Chugai Pharmaceutical Co., Ltd

Author Of 2 Presentations

Neuromyelitis Optica and Anti-MOG Disease Poster Presentation

P0684 - Anti-IL-6 receptor antibody prevents blood-brain barrier disruption in mice with experimental autoimmune encephalomyelitis (EAE) (ID 717)

Speakers
Presentation Number
P0684
Presentation Topic
Neuromyelitis Optica and Anti-MOG Disease

Abstract

Background

Breakdown of blood-brain barrier (BBB), which strictly regulates the entry of immunoglobulin (IgG) and lymphocyte into the central nervous system, is essential to pathogenesis in autoimmune encephalomyelitis such as multiple sclerosis and neuromyelitis optica spectrum disorder (NMOSD). IL-6 increases in serum and cerebrospinal fluid (CSF) in NMOSD patients and its level has been reported to correlate with CSF/serum ratio of albumin, a surrogate marker of BBB function. It is possible that IL-6 are involved in pathogenesis of NMOSD in terms of T and B cells, but roles of IL-6 signal inhibition on BBB function remain unknown.

Objectives

In this study, we examined the effects of anti-IL-6 receptor antibody on BBB function in EAE mice as a CNS autoimmune disease model in which IL-6 concentration in the CNS dramatically increases.

Methods

EAE was induced in female C57BL/6J mice by immunization with myelin oligodendrocyte glycoprotein 35–55 emulsified in adjuvant (Day 0). Pertussis toxin was administered at Days 0 and 2. Control mice were treated with complete Freund's adjuvant and saline alone. Mice were sequentially scored for clinical symptoms of EAE. Anti-IL-6 receptor antibody was intraperitoneally administered on Day 7. On Day 15 or 16, spinal cord, spleen and serum were harvested for immunohistochemistry, flow cytometry and transendothelial electrical resistance (TEER) studies.

Results

Immunohistochemical analysis showed that leakages of albumin and IgG into the spinal cord, which mean BBB permeability, in vehicle-treated EAE mice were higher than those in control mice. The number of CD4-positive T cells also markedly increased in the spinal cord of vehicle-treated EAE mice. Anti-IL-6 receptor antibody significantly reduced those changes in accordance with the prevention of clinical symptoms in EAE mice. It seems that these effects of anti-IL-6 receptor antibody are not only dependent on the inhibition of immune response because anti-IL-6 receptor antibody did not affect T cell differentiation in splenocytes of EAE mice. In addition, the serum of vehicle-treated EAE mice significantly decreased endothelial TEER value of cultured mouse primary endothelial cells, an indicator of permeability, and anti-IL-6 receptor antibody significantly prevented it in vitro.

Conclusions

These results suggest that anti-IL-6 receptor antibody can inhibit the BBB breakdown at least partly by direct effect on the endothelial permeability in EAE mice.

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Experimental Models Poster Presentation

P0951 - Challenge to creation of neuromyelitis optica mice model by AQP4 peptide immunization (ID 719)

Speakers
Presentation Number
P0951
Presentation Topic
Experimental Models

Abstract

Background

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system mainly associated with autoantibodies against the glial water channel protein aquaporin-4 (AQP4). A number of NMOSD related animal models have recently been reported. For example, general NMOSD models are produced by peripheral injection of immunoglobulin from NMOSD patients (NMO-IgG) in experimental autoimmune encephalomyelitis mice or intra-cerebral administration of NMO-IgG with human complement in naïve mice. In addition, AQP4-specific adoptive transfer model was also reported. But AQP4 immune process is not involved in these NMOSD models. On the other hand, creation of an AQP4-immunized mice model with clinical and histologic manifestations of CNS autoimmunity has proven challenging.

Objectives

In the present study, we tried to create AQP4 peptide-induced experimental autoimmune encephalomyelitice mice as NMOSD model.

Methods

Female C57BL/6J mice were used. Mice were subcutaneously immunized with 200 μg of AQP4 p201-220 peptide emulsified in complete Freund’s adjuvant supplemented with Mycobacterium tuberculosis extract H37Ra (Day 0). Pertussis toxin (400 ng) was administered at Days 0 and 2. Mice were sequentially scored for clinical symptoms according to the following scale: 0, no disease; 1, limp tail; 2, hind limb weakness; 3, hind limb paresis; 4, hind limb paralysis; 5, hind limb and fore limb paralysis; 6, moribundity and death.

Results

Total ten mice were immunized, four of which showed clinical symptoms within Day 34; two mice were clinical score 2, the other mice were clinical score 3.

Conclusions

NMOSD like model can be created by AQP4-immunization. Now, we are conducting additional experiments to examine the detailed characterization of this model, for example histopathological profiling such as AQP4 and astrocyte pathology in the spinal cord.

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