A rapid method for labelling CD4+ T cells with ultrasmall paramagnetic iron oxide nanoparticles for magnetic resonance imaging that preserves proliferative, regulatory and migratory behaviour in vitro.
A number of techniques have been developed to track the migration of T cells in vivo, but they all suffer significant shortcomings, including the examination of selected organs rather than the organism as a whole--thus precluding longitudinal studies--or limitations imposed by poor spatial resolution and the application of ionizing radiation. By conjugating the HIV tat peptide to ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles in a reaction yielding a mean valence of 45, a magnetic resonance (MR) contrast agent was synthesised that allowed T cells to be efficiently labelled within just 5 min. The USPIO nanoparticles were incorporated into both the cytoplasm and nucleus of labelled cells, which retained normal in vitro proliferative responses to a polyclonal stimulus; suppressive responses mediated by labelled CD4(+) CD25(+) regulatory T cells; chemotactic responses to the chemokine CXCL-12; and transmigration of an activated endothelial monolayer. We believe that this rapid, efficient and essentially non-toxic approach to labelling both murine and human T cells for MRI holds considerable promise, paving the way for the wider immunological application of this exciting technology.
Garden
O A
OA
Department of Immunology, Imperial College London, Hammersmith Campus, Du Cane Road, W12 ONN, UK.
Reynolds
P R
PR
Yates
J
J
Larkman
D J
DJ
Marelli-Berg
F M
FM
Haskard
D O
DO
Edwards
A D
AD
George
A J T
AJ
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000502:physiology*; D016466:CHO Cells; D002465:Cell Movement; D049109:Cell Proliferation; D002633:Chemotaxis; D006224:Cricetinae; D003432:Cross-Linking Reagents; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D051379:Mice; D008807:Mice, Inbred BALB C; D049329:Nanostructures / Q000737:chemistry*; D013194:Staining and Labeling / Q000379:methods*
D003432:Cross-Linking Reagents; D005290:Ferric Compounds; C000499:ferric oxide