• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.269-276
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• 1993

To ascertain that tegument of Pnragonimus westermoni has specific antigenic proteins, the tegumental fraction was isolated from 10-month-old worms by 0.1% digitonin solution, and subjected to SDS-PAGE and immunoblot. Component proteins of tegumental syncytium comprised of 94, 74 (76-66), 62, 54, 44, 42, 38, 28, 26, 25, 24, 17, 15.5 and 13.5 kDa proteins. Of them, the 94, 44 and 42kDa proteins were more specific to tegument, especially the 94 kDa protein was the most prevailing one. In immunoblot, antigens of the 94, 90, 78, 76, 74, 68, 65, 63, 60, 59 and 54 kDa proteins were commonly detected by 7 sera of 10 human paragonimlasis, but none of them reacted with 5 sera of clonorchiasis. In conclusion, the 94 kDa protein was the major tegumental protein, as well as the specific antigen. The 76 and 66 kDa proteins were the minor components of tegument, which were also specific antigens of R westermcni.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.475-479
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• 2020

Tegumental and excretory-secretory proteins are reported as diagnostic antigens for human opisthorchiasis. Rhophilin associated tail protein1-like (OvROPN1L) protein of Opisthorchis viverrini sperm tail showed potential as a diagnostic antigen. The OvROPN1L recombinant fragments were assayed for diagnostic antigenicity for human opisthorchiasis using indirect ELISA. The strongest antigenic region was a N-terminus peptide of M1 - P56. One synthetic peptide (P1, L3-Q13) of this region showed the highest antigenicity to opisthorchiasis. Sera from other parasitic infections including Strongyloides stercoralis, hookworm, Taenia spp, minute intestinal flukes, Paragonimus spp showed lower reactivity to P1. Peptide P1 is located in the disordered N-terminus of ROPN1L supporting its suitability as linear epitope. In the Platyhelminthes the N-terminal sequence of ROPN1L is diverging with taxonomic distance further suggesting that peptide P1 has potential as diagnostic tool in the genus Opisthorchis/Clonorchis. It should be further evaluated in combination with peptides derived from other O. viverrini antigens to increase its diagnostic power.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1335-1343
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• 2022

COVID-19 is an emerging disease that poses a severe threat to global public health. As such, there is an urgent demand for vaccines against SARS-CoV-2, the virus that causes COVID-19. Here, we describe a virus-like nanoparticle candidate vaccine against SARS-CoV-2 produced by an E. coli expression system. The fusion protein of a truncated ORF2-encoded protein of aa 439~608 (p170) from hepatitis E virus CCJD-517 and the receptor-binding domain of the spike protein from SARS-CoV-2 were expressed, purified and characterized. The antigenicity and immunogenicity of p170-RBD were evaluated in vitro and in Kunming mice. Our investigation revealed that p170-RBD self-assembled into approximately 24 nm virus-like particles, which could bind to serum from vaccinated people (p < 0.001) and receptors on cells. Immunization with p170-RBD induced the titer of IgG antibody vaccine increased from 14 days post-immunization and was significantly enhanced after a booster immunization at 28 dpi, ultimately reaching a peak level on 42 dpi with a titer of 4.97 log₁₀. Pseudovirus neutralization tests showed that the candidate vaccine induced a strong neutralizing antibody response in mice. In this research, we demonstrated that p170-RBD possesses strong antigenicity and immunogenicity and could be a potential candidate for use in future SARS-CoV-2 vaccine development.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.257-264
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• 1983

