title: A novel (19)F agent for detection and quantification of human dendritic cells using magnetic resonance imaging.
abstract: Monitoring of cell therapeutics in vivo is of major importance to estimate its efficacy. Here, we present a novel intracellular label for (19)F magnetic resonance imaging (MRI)-based cell tracking, which allows for noninvasive, longitudinal cell tracking without the use of radioisotopes. A key advantage of (19)F MRI is that it allows for absolute quantification of cell numbers directly from the MRI data. The (19)F label was tested in primary human monocyte-derived dendritic cells. These cells took up label effectively, resulting in a labeling of 1.7 ± 0.1 × 10(13) (19)F atoms per cell, with a viability of 80 ± 6%, without the need for electroporation or transfection agents. This results in a minimum detection sensitivity of about 2,000 cells/voxel at 7 T, comparable with gadolinium-labeled cells. Comparison of the detection sensitivity of cells labeled with (19)F, iron oxide and gadolinium over typical tissue background showed that unambiguous detection of the (19)F-labeled cells was simpler than with the contrast agents. The effect of the (19)F agent on cell function was minimal in the context of cell-based vaccines. From these data, we calculate that detection of 30,000 cells in vivo at 3 T with a reasonable signal to noise ratio for (19)F images would require less than 30 min with a conventional fast spin echo sequence, given a coil similar to the one used in this study. This is well within acceptable limits for clinical studies, and thus, we conclude that (19)F MRI for quantitative cell tracking in a clinical setting has great potential.
authors.affiliation: Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands.
authors.forename: Fernando
authors.initials: F
authors.lastname: Bonetto
authors.forename: Mangala
authors.initials: M
authors.lastname: Srinivas
authors.forename: Arend
authors.initials: A
authors.lastname: Heerschap
authors.forename: Robbie
authors.initials: R
authors.lastname: Mailliard
authors.forename: Eric T
authors.initials: ET
authors.lastname: Ahrens
authors.forename: Carl G
authors.initials: CG
authors.lastname: Figdor
authors.forename: I Jolanda M
authors.initials: IJ
authors.lastname: de Vries
mesh_terms: D019496:Cancer Vaccines; D002452:Cell Count; D002465:Cell Movement; D003287:Contrast Media; D003713:Dendritic Cells / Q000276:immunology / Q000502:physiology*; D005240:Feasibility Studies; D005461:Fluorine; D005466:Fluorocarbons; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*
chemical_list: D019496:Cancer Vaccines; D003287:Contrast Media; D005466:Fluorocarbons; D005461:Fluorine