Lopes van den Broek Sara, García-Vázquez Rocío, Andersen Ida Vang, Valenzuela-Nieto Guillermo, Shalgunov Vladimir, Battisti Umberto M, Schwefel David, Modhiran Naphak, Kramer Vasko, Cheuquemilla Yorka, Jara Ronald, Salinas-Varas Constanza, Amarilla Alberto A, Watterson Daniel, Rojas-Fernandez Alejandro, Herth Matthias M
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Institute of Medicine, Faculty of Medicine & Center for Interdisciplinary Studies on the Nervous System, CISNE, Universidad Austral de Chile, Valdivia, Chile.
Front Nucl Med. 2022 Nov 23;2:1033697. doi: 10.3389/fnume.2022.1033697. eCollection 2022.
COVID-19, caused by the SARS-CoV-2 virus, has become a global pandemic that is still present after more than two years. COVID-19 is mainly known as a respiratory disease that can cause long-term consequences referred to as long COVID. Molecular imaging of SARS-CoV-2 in COVID-19 patients would be a powerful tool for studying the pathological mechanisms and viral load in different organs, providing insights into the disease and the origin of long-term consequences and assessing the effectiveness of potential COVID-19 treatments. Current diagnostic methods used in the clinic do not allow direct imaging of SARS-CoV-2. In this work, a nanobody (NB) - a small, engineered protein derived from alpacas - and an Fc-fused NB which selectively target the SARS-CoV-2 Spike protein were developed as imaging agents for positron emission tomography (PET). We used the tetrazine ligation to F-label the NB under mild conditions once the NBs were successfully modified with cyclooctenes (TCOs). We confirmed binding to the Spike protein by SDS-PAGE. Dynamic PET scans in rats showed excretion through the liver for both constructs. Future work will evaluate binding to the Spike protein with our radioligands.
由严重急性呼吸综合征冠状病毒2（SARS-CoV-2）病毒引起的2019冠状病毒病（COVID-19）已成为一场全球大流行疾病，历经两年多仍未消退。COVID-19主要是一种呼吸系统疾病，可导致被称为“长新冠”的长期后果。对COVID-19患者体内的SARS-CoV-2进行分子成像，将成为研究不同器官病理机制和病毒载量的有力工具，有助于深入了解该疾病及其长期后果的根源，并评估潜在的COVID-19治疗方法的有效性。目前临床上使用的诊断方法无法对SARS-CoV-2进行直接成像。在这项研究中，一种纳米抗体（NB）——一种源自羊驼的小型工程蛋白——以及一种选择性靶向SARS-CoV-2刺突蛋白的Fc融合纳米抗体被开发用作正电子发射断层扫描（PET）的成像剂。一旦纳米抗体用环辛烯（TCO）成功修饰，我们便利用四嗪连接在温和条件下对纳米抗体进行F标记。我们通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）证实了其与刺突蛋白的结合。对大鼠进行的动态PET扫描显示，两种构建体均通过肝脏排泄。未来的工作将评估我们的放射性配体与刺突蛋白的结合情况。
