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Fluorine-18 labeled mouse bone marrow-derived dendritic cells can be detected in vivo by high resolution projection imaging. J Immunol Methods 2002 Feb 01;260(1-2):137-48 PMID: 11792384

Pubmed ID

11792384

Abstract

Immunization with ex vivo generated dendritic cells has become a focus for many clinical applications. The optimal site of injection and the migration pattern of these cells remain to be elucidated. We therefore developed a novel method for labeling mouse bone marrow-derived dendritic cells (BMDC) with the positron emitting radioisotope F-18 using N-succinimidyl-4-[F-18]fluorobenzoate, which covalently binds to the lysine residues of cell surface proteins. When we determined the stability of F-18 labeled BMDC, we found that at 4 h only 44+/-10% of the initial cell-bound activity was retained at 37 degrees C, whereas considerably more (91+/-3%) was retained at 4 degrees C. Labeled cells did not exhibit any significant alteration in cell viability or phenotype as determined by trypan blue exclusion and FACS analysis 24 h after radiolabeling. Furthermore, F-18-labeled BMDC stimulated allogeneic T cells in a mixed leukocyte reaction as potently as did sham-treated BMDC and migrated towards secondary lymphoid tissue chemokine (SLC) in a chemotaxis assay in vitro with the same efficiency as sham-treated BMDC. Migration of F-18-labeled BMDC was studied after footpad injection by (1) ex vivo counting of dissected tissues using a gamma counter and (2) in vivo by imaging mice with PiPET, a 2-mm resolution positron projection imager. After 4 h, the ratio between measured activity in draining vs. contralateral (D/C) lymph nodes (LN) was 166+/-96 (n=7) in the case of live cell injections, whereas if we injected heat-killed F-18-labeled BMDC or F-18-labeled macrophages the D/C ratios were 17+/-2 (n=2) and 14+/-4 (n=2), respectively. Injection of cell-free activity in the form of F-18-labeled 4-fluorobenzoic acid resulted in a D/C ratio of 7+/-2 (n=3), suggesting that the activity measured in the draining lymph node was associated with migrated F-18-labeled BMDC. When F-18-labeled live cells were injected into the footpad, 0.18+/-0.04% (n=7) of footpad activity was found in the draining LN within 4 h, whereas none was found in the contralateral LN. Quantitative assessment of cell migration by PET projection imaging of mice confirmed the ex-vivo counting results. These studies indicate that PET imaging offers a new approach for in vivo studies of dendritic cell biodistribution and migration.

Author List

Olasz EB, Lang L, Seidel J, Green MV, Eckelman WC, Katz SI

Author

Edit Olasz MD, PhD Associate Professor in the Dermatology department at Medical College of Wisconsin




Scopus

2-s2.0-0036469805   56 Citations

MESH terms used to index this publication - Major topics in bold

Animals
Bone Marrow Cells
Dendritic Cells
Fluorescent Dyes
Fluorine Radioisotopes
Image Processing, Computer-Assisted
Mice
Mice, Inbred BALB C
Staining and Labeling
jenkins-FCD Prod-353 9ccd8489072cb19f5b9f808bb23ed672c582f41e