Authors: Marta Kijanka FrankJan Warnders Mohamed El Khattabi Marjolijn Lubde Hooge Gooitzen M van Dam Vasilis Ntziachristos Liesbeth de Vries Sabrina Oliveira Paul M P van Bergen en Henegouwen
Publish Date: 2013/06/19
Volume: 40, Issue: 11, Pages: 1718-1729
Abstract
Molecular optical imaging using monoclonal antibodies is slow with low tumour to background ratio We used antiHER2 VHHs conjugated to IRDye 800CW to investigate their potential as probes for rapid optical molecular imaging of HER2positive tumours by the determination of tumour accumulation and tumour to background levelsThree antiHER2 VHHs 11A4 18C3 22G12 were selected with phage display and produced in Escherichia coli Binding affinities of these probes to SKBR3 cells were determined before and after sitespecific conjugation to IRDye 800CW To determine the potential of VHHIR as imaging probes serial optical imaging studies were carried out using human SKBR3 and human MDAMB231 xenograft breast cancer models Performance of the antiHER2 VHHIR was compared to that of trastuzumabIR and a nonHER2specific VHHIR Imageguided surgery was performed during which SKBR3 tumour was removed under the guidance of the VHHIR signalSitespecific conjugation of IRDye 800CW to three antiHER2 VHHs preserved high affinity binding with the following dissociation constants KD 11A4 19 ± 003 18C3 143 ± 18 and 22G12 32 ± 05 nM Based upon different criteria such as binding production yield and tumour accumulation 11A4 was selected for further studies Comparison of 11A4IR with trastuzumabIR showed ∼20 times faster tumour accumulation of the antiHER2 VHH with a much higher contrast between tumour and background tissue 11A4IR 25 ± 03 trastuzumabIR 14 ± 04 4 h postinjection 11A4IR was demonstrated to be a useful tool in imageguided surgeryWe would like to thank Mies Steenbergen Anton Terwisscha van Scheltinga and Titia Lamberts for technical support We thank Prof Dr Paul van Diest and Prof Dr Willem Mali for interesting discussions We thank QVQ BV for providing pQVQ72 vector This research was supported by the Center for Translational Molecular Medicine MAMMOTH project
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