• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.359-363
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• 1995

The antigenic variation of B. thuringiensis subsp. satto have been investigated for 120 hours during sporulation and crystallization by using SDS-PAGE and Western blot. Most antigens of a vegetative cell were found to disappear as it was in sporulation and crystallization, but protein antigens of 46, 29, 27, and 21 kDa continued to be expressed. The new protein bands of 293, 138, 119, 75, and 68 kDa appeared on days 2 through 5 in modified GYS medium. They were thought to be involved in sporulation and crystallization. The protein of 138 kDa was found to be a major protein of both crystal and spore. The expression patterns were immunologically analyzed by Western blot. The polyclonal antisera against the intact crystal showed strong immunoreactivity to proteins with molecular masses of 293, 138, 68, and 46 kDa. The polyclonal antisera against the spore recognized proteins of 293, 138, 68, and 46 kDa. Both crystals and spores appeared to express the common protein antigens.

• Journal of fish pathology
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• v.37 no.1
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• pp.25-36
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• 2024

In this study, we analyzed the phylogenetic classification, epitope prediction, and pathogenicity of red sea bream iridovirus (RSIV) isolated from rock bream between 2019 and 2023. Phylogenetics based on genes encoding MCP and ATPase indicated that all five RSIV isolates belonged to RSIV subtype II. The deduced amino acid sequence of the MCP for the amplicons (1362 bp) obtained from RSIV isolates had a length of 453 amino acids. Among these, the amino acid sequences of the RSIV-19, 21, 22, and 23 isolates showed 100% identity, while the RSIV-20 isolate showed 99.78% identity with one residue difference at position 306. As a result of antigenicity analysis based on amino acid sequence, the antigenicity score of the RSIV-20 isolate was 0.6386 and the other RSIV isolates were 0.6365. Additionally, the prediction of their antigenic determinants resulted in a total of 17 identical antigenic plots. When each RSIV was inoculated into rock bream, no significant differences were observed with 100% cumulative mortality in all groups. This study provides data on the potential for genetic variation of RSIV isolated in the same marine area over the past five years, and the antigenicity and pathogenicity results of each isolate are expected to be useful information for selecting future vaccine strains.

• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.197-202
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• 1997

Diagnosis of early paragonimiasis is difficult because parasitological evidence is not easily obtained. Antibody tests have been proposed as a good substitute for classical diagnostic techniques. Using the crude extracts of Parnsonimus westermnni eggs, metacercariae. 4- and 7-week Juveniles, and 16-week adults as antigens, we observed the early antibody responses. Sera were obtained from 4 experimental cats, fed 50 metacercariae each, at intervals until 13 weeks post-infection. Antibody (IgG) responses were identified by ELISA using extracts of 4-week juveniles, followed by those of 7- and 16-week worms. Antibody responses were minimal against the metacercarial extracts. Antibodies to p. westemoni egg extracts were elevated after 10 weeks post-infection. In immunoblot analysis, more than nine protein bands in 4-week juveniles reacted with the early infection sera. Antigenic proteins in adult worms were different from those of juveniles. After four weeks of infection, 32 and 35 kDa bands in the adult extracts were increasingly reactive. Egg specific proteins at 28, 46 and 94 kDa were reactive only after 10 weeks. Antigenic components reactin료 to the early infection sera changed during the maturation stages of P. westermani; almost all juvenile antigens were replaced by adult antigen components.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.37-42
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• 1993

Surface proteins of Trichomonqs unginnlis (T vqsinalis) were analyzed to study the antigenic variation. The surface proteins of protozoa were labelled by N- hydrokysuccinimide-biotin (NHS-biotins, the NHS-biotin-labelled proteins were immunoprecipitated with rabbit antiserum to purifjr the antigenic fractions and analysed by SDS-PAGE plus electroblotting. The results obtained in this study were as follows; Biotinylated T. uaginalis-proteins obtained from intact cell and cells disrupted prior to labelling were detected by antibiotin-peroxidase in Western blots. Labelled proteins were immunoprecipitated by T. vcqinalis-immunized rabbit serum and the six bands with, the molecular weights of 46, 60, 68, 90, 130 and 220 kDa were identified as having antigenicity. T unginalis HY-1,HY-15 and ATCC 50148 were immunoprecipitated by immune rabbit serum after biotinylation and there were no difference from antigenic bands among these strains by this tehchnique. In conclusion with the results obtained in the present study, it was assumed that surface proteins of T vaqinclis were labelled by biotinylation and the six labelled bands at 46, 60, 68, 90, 130 and 220 kDa in their molecular weight were identified as having antigenicity by immunoprecipitation (IPI and this biotinylation-IP technique may be used for further study of surface antigen of T vaginalis.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.219-233
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• 1999

