title: Development of a novel antibody-tetrazine conjugate for bioorthogonal pretargeting.
abstract: Recently, bioorthogonal chemistry based on the Inverse Electron-Demand Diels-Alder (IEDDA) cycloaddition between 1,2,4,5-tetrazines and trans-cyclooctene (TCO) analogues added an interesting dimension to molecular imaging. Until now, antibodies (Abs) were tagged with TCO and after pretargeting they were reacted with tetrazines substituted with reporters. However, TCO tags have the tendency to degrade under physiological conditions, and due to their hydrophobic nature are buried within the protein. This results in loss of reactivity and a low Ab functional loading. To circumvent these problems, we report for the first time an approach in which tetrazines are used as tags for antibody (Ab) modification, and TCO as the imaging agent. We developed a new Ab-tetrazine conjugate, which displays a high functional loading, good stability and reactivity. We utilized this immunoconjugate for live-cell imaging together with novel TCO probes, resulting in selective and rapid labeling of SKOV-3 cells. Our approach may be useful for in vivo pretargeted imaging.
authors.affiliation: Laboratory of Medicinal Chemistry, University of Antwerp, Belgium. koen.augustyns@uantwerpen.be.
authors.forename: Agnese
authors.initials: A
authors.lastname: Maggi
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruivo
authors.forename: Jens
authors.initials: J
authors.lastname: Fissers
authors.forename: Christel
authors.initials: C
authors.lastname: Vangestel
authors.forename: Sneha
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Jurgen
authors.initials: J
authors.lastname: Joossens
authors.forename: Frank
authors.initials: F
authors.lastname: Sobott
authors.forename: Steven
authors.initials: S
authors.lastname: Staelens
authors.forename: Sigrid
authors.initials: S
authors.lastname: Stroobants
authors.forename: Pieter
authors.initials: P
authors.lastname: Van Der Veken
authors.forename: Leonie
authors.initials: L
authors.lastname: Wyffels
authors.forename: Koen
authors.initials: K
authors.lastname: Augustyns