This study was supported by the National Institutes of Health (R03NS131908) and the Department of Defense through the Multiple Sclerosis Research Program under Award No. W81XWH-22-1-0517. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense. This study was also supported by East Carolina University startup funds.

All procedures involving mice were performed in compliance with experimental guidelines approved by the East Carolina University Institutional Animal Care and Use Committee (IACUC). Wildtype C57BL/6J female mice between 8-10 weeks of age were used in this study. The animals were obtained from a commercial source (see Table of Materials). EAE was induced following previously published reports12,13,14.
1. Serum collection
<ol>
	<li>Euthanize the experimental mouse by CO2 asphyxiation or isoflurane overdose at the required time point (following institutionally approved protocols) after inducing EAE via MOG35-55 immunization. 
	NOTE: The total number of mice and time points for serum collection can vary according to the specific experiment.</li>
	<li>After the absence of vital signs is confirmed by toe or tail pinch, place the mouse in a dorsal recumbency position on a dissection tray and affix the limbs in position with pins or tape. Orient the mouse body to the LED light source (see Table of Materials) to illuminate the thorax of the animal.</li>
	<li>Spray the mouse fur with 70% ethanol and make a midline incision of 3-4 cm along the abdomen from the pelvis to the xiphoid using the dissector scissors, taking care to avoid any organs and major vessels (Figure 1A-C). To facilitate the procedure, use the forceps to grab the skin over the xiphoid process.</li>
	<li>Cut through the diaphragm laterally and then cut the rib cage anteriorly on both lateral edges using the spring scissors, stopping before reaching the sternum at the midline (Figure 1D). Fold the rib flap that was created over the mouse head to expose the heart (Figure 1E). 
	NOTE: Cutting the sternum should be avoided as this will damage the main thoracic arteries laying adjacent to the bone and reduce the volume of blood that can be collected.</li>
	<li>Insert a 25 G needle connected to a 1 mL syringe into the left ventricle and collect the blood by gently pulling back the plunger (Figure 1F). To facilitate the needle puncture, gently brace the heart against a pair of forceps. 
	NOTE: If the blood does not appear immediately into the syringe, the needle should be slowly rotated, and a different angle should be tested. However, efforts should be made to place the needle properly on the first attempt to avoid creating unnecessary holes in the heart where blood can leak out.</li>
	<li>Transfer the blood into a sterile 1.5 mL tube and allow it to clot for 30 min at room temperature. Remove the clot by centrifugation at 2000 &#215; g for 20 min at 4 &#176;C. Collect the supernatant, which represents the serum fraction, and store single-use aliquots into cryogenic tubes at -80 &#176;C for future testing.</li>
</ol>
2. ELISA assay
<ol>
	<li>Resuspend the lyophilized MOG35-55 peptide (see Table of Materials) in water to obtain a 10 mg/mL stock. Before starting the experiment, dilute the stock to 10 &#956;g/mL in coating buffer (see Table of Materials) and pipette 100 &#956;L/well of the final solution into a 96-well plate. Seal the plate with an adhesive film to avoid evaporation and incubate the plate overnight at 4 &#176;C. 
	NOTE: At least 2 wells should be calculated for each sample and 2 additional wells should be also included for a blank control.</li>
	<li>In parallel, coat the same number of wells with 100 &#956;L/well of bovine serum albumin (BSA) dissolved in coating buffer at 10 &#956;g/mL concentration. These additional wells will serve as background controls. 
	NOTE: It is recommended to coat with BSA the controls wells since the coating and blocking buffers have different compositions. Please note that other encephalitogenic peptides (such as PLP139-151 or MBP84-104) could be used as irrelevant antigens in alternative to BSA.</li>
	<li>The day after, wash the plate 3 times with 200 &#956;L/well of phosphate buffer saline supplemented with 0.05% Tween 20 (PBS-T). Subsequently, add 100 &#956;L/well of a blocking solution made of 3% BSA in PBS (without Tween 20) and incubate the plate sealed for 1 h at 37 &#176;C in a hybridization oven.</li>
	<li>Wash the plate 3 times with 200 &#956;L/well of PBS-T. Dilute each serum sample 1:100 in blocking solution and add 100 &#956;L/well to both MOG35-55 and BSA coated wells. Add the same volume of blocking solution to the wells designated as blanks. Incubate the plate sealed for 2 h at room temperature, with constant shaking (250 rpm).</li>
	<li>Wash the plate 3 times with 200 &#956;L/well of PBS-T. Dilute the HRP-conjugated secondary antibody (1:2000, see Table of Materials) in a solution made of 0.2% BSA in PBS-T and add 100 &#956;L/well to all wells. Incubate the plate sealed for 1 h at room temperature, with constant shaking (250 rpm).</li>
	<li>Wash the plate 3 times with 200 &#956;L/well of PBS-T. Add 100 &#181;L/well of 3,3&#39;,5,5&#39; tetramethylbenzidine (TMB) substrate (see Table of Materials) to all the wells and incubate in the dark for 1-5 min, monitoring the development of a blue color.
	<ol>
		<li>Stop the reaction by adding 100 &#181;L/well of stop solution (see Table of Materials) and measure the optical density (OD) in each well using a plate reader set at a wavelength of 450 nm. 
		&#8203;NOTE: The TMB substrate should be equilibrated at room temperature for 30-60 minutes before adding it to the wells.</li>
	</ol>
	</li>
</ol>
3. Data analysis
<ol>
	<li>Populate an Excel spreadsheet with the OD values read from the plate. Average the OD values obtained from duplicate wells (both MOG35-55 and BSA coated) for each sample.</li>
	<li>For each sample, subtract the mean value of the BSA-coated wells from that of MOG35-55 coated wells. The resulting background corrected values will be proportional to the concentration of anti-MOG35-55 antibodies in the different serum samples. 
	NOTE: Blank wells should result in corrected values around 0.</li>
	<li>Apply a non-parametric statistical test such as the Mann-Whitney U test to compare the average OD values between two experimental conditions. Include at least 3 independent samples for each condition.</li>
</ol>

