• The Journal of Korean Society of Virology
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• v.30 no.2
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• pp.113-124
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• 2000

We had isolated 8 viruses from 91 specimen collected at southwest Cheju Province during early spring 1998 and 2 viruses from 9 specimen collected at Chung Nam Province during early spring 1999. To perform cross-reactivity among 4 mumps vaccine strains and 10 wild-type mumps viruse isolates, we immunized mice and took antisera against each virus. There were no antibody titer differences by indirect immunofluorescence assay (IFA), but most isolated mumps viruses showed a little cross-reactivities with Jeryl Lynn and Rubini strains. It has shown similar result by haemagglutination-inhibition (HAI) test. These results show that 4 mumps strains used as vaccine have the protection ability against endemic wild-type mumps viruses. Also the SH gene analysis was performed to identify genotypes. Most isolated mumps viruses belonged to genotype D. These results indicate that endemic mumps viruses in Korea are different to ones isolated in Japan and China.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1576-1586
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• 2023

Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.630-634
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• 2006

Purpose : This study was conducted to assess the current(2003-2005) prevalence of anti-HBs and immunologic memory for Hepatitis B vaccine in children from the central area of Korea. Methods : Subjects were chosen from children and adolescents who received tests for hepatitis B surface antigen(HBsAg) and anti-HBs at Dankook University Hospital from March 2003 to May 2005. Among these, antibodies to hepatitis B core antigen(IgG anti-HBc) were checked. A single booster vaccination was performed on children whose anti-HBs titers were under 10 mIU/mL. One month after booster vaccination we rechecked the anti-HBs titer. Results : A total of 3,277 subjects were tested for HBsAg/anti-HBs, and 1,913(58.4 percent) of them were positive for anti-HBs. Of these, 29 subjects(0.9 percent) were positive for HBsAg. Positive results for anti-HBs by age were 78.6 percent for 6-12 months of age, 62.7 percent for 1-3 years of age, 51.9 percent for 4-6 years of age, 49.5 percent for 7-12 years of age, 63.4 percent for 13-15 years of age and 72.2 percent for 16-18 years of age. The 80 subjects who were tested negative for HBsAg/anti-HBs received a single booster vaccine, 71 subjects were tested positive for antibodies. IgG anti-HBc titer was checked for 169 of the subjects, 5 subjects were positive. Conclusion : In our study, a significant anamnestic response was observed in 88.8 percent of children. This is believed to be a result of the relatively long immunologic memory effect of the hepatitis B vaccination in children from the central area of Korea.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.622-628
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• 2008

Purpose : The purpose of this study was to evaluate the immunogenicity of the booster immunization with pneumococcal conjugate vaccine in Korean children. Methods : Thirty-nine children aged 12-23 months who visited Kangnam CHA Hospital between September 2006 and December 2006 were enrolled. The children were divided into primary and booster groups depending on their vaccination status for the 7-valent pneumococcal conjugate vaccine. The anti-pneumococcal antibody levels of each serotype included in the vaccine (4, 6B, 9V, 14, 18C, 19F, 23F) were determined by third-generation ELISA. Results : The geometric mean titer (GMT) of antibodies to each pneumococcal serotype in the booster group was higher than in the primary group (P<.05). The percentage of subjects with pneumococcal antibodies ${\geq}0.35{\mu}g/mL$ was 90.5-100% for all serotypes in both the primary and booster groups. The percentage of subjects with pneumococcal antibodies ${\geq}1.0g/mL$ in the booster group was 94.4-100%, which was higher than the primary group except for serotypes 6B and 14 (P<.05). The percentage of subjects with pneumococcal antibodies ${\geq}5.0{\mu}g/mL$ in the booster group was 50.0-94.4% which was higher than the primary group for all serotypes (P<0.05). Conclusion : The immunogenicity of a booster dose of the pneumococcal conjugate vaccine in Korean children was high and the immunogenicity of a primary series was also relatively high. To determine the feasibility of the introduction of the pneumococcal conjugate vaccine and the appropriate schedule for Korean children, further prospective investigation of the immunogenicity of the booster immunization is needed.

