The role of the chemokine receptor CXCR3 in mouse models for IL-12-driven CNS-inflammation and Morbus Alzheimer-like neurodegeneration

The chemokine receptor CXCR3 and its corresponding ligands CXCL9, CXCL10 and CXCL11 are well known to be involved in the trafficking and migration of activated CD4+ Th1 T cells, CD8+ T cells and NK cells during inflammation. Because of the high levels of CXCR3 expression on Th1 and NK cells, this chemokine receptor is used as a prototypical marker for these cells. Functional existence of CXCR3 has also been demonstrated on resident cells of the CNS, although the relevance of CXCR3 for CNS immune and non-immune functions is only scarcely defined. The CXCR3 ligands CXCL9, CXCL10 and CXCL11 are induced in a vast variety of inflammatory CNS diseases with a variable degree of immune cell infiltration, but recently these ligands have also been shown to be induced in neurodegenerative diseases without significant infiltration of immune cells. Taken together, the available data argues for a diverse and complex role of CXCR3 in neuroinflammatory diseases, which is beyond simple immune cell attraction. Furthermore, the impact of CXCR3 in neurodegenerative diseases is almost undiscovered. To further examine the functional role of CXCR3 in CNS disease models, we genetically deleted the CXCR3 receptor in specific CNS disease models. We first focused on the impact of CXCR3 on a highly inflammatory, Th1 cell-mediated immune response in the CNS induced by the CNS-specific production of IL-12 in transgenic mice (GF-IL12 model). Secondly and in contrast to the first model, we examined the role of CXCR3 signaling in a neurodegenerative disease using transgenic mice co-expressing two human Alzheimer’s disease (AD) mutations with only minor inflammatory features (APP/PS1 model). GF-IL12 mice develop ataxia due to severe cerebellar inflammation, but have little overt ocular pathology. In GF-IL12 mice deficient for CXCR3 the incidence of ataxia was drastically reduced, but surprisingly all mice developed cataract and severe inflammatory destruction of the eyes. Histological examination revealed only minimal cerebellar inflammation in the majority of GF-IL12/CXCR3KO mice, but severe retinal disorganization, loss of photoreceptors and lens destruction of the eyes. The number of CD3+, CD11b+ and NK 1.1+ cells were reduced in the cerebellum, but highly increased in the eyes of GF-IL12/CXCR3KO compared to GF-IL12 mice. In addition, high levels of various transcripts of proinflammatory cytokines were found in the cerebellum of GF-IL12 and the eye of GF-IL12/CXCR3KO mice. These findings demonstrate key, but paradoxical functions for CXCR3 in IL-12-induced immune pathology in the CNS, promoting inflammation in the brain yet restricting it in the eye. From this experiment we conclude that CXCR3 can have both striking protective and harmful functions in CNS and ocular inflammation and that this effect does not only depend on the trigger as suggested by previous studies but likely also on the micro-milieu of the affected organ. Early chemokine induction has been described in chronic neurodegenerative diseases such as AD. Descriptive studies in brain tissue from AD patients and the according animal models revealed high levels of the chemokine CXCL10, suggesting an important pathogenetic role of this chemokine and the corresponding receptor CXCR3. To further elucidate the role of CXCR3 in a less inflammatory CNS disease model, we analyzed CXCR3-competent APP/PS1 transgenic mice and APP/PS1/CXCR3-/- transgenic mice for Aβ-deposition, APP-processing and inflammatory gene transcription. Furthermore, microglial phagocytosis assays were used to analyze the impact of CXCR3 on the microglial phagocytosis of Aβ. We found a strongly reduced plaque burden and Aβ peptide-levels APP/PS1/CXCR3-/- compared to APP/PS1 mice. An alternative morphological activation and diminished accumulation of microglia was detected in APP/PS1/CXCR3-/- mice and after cortical injection of Aβ into CXCR3-/- mice. CXCR3 deficiency led to a reduction of proinflammatory cytokine RNA levels like TNF-α and IL-1β in APP/PS1 brain tissue. In vitro, CXCR3-/- and CXCR3 antagonist treated microglia showed enhanced phagocytosis of Aβ. Taken together, we identified CXCR3 as a critical factor modulating the development of the microglial response and thereby the progression of the Alzheimer’s like pathology observed in APP/PS1 mice. The presented studies highlight the potent but also complex functional properties of CXCR3 in both, highly inflammatory and neurodegenerative CNS-disease models. CXCR3 appears to be a novel and promising therapeutic target for AD but our data further underline the functional complexity and unpredictability of this chemokine system in CNS diseases. Until then, therapeutic targeting of CXCR3 has to be proceeded