• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.343-350
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• 2001

The neutralization epitopes of the outer capsid protein VP4 of a porcine rotavirus, Gottfried strain, were studied using neutralizing monocolonal antibodies(N-MAbs). Eight N-MAbs which are specific for the VP4 of Gottfried strain were used for analyzing the antigenic sites of VP4. Three different approaches were used for this analysis; i)testing the serological reactivity of each N-MAb against different G and P types of human and animal rotavirusese ii) analyzing N-MAb-resistant viral escape mutants and iii) performing nucleotide sequence analysis of the VP4 gene of each N-MAb-resistant viral escape mutant. From experimental results, at least four antigenic sites(I, II, III, and IV) were identified. Antigenic site I recognized by N-MAbs 24B9, 23G10, and 26A2 was separated from antigenic site II recognized by N-MAbs 30H5, 32B3, and 29B3. However, these antigenic sites were overlapped with antigenic site III recognized by N-MAb 21A1. The other antigenic site IV recognized by N-MAb 16D2 was separated from antigenic sites I, II, and III.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.319-327
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• 1998

The nucleotide sequences of spike (S) glycoprotein containing antigenic sites A and D of TGEV isolated in Korea were determined and compared with published sequences for TGEVs. The TGEV 133 and DAE5 strains had 97.40% nucleotide sequence similarity. The overall nucleotide sequence similarity of the 133 and DAE5 strains compared with other TGEV strains was between 96.86% and 99.15%. The similarity of the predicted amino acid sequence of the 133 and DAE5 strains was 94.93%. The TGEV 133 and DAE5 strains had 94.93-98.61% amino acid similarity with published sequences of other TGEV strains. The sequences of amino acid codons in the antigenic sites A and D were identical among all the viruses although there were several nucleotide changes in region containing antigenic sites A and D of Korean TGEV isolates. By phylogenetic analysis of the sequences, two Korean isolates 133 and DAE5 seemed to be derived from different lineages. These studies showed that a distinct difference in genome exists among TGEV field strains isolated in Korea.

• Parasites, Hosts and Diseases
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• v.32 no.2
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• pp.111-116
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• 1994

Immunoblot analysis utilizing bovine sera from naturally or experimentally infected with Theileria sergenti were used to determine the immunodominant polypeptides of T sergenti (Korean isolated. The previously recognized major bands, 18 kDa,29 kDa, 34 kDa and 45 kDa, were excised after electrophoresis and transfer to PnF membrane. The individual bands were sequenced. The 34 kDa polypeptide which was the most antigenic and immunogenic peptide was observed in the Western blot. However, Chou-Fasman prediction sites (antigenic site) for antigen determinants of the 45 kDa, 34 kDa, 29 kDa and 18 kDa polypeptide were 6, 4, 2 and 0, respectively. However, the 45 kDa polypetide showed no reaction with anti- T sergenti hyperimmune serum.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.53-63
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• 1998

Total of 1085 swine sera (1996-1997) from nation-wide were tested for the presence of antibodies to influenza A virus. Fifty nine percent of the tested sera showed seropositive by HI test. Positive sera consisted of 24--- of H3, 15--- of H1, and 20--- of the sample had both antibodies, respectively. Sera collected from various region represented 7~27--- seropositivity to H1N1, 15~25--- to H3N2, respectively. Swine influenza field isolate from nasal swab was characterized antigenically and genetically to elucidate its relatedness with other known strains of influenza A virus. The study was focused on the HA gene which is related to pathogenecity and antigenic variability of the influenza virus. By RT-PCR using influenza A/H1N1 specific primers, influenza virus H1N1 specific DNA fragment was amplified from A/Swine/Iowa/15/30(H1N1), US field isolate but not in H3N2 strain. PCR products were sequenced by dideoxy chain termination method to determine nucleotide homology with other strains of influenza A virus. The US field isolate and A/Swine/Indiana/1726/88 strain had 97--- of nucleotide homology and 98--- of amino acid homology. Based on the results obtained from this experiment, the field isolate was genetically related to A/Swine/Indiana/1726/88 and had higher homology with A/Swine/Indiana/1726/88 than with classical swine influenza virus, A/Swine/Iowa/15/30. The field isolate had no amino acid changes at the antigenic site compare to that of the A/Swine/Indiana/1726/88. The proteolytic enzyme cleavage site between HA1 and HA2 had no alteration and the amino acid arginine was intact. There is no evidence has been found that the field isolate has genetic shift or genetic drift which might altered antigenic determinant.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.55.1-55.12
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• 2022

