• 한국수산과학회지
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• 제50권2호
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• pp.169-174
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• 2017

Immunoglobulin M (IgM) was purified from olive flounder Paralichthys olivaceus sera using mannan-binding protein (MBP) and protein L affinity columns (designated as MBPIgM and ProLIgM, respectively). A monoclonal antibody (MAb) against olive flounder IgM was produced. The MBPIgM and ProLIgM had apparent molecular weights of 77, 73, and 28 kDa in SDS-PAGE. Nine hybridomas secreting MAbs against olive flounder IgM were established: five MAbs for MBPIgM (1, 2, 3, 4, and 5) and four for ProLIgM (6, 7, 8, and 9). Western blotting indicated that seven MAbs recognized heavy (H; MAbs 1, 2, 3, 4, 5, 6, and 7) chains and one recognized light (L; MAb 9) chains of IgM, while MAb 8 did not recognize IgM. The results of enzyme-linked immunosorbent assay (ELISA) with bovine serum albumin (BSA, antigen) and the nine MAbs revealed that the optical density (OD) values of sera differed significantly between BSA- and non-immunized fish, despite some sera from non-immunized fish with slight high OD values. These results suggest that the MAbs produced in this study reacted specifically with the IgM from olive flounder.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.318-324
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• 2006

In order to develop an oral vaccine to prevent H. pylori infection, we have expressed the hpaA gene of H. pylori K51 isolated from Korean patients, encoding 29-kDa HpaA that is known to be localized on the cell surface and flagella sheath, in a live delivery vector system, Lactococcus lactis. The hpaA gene, amplified by PCR using the genomic DNA of H. pylori K51, was cloned in the pGEX-2T vector, and the DNA sequence analysis revealed that the hpaA gene of H. pylori K51 had 99.7% and 94.8% identity with individual hpaA genes of the H. pylori 26695 strain (U.K) and the J99 strain (U.S.A). A polyclonal anti-HpaA antibody was raised in rats using GST-HpaA fusion protein as the antigen. The hpaA gene was inserted in an E. coli-L. lactis-shuttle vector (pMG36e) to express in L. lactis. Western blot analysis showed that the expression level of HpaA in the L. lactis transformant remained constant from the exponential phase to the stationary phase, without extracelluar secretion. These results indicate that the HpaA of H. pylori K51 was successfully expressed in L. lactis, and suggest that the recombinant L. lactis expressing HpaA may be applicable as an oral vaccine to induce a protective immune response against H. pylori.

• 한국축산식품학회지
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• 제32권6호
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• pp.706-712
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• 2012

The present study was aimed to produce a chicken polyclonal antibody against Cronobacter muytjensii and to develop an immunoassay for its detection. Purification of anti-C. muytjensii IgY from egg yolk was accomplished using various methods such as water dilution and salt precipitation. As a result, sodium dodecyl sulfate-polyacrylamide gel electrophoresis produced two bands around 30 and 66 kDa, corresponding to a light and a heavy chain, respectively. Indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was performed to determine the effectiveness of the chicken IgY against C. muytjensii. The optimum conditions for detecting C. muytjensii by indirect ELISA and checkerboard titration of the antigen revealed an optimum average absorbance at the concentration of 18 ${\mu}g/mL$, having ca. $10^8$ coated cells per well. The anti-C. muytjensii IgY antibody had high specificity for C. muytjensii and low cross-reactivity with other tested pathogens. In this assay, no cross-reactivity was observed with the other genera of pathogenic bacteria including Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, Enterobacter aerogenes, Salmonella Enteritidis and Listeria monocytogenes. In addition, detection of C. muytjensii in infant formula powder showed a low matrix effect on the detection curve of IC-ELISA for C. muytjensii, with similar detection limit of $10^5$ CFU/mL as shown in standard curve. These findings demonstrate that the developed method is able to detect C. muytjensii in infant formula powder. Due to the stable antibody supply without sacrificing animals, this IgY can have wide applications for the rapid and accurate detection of C. muytjensii in dairy foods samples.

