TY  - JOUR
A1  - Schuhmann, Michael K.
A1  - Bieber, Michael
A1  - Franke, Maximilian
A1  - Kollikowski, Alexander M.
A1  - Stegner, David
A1  - Heinze, Katrin G.
A1  - Nieswandt, Bernhard
A1  - Pham, Mirko
A1  - Stoll, Guido
T1  - Platelets and lymphocytes drive progressive penumbral tissue loss during middle cerebral artery occlusion in mice
JF  - Journal of Neuroinflammation
N2  - Background

In acute ischemic stroke, cessation of blood flow causes immediate tissue necrosis within the center of the ischemic brain region accompanied by functional failure in the surrounding brain tissue designated the penumbra. The penumbra can be salvaged by timely thrombolysis/thrombectomy, the only available acute stroke treatment to date, but is progressively destroyed by the expansion of infarction. The underlying mechanisms of progressive infarction are not fully understood.

Methods

To address mechanisms, mice underwent filament occlusion of the middle cerebral artery (MCAO) for up to 4 h. Infarct development was compared between mice treated with antigen-binding fragments (Fab) against the platelet surface molecules GPIb (p0p/B Fab) or rat immunoglobulin G (IgG) Fab as control treatment. Moreover, Rag1\(^{−/−}\) mice lacking T-cells underwent the same procedures. Infarct volumes as well as the local inflammatory response were determined during vessel occlusion.

Results

We show that blocking of the platelet adhesion receptor, glycoprotein (GP) Ibα in mice, delays cerebral infarct progression already during occlusion and thus before recanalization/reperfusion. This therapeutic effect was accompanied by decreased T-cell infiltration, particularly at the infarct border zone, which during occlusion is supplied by collateral blood flow. Accordingly, mice lacking T-cells were likewise protected from infarct progression under occlusion.

Conclusions

Progressive brain infarction can be delayed by blocking detrimental lymphocyte/platelet responses already during occlusion paving the way for ultra-early treatment strategies in hyper-acute stroke before recanalization.
KW  - ischemic penumbra
KW  - glycoprotein receptor Ib
KW  - T-cells
KW  - ischemic stroke
KW  - thrombo-inflammation
KW  - middle cerebral artery occlusion
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259172
VL  - 18
IS  - 1
ER  - 
TY  - JOUR
A1  - Zadeh-Khorasani, Maryam
A1  - Nolte, Thomas
A1  - Mueller, Thomas D.
A1  - Pechlivanis, Markos
A1  - Rueff, Franziska
A1  - Wollenberg, Andreas
A1  - Fricker, Gert
A1  - Wolf, Eckhard
A1  - Siebeck, Matthias
A1  - Gropp, Roswitha
T1  - NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human peripheral blood mononuclear cells as a model to test therapeutics targeting human signaling pathways
JF  - Journal of Translational Medicine
N2  - Background: Animal models of human inflammatory diseases have limited predictive quality for human clinical trials for various reasons including species specific activation mechanisms and the immunological background of the animals which markedly differs from the genetically heterogeneous and often aged patient population. 
Objective: Development of an animal model allowing for testing therapeutics targeting pathways involved in the development of Atopic Dermatitis (AD) with better translatability to the patient. 
Methods: NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human peripheral blood mononuclear cells (hPBMC) derived from patients suffering from AD and healthy volunteers were treated with IL-4 and the antagonistic IL-4 variant R121/Y124D (Pitrakinra). Levels of human (h) IgE, amount of B-, T- and plasma-cells and ratio of CD4 : CD8 positive cells served as read out for induction and inhibition of cell proliferation and hIgE secretion. Results were compared to in vitro analysis. 
Results: hIgE secretion was induced by IL-4 and inhibited by the IL-4 antagonist Pitrakinra in vivo when formulated with methylcellulose. B-cells proliferated in response to IL-4 in vivo; the effect was abrogated by Pitrakinra. IL-4 shifted CD4 : CD8 ratios in vitro and in vivo when hPBMC derived from healthy volunteers were used. Pitrakinra reversed the effect. Human PBMC derived from patients with AD remained inert and engrafted mice reflected the individual responses observed in vitro. 
Conclusion: NOD-scid IL2R \(\gamma^{null}\) mice engrafted with human PBMC reflect the immunological history of the donors and provide a complementary tool to in vitro studies. Thus, studies in this model might provide data with better translatability from bench to bedside.
KW  - atopic dermatitis
KW  - T-cells
KW  - rheumatoid arthritis
KW  - human interleukin-4
KW  - TGN1412
KW  - oxazolone colitis
KW  - cytokine release
KW  - expression
KW  - antagonists
KW  - responses
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122960
SN  - 1479-5876
VL  - 11
IS  - 4
ER  -