preparation of mog35-55 emulsion for immunization of mouse

Inducción y evaluación de la encefalomielitis autoinmune experimental en ratones

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system (CNS). It shows the presence of perivascular infiltration of inflammatory cells, demyelination, axonal loss, and gliosis1. Its etiology remains unknown, and its clinical aspects, radiographic, and pathological features suggest remarkable heterogeneity in the disease2.
Due to its unknown etiology and complexity, at present, no animal model recapitulates all the clinical and radiological features displayed in human MS3,4. However, various animal models are employed to study different aspects of MS3,4. In these models, disease initiation is typically extremely artificial, and the timeframe of the onset of clinical signs is different between humans and mice. For example, in humans, the pathophysiological processes underlying the disease are undetected for years before the onset of clinical manifestations. Conversely, the experimenters can detect symptoms in animal models within weeks or even days after MS induction4.
Three basic animal models produce the features of demyelination that are characteristic of MS: those that are virus-induced (e.g., Theiler&#39;s murine encephalomyelitis virus), those that are induced by toxic agents (e.g., cuprizone, lysolecithin), and the different variants of experimental autoimmune encephalomyelitis (EAE)5. Each model helps study some specific facets of the disease but none replicates all the features of MS6. Thus, it is critical to choose the correct model considering the specific experimental needs and the scientific questions to be addressed.
Thanks to immunization procedures against myelin-derived antigens, EAE is induced by triggering an autoimmune response to CNS components in susceptible mice. The interplay between a wide range of immunopathological and neuropathological mechanisms causes the development of principal pathological traits of MS (i.e., inflammation, demyelination, axonal loss, and gliosis) in the immunized mice7,8. Mice begin to show clinical symptoms around the second week after immunization and generally show ascending paralysis from the tail to the limb and forelimb. The clinical score (i.e., quantification of the accumulation of disease-related deficits) is generally assessed using a 5-point scale7.
Active immunization with protein or peptide or passive transfer of encephalitogenic T cells can be used to induce EAE in mice with different genetic backgrounds (e.g., SJL/J, C57BL/6, and non-obese-diabetic (NOD) mice). Myelin proteolipid protein (PLP), myelin basic protein (MBP), and myelin oligodendrocyte glycoprotein (MOG) are examples of self-CNS proteins from which immunogens are usually produced. Particularly, SJL/J mice immunized with the immunodominant epitope of PLP (PLP139&#8722;151) develop a relapsing-remitting (RR) disease course, while C57BL/6J mice immunized with the immunodominant MOG35-55 peptide show EAE of a chronic nature1. Despite some limitations, such as providing very little information about MS progression, the role of B cells in the disease, the inside-out mechanisms, or difficulties in studying remyelination, the EAE models have hugely contributed to the understanding of autoimmune and neuroinflammatory processes, increasing the knowledge in the MS field and thus allowing the development of novel therapeutic approaches for this disease4,6.
In the present work, we focused on a particular form of active EAE, the myelin oligodendrocyte glycoprotein peptide 35-55 (MOG35-55)-induced form9,10,11,12. The MOG35-55-induced EAE models a chronic form of MS. After immunization, the mice undergo an asymptomatic phase within the first week after immunization, then the disease typically arises during the second week after immunization, while between the third and fourth weeks after immunization, the disease becomes chronic, with no possibility of full recovery from the accumulated deficits7,8,13. Interestingly, no differences between males and females in incidence, disease onset, course, or progression are observed in most of the studies present in the literature14, even if fewer studies compare the disease in males and females.
In contrast, in humans, these parameters are known to be strongly sexually dimorphic2. MS affects more women than men; however, men generally develop a more aggressive form of the disease2. This evidence has suggested an essential, as well as complex, role of the gonadal hormones15; nevertheless, the role and the mechanism of action of sex hormones in the pathology remain unclear. Moreover, data from animal models support the idea that both estrogens and androgens exert positive effects on different tracts of the pathology in a sex-specific manner16,17.
Some studies also suggest neuroprotective, promyelinating, and anti-inflammatory effects of progesterone18 and, although evidence in MS patients is scarce18, neuroactive steroids (i.e., de novo synthetized steroids by the nervous system, such as pregnenolone, tetrahydroprogesterone, and dihydroprogesterone) might also affect the pathological course19. Collectively, these data support the idea that sex hormones produced both peripherally and inside the CNS have an important and sex-specific role in disease onset and progression. Therefore, in the present work, we urge the collection of separate data from both male and female animals.
From the histopathological point of view, the white matter of the spinal cord serves as the principal site of CNS injury in this model, which is characterized by multifocal, confluent regions of mononuclear inflammatory infiltration and demyelination8. Thus, in describing this protocol for the induction of MOG35-55-induced EAE in C57BL/6J mice, we will take into account the disease outcome in the two sexes and provide some histopathological insights regarding the spinal cords.