Investigating Humoral Response in Autoimmune Demyelination

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	<li>Reich, D. S., Lucchinetti, C. F., Calabresi, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+sclerosis.">Multiple sclerosis.</a> N Engl J Med. 378 (2), 169-180 (2018).</li><li>Baranzini, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=B+cell+repertoire+diversity+and+clonal+expansion+in+multiple+sclerosis+brain+lesions.">B cell repertoire diversity and clonal expansion in multiple sclerosis brain lesions.</a> J Immunol. 163 (9), 5133-5144 (1999).</li><li>Genain, C. P., Cannella, B., Hauser, S. L., Raine, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+autoantibodies+associated+with+myelin+damage+in+multiple+sclerosis.">Identification of autoantibodies associated with myelin damage in multiple sclerosis.</a> Nat Med. 5 (2), 170-175 (1999).</li><li>Ma, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+hypomethylation+programs+underpin+b+cell+activation+in+early+multiple+sclerosis.">Specific hypomethylation programs underpin b cell activation in early multiple sclerosis.</a> Proc Natl Acad Sci U S A. 118 (51), e2111920118 (2021).</li><li>Hauser, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ocrelizumab+versus+interferon+beta-1a+in+relapsing+multiple+sclerosis.">Ocrelizumab versus interferon beta-1a in relapsing multiple sclerosis.</a> N Engl J Med. 376 (3), 221-234 (2017).</li><li>Montalban, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ocrelizumab+versus+placebo+in+primary+progressive+multiple+sclerosis.">Ocrelizumab versus placebo in primary progressive multiple sclerosis.</a> N Engl J Med. 376 (3), 209-220 (2017).</li><li>Didonna, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preclinical+models+of+multiple+sclerosis:+Advantages+and+limitations+towards+better+therapies.">Preclinical models of multiple sclerosis: Advantages and limitations towards better therapies.</a> Curr Med Chem. 23 (14), 1442-1459 (2016).</li><li>Steinman, L., Zamvil, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+successfully+apply+animal+studies+in+experimental+allergic+encephalomyelitis+to+research+on+multiple+sclerosis.">How to successfully apply animal studies in experimental allergic encephalomyelitis to research on multiple sclerosis.</a> Ann Neurol. 60 (1), 12-21 (2006).</li><li>Khare, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myelin+oligodendrocyte+glycoprotein-specific+antibodies+from+multiple+sclerosis+patients+exacerbate+disease+in+a+humanized+mouse+model.">Myelin oligodendrocyte glycoprotein-specific antibodies from multiple sclerosis patients exacerbate disease in a humanized mouse model.</a> J Autoimmun. 86, 104-115 (2018).</li><li>Marta, C. B., Oliver, A. R., Sweet, R. A., Pfeiffer, S. E., Ruddle, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenic+myelin+oligodendrocyte+glycoprotein+antibodies+recognize+glycosylated+epitopes+and+perturb+oligodendrocyte+physiology.">Pathogenic myelin oligodendrocyte glycoprotein antibodies recognize glycosylated epitopes and perturb oligodendrocyte physiology.</a> Proc Natl Acad Sci U S A. 102 (39), 13992-13997 (2005).</li><li>Flach, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoantibody-boosted+t-cell+reactivation+in+the+target+organ+triggers+manifestation+of+autoimmune+cns+disease.">Autoantibody-boosted t-cell reactivation in the target organ triggers manifestation of autoimmune cns disease.</a> Proc Natl Acad Sci U S A. 113 (12), 3323-3328 (2016).</li><li>Didonna, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ataxin-1+regulates+b+cell+function+and+the+severity+of+autoimmune+experimental+encephalomyelitis.">Ataxin-1 regulates b cell function and the severity of autoimmune experimental encephalomyelitis.</a> Proc Natl Acad Sci U S A. 117 (38), 23742-23750 (2020).</li><li>Didonna, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sex-specific+tau+methylation+patterns+and+synaptic+transcriptional+alterations+are+associated+with+neural+vulnerability+during+chronic+neuroinflammation.">Sex-specific tau methylation patterns and synaptic transcriptional alterations are associated with neural vulnerability during chronic neuroinflammation.</a> J Autoimmun. 101, 56-69 (2019).</li><li>Ma, Q., Matsunaga, A., Ho, B., Oksenberg, J. R., Didonna, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oligodendrocyte-specific+argonaute+profiling+identifies+micrornas+associated+with+experimental+autoimmune+encephalomyelitis.">Oligodendrocyte-specific argonaute profiling identifies micrornas associated with experimental autoimmune encephalomyelitis.</a> J Neuroinflammation. 17 (1), 297 (2020).</li><li>Lanz, T. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clonally+expanded+b+cells+in+multiple+sclerosis+bind+ebv+ebna1+and+glialcam.">Clonally expanded b cells in multiple sclerosis bind ebv ebna1 and glialcam.</a> Nature. 603 (7900), 321-327 (2022).</li></ol>

