gms | German Medical Science

63rd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Japanese Neurosurgical Society (JNS)

German Society of Neurosurgery (DGNC)

13 - 16 June 2012, Leipzig

Visualizing migrating monocytes with very small superparamagnetic iron oxide particles after entorhinal cortex lesion in the MRI

Meeting Abstract

  • J. Glumm - Klinik für Neurochirurgie, Helios Klinikum Berlin-Buch, Deutschland; Institut für Zell- und Neurobiologie, Zentrum für Anatomie, Charité - Universitätsmedizin Berlin
  • M. Pohland - Institut für Zell- und Neurobiologie, Zentrum für Anatomie, Charité - Universitätsmedizin Berlin
  • M. Kaminski - Institut für Zell- und Neurobiologie, Zentrum für Anatomie, Charité - Universitätsmedizin Berlin
  • J. Kiwit - Klinik für Neurochirurgie, Helios Klinikum Berlin-Buch, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocP 022

doi: 10.3205/12dgnc409, urn:nbn:de:0183-12dgnc4090

Published: June 4, 2012

© 2012 Glumm et al.
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Outline

Text

Objective: After traumatic brain injury, the lack of classical lymph vessels within brain tissue complicates immune surveillance of the central nervous system (CNS), and therefore cellular emigration out of the CNS parenchyma requires alternate pathways. With new very small superparamagnetic iron oxide particles (VSOP) we wanted to establish a method to monitor the invasion of blood-derived mononuclear cells and their migration out of the CNS into peripheral lymph nodes with magnetic resonance imaging (MRI).

Methods: Five different VSOP were analyzed for their potential to mark monocytes (variation in incubation time, concentration and amount) without compromising their immunological characteristics including FlowCytomix, immunocytochemistry and colloid phantoms. Monocytes were isolated from mice expressing green fluorescent protein (GFP) under the β-actin promoter. For MRI analyzes, VSOP incubated GFP Monocytes were injected in C57black6 mice directly after entorhinal Cortex lesion (ECL). MRI scans were obtained every second day and mice were allowed to survive from a few minutes to 14 days. Whole head/neck sections were analyzed, as well as isolated brains, lymph nodes and spleen.

Results: From the evaluated nanoparticles VSOP-R2 had the least influence on immunological characteristics with 12h incubation in 3 mM. For cytokines there is no increase in IL-1α, IL-10, IL-18 und GM-CSF, but an appropriate increase of TNFα and IL-6. Colloid phantoms showed the incubation time should be longer than 6 but no more than 12hours. Our in vivo MRI studies showed a good distribution along the ECL site. In control animals (PBS injection) we found no increase in T2-weighted sequences. Histological evaluation is still showing a better distribution than MRI of the injected monocytes along cortical fibre tracts, like the alveus and their appearance in the cervical lymph nodes.

Conclusions: Infiltrating monocytes to a central lesion site derived from blood monocytes are considered to play a crucial role after CNS injuries. Their potential in regeneration processes needs to be better understood. In vitro we have established a good incubation protocol for blood derived monocytes with VSOP-R2. So far we can monitor the GFP monocytes within the CNS and are currently optimizing our MRI sequences for the detection in lymph nodes. Our long-term aim is to influence immunity and regeneration in the CNS by specific application of genetically-modified microglial progenitor cells and their monitoring via MRI.