with caution.Die Rolle des CXCR3 Rezeptors in Mausmodellen für IL-12 induzierter Neuroinflammation und Alzheimer-ähnlicher Neurodegeneration Im Rahmen von Entzündungsreaktionen sind der Chemokinrezeptor CXCR3 und die CXCR3-Liganden CXCL9, CXCL10 und CXCL11 maßgeblich an der Steuerung und Migration von aktivierten CD4+ Th1 T Zellen, CD8+ T Zellen und NK Zellen beteiligt. CXCR3 ist der typisches Markermolekül für Th1 und NK Zellen. Die funktionelle Expression von CXCR3 ist auch auf Zellen des ZNS nachgewiesen worden, wobei der Einfluss dieses Rezeptorsystems auf immunologische und nicht-immunologische Prozesse im ZNS noch unzureichend geklärt ist. Im ZNS werden die Liganden CXCL9, CXCL10 und CXCL11 in einer Vielzahl von inflammatorischen Erkrankungen mit variabler Immunzellinfiltration induziert. In der Übersicht diverser Studien zu entzündlichen Erkrankungen des ZNS zeigt sich eine komplexe Rolle des CXCR3 Rezeptorsystems, welche jenseits einfacher Zellrekrutierung liegt. Vergleichend dazu ist der Einfluss des Rezeptors auf den Verlauf neurodegenerativer Erkrankungen ohne signifikante Immunzellinfiltration bisher nahezu ungeklärt. Um die Rolle von CXCR3 besser definieren zu können, wurde der Rezeptor in zwei ZNS Erkrankungsmodellen durch genetischen Knockout deletiert. Der erste Teil der Arbeit fokussiert sich auf eine hochentzündliche, Th1-gesteuerte Immunantwort, die durch die ZNS-spezifische Expression von IL-12 in transgenen Mäusen vermittelt wird (GF-IL12 Modell). Im Gegensatz zum ersten Modell, wurde im zweiten Modell die Rolle von CXCR3 in einer neurodegenerativen Erkrankung mit entzündlichen Prozessen, jedoch ohne signifikante Immunzellinfiltration analysiert (APP/PS1 Modell). Das hierzu verwendete transgene Mausmodell basiert auf der Koexpression zweier humaner Alzheimer-Mutationen (APP/PS1). GF-IL12 Mäuse entwickeln eine progrediente Ataxie, infolge einer starken zerebellären Entzündungsreaktion, jedoch ohne pathologische Veränderungen des Auges. Bei GF-IL12 Mäusen mit CXCR3-Defizienz (GF-IL12/CXCR3KO) kommt es zu einer drastisch verringerten Inzidenz der Ataxie, aber zu einer frühen Bildung von Katarakten, begleitet von einer starken Entzündungsreaktion, welche bis hin zur Atrophie des Auges führt. Histologische Untersuchungen der GF-IL12/CXCR3KO Mäuse belegen eine zum Großteil sehr milde zerebelläre Entzündung, jedoch die Disorganisation der Zellschichten der Retina konkomitierend mit dem Verlust der Photorezeptor-Zellschicht und der Zerstörung der Linse. Im Vergleich zu GF-IL12 Mäusen zeigen GF-IL12/CXCR3KO Tiere eine reduzierte Anzahl von CD3+, CD11b+ und NK 1.1+ Zellen im Zerebellum, jedoch stark erhöhte Populationen dieser Zellen im Auge. Weiterhin wurde die Erhöhung von Zytokin/Chemokin Transkripten im Zerebellum von GF-IL12 und in den Augen von GF-IL12/CXCR3KO Mäusen detektiert. Die vorliegende Arbeit weist auf eine Schlüsselfunktion von CXCR3 in der IL-12 induzierten ZNS-Pathologie hin, welche gewebespezifisch eine Entzündung im Zerebellum fördern, jedoch im Auge unterdrücken kann. Die Induktion von Chemokinen im frühen Stadium von ZNS-Pathologien ist ein Charakteristikum von chronisch neurodegenerativen Erkrankungen, wie der Alzheimer-Erkrankung (AD). In der Vergangenheit wurde in einer Reihe von deskriptiven Studien die Induktion von CXCL10 im Hirngewebe von AD-Patienten und in AD-Maus-Modellen dokumentiert, jedoch nicht funktionell untersucht. In der zweiten Studie wurden APP/PS1 und CXCR3-defiziente APP/PS1 (APP/PS1/CXCR3-/- Mäuse gezüchtet und auf β-Amyloid-(Aβ)-Plaquelast, APP-Prozessierung und Transkription proinflammatorischer Gene untersucht. Weiterhin wurde der Einfluss des CXCR3 Rezeptors auf die Phagozytose von Aβ durch Mikroglia untersucht. Es zeigte sich, dass APP/PS1/CXCR3-/- Mäuse eine stark reduzierte Plaquelast, sowie eine reduzierte Menge an löslichen und unlöslichen Aβ-Peptiden aufweisen. Zudem ließ sich eine differentielle morphologische Aktivierung und verringerte Akkumulation von Mikroglia in APP/PS1/CXCR3-/- Tieren, sowie in CXCR3-/- Mäusen nach intrazerebraler Aβ-Injektion beobachten. Des Weiteren verringert CXCR3-Defizienz im APP/PS1-Model die Genexpression von proinflammatorischen Zytokinen wie TNF-α und IL-1β. In vitro kultivierte, primäre CXCR3-/- Mikroglia phagozytieren signifikant mehr fibrilläres Aβ, was sich darüber hinaus auch in WT Mikroglia nach blockieren des CXCR3 Rezeptors beobachten lässt. Zusammenfassend lässt sich sagen, dass CXCR3 eine wichtige Funktion in der Entwicklung der Alzheimer-ähnlichen Krankheit im APP/PS1 Model hat. Die vorliegenden Modelle für hoch entzündliche und degenerative neurologische Erkrankungen geben Einsicht in potente, aber komplexe Funktionen des CXCR3 Rezeptorsystems. CXCR3 moduliert nicht nur die Verteilung und Aktivierung von infiltrierenden Immunzellen, sondern auch von residenten Immunzellen des ZNS