• Pediatric Infection and Vaccine
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• v.7 no.1
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• pp.120-128
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• 2000

Purpose : Active immunization against hepatitis A with an inactivated vaccine reveals excellent immunogenicity, tolerability and protective efficacy. Inactivated hepatitis A vaccines have been selectively used since 1996 in Korea to prevent hepatitis A. This study was performed to assess the immunogenicity and reactogenicity after two doses of HM175 strain hepatitis A vaccine in healthy Korean children. Methods : 128 healthy children(M/F; 65/63) aged 1 to 15 years, who were seronegative for hepaitatis A, participated in this study. A alum-adsorbed vaccine containing 720 EL.U of antigen form HM175 hepatitis A strain per 0.5 mL dose was injected intramuscularly on the deltoid area. The second dose was given 6 months later, Anti-HAV antibodies were measured by ELISA before and 1 month after each vaccination to assess the immunogenicity. Any local and general adverse events were reported by patients parents with the prepared questionnaire after each vaccination. Results : 120 volunteers(M/F; 60/60) completed the whole series of the study. Seroconversion occurred in all cases after primary and booster vaccination. The mean anti-HAV antibody titer after primary vaccination was 389.2mIU/mL, and 3,609mIU/mL after booster vaccination. And levels of anti-HAV antibodies after booster immunization were significantly higher in female children. The most common local adverse event was soreness on the injection site, but it was mild and resolves within 3 days. Fever was not reported after booster vaccination. Conclusion : Based on these data, we conclude that the inactivated HM175 strain hepatitis A vaccine is highly immunogenic and tolerable in healthy Korean children.

• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.100-108
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• 2011

A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 ($TCID_{50}$) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.

• Journal of Microbiology
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• v.40 no.1
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• pp.1-10
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• 2002

At the dose of 1000 p.f.u. per mouse,100% mortality occurred in mice inoculated with wild-type pseudorabies virus (PrV). In contrast, upon stable deletion of 10 bp nucleotides at the Bsrl site within the TK gene, PrV was rendered to be completely apathogenic. The deletion also caused the virus to be less capable of replicating in respiratory as well as in nervous system tissues. Although animals were exposed to high titers of TK-deleted PrVs, the virus failed to replicate to a high titer as compared to the pathogenic parental virus. In contrast to previous studies the deletion in the TK gene did not prevent the virus from establishing latency. Upon immunosuppression, the latent virus? however, reactivated but replicated at low titers. Interestingly, TK-deleted virus established latency and reactivation, that are occurred only in trigeminal ganglia and the cerebrums and no other tissues involved. Following reactivation, there was no indication of virus shedding in respiratory tissues as confirmed by virus isolation and polymerase chain reaction (PCR) technique targeting at the gB gene of PrV, The non-pathogenic virus with non-shedding characteristics, upon reactivation of the latent virus, would be the important feature of a live virus vaccine candidate.

• 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.

• Korean Journal of Animal Reproduction
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• v.14 no.2
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• pp.107-114
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• 1990

These experiments were undertaken as a basic study to develop immunocontraceptive vaccine and to understand the role of zona pellucidae in early fertilization process by identifying the monoclonal and polyclonal antibody to porcine zona pellucidae and polyclonal antibody to mouse zona pellucidae by indirect ELISA and indirect immunofluorescence test. The results obtained in these experiments were summarized as follows : 1. The titer of the antibodies to zona was determined by indirect ELISA using solubilized porcine zona coated plates. Both monoclonal and rabbit polyclonal antibodies showed very high titers ; O.D at 1 : 12,800 dilution of antibodies was still significantly higher than that of non-immunized control serum. Rabbit anti-mouse zona pellucidae sera also reacted with porcine zona pellucidae. 2. By indirect immunofluorescence test strong fluorescences were observed on the egg treated with homologous and heterologous rabbit polyclonal antibodies and FITC lablled 2nd antibodies and found to crossreact strongly with the eggs from the pig and mouse. While weaken fluorescences were observed on the eggs treated with monoclonal antibodies.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.9-15
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• 2017

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a ${\beta}-lactamase$ secretion system. This was then transformed into ${\Delta}asd$ ${\Delta}crp$ Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.