研究者業績

岡 昌吾

オカ ショウゴ  (Shogo Oka)

基本情報

所属
藤田医科大学 医療科学部 特命教授
学位
薬学博士(京都大学)

J-GLOBAL ID
200901042576668786
researchmap会員ID
1000028666

学歴

 3

論文

 154
  • Keisuke Aoki, Katsuaki Higashi, Sakiho Oda, Asako Manabe, Kayuu Maeda, Jyoji Morise, Shogo Oka, Shinsuke Inuki, Hiroaki Ohno, Shinya Oishi, Motohiro Nonaka
    ACS chemical biology 19(5) 1194-1205 2024年5月17日  
    Immunogenicity is a major caveat of protein therapeutics. In particular, the long-term administration of protein therapeutic agents leads to the generation of antidrug antibodies (ADAs), which reduce drug efficacy while eliciting adverse events. One promising solution to this issue is the use of mirror-image proteins consisting of d-amino acids, which are resistant to proteolytic degradation in immune cells. We have recently reported the chemical synthesis of the enantiomeric form of the variable domain of the antibody heavy chain (d-VHH). However, identifying mirror-image antibodies capable of binding to natural ligands remains challenging. In this study, we developed a novel screening platform to identify a d-VHH specific for vascular endothelial growth factor A (VEGF-A). We performed mirror-image screening of two newly constructed synthetic VHH libraries displayed on T7 phage and identified VHH sequences that effectively bound to the mirror-image VEGF-A target (d-VEGF-A). We subsequently synthesized a d-VHH candidate that preferentially bound the native VEGF-A (l-VEGF-A) with submicromolar affinity. Furthermore, immunization studies in mice demonstrated that this d-VHH elicited no ADAs, unlike its corresponding l-VHH. Our findings highlight the utility of this novel d-VHH screening platform in the development of protein therapeutics exhibiting both reduced immunogenicity and improved efficacy.
  • Katsuaki Higashi, Sakiho Oda, Mai Fujii, Fumiya Nishida, Hayato Matsumoto, Jyoji Morise, Shogo Oka, Motohiro Nonaka
    Journal of biochemistry 175(1) 85-93 2023年12月20日  
    T7 phage libraries displaying random peptides are powerful tools for screening peptide sequences that bind to various target molecules. The T7 phage system has the advantage of less biased peptide distribution compared to the M13 phage system. However, the construction of T7 phage DNA is challenging due to its long 36 kb linear DNA. Furthermore, the diversity of the libraries depends strongly on the efficiency of commercially available packaging extracts. To address these issues, we examined the combination of seamless cloning with cell-free translation systems. Seamless cloning technologies have been widely used to construct short circular plasmid DNA, and several recent studies showed that cell-free translation can achieve more diverse phage packaging. In this study, we combined these techniques to construct four libraries (CX7C, CX9C, CX11C and CX13C) with different random regions lengths. The libraries thus obtained all showed diversity > 109 plaque forming units (pfu). Evaluating our libraries with an anti-FLAG monoclonal antibody yielded the correct epitope sequence. The results indicate that our libraries are useful for screening peptide epitopes against antibodies. These findings suggest that our system can efficiently construct T7 phage libraries with greater diversity than previous systems.
  • 森瀬 譲二, 高倉 大輔, 川崎 ナナ, 野中 元裕, 岡 昌吾
    日本腎臓学会誌 64(3) 179-179 2022年5月  
  • 森瀬 譲二, 飯倉 七奈子, 阿部 沙也佳, 北野 仁望, 高倉 大輔, 川崎 ナナ, 野中 元裕, 岡 昌吾
    日本生化学会大会プログラム・講演要旨集 94回 [1S01a-03] 2021年11月  
  • Haruka Kawade, Jyoji Morise, Sushil K Mishra, Shuta Tsujioka, Shogo Oka, Yasuhiko Kizuka
    Molecules (Basel, Switzerland) 26(17) 2021年8月26日  
    Human natural killer-1 (HNK-1) is a sulfated glyco-epitope regulating cell adhesion and synaptic functions. HNK-1 and its non-sulfated forms, which are specifically expressed in the brain and the kidney, respectively, are distinctly biosynthesized by two homologous glycosyltransferases: GlcAT-P in the brain and GlcAT-S in the kidney. However, it is largely unclear how the activity of these isozymes is regulated in vivo. We recently found that bisecting GlcNAc, a branching sugar in N-glycan, suppresses both GlcAT-P activity and HNK-1 expression in the brain. Here, we observed that the expression of non-sulfated HNK-1 in the kidney is unexpectedly unaltered in mutant mice lacking bisecting GlcNAc. This suggests that the biosynthesis of HNK-1 in the brain and the kidney are differentially regulated by bisecting GlcNAc. Mechanistically, in vitro activity assays demonstrated that bisecting GlcNAc inhibits the activity of GlcAT-P but not that of GlcAT-S. Furthermore, molecular dynamics simulation showed that GlcAT-P binds poorly to bisected N-glycan substrates, whereas GlcAT-S binds similarly to bisected and non-bisected N-glycans. These findings revealed the difference of the highly homologous isozymes for HNK-1 synthesis, highlighting the novel mechanism of the tissue-specific regulation of HNK-1 synthesis by bisecting GlcNAc.

MISC

 75

講演・口頭発表等

 52

共同研究・競争的資金等の研究課題

 30