• Title/Summary/Keyword: neutralizing activity

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Isolation, characterization and neutralizing activity of porcine epidemic diarrhea viruses from Vietnam

  • Do, Van Tan;Truong, Quang Lam;Dao, Hoai Thu;Nguyen, Thi Lan;Kim, Jini;Hahn, Tae-Wook
    • Korean Journal of Veterinary Research
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    • v.61 no.3
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    • pp.23.1-23.8
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    • 2021
  • Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were successfully propagated in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene revealed that all 3 isolates belong to genogroup 2a, which is closely related to other prevalent Asian strains. Amino acid sequence comparisons revealed 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013-2015, suggesting that field PED viruses (PEDVs) evolve continuously. Experiments in animals demonstrated that antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log2) of neutralizing antibody against the homologous strain, and showed a relatively lower level of neutralizing antibody against the field isolates. This finding would be helpful in choosing a PEDV strain for vaccine development.

Porcine epidemic diarrhea viruses from Vietnam: isolation, characterization, and neutralizing activity

  • Van Tan Do;Quang Lam Truong;Hoai Thu Dao;Thi Lan Nguyen;Minna Shin;Kyeong Ryeol Shin;Tae-Wook Hahn
    • Korean Journal of Veterinary Research
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    • v.63 no.2
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    • pp.18.1-18.8
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    • 2023
  • Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death, with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were propagated successfully in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene showed that all 3 isolates belong to genogroup 2b, which is closely related to other prevalent Asian strains. A comparison of the amino acid sequence revealed a 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013-2015, suggesting that field PED viruses (PEDVs) are evolving continuously. Experiments in animals showed that the antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log2) of neutralizing antibodies against the homologous strain and a relatively moderate level of neutralizing antibodies against the field isolates. This finding would be helpful in selecting a PEDV strain for vaccine development.

Effect of disulphide bond position on salt resistance and LPS-neutralizing activity of α-helical homo-dimeric model antimicrobial peptides

  • Nan, Yong-Hai;Shin, Song-Yub
    • BMB Reports
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    • v.44 no.11
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    • pp.747-752
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    • 2011
  • To investigate the effects of disulphide bond position on the salt resistance and lipopolysaccharide (LPS)-neutralizing activity of ${\alpha}$-helical homo-dimeric antimicrobial peptides (AMPs), we synthesized an ${\alpha}$-helical model peptide ($K_6L_4W_1$) and its homo-dimeric peptides (di-$K_6L_4W_1$-N, di-$K_6L_4W_1$-M, and di-$K_6L_4W_1$-C) with a disulphide bond at the N-terminus, the central position, and the C-terminus of the molecules, respectively. Unlike $K_6L_4W_1$ and di-$K_6L_4W_1$-M, the antimicrobial activity of di-$K_6L_4W_1$-N and di-$K_6L_4W_1$-C was unaffected by 150 mM NaCl. Both di-$K_6L_4W_1$-N and di-$K_6L_4W_1$-C caused much greater inhibitory effects on nitric oxide (NO) release in LPS-induced mouse macrophage RAW 264.7 cells, compared to di-$K_6L_4W_1$-M. Taken together, our results indicate that the presence of a disulphide bond at the N- or C-terminus of the molecule, rather than at the central position, is more effective when designing salt-resistant ${\alpha}$-helical homo-dimeric AMPs with potent antimicrobial and LPS-neutralizing activities.

Neutralizing Effects of Antiserum by Repeated Subcutaneous Administration of Recombinant Human Growth Hormone (rhGH)

  • Song, Yeon-Jung;Park, Shin-Hye;Park, Seung-Kook;Yeon, Je-Deuk
    • Biomolecules & Therapeutics
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    • v.10 no.3
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    • pp.175-179
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    • 2002
  • Human growth hormone (hGH) forms antibody by repeated administration. The present study investigated to confirm formation of antibody by repeated subcutaneous administration of hGH for two months in rats and dogs. In this result, hGH-injected sera were significantly higher than control sera by 1:1,000,000 of dilution factor. After antibody formed sera (anti-hGH sera) and control sera were added to 30 $\mu\textrm{g}$/ml hGR, the complex incubated for overnight at $30^{\circ}C$. Anti-hGH sera decreased hGH contents about 90% compared to control sera. Also, body weight gain conducted decreased about 67% compared to control sera in hypophysectomised rat. Inconclusion, repeated administration of hGH formed antibody because hGH was foreign protein to rats and dogs. And formed antibody of hGH was blocked and decreased many efficacy of hGH, the antibody was proved to be neutralizing antibody. Thus, because neutralizing antibodies were decreased pharmacological effects of hGH, administration more than two months were no significance.