The authors declare no competing interests.

Here, a simple and efficient ELISA-based protocol was reported to accurately quantify the humoral response in a relevant animal model of MS pathology. This method has been recently employed to describe the novel role of the ataxin-1 protein in controlling the serum levels of autoantibodies in the MOG35-55/C57BL6J EAE paradigm12. In this regard, a number of factors should be taken into consideration, in order to obtain consistent and biologically meaningful results with this method.
First, it is crucial to collect high quality serum samples and avoid hemolysis. Hemoglobin and other intracellular components released from red blood cells in heavily hemolyzed specimens can interfere with the antigen-antibody reaction and relative color measurement in the ELISA assay. To prevent hemolysis, it is preferable to avoid high negative pressure in the syringe during blood collection as this can cause erythrocytes to rupture.
Second, it is important to dilute the serum samples to obtain OD values within the linear portion of the absorbance curve. Our recommended dilution factor (1:100) was calibrated on the entity of the EAE pathology induced in our mouse strains. Considering the intrinsic level of heterogeneity of this in vivo model, it is highly recommended to perform preliminary titration experiments to identify the ideal dilution factor for the specific EAE pathology that is tested. Likewise, the incubation times with the TMB substrate may be adjusted to avoid the saturation of the chromogenic signal and maintain the OD values within the 0-2 range.
Third, the corrected OD values obtained in this protocol are compatible with a semi-quantitative analysis of autoantibody serum titers between different experimental conditions or for kinetic studies along disease progression. If an absolute quantification of the autoantibody levels is needed, a calibration curve must be implemented in the ELISA design. Multiple antibodies against MOG peptide are commercially available and can be used as reliable standards to calculate the concentration of MOG-specific antibodies in the serum of EAE mice. To capture effects of different magnitude, it is recommended to include a wide range of dilutions for the calibrating antibody (ranging from pg/mL to &#956;g/mL concentrations).
Lastly, this protocol is extremely flexible and can be easily adapted to accommodate different research needs. For instance, the coated encephalitogenic peptide can be varied to assess the autoantibody response in other EAE paradigms. Furthermore, different secondary antibodies can be employed to measure the levels of distinct immunoglobulin classes. To this end, this protocol successfully demonstrated that ataxin-1 controls both IgG and IgM classes of MOG peptide-specific antibodies12. Lastly, it could be envisioned a possible use for detecting autoantibodies in the blood of MS patients. However, substantial differences exist between EAE and MS diseases. While the former is artificially induced via boosting the immune response against a well-defined autoantigen with strong adjuvants, the latter arises spontaneously and no unambiguous autoantigens have been identified yet. Recent evidence suggests the possible involvement of molecular mimicry with viral proteins15. Hence, caveats should always be considered in directly translating observations collected in this animal model to the human disease.
In summary, the present protocol represents an easy and convenient alternative to commercial ELISA kits and could be efficiently combined with other methods such as cell-based assays (CBAs) for the precise estimation of autoantibody release in the context of autoimmune demyelination.

