点击化学实现[89Zr]Zr-DOTA放射免疫偶联，用于治疗诊断的89Zr免疫PET

Click Chemistry Enables [89Zr]Zr-DOTA Radioimmunoconjugation for Theranostic 89Zr-immunoPET

BIOCONJUGATE CHEMISTRY

影响因子:3.9

分区:化学2区 / 生化研究方法2区有机化学2区生化与分子生物学3区化学：综合3区

发表日期:2024 Nov 20

作者: Ryota Imura, Jaewoong Jang, Atsuko Nakanishi Ozeki, Hiroyuki Takahashi, Hiroyuki Ida, Youichiro Wada, Yoshitaka Kumakura, Nobuyoshi Akimitsu

DOI: 10.1021/acs.bioconjchem.4c00274

摘要

有人预测，宏环配体螯合剂1,4,7,10-四氮杂环十二烷-1,4,7,10-四乙酸（DOTA）在锆-89（89Zr）免疫正电子发射断层成像（89Zr-immunoPET）中的应用可能增强89Zr放射免疫偶联物在体内的稳定性。然而，将[89Zr]Zr-DOTA偶联到单克隆抗体（mAb）仍是一个挑战，因为为[89Zr]Zr-DOTA螯合所需的加热处理可能导致抗体部分的热变性。我们开发了一种基于四唑（Tz）偶联双功能DOTA衍生物的合成方法，即2,2',2″-(10-(1-(4-(1,2,4,5-四唑基)苯基)-3,21,26-三氧-6,9,12,15,18-五氧-29-羧基-2,22,25-三氮非庚烷-29-基)-1,4,7,10-四氮杂环十二烷-1,4,7-三酰)三乙酸（DOTAGA-Tz）与逆电子需求Diels-Alder（IEDDA）点击化学反应，将经转-环辛烯修饰的抗体与[89Zr]Zr-DOTAGA偶联，而无需加热。通过体外、离体和体内测试以及与传统的去铁胺（DFO）对照分析，确认了由IEDDA反应生成的[89Zr]Zr-DOTAGA-trastuzumab的稳定性。体内免疫PET成像显示，使用[89Zr]Zr-DOTAGA-trastuzumab可以清楚成像在小鼠异种移植模型中的HER2阳性肿瘤。与[89Zr]Zr-DFO-trastuzumab相比，72小时延迟扫描中[89Zr]Zr-DOTAGA-trastuzumab的肿瘤对比度更佳。这些结果表明，我们的IEDDA连接策略可以有效合成[89Zr]Zr-DOTA-mAb，且能增强89Zr免疫PET在DOTA介导的放射免疫治疗中的治疗诊断潜力。

Abstract

There have been predictions that the use of the macrocyclic chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) in zirconium-89 (89Zr) immuno-positron emission tomography (89Zr-immunoPET) could enhance the in vivo stability of 89Zr radioimmunoconjugates. However, conjugating [89Zr]Zr-DOTA to a monoclonal antibody (mAb) remains a challenge as the heat treatment required for [89Zr]Zr-DOTA chelation can lead to thermal denaturation of the mAb moieties. We developed a method for synthesizing [89Zr]Zr-DOTA-mAb based on a tetrazine (Tz)-conjugated bifunctional DOTA derivative 2,2',2″-(10-(1-(4-(1,2,4,5-tetrazin-3-yl)phenyl)-3,21,26-trioxo-6,9,12,15,18-pentaoxa-29-carboxy-2,22,25-triazanonacosane-29-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid (DOTAGA-Tz) and the inverse electron-demand Diels-Alder (IEDDA) click chemistry reaction where trans-cyclooctene-modified mAbs are conjugated to [89Zr]Zr-DOTAGA without being exposed to heat. The stability of IEDDA-derived [89Zr]Zr-DOTAGA-trastuzumab was confirmed by in vitro, ex vivo, and in vivo testing and comparative analysis against the conventional deferoxamine (DFO) counterpart [89Zr]Zr-DFO-trastuzumab. The in vivo immunoPET imaging using [89Zr]Zr-DOTAGA-trastuzumab clearly visualized human epidermal growth factor receptor 2-positive malignancies in murine xenograft models. Greater tumor contrast was observed from [89Zr]Zr-DOTAGA-trastuzumab at a 72-h delayed scan compared with [89Zr]Zr-DFO-trastuzumab. These findings suggest that our IEDDA ligation approach can be an effective means of synthesizing [89Zr]Zr-DOTA-mAb and can enhance the theranostic potential of 89Zr-immunoPET in DOTA-mediated radioimmunotherapy.