• Title/Summary/Keyword: T antigen

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Western blot diagnosis of vivax malaria with multiple stage-specific antigens of the parasite

  • Son, Eui-Sun;Kim, Tong-Soo;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.39 no.2
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    • pp.171-176
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    • 2001
  • Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), meroxoite surface protein (MSP-1), apical merozoite antigen (AMA- 1), serine repeat antigen (SERA), and exported antigen (EXP- 1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using S antigens (91.9%) rather than using each antigen solely (55.6 - 80%), a combination of 2 (76.3 - 87.5%), 3 (85.6 - 90.6%), or 4 antigens (89.4 - 91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

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Cordyceps militaris Enhances MHC-restricted Antigen Presentation via the Induced Expression of MHC Molecules and Production of Cytokines

  • Shin, Seulmee;Park, Yoonhee;Kim, Seulah;Oh, Hee-Eun;Ko, Young-Wook;Han, Shinha;Lee, Seungjeong;Lee, Chong-Kil;Cho, Kyunghae;Kim, Kyungjae
    • IMMUNE NETWORK
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    • v.10 no.4
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    • pp.135-143
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    • 2010
  • Background: Cordyceps militarys water extract (CME) has been reported to exert antitumor and immunomodulatory activities in vivo and in vitro. However, the therapeutic mechanism has not yet been elucidated. In this study, we examined the effects of CME on the antigen presenting function of antigen presenting cells (APCs). Methods: Dendritic cells (DCs) were cultured in the presence of CME, and then allowed to phagocytose microspheres containing ovalbumin (OVA). After washing and fixing the efficacy of OVA, peptide presentation by DCs were evaluated using CD8 and CD4 T cells. Also, we confirmed the protein levels of proinflammatory cytokines through western blot analysis. Results: CME enhanced both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the expression of both MHC class I and II molecules was enhanced, but there was no changes in the phagocytic activity of exogenous OVA. Furthermore, CME induced the protein levels of iNOS, COX-2, proinflammatory cytokines, and nuclear p65 in a concentration-dependent manner, as determined by western blot. Conclusion: These results provide an understanding of the mechanism of the immuno-enhancing activity of CME on the induction of MHC-restricted antigen presentation in relation to their actions on APCs.

A survey of canine heartworm (Dirofilaria immitis) infections among Jindo dogs (진돗개의 심장사상충 감염률 조사)

  • Lee, Jeong-Chi
    • Korean Journal of Veterinary Service
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    • v.36 no.4
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    • pp.327-332
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    • 2013
  • A survey of canine heartworm (Dirofilaria immitis) infection among 102 Jindo dogs was performed from September to October 1995, using a microfilarial test (modified Knott's test) and an antigen test (DiroCHEK, Synbiotics, USA). The infection rate of 102 Jindo dogs was 1.9% (2/102) by the modified Knott's test, but was 4.9% (5/102) by the antigen test. This result revealed that the antigen test is more accurate than the microfilarial test. Also, 222 Jindo dogs (Male 61, Female 161) were examined for Dirofilaria immitis infection from 1995 to 1997 using an antigen test (DiroCHEK, Synbiotics, USA). Twelve (5.4%) Jindo dogs were positive for Dirofilaria immitis antigen. The infection rates were higher than in male (6.6%, 4/61) than female dogs (5.0%, 8/161). The infection rates of heartworm in Jindo dogs at the age of under 1 year, 1~2 years and over 2 years old were 0.0% (0/39), 4.3% (5/115) and 10.3% (7/68), respectively. The older age had higher infection rates than the younger age (P=0.018). The infection rates of canine heartworm was reported to be the highest (17.6%, P=0.028) in Jodo-myeon, 10.6% in Uisin-myeon and 5.3% in limhoe-myun. But dogs with antigenemia weren't detected in Gogun-myeon. and Jisan-myeon. This study indicates that the prevalence of canine heartworm in Jindo-gun is lower than previously reported (3.1% and 12.3%) which utilized microfilarial tests.

