• Parasites, Hosts and Diseases
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• 제45권4호
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• pp.287-293
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• 2007

The identification and characterization of antigens that elicit human T cell responses is an important step toward understanding of Leishmania major infection and ultimately in the development of a vaccine. Micropreparative SDS-PAGE followed by electro transfer to a PVDF membrane and elution of proteins from the PVDF, was used to separate 2 novel proteins from L. major promastigotes, which can induce antibodies of the IgG2a isotype in mice and also are recognized by antisera of recovered human cutaneous leishmaniasis subjects. Fractionation of the crude extract of L. major revealed that all detectable proteins of interest were present within the soluble Leishmania antigens (SLA). Quantitation of these proteins showed that their expression in promastigotes is relatively very low. Considering the molecular weight, immunoreactivity, chromatographic and electrophoretic behavior in reducing and non-reducing conditions, these proteins are probably 2 isoforms of a single protein. A digest of these proteins was resolved on Tricine-SDS-PAGE and immunoreactive fragments were identified by human sera. Two immunoreactive fragments (36.4 and 34.8 kDa) were only generated by endoproteinase Glu-C treatment. These immunoreactive fragments or their parent molecules may be ideal candidates for incorporation in a cocktail vaccine against cutaneous leishmaniasis.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.95-98
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• 2000

An immunochemical method has been develooped as the most sensitive tool for studying the expression of quinoproteins containing pyrroloquinoline qinone(PQQ) in E. coli. The PQQ was conjugated to bovine serum albumin (BSA), and the conjugant was purified by using a $KwikSep^{TM}$ dextran desalting column chromatography. The PQQ-BSA conjugant was immunized to rabbits, and the IgG fractions of the antisera were purified. The most sensitive antibody against PQQ-BSA conjugant recognized some nanogram quantity of the antigen on the blot, but had little cross reactivity with BSA. Using this batch of the antibody, all the immunochemical assays of quinoproteins in E. coli were preformed. Some six different PQQ-specfic spots were detected by Western blot analysis of the soluble proteins in E. coli were performed. Some six different PQQ-specific spots were detected by Western blot analysis of the soluble proteins in E. coli after two-dimensional gel electrophoresis. Their molecular weights on the blot were estimated to be about 100-, 90-, 72-, 58-, 52-, and 50kDa. Their pI values fell in the range from 4.8 to 5.5. These results stronly suggest that quinoproteins are present in E. coli, and that the protein moieties were covalently bound to PQQ.

• 대한바이러스학회지
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• 제28권1호
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• pp.31-38
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• 1998

In Korea, all domestic made test systems for detecting antibodies in HIV-1 contain the antigens from human immunodeficiency type 1 (HIV-1) subtype B. However, because HIV-1 subtype O is significantly different in amino acid sequences from all other subtypes of HIV-1, there has been a need for developing a test for detecting antibodies in subtype O. For this purpose, the entire nucleotide sequence corresponding to the extracellular domain of the transmembrane glycoprotein of HIV-1 subtype O was synthesized with consideration of Escherichia coli condon usage. Various regions of the extracellular domain were cloned into E. coli expression vectors and tested for levels of protein production. The nucleotide sequence, named ECTM, that can encode a 129 amino acid-long peptide, was found to be expressed at a high level in E. coli. The protein of approximately 17 kDa specifically reacted with sera from individuals infected with HIV-1 subtype O. The ECTM protein was purified to near homogeneity by the CM-T gel chromatography, using concentrated, denatured inclusion bodies. In Western blot analysis, the purified viral antigen reacted with sera from individuals infected with subtype O more efficiently than subtype B. The enzyme linked immunoabsorbent assay (ELISA) system was developed using the subtype O viral protein and compared with the commercially available kit lacking the antigens from subtype O. The ELISA kit containing the subtype O antigen ECTM alone efficiently reacted with sera from individuals infected with subtype O. The subtype O antigen-containing kit produced a positive absorbence even when sera were diluted 512-fold, suggesting a high sensitivity. The commercially available kit also reacted with subtype O sera, but produced a negative result at a dilution of 8-fold. Our results suggest that the currently available kit may not be able to efficiently detect subtype O sera and that the viral protein developed in this study may be added to the current system to maximize the detection of sera from individuals infected with subtype O.

• 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.

• 생명과학회지
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• 제11권4호
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• pp.385-391
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• 2001

Filamentous hemagglutinin (FHA) is considered as an essential immunogenic component for incorporation into acellular vaccines against Bordetella pertussis, the causative agent of whooping cough. Classically, antipertussis vaccination has employed an intramuscular route. An alternative approach to stimulate mucosal and systemic immune responses is oral immunization with recombinant live vaccine carrier strains of Salmonella typhimurium. An attenuated live Salmonella vaccine sgrain($\Delta$cya $\Delta$crp) expressing recombinant FHA(rFHA) was developed. Stable expressionof rFHA was achieved by the use of balanced-lethal vector-host system. which employs an asd deletion in the host chromosome to impose in obligate requirement for diaminopimelic acid. The chromosomal $\Delta$asd mutation was complemented by a plasmid vector possessing the asd$^{+}$ gene. A 3 kb DNA fragment encoding immuno dominant regionof FHA was subcloned in-frame downstream to the ATG translation initiation codon in the multicopy Asd$^{+}$ pYA3341 vector to create pYA3457. Salmonella vaccine harboring pYA3457 expressed approximately 105kDa rFHA protein. The 100% maintenance of [YA3457 in vaccine strain was confirmed by stability examinations. Additionally, a recombinant plasmid pYA3458 was constructed to overpress His(8X)-tagged rFHA in Essherichia coli. His-tagged rFHA was purified from the E. coli strain harboring pYA3458 using Ni$^{2+}$-NTA affinity purification system.>$^{2+}$-NTA affinity purification system.

• 한국어병학회지
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• 제34권1호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3495-3501
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• 2014

Melanoma-associated antigen (MAGE) family genes have been considered as potentially promising targets for anticancer immunotherapy. MAGED4 was originally identified as a glioma-specific antigen. Current knowledge about MAGED4 expression in glioma is only based on mRNA analysis and MAGED4 protein expression has not been elucidated. In the present study, we investigated this point and found that MAGED4 mRNA and protein were absent or very lowly expressed in various normal tissues and glioma cell line SHG44, but overexpressed in glioma cell lines A172,U251,U87-MG as well as glioma tissues, with significant heterogeneity. Furthermore, MAGED4 protein expression was positively correlated with the glioma type and grade. We also found that the expression of MAGED4 inversely correlated with the overall methylation status of the MAGED4 promoter CpG island. Furthermore, when SHG44 and A172 with higher methylation were treated with the DNA demethylating agent 5-aza-2'-deoxycytidine (5-AZA-CdR) reactivation of MAGED4 mRNA was mediated by significant demethylation in SHG44 instead of A172. However, 5-AZA-CdR treatment had no effect on MAGED4 protein in both SHG44 and A172 cells. In conclusion, MAGED4 is frequently and highly expressed in glioma and is partly regulated by DNA methylation. The results suggest that MAGED4 might be a promising target for glioma immunotherapy combined with 5-AZA-CdR to enhance its expression and eliminate intratumor heterogeneity.

• 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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• 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.

• 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.