Current Affiliation Organization 【 display / non-display 】

Current Affiliation Organization 【 display / non-display 】

Graduate School 【 display / non-display 】

Graduate School 【 display / non-display 】

Academic degree 【 display / non-display 】

Academic degree 【 display / non-display 】

External Career 【 display / non-display 】

External Career 【 display / non-display 】

Affiliated academic organizations 【 display / non-display 】

Affiliated academic organizations 【 display / non-display 】

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

Research Areas 【 display / non-display 】

Research Areas 【 display / non-display 】

Published Papers 【 display / non-display 】

Published Papers 【 display / non-display 】

• Shiga toxin type 2 B subunit protects mice against toxin challenge when leashed and bundled by a stable pentameric coiled-coil molecule.

  Yukihiro Tamaki , Tetsuya Harakuni

  Vaccine ( Elsevier )  42 ( 7 ) 1757 - 1767   2024.03 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  Vaccines against Shiga toxin (Stx)-producing Escherichia coli (STEC) have not yet been developed. Two immunologically distinct serotypes of Stx (Stx1 and Stx2) are the main virulence factors of STEC. Thus, blocking their B subunits (StxB) from binding to the cell surface receptor globotriaosylceramide (Gb3) efficiently prevents the action of these toxins. We expressed Stx1B and Stx2B in E. coli inclusion bodies and reassembled them into pentamers by a stepwise dialysis. Stx1B pentamer fully protected mice against Stx1 challenge, but Stx2B pentamer failed to protect mice against Stx2 challenge. To explain those observations, we proposed that the pentamer of Stx2B readily dissociates into its constituent monomers, especially under in vivo conditions, thus being unable to induce pentamer-specific immunity. To increase pentamer stability, we fused the B subunit to a pentameric coiled-coil domain of the cartilage oligomeric matrix protein (COMP). This “five-to-five” fusion hybrid molecule (Stx2B–COMP) was shown to be protective against Stx2 challenge, demonstrating that the Stx2B subunit when leashed and bundled by a rigid pentameric coiled-coil domain mount a pentamer-specific immune response and efficiently neutralize the toxin both in vitro and in vivo. Our data strongly suggest that the Stx2B subunit moiety fluctuates between a pentameric and monomeric state within the fusion protein, which may increase the likelihood of the immune system recognizing the pentameric conformation for toxin neutralization.

• Characterization of the RAGE-binding protein, <i>Strongyloides</i> venestatin, produced by the silkworm-baculovirus expression system

  Tsubokawa, D; Lee, JM; Hatta, T; Mikami, F; Maruyama, H; Arakawa, T; Kusakabe, T; Tsuji, N

  INFECTION GENETICS AND EVOLUTION   75   103964 - 103964   2019.11 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  The receptor for advanced glycation end products (RAGE) recognizes Ca++-binding proteins, such as members of the S100 protein family released by dead or devitalized tissues, and plays an important role in inflammatory responses. We recently identified the Ca++-binding protein, venestatin, secreted from the rodent parasitic nematode, Strongyloides venezuelensis. We herein characterized recombinant venestatin, which is abundantly produced by the silkworm-baculovirus expression system (silkworm-BES), particularly in its interaction with RAGE. Venestatin from silkworm-BES possessed a binding capacity with Ca++ ions and vaccine immunogenicity against S. venezuelensis larvae in mice, which is similar to venestatin produced by the E. coli expression system (EES). Venestatin from silkworm-BES had a higher affinity for human recombinant RAGE than that from EES, and their affinities were Ca++-dependent. RAGE in the mouse lung co-immunoprecipitated with venestatin from silkworm-BES administered intranasally, indicating that it bound endogenous mouse RAGE. The present results suggest that venestatin from silkworm-BES affects RAGE-mediated pathological processes.

