• Journal of Veterinary Science
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• v.23 no.1
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• pp.7.1-7.14
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• 2022

Background: Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives: Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods: SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results: Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions: Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.133-137
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• 2017

Three swine farms which were suffering from slight economic loss due to suckling piglets' diarrhea, were selected to apply commercialized multivalent vaccine for sow use; $SUISENG^{(R)}$ (Hipra, Spain). Farms were pre-diagnosed with clinical symptoms and molecular detection of C. perfringens Type A and C and E. coli pili by PCR. Sows were vaccinated twice 2 ml of the vaccine at 6 and 3 weeks ante partum intramuscularly according to the manufacturer's instruction. All vaccinated sows did not show any adverse reaction or clinical signs; hypersensitivity, fever, granuloma or abscess on the injection site, appetite loss, and so on. Also, no reproductive disorder was appeared in vaccinated sows compared with non-vaccinated control sows. The results suggested that piglets born from vaccinated sows show significantly better performance in regard of the diarrhea index and mean daily weight gain compared with piglets from non-vaccinated sows. Therefore, the commercial vaccine for the prevention of neonatal diarrhea is found to be effective in reducing diarrhea in the first suckling period of piglets after birth.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.139-146
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• 1998

Recombinant polioviruses have been developed by many research groups for use as vaccine vector because poliovirus induces mucosal immunity as well as humoral immunity through oral uptake. We assessed the potential use of poliovirus as a T-cell epitope carrier. Recombinant poliovirus V129 5L was constructed to have a substituted T-helper epitope from the core protein of Hepatitis B virus at neutralization antigenic site 1 on its VP1 capsid protein. The recombinant virus replicated less efficiently than type 1 poliovirus Mahoney strain. The V129 5L formed a little smaller plaques than the Mahoney strain and showed some 1.25 log unit lower titer at the peak in the one-step growth kinetics though it had similar growth profile to that of the Mahoney strain. Since V129 5L recombinant virus was genetically stable even after 24 successive passages in HeLa cells, the antigenic site 1 on VP1 capsid protein was confirmed for its ability of carrying T cell epitope. The genetic stability of V129 5L also indicated that recombinant poliovirus can be successfully utilized for the development of the multivalent vaccines.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.5-11
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• 2008

Primary rotavirus gastroenteritis infection usually occurs in infants under 2 years of age worldwide regardless of level of hygiene, quality of water, food or sanitation or type of behavior. In Korea, the disease mostly occurred in infants under 2 year old, and usually in late fall to early winter with the highest incidence shown in November until early 1990s. However, since then, relatively the age incidence of this infection has increased in children over 2 years old, and it has mainly occurred in late winter to early spring with the highest incidence shown between February and March. And rotavirus gastroenteritis serotypes varied year to year as well as varied by year within the same region in our country. The comparison of severity scores between age groups in Korea showed that severity score was lowest in infants less than 3 months and highest in infants more than 6 months and less than 12 months, and hospitalization period between age groups was longest in infants older than 3 months and less than 3 months and highest in infants more than 6 months and less than 12 months and less than 6 months. In this aspect, rotavirus vaccines should be given to infants less than 2 years of age in whom the incidence of rotavirus gastroenteritis is the highest, and vaccination should be ideally started before 3 months considering hospitalization period and severity of rotavirus gastroenteritis. However, It should be careful for the introduction of new rotavirus vaccine, and the effectiveness of rotavirus vaccines should be assessed by long-term post marketing surveillance. And we guess an multivalent vaccine may be an ideal rotavirus vaccine to prevent primary infection caused by variable rotavirus strains in Korea. In addition, clinical epidemiology studies on rotavirus gastroenteritis which evaluate the age and serotypes related severity should be continuously conducted in various regions.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.789-797
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• 2010

The limited information on differential gene expression in the different serotypes of Actinobacillus pleuropneumoniae has significantly hampered the research on the pathogenic mechanisms of this organism and the development of multivalent vaccines against A. pleuropneumoniae infection. To compare the gene expressions in the A. pleuropneumoniae strains CVCC259 (serotype 1) and CVCC261 (serotype 3), we screened the differentially expressed genes in the two strains by performing representational difference analysis (RDA). Northern blot analyses were used to confirm the results of RDA. We identified 22 differentially expressed genes in the CVCC259 strain and 20 differentially expressed genes in the CVCC261 strain, and these genes were classified into 11 groups: (1) genes encoding APX toxins; (2) genes encoding transferrin-binding protein; (3) genes involved in lipopolysaccharide (LPS) biosynthesis; (4) genes encoding autotransporter adhesin; (5) genes involved in metabolism; (6) genes involved in the ATP-binding cassette (ABC) transporter system; (7) genes encoding molecular chaperones; (8) genes involved in bacterial transcription and nucleic acid metabolism; (9) a gene encoding protease; (10) genes encoding lipoprotein/membrane protein; and (11) genes encoding various hypothetical proteins. This is the first report on the systematic application of RDA for the analysis of differential gene expression in A. pleuropneumoniae serotypes 1 and 3. The determination of these differentially expressed genes will serve as an indicator for future research on the pathogenic mechanisms of A. pleuropneumoniae and the development of a multivalent vaccine against A. pleuropneumoniae infection.