• IMMUNE NETWORK
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• 제9권4호
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• pp.138-146
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• 2009

Background: The MHC region of the chromosome contains a lot of genes involved in immune responses. Here we have investigated the mouse NG29/Cd320 gene in the centrometrically extended MHC region of chromosome 17. Methods: We cloned the NG29 gene by RT-PCR and confirmed the tissue distribution of its gene expression by northern blot hybridization. We generated the NG29 gene expression constructs and polyclonal antibody against the NG29 protein to perform the immunofluorescence, immunoprecipitation and flow cytometric analysis. Results: The murine NG29 gene and its human homologue, the CD320/8D6 gene, were similar in the gene structure and tissue expression patterns. We cloned the NG29 gene and confirmed its expression in plasma membrane and intracellular compartments by transfecting its expresssion constructs into HEK 293T cells. The immunoprecipitation studies with rabbit polyclonal antibody raised against the NG29-NusA fusion protein indicated that NG29 protein was a glycoprotein of about 45 kDa size. A flow cytometric analysis also showed the NG29 expression on the surface of Raw 264.7 macrophage cell line. Conclusion: These findings suggested that NG29 gene in mouse extended MHC class II region was the orthologue of human CD320 gene even though human CD320/8D6 gene was located in non-MHC region, chromosome 19p13.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1475-1481
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• 2008

B3 antibody specifically binds the $Lewis^Y$-related carbohydrate antigen of many carcinomas, and it is used as a model antibody in this study. In a previous study, the Fab fragment of the antibody was fused to a 38 kDa truncated form of Pseudomonas exotoxin A, PE38, to make Fab-PE38, where PE38 is fused to the Fd fragment of the Fab domain. This parent monomer molecule, Fab-PE38, had no cysteine in the hinge region, and it could not make a disulfide bond to form a disulfide bond bridged homodimer. In this study, we constructed three different kinds of divalent Fab-toxin fusion homodimers where the toxin is fused to the light chain of Fab, $(Fab-PE38fl)_2$. In addition to the PE38 toxin fused to the light chain, these three molecules have different hinge sequences hi, h2, and h3 making Fabh1-, Fabh2-, and Fabh3-PE38fl monomers, respectively. These hinges contain only one cysteine on different positions of the hinge sequence. The disulfide bond between the hinge region of two monomers forms homodimers $(Fabh1-PE38fl)_2$, $(Fabh2-PE38fl)_2$, and $(Fabh3-PE38fl)_2$. The refolding yields of these dimers were 5-16-fold higher than a previously constructed dimer where the PE38 was fused to the Fd fragment $(Fabh2-PE38)_2$ [8]. Our data suggest that the steric repulsion between the two PE38s in $(Fabh1-PE38)_2$ during disulfide bridge formation is relieved by fusing it at the end of the light chain. The best cytotoxicity value of these dimers showed about 2.5-fold higher on an MCF7 cell line than that of the monovalent reference molecule in ng/ml scale, which is 15-fold higher in pM scale.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.912-918
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• 2003

Mitotic centromere-associated kinesin (MCAK), which is a novel kinesin with a central motor domain, is believed to playa role in mitotic segregation of chromosome during the M phase of the cell cycle. In the present study, it is shown that a rabbit polyclonal antibody has been produced using the N-terminal region (187 aa) of human MCAK expressed in E. coli as the antigen. To express the N-terminal region in E. coli, the MCAK cDNA fragment encoding N-terminal 187 aa was obtained by PCR and was then inserted into the pET 3d expression vector. Molecular mass of the N-terminal region overexpressed in the presence of IPTG was 23.2 kDa on SDS-PAGE, and the protein was insoluble and mainly localized in the inclusion body that could be easily purified from the other cellular proteins. The N-terminal region was purified by electro-elution from the gel after the inclusion body was resolved on the SDS-PAGE. The antiserum obtained after tertiary immunization with the purified protein specifically recognized HsMCAK when subjected to Western blot analysis, and showed a fluctuation of the protein level during the cell cycle of human Jurkat T cells. Synchronization of the cell-cycle progression required for recovery of cells at a specific stage of the cell cycle was performed by either hydroxyurea or nocadazole, and subsequent release from each blocking at 2, 4, and 7 h. Northern and Western analyses revealed that both mRNA and protein of HsMCAK reached a maximum level in the S phase and declined to a basal level in the G1 phase. These results indicate that a polyclonal antibody raised against the N-terminal region (187 aa) of HsMCAK, overexpressed in E. coli, specifically detects HsMCAK (81 kDa), and it can analyze the differential expression of HsMCAK protein during the cell cycle.

