Design of an Anti-HMGB1 Synthetic Antibody for In Vivo Ischemic/Reperfusion Injury Therapy

Authors

• Keiichi Yoshimatsu, Missouri State UniversityFollow
• Hiroyuki Koide, University of Shizuoka
• Chiaki Kiyokawa, University of Shizuoka
• Anna Okishima, University of Shizuoka
• Kaito Saito, University of Shizuoka
• Tatsuya Fukuta, University of Shizuoka
• Yu Hoshino, Kyushu University
• Tomohiro Asai, University of Shizuoka
• Yuri Nishimura, Kyushu University
• Yoshiko Miura, Kyushu University
• Naoto Oku, University of Shizuoka
• Kenneth J. Shea, University of California, Irvine

Abstract

High-mobility group box 1 (HMGB1) is a multifunctional protein. Upon injury or infection, HMGB1 is passively released from necrotic and activated dendritic cells and macrophages, where it functions as a cytokine, acting as a ligand for RAGE, a major receptor of innate immunity stimulating inflammation responses including the pathogenesis of cerebral ischemia/reperfusion (I/R) injury. Blocking the HMGB1/RAGE axis offers a therapeutic approach to treating these inflammatory conditions. Here, we describe a synthetic antibody (SA), a copolymer nanoparticle (NP) that binds HMGB1. A lightly cross-linked N-isopropylacrylamide (NIPAm) hydrogel copolymer with nanomolar affinity for HMGB1 was selected from a small library containing trisulfated 3,4,6S-GlcNAc and hydrophobic N-tert-butylacrylamide (TBAm) monomers. Competition binding experiments with heparin established that the dominant interaction between SA and HMGB1 occurs at the heparin-binding domain. In vitro studies established that anti-HMGB1-SA inhibits HMGB1-dependent ICAM-1 expression and ERK phosphorylation of HUVECs, confirming that SA binding to HMGB1 inhibits the proteins’ interaction with the RAGE receptor. Using temporary middle cerebral artery occlusion (t-MCAO) model rats, anti-HMGB1-SA was found to accumulate in the ischemic brain by crossing the blood-brain barrier. Significantly, administration of anti-HMGB1-SA to t-MCAO rats dramatically reduced brain damage caused by cerebral ischemia/reperfusion. These results establish that a statistical copolymer, selected from a small library of candidates synthesized using an “informed” selection of functional monomers, can yield a functional synthetic antibody. The knowledge gained from these experiments can facilitate the discovery, design, and development of a new category of drug.

Department(s)

Chemistry and Biochemistry

Document Type

Article

DOI

10.1021/jacs.3c06799

Publication Date

10-25-2023

Recommended Citation

Yoshimatsu, Keiichi; Koide, Hiroyuki; Kiyokawa, Chiaki; Okishima, Anna; Saito, Kaito; Fukuta, Tatsuya; Hoshino, Yu; Asai, Tomohiro; Nishimura, Yuri; Miura, Yoshiko; Oku, Naoto; and Shea, Kenneth J., "Design of an Anti-HMGB1 Synthetic Antibody for In Vivo Ischemic/Reperfusion Injury Therapy" (2023). Faculty Scholarship. 534.
https://bearworks.missouristate.edu/articles00/534

Journal Title

Journal of the American Chemical Society