Purpose : Respiratory syncytial virus(RSV) is the major cause of lower respiratory tract infection in infants and young children. This study was performed to analyze antigenic and genetic variation of G protein of subgroup A RSV. Methods : One hundred seventy-nine strains isolated at the Seoul National University Children's Hospital over 8 years-period from 1990 through 1998 were analysed for antigenic and genetic variability. Analysis was made by reactivity with monoclonal antibodies raised against RSV, and by restriction mapping and, for selected strains, nucleotide sequencing following amplification of full sequence of G gene by reverse transcription-polymerase chain reaction. Results : Restriction fragment analysis of the amplified G protein gene revealed 23 restriction patterns, 12 of which included more than 2 isolate, and the most frequent genetic type comprised 30% of the strains. Indirect immunofluorescent staining with monoclonal antibodies revealed 6 antigenic types with one predominant pattern accounting for 91% of the total strains. The most frequent antigenic type had 21 restriction patterns, and some viruses with same restiction pattern had different monoclonal antibody reaction pattern. Nucleotide sequence homology of subgroup A was 91~93% between reference(A2, Long) and Korean isolates, 93~99% among Korean isolates. Maximum-parsimony analysis demonstrated that Korean isolates were distinct from reference strains and subgroup A strains were clustered in 4 groups. Conclusion : The restriction analysis pattern of G protein gene identified greater diversity within subgroup A than was seen with the monoclonal analysis and a variety of antigenic and genetic types of RSV are circulating in Korea which are different from reference strains or strains isolated from other countries.

• Parasites, Hosts and Diseases
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• v.37 no.2
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• pp.109-115
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• 1999

The present study observed the variation of antigenicity of Pneumocystis carinii and serum IgG antibody reastion to the antigens from different localtities in Korea. Antigens of rat P,carinii and sera of inhabitants were collected at Chunchon, Chungju, Kwangju and Seoul during 1995-1996. Enzyme-Linked Immunosorbent Assay and immunoblot were used for immune reaction. Absorbance of 1,294 human sera ranged between 0.01and 0.93. Sera from Chunchon showed higher absorbances than those from other areas. Immunoblotting revealed IgG antibody reactions to 116,100, and 45-55 kDa antigenic bands of rat P.carinii, but the frequencies of positive reaction to individual bands were variable by localities. Total 62.6% reacted to 100kDa band and 32.0% to 45-55 kDa bands. For the reaction to 116kda, the reaction rate was 60.0% of the sera showed the reaction to 116kda band while 37.7% reacted to 100kda, the reaction rate was 60.0% to 82.6% by localities. It is found that the reaction rates of the human sera to rat P.carinii antigen are variable according to the localities. Also, the high molecular antigen of 116kDa of rat P.carinii is the most frequent antigenic band reaction to human sera.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.49-55
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• 2001

Bacillus anthracis is a gram-positive spore-forming bacterium that causes the disease anthrax. The anthrax toxin contains three components, including the protective antigen (PA), which binds to eucaryotic cell surface receptors and mediates the transport of toxins into the cell. In this study, the entire 2,294-nucleotide protective antigen gene (pag) was sequenced from 4 of B. anthracis strains to identify potential variation in the toxin and to further our understanding of B. anthracis evolution in Korea. Sequence alignment of the entire PA gene from 30 strains representative of the four B. anthracis diversity groups revealed mutations. The mutation of B. anthracis BAK are located adjacent to a highly antigenic region crossing the junction between PA domains 3 and 4 shown to be critical to LF binding. The different mutational combinations observed in this study give rise to 11 PA genotypes and 4PA phenotypes. Three-dimensional analysis of all the amino acid changes (Ala to Val) observed in BAK indicated that these changes are not only close sequentially but also very close in three-dimensional space to the antigenic region importan tfor LF binding. Phylogenetic (cladistic) analysis of the pag corresponded with previous strain grouping based on chromosomal variation, suggesting that plasmid evolution in B. anthracis has occurred with little or no horizontal transfer between the different strains.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.81-83
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• 1989