• Tuberculosis and Respiratory Diseases
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• 제49권5호
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• pp.558-567
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• 2000

배경 : 현행 도말 및 배양 등의 미생물학적 검사법의 제한점을 보완할 수 있는 신속하고 간편한 결핵진단 방법의 하나로서 가장 많이 연구되어 온 분야가 혈청학적인 방법이다. 이 중 현재까지 결핵의 혈청학적 진단에 유용성이 높은 것을 평가되는 항원의 하나가 38-kDa으로 대표되는 결핵균 분비항원이다. 이 38-kDa을 주항원 성분으로 하여, 간편하게 실험할 수 있도록 kit화된 수입제품이 국내에서 널리 시판되고 있는 실정에서 국내의 회사에서 개발한 ELISA kit(Erum Biotech Co.)를 이용하여 폐결핵의 혈청학적 진단이 얼마나 유용한 지를 평가하고자 하였다. 방법 : 도말 및 배양검사장 균양성으로 진단된 후 항결핵치료를 받고 있는 폐결핵환자 333명(검사당시 균양성 환자 212명, 균음전된 환자 121명), 건강 성인 80명, 그리고 국립마산결핵병원에서 1년 이상 근무하며 환자와 접촉을 자주 하게되는 접촉군 61명 등 총 474명을 대상으로 하여 결핵의 혈청학적 진단용 ELISA kit를 이용하여 시험하였다. 결과 : 1) 균양성 활동성 폐결핵환자 212명에 대한 ELISA kit의 양성반응률은 82.1%, 균음성 활동성 폐결핵환자 121명에 대한 양성반응률은 73.6%로 이 두 군 사이에는 통계학적으로 유의한 차이가 없었다(p>0.05). 2) 접촉 대조군 61명에 대한 양성반응률은 14.8%, 건강 대조군 80명에 대한 양성반응률은 2.5%로 이 두 군 사이에는 통계적으로 유의한 차이가 있었다(plt;0.001). 3) 활동성 폐결핵환자 333명 모두에 대한 양성반응률은 78.90%, 대조군 141명 모두에 대한 양성반응률은 7.8%로 이 두 군 사이에는 통계적으로 유의한 차이가 있었다(p<0.001). 4) ELISA kit의 민감도는 78.9%, 특이도는 97.5%였으며, 유병율이 60.1% 수준일 때의 양성예측율은 96.1%, 음성예측율은 65.0%였다. 결론 : ELISA kit는 민감도나 특이도 면에서 수입시판되고 있는 ICT와 비교할 때 비슷한 결과를 보이며, 전통적으로 결핵을 진단하는 데 사용하던 흉부 X-선 사진, 항산균 염색 및 배양 등과 함께 보조적인 도구로 사용 할 수 있을 것으로 생각된다.

• 대한수의학회지
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• 제61권2호
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• pp.19.1-19.7
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• 2021

Feline panleukopenia virus (FPV) causes leukopenia and severe hemorrhagic diarrhea, killing 50% of naturally infected cats. Although intact FPV can serve as an antigen in the hemagglutination inhibition (HI) test, an accidental laboratory-mediated infection is concern. A non-infectious diagnostic reagent is required for the HI test. Here, we expressed the viral protein 2 (VP2) gene of the FPV strain currently prevalent in South Korea in a baculovirus expression system; VP2 protein was identified by an indirect immunofluorescence assay, electron microscopy (EM), Western blotting (WB), and a hemagglutination assay (HA). EM showed that the recombinant VP2 protein self-assembled to form virus-like particles. WB revealed that the recombinant VP2 was 65 kDa in size. The HA activity of the recombinant VP2 protein was very high at 1:2¹⁵. A total of 143 cat serum samples were tested using FPV (HI-FPV test) and the recombinant VP2 protein (HI-VP2 test) as HI antigens. The sensitivity, specificity, and accuracy of the HI-VP2 test were 99.3%, 88.9%, and 99.3%, respectively, compared to the HI-FPV test. The HI-VP2 and HI-FPV results correlated significantly (r = 0.978). Thus, recombinant VP2 can substitute for intact FPV as the serological diagnostic reagent of the HI test for FPV.