CXCR3 modulates glial accumulation and activation in cuprizone-induced demyelination of the central nervous system.

peer reviewed[en] BACKGROUND: The functional state of glial cells, like astrocytes and microglia, critically modulates the course of neuroinflammatory and neurodegenerative diseases and can have both detrimental and beneficial effects. Glial cell function is tightly controlled by cellular interactions in which cytokines are important messengers. Recent studies provide evidence that in particular chemokines are important modulators of glial cell function. During the course of CNS diseases like multiple sclerosis or Alzheimer's disease, and in the corresponding animal models, the chemokines CXCL9 and CXCL10 are abundantly expressed at sites of glial activation, arguing for an important role of these chemokines and their corresponding receptor CXCR3 in glial activation. To clarify the role of this chemokine system in glial cell activation, we characterized the impact of CXCR3 on glial activation in a model of toxic demyelination in which glial activation without a prominent influx of hematogenous cells is prototypical. METHODS: We investigated the impact of CXCR3 on cuprizone-induced demyelination, comparing CXCR3-deficient mice with wild type controls. The clinical course during cuprizone feeding was documented for five weeks and for the subsequent four days withdrawal of the cuprizone diet (5.5 weeks). Glial activation was characterized using histological, histomorphometric and phenotypic analysis. Molecular analysis for (de)myelination and neuroinflammation was applied to characterize the effect of cuprizone on CXCR3-deficient mice and control animals. RESULTS: CXCR3-deficient mice displayed a milder clinical course during cuprizone feeding and a more rapid body weight recovery after offset of diet. In the CNS, CXCR3 deficiency significantly attenuated the accumulation and activation of microglia and astrocytes. Moreover, a deficiency of CXCR3 reduced the expression of the microglial activation markers CD45 and CD11b. Compared to controls, we observed a vast reduction of RNA levels for proinflammatory cytokines and chemokines like Ccl2, Cxcl10, Tnf and Il6 within the CNS of cuprizone-treated mice. Lastly, CXCR3 deficiency had no major effects on the course of demyelination during cuprizone feeding. CONCLUSIONS: The CXCR3 chemokine system is critically involved in the intrinsic glial activation during cuprizone-induced demyelination, which significantly modulates the distribution of glial cells and the local cytokine milieu

