Research Institute of Veterinary Medicine

Daejeon, South Korea

Research Institute of Veterinary Medicine

Daejeon, South Korea
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Kamau A.N.,Chungnam National University | Park J.-E.,Chungnam National University | Shin H.-J.,Chungnam National University | Shin H.-J.,Research Institute of Veterinary Medicine
Virus Research | Year: 2017

Porcine epidemic diarrhea virus (PEDV) infects swine intestinal cells causing enteric disease. Research has shown that the entry into these cells is through porcine aminopeptidase N (pAPN) receptor. To gain insights into mechanisms of PEDV-pAPN interactions, the present study aimed at identifying the domain that is critical for PEDV binding. To this end, NIH3T3 cell lines constitutively expressing pAPN or pAPN mutants were generated. The mutants were; domain VII deletion mutant and domains IV–VI deletion mutant. In the latter, domain VII was linked to the transmembrane segment through domain III. Results showed PEDV infection was restricted to pAPN and pAPN domain VII expressing NIH3T3 cells. Further, reducing PEDV titre 10 fold resulted in 37.8% decrease in foci indicating positive correlation. A time course test at 12, 24, 36, 48 and 60 h showed that foci increased 6 fold in the overall time range. Also, PEDV harvested from pAPN or domain VII expressing NIH3T3 cells was induced indirect plaques in Vero cells confirming successful entry and replication. Collectively, our results demonstrate that PEDV recognizes pAPN and that the main interactive point is lodged within domain VII of the pAPN. These findings are important for therapeutic development as well as creating a platform for future studies on PEDV. © 2016 Elsevier B.V.


Park J.-E.,Chungnam National University | Cruz D.J.M.,Chungnam National University | Shin H.-J.,Chungnam National University | Shin H.-J.,Research Institute of Veterinary Medicine
Archives of Virology | Year: 2010

The hemagglutination (HA) activity of porcine epidemic diarrhea virus (PEDV) was investigated. Two cell-adapted strains of PEDV (KPEDV-9 and SM98LVec) were subjected to HA test against erythrocytes of various origin. Both strains showed HA activity with rabbit erythrocytes only after treatment with trypsin or neuraminidase. Optimal conditions for inducing HA activity of PEDV were 2 h incubation at 37°C using phosphate-buffered saline containing 0.1% BSA. These results suggest that the HA activity of PEDV is most likely caused by proteolytic action on it, which could be developed as a new diagnostic method to rapidly detect and differentiate PEDV infections from other enteric diseases. © Springer-Verlag 2010.


Lee G.-S.,Research Institute of Veterinary Medicine | Hong E.-J.,Research Institute of Veterinary Medicine | Gwak K.-S.,Seoul National University | Park M.-J.,Seoul National University | And 4 more authors.
Fitoterapia | Year: 2010

Chamaecyparis obtusa (C. obtusa) is a conifer in the cypress family Cupressaceae, native to northeast Asia. The essential oils of C. obtusa have antibacterial and antifungal effects and several products such as hygienic bands, aromatics, and shampoos contain these oils as a natural source of antimicrobial/antifungal agents. Interestingly, some consumers suffering from baldness and/or other forms of hair loss have reported a hair growth promoting effect of shampoos containing these oils. In the present study, the hair growth promoting effect of C. obtusa oils was elucidated in an animal model. C. obtusa oils promoted the early phase of hair growth in shaved mice. In addition, we examined the molecular effect of C. obtusa oils on the regulation of hair morphogenesis and hair growth using the human keratinocyte cell line HaCaT. In the current study of hair growth regulating genes, the expressions of vascular endothelial growth factor (VEGF), transforming growth factor (TGFβ1), and keratinocyte growth factor(KGF) have been analyzed by real-time PCR in HaCaT cells. The essential oils of C. obtusa were divided into seven fractions for treatment of HaCaT cells. VEGF transcripts were induced by fractions 6 and 7; however, TGFβ1 and KGF mRNA levels were unchanged by C. obtusa oils or fractions. Fraction 7 was separated into seven sub-fractions and studied further. Sub-fractions E and D significantly increased VEGF and KGF gene expression without up-regulating the hair growth inhibition factor, TGFβ1. The components of the two sub-fractions were further analyzed by gas chromatography and mass spectrometry. Cuminol, eucarvone, and calamenene were common to these two sub-fractions, although the effects of these individual components were not determined. Taken together, these results suggest that C. obtusa oils promote hair growth in an animal model and a positive regulator of hair growth, VEGF, was induced by particular components of these oils. © 2009 Elsevier B.V. All rights reserved.


