4312

Imaging Technologies and Applications

In vivo tracking of immunotherapeutic cell types by fluorine MRI

Tuesday, Apr 21, 2009, 1:00 PM - 5:00 PM

Hall B-F, Poster Section 20

20

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B. M. Helfer, A. D. Nelson, J. M. Janjic, E. T. Ahrens, P. K. Kalinski, J. De Vries, R. B. Mailliard. Celsense Inc, Pittsburgh, PA, Carnegie Mellon University, Pittsburgh, PA, University of Pittsburgh, Pittsburgh, PA, Radbound University, Nijmegen, Netherlands

Cell therapy is one field of research aiming to target and destroy cancer cells. A current limitation of cell therapy is the inability to track the movement of these cells once they are administered to a patient. Natural killer cells (NK), T cells and dendritic cells (DC) are a few of the cell types being used therapeutically; here we utilize a novel fluorine-based (¹⁹F) MRI tracer agent to label these clinically relevant human immune cells ex-vivo without a transfection reagent. The application of this tracer across several phagocytic and nonphagocytic cell types without toxicity or altered proliferative characteristics supports the utility of ¹⁹F cell labeling. Furthermore, we are able to visualize labeled cells by MRI in phantom studies as well as in-vivo after injection. Due to minimal fluorine in mammalian tissues, administration of a fluorine label creates a more precise image than a method based on hydrogen imaging alone. Pairing of the ¹⁹F MR image with conventional ¹H MRI, taken during the same MRI session, provides clear cell localization within anatomic context. NMR analysis of labeled cells and phantom controls are able to determine the fluorine content per cell, which can then be applied to MR image to calculate the number of labeled cells detected by MRI. The non-invasive visual specificity of ¹⁹F labeled cells provided by MRI demonstrates a potential clinical application of this for cell therapy in the treatment of cancer.