In order to obtain more specific antigenic preparation for the diagnosis of human paragonlmiasis, crude saline extract of whole worm (=PwWWE), secretory.excretory components (PwSEC) and secretion-excretion-free somatic extract (PwSM) of 12 week-old ParagoninBus westermani were filtrated through Sephadex G-200 gel column. The adult Paragonimus worms were obtained from expevimentally infected doge. A total of 11 antigenic solutions was Iyophilised or diluted to adjust protein content of 1mg/ml. To evaluate the antigenicity of crude antigens and fractions, micro-ELISA was done with the sera from P westermani in(ected cases, C. sinensis infected cases and non-infected control cases to detect Paragonimus specific IgG antibody. The results were as follows: 1. When the PwWWE was filtrated through Sephadex G-200 gel, it was separated into three fractions; PwWWE Fr. 1, PwWWE Fr. 2 and PwWWE Fr. 3. The percentage of protein content was 28.0%, 21.6% and 50.4% respectively. The PwSM was also. separated into three fractions; PwSM Fr. 1, PwSM Fr. 2, PwSM Fr. 3. and their percentage of protein content was 41.3%, 38.6% and 20.1%. However, the PwSEC showed different fractionation pattern; i.e. fraction 1 (=PwSEC Fr.1) and 3 (PwSEC Fr. 3) without fraction 2. The percentage of protein content was 14.0% in PwSEC Fr. 1 and 86.0% in PwSEC Fr. 3. 2. When the antigenicity of each Paragonimus crude antigen and fractionated antigen was evaluated for specific IgG aritibody by micro-ELISA in 10 human paragonimiasis sera, PwSEC Fr, 1 was the most potent antigen showing the mean absorbance 1.98. The PwWWE Fr. 1, PwSEC, PwWWE were next to that: their mean absorbance were 1.72, 1.38 and 0.83 respectively. The antigenicity of fractions 2 and 3 was much weaker in binding specific IgG antibody. 3. When the antigens were reacted in micro-ELISA with 10 human clonorchiasis sera, most antigens showed weak reactivity. Each fraction 1 of crude antigens reacted higher than other fractions or crude antigens; the mean absorbance was 0.17 in fraction 1, but in others the absorbances were about 0.06. 4. With non-infected control sera, the result of micro-RLISA revealed almost same pattern with those of the clonorchiasis sera. From the above results, it became apparent that PwWWE Fr. 1, especially PwSEC Fr. 1 was the most potent antigen reacted with Paragonisfaus specific IgG antibody.

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.875-882
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• 1997

To produce the recombinant fibronectin-binding protein(FnBP) for development of subunit vaccine against Staphylococcus aureus. The fnbp gene was amplified from the chromosomal DNA of S aureus KNU 196 strain using the polymerase chain reaction, and cloned into pGEX-4T-2. Then, the recombinant FnBP fused with glutathione-S-transferase was produced in E coli, purified by affinity chromatography, and identified its antigenicity and immunogenicity by Western blot. The recombinant FnBP produced in this study is considered to have the same property of native FnBP purified from S aureus, and is expected to be useful as a candidate for S aureus subunit vaccine.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.273-277
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• 2006

To investigate the antigenicity and protective immunity of outer membrane protein H (OmpH) in Pasteurella multocida D:4, the recombinant OmpH protein was produced in Escherichia coli. The truncated and Trx-fused form of recombinant OmpH (53 kDa) was purified, and used as an antigen in the immunization and challenge experiment. The immunized mice with the recombinant OmpH produced a high-titer antibody, and had protective immunity against P. multocida as same level as the mice immunized with formalin-killed whole cell.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.445-450
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• 2016

Thermal-stable soluble proteins (TSSP) in livestock products has been recently reported. Therefore, the development of antibodies and immunoassay using a TSSP is useful because the presence of TSSP can be measured on processed food. In this study, the existence of TSSPs in pork fat and meat was confirmed and their antigenicity was investigated. The extracts from pork fat and meat by heating method were analyzed by SDS-PAGE with 5% stacking and 12% separating gels. The protein profiles from the raw pork fat and meat extracts (major band ranged 25 to 100 kDa) without cooking and heating treatments were significantly different compared to those from cooked and heated pork fat and meat extracts (several major bands > 100 kDa and < 30 kDa). This meant that non thermal-stable soluble proteins ranged from 25 to 100 kDa may be denaturated to insoluble proteins by cooking and heating treatments, and TSSPs were in pork fat and meat at kept their properties. The confirmed TSSPs were used as an immunogen to investigate their antigenicity. Eight mice (5 mice for pork fat and 3 mice for pork meat) were separately immunized with the TSSPs of pork fat and meat, and the anti-sera obtained from the immunized mice showed high titer values. Polyclonal antibodies against each target protein showed the specific reaction to pork fat and meat, individually. These indicated that TSSP could be used as an immunogen to produce antibodies such as monoclonal and polyclonal antibodies. In addition, antibodies specific to TSSP from pork fat and meat may be used as a bio-receptor in immunoassays for the identification of fraudulent adulteration with pork fat and meat in livestock products.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.13-18
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• 1990