Monoclonal antibodies against structural proteins of bovine viral diarrhea virus (소 설사병 바이러스 구조단백에 대한 단크론항체 성상에 대한 연구)

  • Kweon, Chang-hee;Zee, Yuan Chun;Woo, Hee-jong
    • Korean Journal of Veterinary Research
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    • v.32 no.1
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    • pp.83-90
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    • 1992
  • Monoclonal antibodies against structural proteins of bovine viral diarrhea virus(BVDV) were derived by classical hybridoma techniques. These antibodies were characterized by serum neutralization, immunoblotting and immunoprecipitation. The neutralizing monoclonal antibody reacted with the 56kd to 54kd(M.W.) viral protein in western blotting and immunoprecipitation analysis. Although there was no neutralizing activity, another monoclanal antibody reacted with the 45kd protein by immunoprecipitation and with both the 45kd and 36kd proteins in immunoblotting analysis. respectively. Densitometer scanning of purified BVDV and the immunopreipitation of whole virus particles with neutralizing monoclonal antibody revealed the presence of more than twelve viral polypeptides. Although no possible precursor form of protein was identified with the neutralizing monoclonal antibody. the presence of intact virion was detected in the infected cell supernatant immediatelty after pulse labeling, indicating rapid translational processing as well as packaging of the virus. The partial peptide mapping of 45kd and 36kd proteins with Staphylococcus aureus V 8 protease showed that these two proteins are related.

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Antigastritic and Anti Helicobacter pylori Effects of Baicalein from Scutellaria Baicalensis (황금 Baicalein의 위염 및 H. pylori균에 미치는 효과)

  • Kang, Min-Hee;Lee, Jung-Hun;Lee, Yong-Soo;Son, Kun-Ho;Lee, Dong-Hwa;Kim, Yeong-Shik;Kang, Sam-Sik;Bang, Hyo-Choon;Jeong, Choon-Sik
    • YAKHAK HOEJI
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    • v.51 no.1
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    • pp.68-74
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    • 2007
  • Scutellaria Radix, the dried roots of Scutellaria baicalensis Georgi (Labiatae), has been used in oriental traditional medicine for treatment of fever urine disorder, diarrhea, inflammation. Present study was carried out for the gastroprotective effect of chrysin, baicalein, baicalin, wogonin from Scutellaria baicalensis. This reports evaluated antioxidant effect, antibacterial activity against Helicobacter pylori and HCI-ethanol-induced gastric lesion in rats and showed the significant effectiveness. It may be regarded that the antigastritic effects and antibacterial activity of baicalin, baicalein from Scutellaria baicalensis are originated from acid-neutralizing capacity, free radical scavenging effects and the antibacterial activity against Helicobacter pylori.

Expression of VP2 of Aquatic Birnavirus GC-1 Isolated from Rockfish (Sebastes schlegeli), Rearing in Seawater in Korea (국내 해산양식어 조피볼락에서 분리된 수생버나바이러스 GC-1의 VP2 발현)

  • Joh, Seong-joon;Sung, Haan-woo;Lee, Yun-jeong;Kim, Jae-hong;Kang, Shien-young
    • Korean Journal of Veterinary Research
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    • v.43 no.3
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    • pp.449-456
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    • 2003
  • The VP2 gene of aquatic birnavirus, Korean isolate (GC-1) was cloned and expressed using the baculovirus expression system. The VP2 gene and VP2 partial gene, which contained a neutralizing epitope, were constructed for recombinant transfer vectors, for baculovirus expression. The expressed recombinant proteins were confirmed by indirect immuno fluorescence antibody (IFA), SDS-PAGE and Western blot. The level of expression was checked at regular time using IFA and Western blot. To measure the neutralizing activity of recombinant proteins against GC-1 strain, the antisera against recombinant proteins were produced by using guinea pigs. The result showed that the antisera neutralized the GC-1 strain. However, the neutralizing titer was higher in antisera against the VP2 gene expressed recombinant protein than that of VP2 partial gene recombinant protein.

Studies on the production and characterization of monoclonal antibodies against bovine rotaviruses isolated in Korea (소 로타바이러스(국내분리주)에 대한 단크론항체 생산 및 특성에 관한 연구)

  • Ahn, Jae-moon;Cho, Sun-hee;Kang, Shien-young
    • Korean Journal of Veterinary Research
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    • v.36 no.2
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    • pp.395-403
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    • 1996
  • Monoclonal antibodies(MAbs) against field isolates of the bovine rotavirus A strain(G6), V strain(G10) and reference I-801 strain(G8) were produced and characterized. Six MAbs(4C2, 4D9, 5E1, 5E7, 5D5, 3E4) against A strain had neutralizing activity and reacted only with the G6 bovine rotaviruses determined by fluorescence focus neutralization (FFN) test. Otherwise, five neutralizing MAbs(1G2, 2G6, 5E2, 5E12, 5H7) against I-801 strain neutralized the G6 and G8 bovine rotaviruses. Five non-neutralizing MAbs(5F12, 7F12, 5E11, 2A11, 2B12) were VP6-specific and cross-reacted with all bovine and porcine rotaviruses examined by fluorescence antibody(FA) test. None of the MAbs reacted with bovie viral diarrhea virus(BVDV) and bovine coronavirus(BCV) determined by FA and FFN test.

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