Background: ASF was first reported in Kenya in 1910 in 1921. In China, ASF spread to 31 provinces including Henan and Jiangsu within six months after it was first reported on August 3, 2018. The epidemic almost affected the whole China, causing direct economic losses of tens of billions of yuan. Cause great loss to our pig industry. As ELISA is cheap and easy to operate, OIE regards it as the preferred serological method for ASF detection. P54 protein has good antigenicity and is an ideal antigen for detection. Objective: To identify a conservative site in the African swine fever virus (ASFV) p54 protein and perform a Cloth-enzyme-linked immunosorbent assay (ELISA) for detecting the ASFV antibody in order to reduce risks posed by using the live virus in diagnostic assays. Method: We used bioinformatics methods to predict the antigen epitope of the ASFV p54 protein in combination with the antigenic index and artificially synthesized the predicted antigen epitope peptides. Using ASFV-positive serum and specific monoclonal antibodies (mAbs), we performed indirect ELISA and blocking ELISA to verify the immunological properties of the predicted epitope polypeptide. Results: The results of our prediction revealed that the possible antigen epitope regions were A23-29, A36-45, A72-94, A114-120, A124-130, and A137-150. The indirect ELISA showed that the peptides A23-29, A36-45, A72-94, A114-120, and A137-150 have good antigenicity. Moreover, the A36-45 polypeptide can react specifically with the mAb secreted by hybridoma cells, and its binding site contains a minimum number of essential amino acids in the sequence 37DIQFINPY44. Conclusions: Our study confirmed a conservative antigenic site in the ASFV p54 protein and its amino acid sequence. A competitive ELISA method for detecting ASFV antibodies was established based on recombinant p54 and matching mAb. Moreover, testing the protein sequence alignment verified that the method can theoretically detect antibodies produced by pigs affected by nearly all ASFVs worldwide.

• 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.

• The Korean Journal of Zoology
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• v.22 no.3
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• pp.115-124
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• 1979

Two homotetrameric lactate dehydrogenase isozymes from Fluta alba and one from Ophicephalus argus were purified by combination of gel filtration and DEAE-cellulose chromatogrphy. The final preparations were isozymically pure and used to elicit antibodies in rabbits. The immunochemical reactivities demonstrated that the amino acids of active site is not to be included in the antigenic determinants, that antibodies or unknown component of immunized rabbit serum might be responsible for the electrophoretic abnormality and that two subunits share common antigenic determinants, reflecting that these polypeptides have a common evolutionary origin.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.141-146
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• 1984

Two PVY strains (PVY-VB and PVY-VN) isolated from tobacco in Korea were compared for their serological relationship with other 8 strains which were obtained from tobacco or potato in different countries. One of these strains, PVY-Argentina showed the spur reaction to PVY-VB and PVY-VN antisera in SDS-agar gel double diffusion plates. The two Korean PVY strains were closely related to other strains except for one, PVY-Argentina when antigen-antibody reciprocal absorption tests were conducted. It is suggested that the strain, PVY-Argentina, is a new serotype containing a specific antigenic site different from other 9 strains tested.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.301-310
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• 1992

This work was performed to investigate the possibility of using J96 hemolysin(Hly, Hly A) vaccine against urinary tract infecting Escherichia coli. Based on the known sequence of J96 hemolysin which was originally isolated from a pyelonephritis patient, ten 20-mer oligonucleotide probes were synthesized. Radioactive labelled 8 probes showed positive colony blots against most of the hemolysin producing wild type E. coli, while HA484 and HA661 showed 28.3, 71.7% positive blots, respectively. This result means that hemolysin genes are highly conserved. Also, 12 anti-Hly MABs(monoclonal antibodies) showed more than 90% positive immunoblots against secreted hemolysin from wild type E. coli. Especially, the result that MAB132 neutralized hemolysin from all of the wild type E. coli augments the idea that hemolysin will be effective as a vaccine.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.31-38
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• 1997

The skin ulcer in Leishmcnio mcior infection is known to be variable according to the inoculation sites even in a susceptible host. The present study traced the immunoblot patterns by the site of inoculation and duration of infection in BALB/c mice. L. mqior were subcutaneously inoculated on the nose, footpad, and back of the mice, in a dose of 3 × 106 promastigotes. Sera of the mice were collected every 10 days after inoculation. SDS-PAGE separated soluble protein bands of the promastigotes and immunoblot was carried out with the infection sera. The skin ulcer first appeared on the nose at 15 days, and on the footpad at 17 days after inoculation. The ulcer on the back appeared after 90 days. In the mice with ulcer on the nose or footpad, serum IgG antibody reacted to 202, 139, 98, 83, 81, 67, 65, 62, 59, 54, 52, 42, 26, and 23 kDa bands at 20 days after inoculation. In mice inoculated on the back, however, the immunoblot showed visible reactions with 202, 83, 81 74, 67, 65, 62, 59, 54, 52,20 and 17 kDa bands at 90 days after inoculation. The present result showed that the antigenic protein bands of L. mqior promastigotes were differed by the inoculation site and duration of infection. Since the skin ulcer and the serum antibodies to antigenic bands between 67-52 kDa appeared simultaneously, it is suggested that the serum IgG antibodies may play a role in formation of the skin ulcer in BALB/c mice.