Establishment of an efficient method generating high-affinity mutant antibodies for the development of next-generation diagnostic agents

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K15268
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 47020:Pharmaceutical analytical chemistry and physicochemistry-related
• Research Institution: Kyoto Pharmaceutical University (2023); Kobe Pharmaceutical University (2022)
• Principal Investigator: Kiguchi Yuki 京都薬科大学, 薬学部, 助教 (40845880)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 抗体工学 / 枠組み配列 / アミノ酸挿入 / 試験管内親和性成熟 / ファージ提示

Outline of Final Research Achievements

Antibody engineering, which modifies the structure of antibodies at the genetic level, is a powerful method for producing high-affinity antibodies that are essential for the establishment of highly sensitive immunoassays. In this study, to explore the potential of “insertion of amino acids into the framework region (FR)” as a strategy for antibody engineering, libraries of amino acids inserted into VH-FR1, the most N-terminal region of the single-chain Fv fragment (scFv) against cortisol, was prepared, and high-affinity clones were explored. The results showed that the libraries with the insertion position between the 6th and 7th amino acid yielded several clones over 30-fold improved affinity compared to the wild-type scFv. The immunoassays using the obtained clones were sensitive enough for clinical application.

Free Research Field

分析化学

Academic Significance and Societal Importance of the Research Achievements

抗体工学の潜在力を最大限に発揮するには、親和力が向上した変異体の出現率が高いライブラリーを構築することが重要である。本研究の成果により、これまで変異の導入部位としては全く顧みられなかったVH-FR1 へ少数のアミノ酸を「挿入」する戦略が、従来の「CDR重視かつアミノ酸置換」による変異導入法に代わる新たな試験管内親和性成熟のアプローチとして有用であることが示唆された。この知見は高親和力抗体を迅速に創出する指針として極めて重要であり、抗体機能の理解についても新たな視点を加えられたと考えられる。