• Korean Journal of Veterinary Service
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• v.32 no.1
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• pp.19-25
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• 2009

Porcine reproductive and respiratory syndrome (PRRS) virus is the etiological agent of diseases characterized by reproductive losses in sows and respiratory disorders in piglets. The PRRS virus is a small enveloped virus containing a positive-sense, single-stranded RNA genome. In the present study, ORF6 gene of Korean PRRS virus isolate, CNV, was cloned and expressed in baculovirus expression system. The ORF6 gene and expressed protein in the recombinant virus were confirmed by PCR/indirect fluorescence antibody (IFA) test and Western blotting, respectively. The recombinant protein with a molecular weight of approximately 24KDa was confirmed by Western blotting using His6 and PRRS virus-specific antiserum. Expressed ORF6 protein was applied for IFA to detect antibody against PRRS virus using field porcine sera. However, the sensitivity and specificity of developed IFA using expressed ORF6 protein were considerably low compared to those of commercial ELISA kit. This results suggest that IFA using expressed ORF6 protein could not be used as a diagnostic test for PRRS virus infection without further improvements.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.444-446
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• 2001

Objectives : Toxoplasmosis is a member of the zoonosis group and may cause congenital infection . Antibody positive rates of toxoplasmosis were examined in high school students in Cheju, Korea to facilitate the study aim of examining the seroprevalence of Toxoplasma gondii in school teachers of child-bearing age in Cheju Island. Methods : The study population comprised teachers of child-bearing age in primary, middle and high schools, aged 35 years and younger, who wished to be tested for Toxoplasma gondii antibodies (IgG) by the indirect latex agglutination test (ILA) and the enzyme-linked immunosorbent assay (ELISA) method. Results : The overall antibody positive rate was 3.8% in the study subjects (n=314), a rate which showed no significant difference due to birth place, history of bringing up pets, or history of contacting a cat. Conclusion : We confirmed that the seroprevalence of Toxoplasma gondii in a population of child-bearing teachers in Cheju Island was the same as that previously reported in other parts of Korea.

• Journal of fish pathology
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• v.34 no.1
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• pp.111-115
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• 2021

Immunoglobulin M (IgM) of sevenband grouper (Epinephelus septemfasciatus) was purified by mannan-binding protein (MBP) affinity column. The purified IgM had an apparent molecular weights of 76 (heavy chain) and 28 (light chain) kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Eight hybridoma clones secreting monoclonal antibodies (mAbs) against sevenband grouper IgM were established. Antibody detection enzyme-linked immunosorbent assay (ELISA) with bovine serum albumin (BSA, antigen) and the 8 mAbs revealed that optical density (OD) values were clearly different between sera from BSA-immunization and non-immunization of sevenband grouper. These results suggest that the produced mAbs in this study are specifically reacted with IgM of sevenband grouper.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.335-338
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• 2023

The COVID-19 pandemic, triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has not only impacted human health on a global scale but also raised concerns about the vulnerability of a wide array of animals that are in close contact with humans. Particularly, the potential for infection and the subsequent immune response in domestic pets such as dogs and cats remain largely unexplored under natural living conditions. In this study, we have undertaken the task of detecting and tracking the presence of antibodies against SARS-CoV-2 in a small cohort of household pets-specifically, two dogs and two cats. Employing techniques such as the indirect ELISA and plaque reduction neutralization tests, we observed that the neutralizing antibodies against SARS-CoV-2 in these animals were maintained for a duration of up to six months following their initial positive test result. This duration mirrors the antibody response documented in human cases of COVID-19, suggesting a comparable post-infection immune response timeline between humans and these domestic animals.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.405-411
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• 2011

Avian influenza virus vaccines produced in oil-emulsified inactivated form with antigen content of at least 160 hemagglutinin units (HAU) induced immunity in birds. However, in addition to enhancing the effect of the adjuvant(s), other additional supplemented biological compounds included in inactivated vaccines could produce higher levels of antibody. We examined in chickens, Vietnamese ducks, and muscovy ducks the adjuvant effect of Sophy ${\beta}$-glucan (SBG), a ${\beta}$-1,3-1,6 glucan produced by the black yeast Aureobasidium pollulans strain AF0-202, when administered with an avian influenza H5 subtype vaccine. In Experiment 1, 40 chickens (ISA Brown hybrid), allocated to four groups of ten each, were immunized with Oil-H5N1(VN), Oil-H5N1(CN), Oil-H5N2(CN), and saline (control group), respectively. In Experiment 2, chickens (ISA Brown hybrid), muscovy ducks (French hybrid), and Vietnamese ducks (indigenous Vietnamese) were used to further assess the effect of SBG on immunogenicity of the Oil-H5N1(VN) Vietnamese vaccine. ELISA and hemagglutination inhibition (HI) assays were used to assess the antibody response. The H5 subtype vaccines initiated significantly higher immune responses in the animals dosed with SBG, with 1.0-1.5 $log_2$ higher HI titers and 10-20% ELISA seroconversion, compared with those not dosed with ${\beta}$-glucan. Notably, some of the animals dosed with SBG induced HI titers higher than 9.0 $log_2$ following boosting immunization. Taken together, our serial studies indicated that SBG is a potential effector, such as enhancing the immune response to the H5 vaccines tested.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.4
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• pp.587-596
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• 2006