A DNA sequence encoding the adr subtype preS2 region of hepatitis B virus envelope protein was fused to 5' end of lacZ gene yielding a plasmid pTSZ, in order to produce a preS2-$\beta$-galactosidase fusion protein. Serial deletions from 3' and 5' end of preS2 were constructed in plasmids, which were expressed and their antigenicities were examined with the monoclonal antibody H8. Deletions from amino and carboxy terminal to certain points did not affect the antigenicity, but the longer deletions destroyed the antigenicity. End points of deleted preS2 sequence were determined by DNA sequencing. As a result, each end of preS2 epitope was located in the region of amino acid residue 130-132 and 140-142, respectively. Residue 143 may be supplementary for antigenic epitope since the deletion from carboxy terminal to residue 143 revealed partial defect of antigenicity. In the interval of antigenic epitope the amino acid differences between adr and adw2 subtype occurred ar residue 130, 132, and 141. This result indicated that one or more of the three residues are responsible for the binding specificity of monoclonal antibody H8 to adr subtype preS2 fusion protein.

• Journal of Microbiology
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• v.37 no.4
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• pp.234-242
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• 1999

To obtain the recombinant circumsporozoite (CS) protein for the diagnosis of patients and seroepidemiology of Plasmodium vivax malaria which have been prevalent in northern part of Kyonggido, the CS protein gene was amplified by the polymerase chain reaction (PCR) from genomic DNA of the Korean vivax malaria patient. The gene consists of 1,123 nucleotides except signal peptide sequences and had an uninterrupted reading frame encoding a protein of 374 amino acids with a central region of 20 tandem repeats of the nonapeptide. The CS protein gene was expressed in Escherichia coli and purified, the molecular weight of recombinant CS protein was about 44 kDa (monomer) under denaturing purification and about 65 kDa (dimer) under native purification by SDS-PAGE. The purified recombinant CS protein which has antigenicity to malaria patients in Western blot analysis and Enzyme-linked immunosorbent assay, reacted only with the serum of P. vivax (PV210) infected malaria patients with no cross reaction to the P. falciparum malaria patient. The recombinant CS protein purified in this study will serve as a useful antigen to support the diagnosis of malaria patients and seroepidemiology.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.25-31
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• 2010

Papaya ringspot virus (PRSV) causes the most widespread and devastating disease in papaya. Isolates of PRSV originating from different geographical regions in south India were collected and maintained on natural host papaya. The entire coat protein (CP) gene of Papaya ringspot virus-P biotype (PRSV-P) was amplified by RTPCR. The amplicon was inserted into pGEM-T vector, sequenced and sub cloned into a bacterial expression vector pRSET-A using a directional cloning strategy. The PRSV coat protein was over-expressed as a fusion protein in Escherichia coli. SDS-PAGE gel revealed that CP expressed as a ~40 kDa protein. The recombinant coat protein (rCP) fused with 6x His-tag was purified from E.coli using Ni-NTA resin. The antigenicity of the fusion protein was determined by western blot analysis using antibodies raised against purified PRSV. The purified rCP was used as an antigen to produce high titer PRSV specific polyclonal antiserum. The resulting antiserum was used to develop an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) assay and compared its sensitivity levels with ELISA based assays for detection of PRSV isolates. IC-RT-PCR was shown to be the most sensitive test followed by dot-blot immunobinding assay (DBIA) and plate trapped ELISA.