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Immunology 2018
J u l y 0 5 - 0 7 , 2 0 1 8
V i e n n a , A u s t r i a
Page 90
Journal of Clinical Immunology and Allergy
ISSN 2471-304X
1 5
t h
I n t e r n a t i o n a l C o n f e r e n c e o n
Immunology
M
icroglia are the resident immune cells of the central nervous system. A frequently used marker for
in vivo
activated microglia
is the 18kDa translocator protein (TSPO). TSPO is widely used as a Positron Emission Tomography (PET) imaging target
to visualize injured brain areas and microglial activation. TSPO, formerly known as the peripheral benzodiazepine receptor, is a
cholesterol binding protein localized to the outer mitochondrial membrane. Despite the proposed roles of TSPO, little is known
about the cells expressing TSPO, namely the microglia and astrocytes, in neuroinflammatory and neurodegenerative disorders.
However, localisation of TSPO in relation to lesions and cell types is unknown. Therefore, we performed immunohistochemistry
on brain tissue containing different white and grey matter. Multiple sclerosis (MS) lesions (n = 56) were compared with brain
tissues from healthy controls (n = 10) to determine expression of TSPO. Low levels of TSPO expression were found in the
white matter of healthy controls (16.9±2.4%) and normal appearing white matter (NAWM) (22.9±16.4%) in MS cases. Conversely,
significantly increased levels of TSPO expression were observed in microglia of active white matter lesions (12.9±7.5%) and the
rim of chronic active lesions (15.1±8.5%) in MS cases compared to controls (1.2±0.6%) and NAWM (0.7±0.8%). Furthermore,
TSPO was also found to be expressed in astrocytes at the centre of active lesions. These findings show the localisation of TSPO
in MS lesions in the brain and highlight that PET imaging using TSPO ligands in people with MS not only reflects microglia and
macrophage activity
in vivo
but also the response of astrocytes, as well as cells of the adaptive immune response.
s.amor@vumc.nlDifferential expression of translocator protein
(TSPO) in multiple sclerosis reflects activated
microglia and astrocytes
Sandra Amor
1,2
, Erik Nutma
1
, Jodie Stephenson
1,2
, Rianne P G
Gorter
1
, Paul van der Valk
1
, Paul M Matthews
3
and David R Owen
4
1
VU University of Amsterdam, the Netherlands
2
Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University
of London, UK
3
Imperial College London, UK
Insights Allergy Asthma Bronchitis 2018, Volume: 4
DOI: 10.21767/2471-304X-C1-003