• Journal of fish pathology
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• v.37 no.1
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• pp.71-78
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• 2024

Streptococcosis, caused by Streptococcus iniae and Streptococcus parauberis is an important bacterial disease that affects in olive flounder in Korea. In Korea, multivalent bacterial vaccines are used to prevent streptococcal diseases in aquaculture. In this study, commercial vaccines containing formalin-inactivated bacterial cells of S. iniae and S. parauberis were administered at six fish farms and one unvaccinated fish farm were designated for investigation (Wando; 4 sites and Jeju; 3 sites). Blood was collected from vaccinated and unvaccinated olive flounders, and titers of antibodies against S. iniae and S. parauberis in serum were analyzed using ELISA. After a one shot vaccination in the farms at Jeju (farm A) and Wando (farm D), the proportion of individuals with specific antibodies against S. parauberis OD values of 0.4 or higher was 60% and 53.5%, respectively. But after booster vaccination, the proportion of individuals with serum OD values of 0.4 or higher was higher substantially increased to 96.6% (farm A) and 100% (farm D). The levels of S. parauberis specific antibodies of olive flounder were increased after vaccination in three fish farms (farm D, E, and F), but not S. iniae specific antibodies.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.128-134
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• 2013

Salmonella enterica serovar typhi, a Gram-negative food-borne pathogen, causes typhoid fever in humans. OmpC is an outer membrane porin of S. typhi expressed throughout the infection period. OmpC is potentially an attractive antigen for multivalent vaccines and diagnostic kit designs. In this study we combined in silico, in vitro and in vivo approaches to analyze various aspects of OmpC's antigenic properties. The conserved region, in addition to secondary and tertiary structures, and linear B cell epitopes, were predicted. A number of results obtained from in silico analyses were validated by experimental studies. OmpC was amplified, cloned and then expressed, with the recombinant protein then being purified. BALB/c mice were immunized by purified denatured OmpC. The titer of antibody was raised. Results of challenges with the pathogen revealed that the immunity is non-protective. Most of the theoretical and experimental results were in consensus. Introduced linear B cell epitopes can be employed for the design of diagnostic kits based on antigen-antibody interactions.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.320-325
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• 2012

Rotavirus and hepatitis A virus (HAV) spread by the fecal-oral route and infections are important in public health, especially in developing countries. Here, two antigenic epitopes of the HAV polyprotein, domain 2 (D2) and domain 3 (D3), were recombined with rotavirus VP7, generating D2/VP7 and D3/VP7, cloned in a baculovirus expression system, and expressed in Spodoptera frugiperda 9 (Sf9) insect cells. All were highly expressed, with peak expression 2 days post-infection. Western blotting and ELISA revealed that two chimeric proteins were antigenic, but only D2/VP7 was immunogenic and elicited neutralizing antibody responses against rotavirus and HAV by neutralization assay, implicating D2/VP7 as a multivalent subunit-vaccine Candidate for preventing both rotavirus and HAV infections.

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.21-26
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• 2010

As the causative agent of Anthrax, Bacillus anthracis causes an acute fatal disease in herbivores such as cattle, sheep, and horses as well as humans. The therapeutics and prevention of anthrax currently available are based on antibiotics and the live attenuated vaccine strains, which may be problematic due to the emergency of antibiotic resistant strains or residual virulence in those vaccine strains. Therefore, it has been required to develop novel therapeutics and vaccines which are safer and applicable to humans. Recently, the development of the multivalent vaccine targeting both spores and vegetative cells of B. anthracis along with anthrax toxin has been reported. In our attempts to screen potential candidates for those multivalent vaccines, the whole genomic expression library of B. anthracis was constructed in this study. To the end, the partial digests of the genomic DNA from B. anthracis (ATCC 14578) with Sau3AI were ligated with the inducible pET30abc expression vectors, resulting in approximately $1{\times}10^5$ clones in E. coli BL21(DE3). The redundancy test by DNA nucleotide sequencing was performed for the randomly selected 111 clones and found 56 (50.5%) B. anthracis genes, 17 (15.3%) vector sequences, and 38 (34.2%) unknown genes with no sequence homology by BLAST. An inducible expression of the recombinant proteins was confirmed by Western blot. Interestingly, some clones could react with the antiserum against B. anthracis. These results imply that the whole genomic library constructed in this study can be applied for analyzing the immunomes of B. anthracis.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.73-82
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• 2008

Dental caries is an infectious disease caused by mutans streptococci, and is a primary etiologic agent of dental caries in humans. The molecular pathogenesis of mutans streptococcal-associated dental caries occurs in three phases. Firstly, S. mutans attaches to tooth surface via a cell surface adhesion termed antigen I/II. In the second phase, the glucosyltransferase(GTFs) synthesize polymers like glucans in the presence of sucrose. In the third phase, the multivalent glucans interacts with glucan binding proteins (GBPs) and they make dental plaque and accumulation of microorganisms. Many studies and clinical trials have indicated that a mucosal immune response to these antigens(Ag I/II, GTFs, GBPs) of S. mutans can influence the pathogenesis of dental caries. So these antigens can be important vaccine candidates for immunologic intervention against dental caries. In this study, we cloned the genes for GTFb, GTFc, GTFd from S. mutans GS-5 and did the nucleotide sequence analysis. And the recombinant proteins of GTFd and N-terminus of GTFd were expressed. Intact GTF which we get from this experiment can be used for antibody production specific for any GTF activity domain through animal experiment.