• 동의생리병리학회지
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• 제24권4호
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• pp.616-623
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• 2010

Three herbal formulas (Bangpungtongsung-san, Ohyaksungi-san, and Ojeok-san) for wind-cold and heat pain symptom were applied to investigate the immunological activities on antigen (Ag)-specific or Ag-non-specific immune responses in murine macrophage cell line (RAW 264.7) and ovalbumin (OVA)-immunized mice. This study was carried out in nitric oxide (NO) synthesis in RAW 264.7 cells and cellular proliferation in mouse splenocytes according to three herbal formulas. C57BL/6 mice were immunized intraperitonially with OVA/aluminium ($100\;{\mu}g/200\;{\mu}g$/mouse) on day 1, 8, and 15. Three herbal formulas were administrated to mice orally for 3 weeks from day 1. On day 22, OVA-, lipopolysaccharide (LPS)-, and concanavalin A (Con A)-stimulated splenocyte proliferation and antibodies (OVA-specific antibodies of the IgG, lgG1, and total IgM classes) in plasma were measured. Ohyaksungi-san increased NO synthesis in RAW 264.7 cells. Ojeok-san and Ohyaksungi-san significantly enhanced cellular proliferation by LPS and Con A in splenocytes from OVA-immunized mice (p<0.001). Three herbal formulas for wind-cold and heat pain symptom also significantly enhanced plasma OVA-specific IgG, IgG1, and total IgM levels compared with the OVA/Alum group. These results suggested that three herbal formulas for wind-cold and heat pain symptom could be used as stimulator of immune response.

• 생명과학회지
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• 제15권2호
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• pp.253-260
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• 2005

인체 MCAK 단백질을 Escherichia. coli에서 재조합 단백질로 발현하였다. 이를 SDS-PAGE 후 electroelution으로 정제하고 항원으로 사용하여 rat에서 다클론성 항체생성을 유도한 결과, 생성된 항체는 Western blot analysis에 의해 인체 MCAK 단백질 (81 kDa)을 특이적으로 인식할 수 있었으며, Jurkat T cells과 293T cells에 있어서 MCAK 단백질의 대부분이 핵 내에 위치함을 확인할 수 있었다. 세포주기에 따른 MCAK 단백질의 발현양의 변화를 조사하기 위해, Jurkat T cells을 Hydroxy urea 또는 Nocodazole의 처리로 $G_{1}/S$ boundary 그리고 $G_{2}/M$ boundary에 blocking하고 이로부터 release 시키는 시간을 달리하여 다양한 세포주기상에 위치한 Jurkat T cells을 확보하였다. 각각의 Jurkat T cells로부터 cell lysate를 얻어서 Western blot analysis를 시도한 결과, MCAK 발현양은 S phase에서 가장 높았으며 MCAK의 SDS-PAGE상의 mobility가 81 kDa에서 84 kDa로 shift됨을 확인하였다. MCAK의 전기영동상의 mobility shift에 의한 slow moving $p84^{HsMCAK}$는 S phase 후반부터 나타나기 시작하며 $G_{2}/M$ phase에 최대였고 $G_{1}$, phase에서는 확인되지 않았다. 이는 세포주기에 따라 MCAK의 단백질의 인산화 양상이 달라짐을 시사한다. 생성된 항체를 이용한 Immunocytochemical analysis의 결과, 인체 MCAK 단백질은 세포주기의 interphase에서는 주로 중심체와 핵에 존재하며, M phase의 각 단계에 따라서 spindle pole, centromere, spindle fiber 또는 midbody에 존재함을 확인하였다. 이러한 연구 결과는 E. coli에서 발현된 재조합 HsMCAK 단백질을 항원으로 하여 rat에서 생산한 다클론성 항체가 HsMCAK 단백질을 특이적으로 인식할 수 있음과 또한 HsMCAK 단백질의 인산화를 나타내는 SDS-PAGE상의 mobility-shift가 $G_{2}/M$ phase에 최대에 도달하는 양상으로 세포주기에 따라 변동됨을 나타내며, HsMCAK의 인산화와 HsMCAK의 세포 내 위치간의 관련성을 시사한다. 아울러 이러한 연구결과는 hamster 및 Xenopus 등에서 주로 연구되고 있는 MCAK의 세포주기상의 주요기능이 인체세포에도 적용될 수 있음을 시사한다.