Bioorthogonal Fluorophore Linked DFO–Technology Enabling Facile Chelator Quantification and Multimodal Imaging of Antibodies
View/ Open
Author
Meimetis, Labros
Boros, Eszter
Carlson, Jonathan
Ran, Chongzhao
Caravan, Peter
Weissleder, Ralph
Published Version
https://doi.org/10.1021/acs.bioconjchem.5b00630Metadata
Show full item recordCitation
Meimetis, Labros G., Eszter Boros, Jonathan C. Carlson, Chongzhao Ran, Peter Caravan, and Ralph Weissleder. 2015. “Bioorthogonal Fluorophore Linked DFO—Technology Enabling Facile Chelator Quantification and Multimodal Imaging of Antibodies.” Bioconjugate Chemistry 27 (1): 257–63. https://doi.org/10.1021/acs.bioconjchem.5b00630.Abstract
Herein we describe the development and application of a bioorthogonal fluorogenic chelate linker that can be used for facile creation of labeled imaging agents. The chelate linker is based on the trans-cyclooctene(TCO)-tetrazine(Tz) chemistry platform and incorporates deferoxamine (DFO) as a Zr-89 PET tracer and a BODIPY fluorophore for multimodal imaging. The rapid (<3 min) ligation between mAb-TCO and Tz-BODIPY-DFO chelator is monitored using fluorescence and allows for determination of labeling completion. Utilizing BODIPY as the linker between mAb and DFO facilitates in chelator quantification using spectrophotometry, allowing for an alternative to traditional methods (mass and isotope dilution assay). Radiolabeling with Zr-89 to form Zr-89-DFO-BODIPY-trastuzumab was found to be quantitative after incubation at room temperature for 1 h (1.5 mCi/mg specific activity). The cell binding assay using HER2+ (BT474) and HER2- (BT20) cell lines showed significant binding to Zr-89-DFO-BODIPY-trastuzumab (6.45 +/- 1.87% in BT474 versus 1.47 +/- 0.39% in BT20). In vivo PET imaging of mice bearing BT20 or BT474 xenografts with Zr-89-DFO-BODIPY-trastuzumab showed high tumor conspicuity, and biodistribution confirmed excellent, specific probe uptake of 237.3 +/- 14.5% ID/g in BT474 xenografts compared to low, nonspecific probe uptake in BT20 xenografts (16.4 +/- 5.6% ID/g) 96 h p.i. . Ex vivo fluorescence (465ex/520em) of selected tissues confirmed superb target localization and persistence of the fluorescence of Zr-89-DFO-BODIPY-trastuzumab. The described platform is universally adaptable for simple antibody labeling.Terms of Use
This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAPCitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:41384212
Collections
- HMS Scholarly Articles [17875]
Contact administrator regarding this item (to report mistakes or request changes)