Autor destacado: Creación de un modelo experimental versátil de encefalomielitis autoinmune relevante para ratones machos y hembras 

Modelización de la esclerosis múltiple en los dos sexos: encefalomielitis autoinmune experimental inducida por MOG35-55

Watch this Scientific Journal Video about Preparation of MOG35-55 Emulsion for Immunization of Mouse at JoVE.com

Preparation of MOG35-55 Emulsion for Immunization of Mouse  

Preparación de la emulsión MOG35-55 para la inmunización de ratones

Para comenzar, prepare el péptido de glicoproteína de oligodendrocitos de mielina en una solución de 35 a 55, o MOG 35 a 55, en un vaso de precipitados de vidrio. Para ello, añada el componente líquido al vaso de precipitados y, a continuación, añada la cepa de mycobacterium tuberculosis adecuada. Coloque el vaso de vidrio que contiene la solución en un baño de hielo.Usando una jeringa de vidrio con una aguja de calibre 18, inicie el proceso de emulsificación y continúe emulsionando la solución durante un mínimo de 15 minutos. Para evaluar la calidad de la emulsión, dispense una gota de la emulsión en un recipiente transparente lleno de agua. Considere que la emulsión está lista si la gota mantiene su estructura y permanece intacta.Transfiera la emulsión directamente a las jeringas de un mililitro designadas para fines de inmunización. Guarde las jeringas llenas a cuatro grados centígrados hasta que estén listas para usar.

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JoVE Journal

Neuroscience

Preparation of MOG35-55 Emulsion for Immunization of Mouse

101 vistas. Para comenzar, prepare el péptido de glicoproteína de oligodendrocitos de mielina en una solución de 35 a 55, o MOG 35 a 55, en un vaso de precipitados de vidrio. Para ello, añada el componente líquido al vaso de precipitados y, a continuación, añada la cepa de mycobacterium tuberculosis adecuada. Coloque el vaso de vidrio que contiene la solución en un baño de hielo.Usando una jeringa de vidrio con una aguja de calibre 18, inicie el proceso de emulsificación y continúe emul...

Video: Preparation of MOG35-55 Emulsion for Immunization of Mouse  

Modeling Multiple Sclerosis in the Two Sexes: MOG35-55-Induced Experimental Autoimmune Encephalomyelitis

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system (CNS). It is characterized by different prevalence in the sexes, affecting more women than men, and different outcomes, showing more aggressive forms in men than in women. Furthermore, MS is highly heterogeneous in terms of clinical aspects, radiological, and pathological features. Thus, it is necessary to take advantage of experimental animal models that allow the investigation of as many aspects of the pathology as possible. Experimental autoimmune encephalomyelitis (EAE) represents one of the most used models of MS in mice, modeling different disease features, from the activation of the immune system to CNS damage. Here we describe a protocol for the induction of EAE in both male and female C57BL/6J mice using myelin oligodendrocyte glycoprotein peptide 35-55 (MOG35-55) immunization, which leads to the development of a chronic form of the disease. We also report the evaluation of the daily clinical score and motor performance of these mice for 28 days post immunization (28 dpi). Lastly, we illustrate some basic histological analysis at the CNS level, focusing on the spinal cord as the primary site of disease-induced damage.

Experimental autoimmune encephalomyelitis is one of the most widely used murine models of multiple sclerosis. In the current protocol, C57BL/6J mice of both sexes are immunized with myelin oligodendrocyte glycoprotein peptide, resulting mainly in ascending paresis of the tail and limbs. Here we discuss the protocol of EAE induction and evaluation.