TY - JOUR
T1 - Enzymatic single-chain antibody tagging: A universal approach to targeted molecular imaging and cell homing in cardiovascular disease
AU - Ta, Hang T
AU - Prabhu, Sandeep
AU - Leitner, Ephraem
AU - Jia, Fu
AU - von Elverfeldt, Dominik
AU - Jackson, Katherine E
AU - Heidt, Timo
AU - Nair, Ashish Kumar Narayan
AU - Pearce, Hannah
AU - Von Zur Muhlen, Constantin
AU - Wang, Xiaowei
AU - Peter, Karlheinz
AU - Hagemeyer, Christoph Eugen
PY - 2011
Y1 - 2011
N2 - Antibody-targeted delivery of imaging agents can enhance the sensitivity and accuracy of current imaging techniques. Similarly, homing of effector cells to disease sites increases the efficacy of regenerative cell therapy while reducing the number of cells required. Currently, targeting can be achieved via chemical conjugation to specific antibodies, which typically results in the loss of antibody functionality and in severe cell damage. An ideal conjugation technique should ensure retention of antigen-binding activity and functionality of the targeted biological component. Objective: To develop a biochemically robust, highly reproducible, and site-specific coupling method using the Staphylococcus aureus sortase A enzyme for the conjugation of a single-chain antibody (scFv) to nanoparticles and cells for molecular imaging and cell homing in cardiovascular diseases. This scFv specifically binds to activated platelets, which play a pivotal role in thrombosis, atherosclerosis, and inflammation. Methods and Results: The conjugation procedure involves chemical and enzyme-mediated coupling steps. The scFv was successfully conjugated to iron oxide particles (contrast agents for magnetic resonance imaging) and to model cells. Conjugation efficiency ranged between 50 and 70 , and bioactivity of the scFv after coupling was preserved. The targeting of scFv-coupled cells and nanoparticles to activated platelets was strong and specific as demonstrated in in vitro static adhesion assays, in a flow chamber system, in mouse intravital microscopy, and in in vivo magnetic resonance imaging of mouse carotid arteries. Conclusions: This unique biotechnological approach provides a versatile and broadly applicable tool for procuring targeted regenerative cell therapy and targeted molecular imaging in cardiovascular and inflammatory diseases and beyond.
AB - Antibody-targeted delivery of imaging agents can enhance the sensitivity and accuracy of current imaging techniques. Similarly, homing of effector cells to disease sites increases the efficacy of regenerative cell therapy while reducing the number of cells required. Currently, targeting can be achieved via chemical conjugation to specific antibodies, which typically results in the loss of antibody functionality and in severe cell damage. An ideal conjugation technique should ensure retention of antigen-binding activity and functionality of the targeted biological component. Objective: To develop a biochemically robust, highly reproducible, and site-specific coupling method using the Staphylococcus aureus sortase A enzyme for the conjugation of a single-chain antibody (scFv) to nanoparticles and cells for molecular imaging and cell homing in cardiovascular diseases. This scFv specifically binds to activated platelets, which play a pivotal role in thrombosis, atherosclerosis, and inflammation. Methods and Results: The conjugation procedure involves chemical and enzyme-mediated coupling steps. The scFv was successfully conjugated to iron oxide particles (contrast agents for magnetic resonance imaging) and to model cells. Conjugation efficiency ranged between 50 and 70 , and bioactivity of the scFv after coupling was preserved. The targeting of scFv-coupled cells and nanoparticles to activated platelets was strong and specific as demonstrated in in vitro static adhesion assays, in a flow chamber system, in mouse intravital microscopy, and in in vivo magnetic resonance imaging of mouse carotid arteries. Conclusions: This unique biotechnological approach provides a versatile and broadly applicable tool for procuring targeted regenerative cell therapy and targeted molecular imaging in cardiovascular and inflammatory diseases and beyond.
UR - http://circres.ahajournals.org/content/109/4/365
U2 - 10.1161/CIRCRESAHA.111.249375
DO - 10.1161/CIRCRESAHA.111.249375
M3 - Article
SN - 0009-7330
VL - 109
SP - 365
EP - 373
JO - Circulation Research
JF - Circulation Research
IS - 4
ER -