  • Access this article
    DOI
  • Search related information
    PubMed

• CD11 c-specific bio-nanocapsule enhances vaccine immunogenicity by targeting immune cells

  Matsuo, H; Somiya, M; Iijima, M; Arakawa, T; Kuroda, S

  JOURNAL OF NANOBIOTECHNOLOGY ( Journal of Nanobiotechnology )  16 ( 1 ) 59   2018.08 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  • Access this article
    DOI
  • Search related information
    PubMed

• Fiber knob domain lacking the shaft sequence but fused to a coiled coil is a candidate subunit vaccine against egg-drop syndrome

  Harakuni, T; Andoh, K; Sakamoto, R; Tamaki, Y; Miyata, T; Uefuji, H; Yamazaki, K; Arakawa, T

  VACCINE ( ELSEVIER SCI LTD )  34 ( 27 ) 3184 - 3190   2016.06 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  Egg-drop syndrome (EDS) virus is an avian adenovirus that causes a sudden drop in egg production and in the quality of the eggs when it infects chickens, leading to substantial economic losses in the poultry industry. Inactivated EDS vaccines produced in embryonated duck eggs or cell culture systems are available for the prophylaxis of EDS. However, recombinant subunit vaccines that are efficacious and inexpensive are a desirable alternative. In this study, we engineered chimeric fusion proteins in which the trimeric fiber knob domain lacking the triple beta-spiral motif in the fiber shaft region was genetically fused to trimeric coiled coils, such as those of the engineered form of the GCN4 leucine zipper peptide or chicken cartilage matrix protein (CMP). The fusion proteins were expressed predominantly as soluble trimeric proteins in Escherichia coli at levels of 15-80 mg/L of bacterial culture. The single immunization of chickens with the purified fusion proteins, at a dose equivalent to 10 mu g of the knob moiety, elicited serum antibodies with high hemagglutination inhibition (HI) activities, similar to those induced by an inactivated EDS vaccine. A dose-response analysis indicated that a single immunization with as little as 1 mu g of the knob moiety of the CMP-knob fusion protein was as effective as the inactivated vaccine in inducing antibodies with HI activity. The immunization of laying hens had no apparent adverse effects on egg production and effectively prevented clinical symptoms of EDS when the. chickens were challenged with pathogenic EDS virus. This study demonstrates that the knob domain lacking the shaft sequence but fused to a trimeric coiled coil is a promising candidate subunit vaccine for the prophylaxis of EDS in chickens. (C) 2016 Elsevier Ltd. All rights reserved.

  • Access this article
    DOI
  • Search related information
    PubMed

• Cholera toxin B subunit pentamer reassembled from <i>Escherichia coli</i> inclusion bodies for use in vaccination

  Tamaki, Y; Harakuni, T; Yamaguchi, R; Miyata, T; Arakawa, T

  VACCINE ( Vaccine )  34 ( 10 ) 1268 - 1274   2016.03 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

  　View Summary

  The cholera toxin B subunit (CTB) is secreted in its pentameric form from Escherichia coli if its leader peptide is replaced with one of E. coli origin. However, the secretion of the pentamer is generally severely impaired when the molecule is mutated or fused to a foreign peptide. Therefore, we attempted to regenerate pentameric CTB from the inclusion bodies (IBs) of E. coli. Stepwise dialysis of the IBs solubilized in guanidine hydrochloride predominantly generated soluble high-molecular-mass (HMM) aggregates and only a small fraction of pentamer. Three methods to reassemble homogeneous pentameric molecules were evaluated: (i) using a pentameric coiled-coil fusion partner, expecting it to function as an assembly core; (ii) optimizing the protein concentration during refolding; and (iii) eliminating contaminants before refolding. Coiled-coil fusion had some effect, but substantial amounts of HMM aggregates were still generated. Varying the protein concentration from 0.05 mg/mL to 5 mg/mL had almost no effect. In contrast, eliminating the contaminants before refolding had a robust effect, and only the pentamer was regenerated, with no detectable HMM aggregates. Surprisingly, the protein concentration at refolding was up to 5 mg/mL when the contaminants were removed, with no adverse effects on refolding. The regenerated pentamer was indistinguishable in its biochemical and immunological characteristics from CTB secreted from E. coli or choleragenoid from Vibrio cholerae. This study provides a simple but very efficient strategy for pentamerizing CTB with a highly homogeneous molecular conformation, with which it may be feasible to engineer CTB derivatives and CTB fusion antigens. (C) 2016 Elsevier Ltd. All rights reserved.

