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• B subunit of the type 2 Shiga toxin e variant (Stx2e) bundled by a five-stranded α-helical coiled coil protects piglets from porcine edema disease (vol. 61, 127140, 2025)

  Arakawa, T; Uefuji, H; Tamaki, Y; Oogai, S; Arakawa, H

  VACCINE ( Vaccine )  62   127582   2025.08 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• B subunit of the type 2 Shiga toxin e variant (Stx2e) bundled by a five-stranded α-helical coiled coil protects piglets from porcine edema disease

  Arakawa, T; Uefuji, H; Tamaki, Y; Oogai, S; Arakawa, H

  VACCINE ( Vaccine )  61   127140   2025.08 [ Peer Review Accepted ]

  Type of publication: Research paper (scientific journal)

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• 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.

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

  Tamaki, Y; Harakuni, T; Arakawa, T

  VACCINE ( Vaccine )  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.

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• 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)

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  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.

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• 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

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• 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 】

• Construction of a technological platform for controlling the ratio of VLP component proteins and its application to the development of recombinant vaccines

  Grant-in-Aid for Scientific Research(C)

  Project Year: 2024.04  -  2027.03 

  Direct: 3,600,000 (YEN)  Overheads: 4,680,000 (YEN)  Total: 1,080,000 (YEN)

• Construction of a technological platform for controlling the ratio of VLP component proteins and its application to the development of recombinant vaccines

  Grant-in-Aid for Scientific Research(C)

  Project Year: 2024.04  -  2027.03 

  Direct: 3,600,000 (YEN)  Overheads: 4,680,000 (YEN)  Total: 1,080,000 (YEN)

• Challenging research (sprout)

  Project Year: 2022.06  -  2025.03 

  Direct: 4,900,000 (YEN)  Overheads: 6,370,000 (YEN)  Total: 1,470,000 (YEN)

• Challenging research (sprout)

  Project Year: 2022.06  -  2025.03 

  Direct: 4,900,000 (YEN)  Overheads: 6,370,000 (YEN)  Total: 1,470,000 (YEN)

• 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)

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• NIAC 

  2022.06

  　

  　

  

• 2011.10

  　

  　

• 2024.04

  　

  　

• 2023.04

  　

  　

• 2015.10