Body Fluid Cytokine Levels in Mild Cognitive Impairment and Alzheimer’s Disease: a Comparative Overview

This article gives a comprehensive overview of cytokine and other inflammation associated protein levels in plasma, serum and cerebrospinal fluid (CSF) of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). We reviewed 118 research articles published between 1989 and 2013 to compare the reported levels of 66 cytokines and other proteins related to regulation and signaling in inflammation in the blood or CSF obtained from MCI and AD patients. Several cytokines are evidently regulated in (neuro-) inflammatory processes associated with neurodegenerative disorders. Others do not display changes in the blood or CSF during disease progression. However, many reports on cytokine levels in MCI or AD are controversial or inconclusive, particularly those which provide data on frequently investigated cytokines like tumor necrosis factor alpha (TNF-α) or interleukin-6 (IL-6). The levels of several cytokines are possible indicators of neuroinflammation in AD. Some of them might increase steadily during disease progression or temporarily at the time of MCI to AD conversion. Furthermore, elevated body fluid cytokine levels may correlate with an increased risk of conversion from MCI to AD. Yet, research results are conflicting. To overcome interindividual variances and to obtain a more definite description of cytokine regulation and function in neurodegeneration, a high degree of methodical standardization and patients collective characterization, together with longitudinal sampling over years is essential

CNS-targeted production of IL-17A induces glial activation, microvascular pathology and enhances the neuroinflammatory response to systemic endotoxemia.

Interleukin-17A (IL-17A) is a key cytokine modulating the course of inflammatory diseases. Whereas effector functions of IL-17A like induction of antimicrobial peptides and leukocyte infiltration could clearly be demonstrated for peripheral organs, CNS specific effects are not well defined and appear controversial. To further clarify the functional significance of IL-17A in the CNS, we generated a transgenic mouse line with astrocyte-restricted expression of the IL-17A gene. GFAP/IL-17A transgenic mice develop normally and do not show any signs of neurological dysfunction. However, histological characterization revealed astrocytosis and activation of microglia. Demyelination, neurodegeneration or prominent tissue damage was not observed but a vascular pathology mimicking microangiopathic features was evident. Histological and flow cytometric analysis demonstrated the absence of parenchymal infiltration of immune cells into the CNS of GFAP/IL-17A transgenic mice. In GFAP/IL-17A mice, LPS-induced endotoxemia led to a more pronounced microglial activation with expansion of a distinct CD45(high)/CD11b(+) population and increased induction of proinflammatory cytokines compared with controls. Our data argues against a direct role of IL-17A in mediating tissue damage during neuroinflammation. More likely IL-17A acts as a modulating factor in the network of induced cytokines. This novel mouse model will be a very useful tool to further characterize the role of IL-17A in neuroinflammatory disease models

CXCR3 promotes plaque formation and behavioral deficits in an Alzheimer's disease model.

peer reviewedChemokines are important modulators of neuroinflammation and neurodegeneration. In the brains of Alzheimer's disease (AD) patients and in AD animal models, the chemokine CXCL10 is found in high concentrations, suggesting a pathogenic role for this chemokine and its receptor, CXCR3. Recent studies aimed at addressing the role of CXCR3 in neurological diseases indicate potent, but diverse, functions for CXCR3. Here, we examined the impact of CXCR3 in the amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mouse model of AD. We found that, compared with control APP/PSI animals, plaque burden and Aβ levels were strongly reduced in CXCR3-deficient APP/PS1 mice. Analysis of microglial phagocytosis in vitro and in vivo demonstrated that CXCR3 deficiency increased the microglial uptake of Aβ. Application of a CXCR3 antagonist increased microglial Aβ phagocytosis, which was associated with reduced TNF-α secretion. Moreover, in CXCR3-deficient APP/PS1 mice, microglia exhibited morphological activation and reduced plaque association, and brain tissue from APP/PS1 animals lacking CXCR3 had reduced concentrations of proinflammatory cytokines compared with controls. Further, loss of CXCR3 attenuated the behavioral deficits observed in APP/PS1 mice. Together, our data indicate that CXCR3 signaling mediates development of AD-like pathology in APP/PS1 mice and suggest that CXCR3 has potential as a therapeutic target for AD

Astrocyte-specific expression of interleukin 23 leads to an aggravated phenotype and enhanced inflammatory response with B cell accumulation in the EAE model