  • Access this article
    DOI
  • Search related information
    PubMed

display all >>

Other Papers 【 display / non-display 】

Other Papers 【 display / non-display 】

• 鶏の産卵低下症候群(EDS)に対する組換えワクチン抗原の構築とその効果

  原國哲也, 安藤清彦, 坂元隆一, 上藤洋敬, 宮田健, 山崎憲一, 新川武

  日本ワクチン学会学術集会プログラム・抄録集   19th   112   2015

   

  J-GLOBAL

• Plants are not just passive creatures!

  Arakawa T, Langridge WH

  Nature Medicine ( その他の出版社 )  ( 4 ) 550 - 551   1998.03

   

  DOI

Industrial Property 【 display / non-display 】

Industrial Property 【 display / non-display 】

• Porcine circovirus 2 VLP vaccine

  Industrial Property No PCT/JP2020/024491  (2019.08.20)

Grant-in-Aid for Scientific Research 【 display / non-display 】

Grant-in-Aid for Scientific Research 【 display / non-display 】

• Grant-in-Aid for Scientific Research(B)

  Project Year: 2021.04  -  2025.03 

  Direct: 13,200,000 (YEN)  Overheads: 17,160,000 (YEN)  Total: 3,960,000 (YEN)

• Grant-in-Aid for Scientific Research(C)

  Project Year: 2021.04  -  2024.03 

  Direct: 3,200,000 (YEN)  Overheads: 4,160,000 (YEN)  Total: 960,000 (YEN)

• Studies on development of the Babesia parasites that express cytokine for non-specific immune activation

  Challenging research (sprout)

  Project Year: 2018.06  -  2020.03 

  Investigator(s): KAWAZU Shin-ichiro 

  Direct: 4,800,000 (YEN)  Overheads: 6,240,000 (YEN)  Total: 1,440,000 (YEN)

  　View Summary

  The object of this study was to express cytokines such as interferon in haemoprotozoan Babesia parasite that causes asymptomatic infection in cattle. The parasite which expresses cytokine can modify immunity of the host animal accordingly regardless the types of pathogens such as viruses, bacteria, and parasites to reduce the damage caused by chronic debilitating infections caused by these pathogens. In order to develop a basic technology to produce Babesia parasite which expreses cytokines, an experimental system for editing the parasite genome with the CRISPR / Cas9 system and a knockdown experimental system applying the glucosamine (GlcN)-induced glmS ribozyme were established in non-domestic parasite species Babesia bovis.

• Recombinant toxoid vaccine development against Shiga toxin type 2

  Grant-in-Aid for Scientific Research(C)

  Project Year: 2018.04  -  2021.03 

  Investigator(s): Arakawa Takeshi 

  Direct: 3,400,000 (YEN)  Overheads: 4,420,000 (YEN)  Total: 1,020,000 (YEN)

  　View Summary

  In this study we evaluated the mechanism of the B pentamer expression in Escherichia coli heat-labile toxin (LT). We found that the secretory expression of the LTB when fused to the heterologous vaccine antigens was significantly reduced. We also found that LTB, as compared with a homologous toxin protein pentamer (cholera toxin B subunits), exhibited a significantly reduced protein refolding efficiency. Thus, we decided to develop a new LTB preparation method based on a pentamerization process taken placed within the E. coli cytoplasm achieved through the introduction of several amino acid replacements within the LTB primary structure.

• Grant-in-Aid for Scientific Research(C)

  Project Year: 2015.04  -  2018.03 

  Direct: 3,700,000 (YEN)  Overheads: 1,110,000 (YEN)  Total: 4,810,000 (YEN)

display all >>

SDGs 【 display / non-display 】

SDGs 【 display / non-display 】

Social Activity 【 display / non-display 】

Social Activity 【 display / non-display 】

• NIAC 

  2022.06

  　

  　

  

• 2011.10

  　

  　

• 2024.04

  　

  　

• 2023.04

  　

  　

• 2015.10