient in patients with lamivudine resistant HBV.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.173-177
• /
• 2006

In this study, a novel strategy was developed for the highly selective immobilization of proteins, using the polyhydroxyalkanoate (PHA) depolymerase substrate binding domain (SBD) as an active binding domain. In order to determine the appropriacy of this method for immunodiagnostic assays, the single-chain antibody (ScFv) against the hepatitis B virus (HBV) preS2 surface protein and the severe acute respiratory syndrome coronavirus (SARS-CoV) envelope protein (SCVe) were fused to the SBD, then directly immobilized on PH A-coated slides via microspotting. The fluorescence-labeled HBV antigen and the antibody against SCVe were then utilized to examine specific interactions on the PHA-coated surfaces. Fluorescence signals were detected only at the spotted positions, thereby indicating a high degree of affinity and selectivity for their corresponding antigens/antibodies. Furthermore, we detected small amounts of ScFv-SBD (2.7 ng/mL) and SCVe-SBD fusion proteins (0.6ng/mL). Therefore, this microarray platform technology, using PHA and SBD, appears generally appropriate for immunodiagnosis, with no special requirements with regard to synthetic or chemical modification of the biomolecules or the solid surface.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.3
• /
• pp.490-497
• /
• 2004

Although the E. coli heat-labile enterotoxin B subunit (LTB) is known to be a potent mucosal adjuvant towards co-administrated unrelated antigens and immunoregulator in T-helper 1-type-mediated autoimmune diseases, a more efficient and useful LTB is still required for prospective vaccine adjuvants. To determine whether a novel chimeric LTB subunit would produce an enhanced mucosal adjuvant activity and immune response, a number of LTB subunits were genetically fused with chimeric proteins using the epitope genes of the envelope glycoprotein E2 (gp51-54) from the classical swine fever virus (CSFV). It was found that the total serum immunoglobulin (Ig) levels of BALB/c mice orally immunized with chimeric proteins containing an N-terminal linked LTB subunit (LE1, LE2, and LE3) were higher than those of mice immunized with LTB, E2 epitope, and chimeric proteins that contained a C-terminal linked LTB subunit. In particular, immunization with LE1 markedly increased both the total serum Ig and fecal IgA level compared to immunization with LTB or the E2 epitope. Accordingly, the current results demonstrated that the LTB subunit in a chimeric protein exhibited a strong mucosal adjuvant effect as a carrier molecule, while the chimeric protein containing the LTB subunit stimulated the mucosal immune system by mediating the induction of antigen-specific serum Ig and mucosal IgA. Consequently, an LE1-mediated mucosal response may contribute to the development of effective antidiarrhea vaccine adjuvants.

• The Journal of Korean Society of Virology
• /
• v.28 no.1
• /
• pp.21-30
• /
• 1998

Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying T7 promoter and the poly-histidine leader, sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography. The overexpressed gp41 fusion protein was purified by centrifugation, $C_4$ chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic - expression purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.