Background!#!Interleukin 23 is a critical cytokine in the pathogenesis of multiple sclerosis. But the local impact of interleukin 23 on the course of neuroinflammation is still not well defined. To further characterize the effect of interleukin 23 on CNS inflammation, we recently described a transgenic mouse model with astrocyte-specific expression of interleukin 23 (GF-IL23 mice). The GF-IL23 mice spontaneously develop a progressive ataxic phenotype with cerebellar tissue destruction and inflammatory infiltrates with high amounts of B cells most prominent in the subarachnoid and perivascular space.!##!Methods!#!To further elucidate the local impact of the CNS-specific interleukin 23 synthesis in autoimmune neuroinflammation, we induced a MOG35-55 experimental autoimmune encephalomyelitis (EAE) in GF-IL23 mice and WT mice and analyzed the mice by histology, flow cytometry, and transcriptome analysis.!##!Results!#!We were able to demonstrate that local interleukin 23 production in the CNS leads to aggravation and chronification of the EAE course with a severe paraparesis and an ataxic phenotype. Moreover, enhanced multilocular neuroinflammation was present not only in the spinal cord, but also in the forebrain, brainstem, and predominantly in the cerebellum accompanied by persisting demyelination. Thereby, interleukin 23 creates a pronounced proinflammatory response with accumulation of leukocytes, in particular B cells, CD4+ cells, but also γδ T cells and activated microglia/macrophages. Furthermore, transcriptome analysis revealed an enhanced proinflammatory cytokine milieu with upregulation of lymphocyte activation markers, co-stimulatory markers, chemokines, and components of the complement system.!##!Conclusion!#!Taken together, the GF-IL23 model allowed a further breakdown of the different mechanisms how IL-23 drives neuroinflammation in the EAE model and proved to be a useful tool to further dissect the impact of interleukin 23 on neuroinflammatory models

Transgenic IL-17A acts synergistically with other inflammatory stimuli and potentiates LPS induced microgial activation.

<p>GF/IL17 transgenic animals and littermate controls between 2 and 3 month were injected twice with 50 µg LPS i.p. in 24 hours or treated with mock injections of PBS. (<b>A</b>) Quantitative rt-PCR revealed a strong upregulation of the expression of inflammatory cytokines <i>Tnf</i>, <i>Il1b</i>, and <i>Ccl2</i> by LPS treatment whereas <i>Il6</i> was not induced following endotoxemia. This effect was markedly pronounced in GF/IL17 transgenic animals (<i>Tnf</i>: p < 0,01; <i>Il1b</i>: p < 0,05). Furthermore <i>Ccl2</i> expression was strikingly upregulated in some of the LPS treated GF/IL17 mice compared with LPS treated wild-type controls but due to the high interindividual variance not considered as significant. (<b>B</b>) Representative flow cytometry profiles from mock- or LPS-treated GF/IL17 and WT mice. LPS treatment induced a population of CD45^high/CD11b⁺ activated microglia in both WT and GF/IL17 mice. Chronic IL-17A stimulation strikingly augmented this effect, respectively. The numbers above the indicated gate show the mean percentages of FSC/SSC gated populations. (<b>C</b>) For the statistical analysis of infiltrating cell numbers a ratio between CD45^high/CD11b⁺ activated microglia and CD45^dim/CD11b⁺ resting microglia was calculated for each individual mouse.GF/IL17 transgenic animals exhibited a significantly elevated ratio of CD45^high/CD11b⁺ activated to CD45^dim/CD11b⁺ microglia after LPS treatment, respectively (p < 0,05). (<b>D</b>) Lectin immunohistochemistry revealed a pronounced accumulation of activated microglia (arrows) in the periventricular regions (asterisk: choroid plexus) after LPS treatment in GF/IL17 mice. (<b>E</b>) Intracellular staining of TNF-α after LPS treatment. Only CD45 positive microglia and monocytes/macrophages are stained by anti TNF-α antibody (left histogram) whereas GLAST positive astrocytes are negative for TNF-α (right histogram). In GF/IL17 transgenic mice (light gray) compared with wildtype mice (dark gray) CD45 positive microglia and monocytes/macrophages exhibit a stronger intracellular TNF-α staining after LPS treatment.</p