Efficient Generation of BLCL Expressing Foreign Antigen as Antigen-presenting Cells with Recombinant Retroviruses

  • Hyun-Il Cho;Soon-Young Pail;Il-Hoan OH;Kyun-Jung Ahn;Dong-Wook Kim
    • Journal of Microbiology
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    • v.39 no.4
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    • pp.300-304
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    • 2001
  • Epstein-Barr Virus(EBV)-transformed lymphoblastoid B cell lines, BLCL which expresse antigens, are potential antigen-presenting cells(APCs) for the induction of CTL in vitro. However transfection of BLCLs with subsequent selection by antibiotics is notoriously difficult because plating efficiencies of BLCLsare reported to be 1% or less. To generated stable transfectants of BLCLs we produced high titers of retroviruess encoding pp 65 antigen of human cytomegalovirus of foreign antigens and trans-duced them of BLCLs. The pp 65 gene was cloned into the retroviral vector pLXSN. The recombinant retroviral vector was transfected to ecotropic packaging cell line, CP&E86, and this polyclonal recom-binant retrovirus was transduced to PA317 that is amphotropic pakaging cell line. The titers of colned PA317 amphotropic retroviruses ranged from 5 to $\times$10$^{6}$ colony forming units (CFU)per ml (CFU/ml) We performed three rounds of consecutive transductions to BLCLs in order to improve the clon-ing effieiencies. The expression of recombinant HCMV-pp65 antigen was more than 20% after the final transduction. THe third-transduced BLCLs were easily selected in optimal concentration of G418. BLCLs expressing foreign antigens could be used as target cells for CTL assay and/or as APCs for induction of in vitro CTL responses specific for viral and tumor antigens.

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Studies on the Applicability of Various Antigen Preparations in Immunoblot Diagnosis of Paragonimiasis (폐흡충증 진단에 있어서 각종 항원의 적용성)

  • Lee, Dong-Soo;Chung, Myung-Sook;Joo, Kyoung-Hwan;Rim, Han-Jong
    • Journal of agricultural medicine and community health
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    • v.17 no.1
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    • pp.46-55
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    • 1992
  • A systematic study was conducted to identify and isolate a serologically pertinent antigen with high specific activity and low cross reactivity from P.westermani antigen. Differential centrifugation of the homogenate yield three particulate and one soluble fractions ; the $480{\times}G$ pellet(Pw1), the $7650{\times}G$ pellet(Pw2) treated with n-butanol(Pw3), and $100000{\times}G$ supernatnat(Pw4). Comparison of antigenicity of these antigens, based upon differential centrifugation, to that of saline extract of P. westermani worm(SEP) was performed by SDS-PAGE and immunoblot techniques. The results obtained were as follows : 1) The ratio of absorbance value of ELISA against paragonimiasis positive pool sera to that of negative sera was highest when using Pw3 as antigen and that was lowest using Pwl. 2) Silver stained and SDS-PAGE of each antigen showed 34 and 13Kd band as common antigen band, but Pw2 didn't show clear band. 3) By immunoblot 55 and 34Kd bands using SEP and Pw4 showed strong positive reaction without cross reaction with sera from other helmenthic infections. Using Pw3, 10Kd band was observed as specific band. In conclusion, Pw3($100000{\times}G$ pellet urea soluble, treated with n-butanol) and Pw4($100000{\times}G$ supernatant) were usable for ELISA and immunoblot technique.

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Cyclooxygenase Inhibitors, Aspirin and Ibuprofen, Inhibit MHC-restricted Antigen Presentation in Dendritic Cells

  • Kim, Hyun-Jin;Lee, Young-Hee;Im, Sun-A;Kim, Kyungjae;Lee, Chong-Kil
    • IMMUNE NETWORK
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    • v.10 no.3
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    • pp.92-98
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    • 2010
  • Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve pain, reduce fever and inhibit inflammation. NSAIDs function mainly through inhibition of cyclooxygenase (COX). Growing evidence suggests that NSAIDs also have immunomodulatory effects on T and B cells. Here we examined the effects of NSAIDs on the antigen presenting function of dendritic cells (DCs). Methods: DCs were cultured in the presence of aspirin or ibuprofen, and then allowed to phagocytose biodegradable microspheres containing ovalbumin (OVA). After washing and fixing, the efficacy of OVA peptide presentation by DCs was evaluated using OVA-specific CD8 and CD4 T cells. Results: Aspirin and ibuprofen at high concentrations inhibited both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the DCs generated in the presence of low concentrations of the drugs exhibit a profoundly suppressed capability to present MHC-restricted antigens. Aspirin and ibuprofen did not inhibit the phagocytic activity of DCs, the expression level of total MHC molecules and co-stimulatory molecules on DCs. Ibuprofen rather increased the expression level of total MHC molecules and co-stimulatory molecules on DCs. Conclusion: These results demonstrate that aspirin and ibuprofen inhibit the intracellular processing event of the phagocytosed antigen, and further suggest that prolonged administration of NSAIDs in high doses may impair the capability of DCs to present antigens in asiociation with MHC molecules.