Most of oral streptococci express the Antigen I/II (AgI/II) proteins, cell wall anchored adhesions. AgI/II protein binds to salivary agglutinin glycoprotein, a component of tooth pellicle and to ligands in other bacteria. These associations play important roles in bacterial colonization. Recently, it was reported that diverse host molecules also interact with AgI/II protein and that these interactions induce inflammatory responses from host cells. Among mutans streptococci containing -type hemolytic activity, Streptococcus mutans is a causative agent for dental caries. Compared with many other strains of S. mutans, GS-5 strain is unique in that this bacterium expresses truncated secretory AgI/II protein due to the nonsense mutation in the agI/II gene. This indicates that S. mutans GS-5 has a different clinical role and a recent report supported this idea based on the results from clinically isolated S. mutans strains. Previously, we had cloned agI/II gene from S. mutans GS-5 and generated recombinant N-terminal AgI/II protein. In this study, we further produced a hybridoma line expressing anti-AgI/II monoclonal antibodies named as 1C11A. This antibody showed high sensitivity to AgI/II protein in Western blot and ELISA. This new reagent will provide a basis for investigating the mechanisms of AgI/II-related diseases.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.82-88
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• 1999

In this study, to evaluate newly developed Japanese encephalitis (JE) vaccine candidate CJ50003, we assessed its immunogenicity along with a previously commercialized inactivated JE Biken vaccine. The CR0003 viral antigens produced in Vero cells were administered suhcutaneouly to mice either with alum-adjuvanled or free form. The ELISA titers and neutralizing (NEUV antibody titers accounting for major protective immunity in JE were determined. Mice given alum-adjuvanted vaccine had a 10 times higher antigen-specific NEUT antibody response than did those which {lad received free antigens. This NEUT antibody response was maintained until day 168 with NEUT titer more than 1:160. Even with the 0.5 ng of alum-adjuvanted antigen dose, NEUT titer was induced more than 1:10 which is considered as an evidence for seroconversion and protection. Thc mice immune sera had a similar rate of cross-reactivity against three different viral antigens, Nakayama-NlH, P3 and SA14; as determined by ELISA assay. In a mice challenge model, vaccination with the GI50003 conferred more protection than with commercialized Biken vaccine against Nakayama virus. These data demonstrated that CJ50003 vaccine candidate has an excellent prophylactic efficacy and implicated it has a strong potential for further development and commercialization.

• Journal of fish pathology
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• v.26 no.3
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• pp.241-254
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• 2013

In order to establish bio-marker systems for the screening of endocrine-disrupting chemicals contaminated in various environment, Vitellogenin(Vtg) bio-marker have been developed to detect Scorpion fish's(Sebastiscus marmoratus) Vtg. Vtg has been induced by administration of estradiol into S. marmoratus, and purified by gel filtration and ion-exchange chromatography from serum of the fish. After immunization of the purified Vtg into BALB/c mouse, hybridomas secreting anti-Vtg antibodies have been produced. The size of induced Vtg in the serum was about 440 kDa by gel filtration using Sepharose CL-6B. By SDS-PAGE analysis, the main band of Vtg, however, was at 175 kDa, and several minor bands have been detected with the main band. Eight different monoclonal antibodies have been produced from established hybridomas and the antibodies did not cross-react with sera from different species of fishes tested in this study except with that of Sebastes hubbsi. These results suggested that the monoclonal antibody of S28 and S15 can used as capture and tracer antibodies for ELISA and ICG assays. The detection systems developed in this study can be used as Bio-marker assays to check endocrine disrupting activity of various chemicals as well as to detect known endocrine disrupting chemicals contaminated in environment.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.3
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• pp.257-265
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• 2021

The COVID-19 virus is a β-genus virus that causes infection by mediating the angiotensin convertible enzyme 2 (ACE2) receptor, which is distributed in large numbers in the human respiratory tract. The disease requires effective post-management of antibody production by complete healers and vaccinators because there is no perfect remedy for the virus infection. This study aimed to develop recombinant proteins specifically responsive to neutralizing antibodies in clinical specimens and use them to develop a rapid diagnostic kit to diagnose neutralizing antibodies quickly and conveniently against the COVID-19 virus and confirm the possibility of commercialization through a performance evaluation. Rapid diagnostic kits using COVID-19 S1 RBD recombinant proteins can be applied to rapid diagnostic kits, with positive percentage agreement (PPA) and negative percentage agreement (NPA) of 100% and 98.3%, respectively, compared to the U.S. FDA-approved ELISA kits. If the performance of the rapid diagnostic kit is improved and neutralizing antibodies can be analyzed quantitatively using quantitative analysis equipment, it can be used as important data to predict immunity to the COVID-19 virus and determine additional vaccinations.

• Parasites, Hosts and Diseases
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• v.47 no.3
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• pp.219-225
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• 2009

The seroprevalence of cryptosporidiosis was examined using patients' sera collected from hospitals located in 4 different areas of the Republic of Korea. ELISA was used to measure antibody titers against Cryptosporidium parvum antigens from a total of 2,394 serum samples, which were collected randomly from patients in local hospitals; 1)Chungbuk National University Hospital, 2) Konkuk University Hospital, 3) local hospitals in Chuncheon, Gangwon-do (province), 4) Jeonnam National University Hospital, from 2002 through 2003. Of the2,394 samples assayed, 34%, 26%, and 56% were positive for C. parvum-specific IgG, IgM, and IgA antibodies, respectively, Positive IgG titers were most common in sera from Jeonnam National University Hospital, Gwangju, Jeollanam-do, and positive IgM titers were most common in sera from Chungbuk National University Hospital, Cheongju, Chuncheonqbuk-do. The seropositivity was positively correlated with age for both the IgG and IgA antibodies but was negatively correlated with age for the IgM antibodies. Western blotting revealed that 92%, 83%, and 77% of sera positive for IgG, IgM, and IgA ELISA reacted with 27-kDa antigens, respectively. These results suggested that infection with Cryptosporidium in hospital patients occurs more commonly than previously reported in the Republic of Korea.