Transgenic CNS expression of IL-17A induces glial activation

<p>. <b>(A)</b> IHC for GFAP in the hippocampus of WT and GF/IL17 transgenic mice at 9 month. GFAP-staining revealed a strong astrocytic activation by morphological criteria in GF/IL17 mice. <b>(B)</b> Astrocytosis was confirmed by anti-GFAP immunoblotting. Whole brain lysates were analyzed by immunoblotting for the presence of GFAP. Anti-tubulin immunoblotting served as internal loading control on the same membrane. <b>(C)</b> Densitometric quantifications (arbitrary densitometry units) from immunoblots of B after normalization by tubulin densitometry units obtained from the same immunoblot. (*p < 0.05). <b>(D)</b> Tomato-lectin-staining in the hippocampus revealed an activated microglial morphology in GF/IL17A transgenic animals characterized by rounded cell bodies and microglial clustering (open arrows). In addition Lectin staining displayed prominent microvasculature in GF/IL17 mice compared with WT controls (closed arrows; see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057307#pone-0057307-g003" target="_blank">Figure 3</a> for vascular pathology). <b>(E)</b> IHC of frozen brain sections for Iba1 (red), CD68 (green) and Dapi (blue). GF/IL17 mice showed a strong immunoreactivity for the activation marker CD68 in Iba1 stained microglia (white arrows indicating colocalisation of the lysosomal markes CD68 and Iba1, age: 9 month). (F) Representative flow cytometric analysis of surface marker expression from freshly isolated microglia in GF/IL17 mice (red) and WT littermate controls (blue). Dashed histogram: isotype control. Histograms were gated on microglial population according to forward/side scatter profile. GF/IL17 mice displayed similar surface expression levels for CD45 compared with WT whereas CD11b expression was upregulated in GF/IL17 mice compared with WT. (G) Statistical analysis of mean fluorescence intensity of freshly isolated microglia in GF/IL17 mice (red) and WT littermate controls (blue). Comparable expression levels of CD45 in GF/IL17 and WT mice whereas CD11b expression levels were significantly upregulated in GF/IL17 mice compared with WT controls (*p < 0.05).</p

Astrocytic expression of IL-17A induces a vascular pathology with capillary calcifications, microvascular rarefaction and thickening of endothelial layer and basement membrane of vessel walls without disturbing blood-brain barrier integrity.

<p>GFAP immunohistochemistry (<b>A–B</b>), lectin (<b>C</b>) and Alizarin red S staining (<b>D</b>) of the thalamus in WT mice (<b>A</b>) and GF/IL17 transgenic animals (<b>C–D</b>) at the age of 09 month. Microvessels surrounded by GFAP positive astrocytic endfeet and laminin stained endothelia are filled with hematoxillin positive material (white arrows). Around calcified microvessels astrocytes display an activated morphology. Deposits are labelled orange/red in Alizarin red S staining (<b>D</b>) confirming vascular calcifications. Transmission electron microscopy of capillaries in the corpus callosum of (<b>E</b>) wild-type mice and (<b>F</b>) GF/IL17 transgenic mice at the age between 10 and 12 month exhibit morphological criteria of microangiopathy: the endothelial cell layer <i>(Endo)</i> appears enlarged compared with WT. Basement membrane <i>(red-colorored)</i> surrounding the vascular endothelium appears heavily thickened in TG animals. GF/IL17 mice display numerous duplications of the basement membrane spanning the perivascular space harbouring pericytes <i>(green colored)</i>. Inside capillaries erythrocytes <i>(Ery)</i> are detectable. Scale bar represents 1 µm. (<b>G</b>) Measurement of basement membrane thickness revealed a significant diameter increase in GF/IL17 mice (p < 0,05) (<b>H</b>) Confocal microscopy of 50 µm sections labelled with anti-laminin displayed a dense microvascular network in the white matter of WT animals. (<b>I</b>) Rarefaction of microvasculature in corresponding areas in GF/IL17 mice. Furthermore arterioles appear thickened. (Age: 10–12 month of both transgenic and wild-type mice) (<b>J</b>) To examine blood-brain barrier integrity Evans blue dye (EBD) extravasation into tissue was quantified. Levels of tissue EBD in brains and spinal cord are equal in WT and GF/IL17 mice. Liver tissue served as positive controls.</p

Regulation of inflammation related genes in GF/IL17 mice relative to littermate controls (arbitrary units).

<p>Regulation of inflammation related genes in GF/IL17 mice relative to littermate controls (arbitrary units).</p