The flagella antigenic variation of nine Bacillus thuringiensis serovar kurstaki temperature-sensitive mutants grown at the permissive temperature (3$0^{\circ}C$) was detected by a serological agglutination between H-antigen and antiserum. The flagella antigens were injected to rabbits to prepared their antisera, and then their homologous and heterologous titers of the antisera were measured. The homologous titers were ranged from 1:6,400 to 1:12,800, but the heterologous titers were very low. The H-antigen of the wild type strain was not agglutinated to 4 heterologous antisera, ts-U23 not to 7, ts-U3l not 5, ts-U32 not to 4, ts-U33 not to 7, ts-U7l not to 4, ts-U73 not to 6, ts-U74 not to 6, ts-U91 not to 4 and ts-U603 not to 4 antisera.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.365-376
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• 1995

Antigenic localization in Parofonimn iloktsuenensis worm tissues (tegument, intestine and vitelline gland) in different developmental stages of 2 weeks, 3 weeks, 4 weeks, 5 weeks and 33 weeks from albino rats (Sprague-Dawley) infected with P iloktsuenensis was observed by electron microscopy. These worm tissues of different developmental stage of R iloktsuenensis was observed on electromicrograph by immunogold labeling method using R iLoktsuenensis infected rat serum of 10 weeks. Antigenic localization was demonstrated as labeling of gold particles in tissues on electronmicrograph. In tegument, gold particles were labeled on tegumental tissue, generally more numerous on secretory granules in tegumental syncytium 2 weeks than those on the other elder developmental stages, but there was a little variation in antigenicity according to individual worm tissue. In general, antigenicity in tegumental tissue was not strong (gold particles: 0.1-5/1 Mm2). In intestine, a large number of gold particles (15-18/1 Mm2) were labeled in intestinal epithelium. Gold particles were concentrated especially on secretory granules in cytoplasm, and gold particles were labeled not only in cytoplasmic protrusions, but also in intestinal luminal contents. Intencity of labeling of gold particles was not correlated with developmental stage of worms. In vitelline gland, a large number of gold particles were labeled on vitelline globules. The gold particles in vitelline globules (8- 11/1 Mm2) were concentrated in protoplasm among segmental globules . Key words: Pnragonimus iloktsuenensis, immunogold labeling method, tissue antigen ultrastructure.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.61-67
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• 1994

One fundamental problem in developing an AIDS vaccine is antigenic variation of HIV. Despite a substantial induced immune response in gp120-immunized monkeys and humans, high titers of V3-directed type specific neutralizing antibodies may not be sufficient to neutralize continuously emerging new isolates. Several studies analyzing anti-gp120 antibodies in HIV-infected individuals have clearly indicated that most broadly neutralizing antibodies are directed to conformation-dependent epitopes. Therefore, it seems important to evaluate the potential efficacy of candidate gp120 vaccines at inducing such antibodies, that might be potentially protective against multiple HIV strains. One concern in the development of any recombinant protein as a vaccine is its stability when mixed with an adjuvant. This could be a particularly important factor for recombinant gp120, given the conformational nature of its major, broadly neutralizing, epitopes. We hypothesized that gp120 complexed with recombinant CD4 could stabilize the conformation-dependent epitopes and effectively deliver these epitopes to the immune system. In this study, a soluble gp120-CD4 complex in Syntex Adjuvant Formulation was tested in mice to analyze the anti-gp120 antibody response. With the aim of defining the fine specificity and neutalizing activities of the immune response, 17Mabs were generated and characterized. The studies indicate that the gp120-CD4 complex elicits neutralizing anti-gp120 antibodies, most of which are directed to the conformation dependent epitopes.