Overexpression and Purification of PreS Region of Hepatitis B Virus Antigenic Surface Protein adr Subtype in Escherichia coli

  • Abbas, Naaz;Ahmad, Aftab;Shakoori, Abdul Rauf
    • BMB Reports
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    • v.40 no.6
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    • pp.1002-1008
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    • 2007
  • PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli $DH5\alpha$ cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-$41^{\circ}C$) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at $37^{\circ}C$ for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at $-80^{\circ}C$.

ELISA detection of IgG antibody against a recombinant major surface antigen (Nc-p43) fragment of Neospora caninum in bovine sera

  • Ahn, Hye-Jin;Kim, Sera;Kim, Dae-Yong;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.41 no.3
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    • pp.175-177
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    • 2003
  • An ELISA was established to measure bovine IgG directed against the recombinant antigenic determinant of Nc-p43, a major surface antigen of Neospora caninum. In a previous study, two thirds of the C-terminal of the molecule was expressed as a $6{\;}{\times}{\;}His$ tagged protein (Ncp43p) for ELISA using 2/3 of the N-terminal of SAG1 from Toxoplasma gondii as a control (TgSAG1A). Among 852 cattle sera collected from stock farms scattered nation-wide, 103 sera (12.1%) were found to react with Ncp43p positively, but no positive reaction was observed with TgSAG1A. This study shows that Ncp43p could be available as an efficient antigen for the diagnosis of neosporosis in cattle. Furthermore, it together with TgSAG1A, could be useful for the differential diagnosis of N. caninum and T.gondii infections in other mammals.

Induction of Potent Antigen-specific Cytotoxic T Cell Response by PLGA-nanoparticles Containing Antigen and TLR Agonist

  • Lee, Young-Ran;Lee, Young-Hee;Kim, Ki-Hyang;Im, Sun-A;Lee, Chong-Kil
    • IMMUNE NETWORK
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    • v.13 no.1
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    • pp.30-33
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    • 2013
  • Previously we showed that biodegradable nanoparticles containing poly-IC or CpG oligodeoxynucleotide (ODN) together with ovalbumin (OVA) were efficient at inducing MHC-restricted presentation of OVA peptides in dendritic cells. The CTL-inducing activities of the nanoparticles were examined in the present study. Nanoparticles containing poly-IC or CpG ODN together with OVA were prepared using biodegradable polymer poly(D,L-lactic acid-co-glycolic acid), and then were opsonized with mouse IgG. The nanoparticles were injected into the tail vein of mice, and 7 days later the OVA-specific CTL activities were measured using an in vivo CTL assay. Immunization of mice with the nanoparticles containing poly-IC or CpG ODN together with OVA elicited potent OVA-specific CTL activity compared to those containing OVA only. In accordance with these results, nanoparticles containing poly-IC or CpG ODN together with OVA exerted potent antitumor activity in mice that were subcutaneously implanted with EG7.OVA tumor cells. These results show that encapsulation of poly-IC or CpG ODN together with antigen in biodegradable nanoparticles is an effective approach for the induction of potent antigen-specific CTL responses in vivo.

Radiotherapy and immune checkpoint blockades: a snapshot in 2016

  • Koo, Taeryool;Kim, In Ah
    • Radiation Oncology Journal
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    • v.34 no.4
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    • pp.250-259
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    • 2016
  • Immune checkpoint blockades including monoclonal antibodies (mAbs) of cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) have been emerged as a promising anticancer therapy. Several immune checkpoint blockades have been approved by US Food and Drug Administration (FDA), and have shown notable success in clinical trials for patients with advanced melanoma and non-small cell lung cancer. Radiotherapy is a promising combination partner of immune checkpoint blockades due to its potent pro-immune effect. This review will cover the current issue and the future perspectives for combined with radiotherapy and immune checkpoint blockades based upon the available preclinical and clinical data.