Cell-type specific multiscale imaging of leukocytes through the combination of protein tagging and radiochemical labelling
Principal investigators: Christian Paul Konken, Henning Mootz
Former principal investigator: Andrea Rentmeister
Project number: CRC 1450 A01
Project term: 01/2021–12/2028
This project provides innovative solutions for in vivo imaging of distinct leukocyte populations, crucial for understanding their dynamics and roles in inflammation. By using radioactive labels, robust readouts are achieved in whole-body imaging experiments. Existing ex vivo labeling methods for immune cells, such as monocytes, macrophages, and ER-HoxB8-derived myeloid progenitor cells, face challenges in maintaining long-term label stability in vivo. To address this, versatile platforms have been developed based on SNAP-Tag substrate complexes and specific nanobody-based cell labeling. The nanobody platform utilizes the MoonTag peptide epitope and its corresponding MoonTag nanobody to genetically tag cells on the surface, enabling enhanced tracking through fluorescent and radioactive labeling. In vitro validation has shown successful signal amplification correlating with the number of tags, while in vivo PET imaging in tumor xenografts demonstrated effective use of the poly-MoonTag epitope and 68Ga-labeled MoonTag nanobody (see graphical outline). Future efforts will focus on improving the signal-to-noise ratio by using better suitable and further chemically functionalized nanobodies. Additionally, new methods will be developed to enhance the inherently low specific activity in standard labeling procedures. The goal is to successfully implement these validated and further improved tagging strategies for immune cell imaging in vivo. We are strongly connected to several projects within the CRC and would be happy to answer your questions.
The names of the principal investigators in our network have been bolded. Publications released prior to 2021, when funding for our network commenced, represent previous project-related work.
2025
Schöning J, Rosner L, Depke DA, Huwel S, Kukhar A, Schäfers M, Rentmeister A. Toolbox of Clickable Benzylguanines for Labeling of HoxB8-Derived Macrophages via SNAP-Tag and Bioorthogonal Chemistry. Bioconjug Chem 2025;36: 34-43. Abstract
2024
Pasch T, Bäumer N, Bäumer S, Buchholz F, Mootz HD. Towards targeted Cas9 (CRISPR-Cas) delivery: Preparation of IgG antibody-Cas9 conjugates using a split intein. J Pept Sci 2024Abstract
2022
Rösner L, Konken CP, Depke DA, Rentmeister A, Schäfers M. Covalent labeling of immune cells. Curr Opin Chem Biol 2022;68: 102144. Abstract
2021
Depke DA, Konken CP, Rösner L, Hermann S, Schäfers M, Rentmeister A. A novel (18)F-labeled clickable substrate for targeted imaging of SNAP-tag expressing cells by PET in vivo. Chem Commun (Camb) 2021;57: 9850-9853. Abstract
Reille-Seroussi M, Meyer-Ahrens P, Aust A, Feldberg A-L, Mootz HD. Genetic Encoding and Enzymatic Deprotection of a Latent Thiol Side Chain to Enable New Protein Bioconjugation Applications. Angew Chem Int Ed Engl 2021;60: 15972-15979. Abstract
Westerich KJ, Chandrasekaran KS, Gross-Thebing T, Kueck N, Raz E, Rentmeister A. Bioorthogonal mRNA labeling at the poly(A) tail for imaging localization and dynamics in live zebrafish embryos. Chem. Sci. 2020;11: 3089-3095. Abstract
2019
Anhäuser L, Hüwel S, Zobel T, Rentmeister A. Multiple covalent fluorescence labeling of eukaryotic mRNA at the poly(A) tail enhances translation and can be performed in living cells. Nucleic Acids Res 2019;47: e42. Abstract
Bhagawati M, Terhorst TME, Füsser F, Hoffmann S, Pasch T, Pietrokovski S, Mootz HD. A mesophilic cysteine-less split intein for protein trans-splicing applications under oxidizing conditions. Proc Natl Acad Sci U S A 2019;116: 22164-22172. Abstract
2018
Konken CP, Haufe G, Brömmel K, Wünsch B, Schäfers M, Wagner S, Hugenberg V. Development of symmetric O-BODIPYs with different optical properties as building blocks for the synthesis of ligands for multimodal imaging. Dyes Pigment. 2018;158: 88-96. Abstract
Pirzer T, Becher K-S, Rieker M, Meckel T, Mootz HD, Kolmar H. Generation of Potent Anti-HER1/2 Immunotoxins by Protein Ligation Using Split Inteins. ACS Chem Biol 2018;13: 2058-2066. Abstract
2017
Bachmann A-L, Mootz HD. N-terminal chemical protein labeling using the naturally split GOS-TerL intein. J Pept Sci 2017;23: 624-630. Abstract
Muttach F, Muthmann N, Reichert D, Anhäuser L, Rentmeister A. A benzylic linker promotes methyltransferase catalyzed norbornene transfer for rapid bioorthogonal tetrazine ligation. Chem. Sci. 2017;8: 7947-7953. Abstract
