title: Cell labeling for magnetic resonance imaging with the T1 agent manganese chloride.
abstract: There is growing interest in using MRI to track cellular migration. To date, most work in this area has been performed using ultra-small particles of iron oxide. Immune cells are difficult to label with iron oxide particles. The ability of adoptively infused tumor specific T cells and N cells to traffic to the tumor microenvironment may be a critical determinant of their therapeutic efficacy. We tested the hypothesis that lymphocytes and B cells would label with MnCl2 to a level that would allow their detection by T1-weighted MRI. Significant signal enhancement was observed in human lymphocytes after a 1 h incubation with 0.05-1.0 mM MnCl2. A flow cytometry-based evaluation using propidium iodide and Annexin V staining showed that lymphocytes did not undergo apoptosis or necrosis immediately after and 24 h following a 1 h incubation with up to 1.0 mM MnCl2. Importantly, NK cells and cytotoxic T cells maintained their in vitro killing capacity after being incubated with up to 0.5 mM MnCl2. This is the first report to describe the use of MnCl2 to label lymphocytes. Our data suggests MnCl2 might be an alternative to iron oxide cell labeling for MRI-based cell migration studies.
authors.affiliation: Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892-1065, USA.
authors.forename: Ichio
authors.initials: I
authors.lastname: Aoki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Kai-Hsiang
authors.initials: KH
authors.lastname: Chuang
authors.forename: Afonso C
authors.initials: AC
authors.lastname: Silva
authors.forename: Takehito
authors.initials: T
authors.lastname: Igarashi
authors.forename: Chuzo
authors.initials: C
authors.lastname: Tanaka
authors.forename: Richard W
authors.initials: RW
authors.lastname: Childs
authors.forename: Alan P
authors.initials: AP
authors.lastname: Koretsky
mesh_terms: D002465:Cell Movement; D002478:Cells, Cultured; D002712:Chlorides; D003287:Contrast Media; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008214:Lymphocytes / Q000166:cytology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D017895:Manganese Compounds; D013194:Staining and Labeling
chemical_list: D002712:Chlorides; D003287:Contrast Media; D017895:Manganese Compounds; C025340:manganese chloride