Park J.E.,Research Institute of Veterinary Medicine | Lee D.W.,Merial Co. | Shin H.J.,Research Institute of Veterinary Medicine
Journal of Applied Poultry Research | Year: 2011

Laboratory tests to identify the viral genome, the antigen, or specific antibodies are used for a definitive diagnosis of avian metapneumovirus (AMPV) infection. Methods that can be used for antibody determination are the virus neutralization test and the enzyme-linked immunosorbent assay. To monitor the presence of AMPV in Korean chickens, sera were taken from chickens in 20 flocks. Of the 197 serum samples tested by enzyme-linked immunosorbent assay, 144 (73.1%) were positive for AMPV. The incidence of AMPV antibodies was higher in broilers (97.3%; 36 of 37 chickens) than in layers (67.5%; 108 of 160 chickens). Age was a factor, with very few positive samples obtained from young birds and the highest positive rates obtained for birds more than 100 d old. © 2011 Poultry Science Association, Inc.


Kamau N.A.,Chungnam National University | Lee D.W.,Merial Korea | Kheong C.K.,Merial Singapore | Park J.E.,Chungnam National University | Shin H.J.,Research Institute of Veterinary Medicine
Journal of Applied Poultry Research | Year: 2010

In the absence of stabilizers, vaccines administered in water are likely to be inactivated by free chlorine or other metals. Vac-Pac Plus, developed by Animal Science Products Inc. (Nacogdoches, TX), is a powdered stabilizer for vaccines administered via drinking water. The efficacy of this product was demonstrated in this study by its ability to preserve the viability of live infectious bronchitis vaccine reconstituted in water containing free chlorine. Maintenance of viable vaccine during administration is requisite for effective immune stimulation and response after vaccination. © 2010 Poultry Science Association, Inc.


Kamau N.A.,Chungnam National University | Park J.Y.,Chungnam National University | Park J.E.,Chungnam National University | Hyun B.H.,Ministry of Agriculture, Fisheries and Food | And 4 more authors.
Journal of Animal and Veterinary Advances | Year: 2010

The swine enteric disease, porcine epidemic diarrhea is caused by Porcine Epidemic Diarrhea Virus (PEDV). The disease continues to be economically significant in the swine industry especially in outbreak events. One of the prerequisites in disease management and epidemiological investigations is knowledge of factors underlying disease transmission and spread. The susceptibility of mice to PEDV was investigated as vectors in transmission. To prove this possibility, specific pathogen free mice were inoculated through oral, intranasal and intraperitoneal routes and investigate the presence of virus in tissues. As per results, PEDV was not able to replicate in the mice and there was no antibody reaction indicating that they are implausible vectors in PEDV transmission. © Medwell Journals, 2010.


Paudel S.,Chungnam National University | Park J.E.,Chungnam National University | Jang H.,Komipharm International Co. | Shin H.J.,Chungnam National University | Shin H.J.,Research Institute of Veterinary Medicine
Veterinary Quarterly | Year: 2014

Background: Porcine epidemic diarrhea virus (PEDV) is an economically important pathogen of swine.Objective: Serum neutralization (SN) and enzyme-linked immunosorbent assay (ELISA) test results as well as the utility of spike proteins S1, S2, and S3 and entire nucleocapsid protein were compared.Animals and methods: Serum samples from 400 pigs vaccinated against PEDV strain SM98P were collected from 78 farms in Korea. SN test and ELISA were performed to confirm the presence of antibodies. For prokaryotic expression of partial fragments of spike protein the size and location of S1, S2, and S3, and full nucleocapsid protein, polymerase chain reaction was performed using specific primers.Results: Comparison of these results demonstrated that there was a correlation between the SN and ELISA results. Sera with higher neutralizing activity also had higher IgG titer. The antibody profiling data presented the correlation of neutralizing activity with the level of spike protein antibody. In particular, the S3 region may have an important role in neutralizing activity.Conclusions: We confirmed that the carboxy-terminal region that includes the endodomain of the S protein induced stronger neutralizing activity than the region that includes the ectodomain.Clinical relevance: The region of the S protein may have a stronger neutralizing KPEDV-9 epitope and could be useful for the evaluation of future PEDV vaccine efficacy. © 2014 Taylor & Francis.

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