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by focal infiltration of immune cells into the brain parenchyma, breakdown of myelin sheaths wrapping axons, glia activation, and neuronal loss1. In addition to the well-established role of pathogenic T cells, multiple lines of evidence have highlighted the involvement of B cells in mediating the autoimmune response against the CNS. B cells undergo clonal expansion in the MS brain and antibodies against myelin components have been detected within demyelinated lesions2,3. The selective activation of peripheral B cells at disease onset has been recently documented, suggesting a putative role for this immune cell compartment in disease initiation as well4. The success of B cell-depleting therapies such as anti-CD20 monoclonal antibodies further corroborates the mechanistic connection between aberrant B cell functioning and autoimmune demyelination5,6. From a molecular standpoint, B cells can contribute to disease via autoantigen presentation, pro-inflammatory cytokine secretion, and autoreactive antibody production.
Multiple animal models have been developed to recapitulate specific features of the complex MS phenotype. Among them, experimental autoimmune encephalomyelitis (EAE) is the most widely used in vivo paradigm and relies on the immunization of experimental animals with short peptides derived from myelin proteins such as myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP)7. EAE immunized animals develop a demyelinating pathology that resembles MS in many aspects, including a robust humoral response against the encephalitogenic peptide8. For this reason, EAE studies have been instrumental in dissecting the function of B cells and autoantibodies in the context of disease. For instance, it was demonstrated that MOG-specific antibodies isolated from MS patients can aggravate the clinical course in EAE models9. Notably, the proline residue at position 42 in human MOG was shown to be critical for determining autoantibody pathogenicity10. More recently, MOG-specific autoantibodies have been found to promote disease not only by mediating myelin loss but also via boosting the reactivation of autoreactive T cells within the CNS11. 
Considering the importance of antibody responses in CNS autoimmunity, this article presents an ELISA-based protocol to efficiently measure the serum levels of autoreactive antibodies in C57BL/6J mice EAE immunized with MOG35-55 peptide. In the first part of the protocol, the method to collect serum via intracardiac puncture will be described. Subsequently, the procedures to set up the ELISA assay and acquire the data will be detailed. Lastly, data analysis and interpretation will be discussed.

<table><tbody><tr><td>1 mL syringes</td><td>BD Biosciences</td><td>309628</td><td></td></tr><tr><td>1.5 mL microcentrifuge tubes</td><td>Fisher</td><td>05-408-129</td><td></td></tr><tr><td>25 G needles</td><td>BD Biosciences</td><td>305122</td><td></td></tr><tr><td>3,3&#039;,5,5&#039;-tetramethylbenzidine (TMB) substrate</td><td>Thermo Fisher</td><td>N301</td><td>Store at 4 &amp;deg;C</td></tr><tr><td>Adhesive seals</td><td>Thermo Fisher</td><td>AB0558</td><td></td></tr><tr><td>Bovine serum albumin (BSA)</td><td>Sigma</td><td>A7906</td><td>Store at 4 &amp;deg;C</td></tr><tr><td>C57BL/6J female mice</td><td>The Jackson Laboratory</td><td>000664</td><td>Animals between 8-10 weeks of age should be used for EAE experiments</td></tr><tr><td>Cryogenic tubes</td><td>Fisher</td><td>10-500-25</td><td></td></tr><tr><td>Dissection tray</td><td>Fisher</td><td>S111022</td><td></td></tr><tr><td>Dissector scissors</td><td>Fine Science Tools</td><td>14082-09</td><td></td></tr><tr><td>ELISA coating buffer</td><td>BioLegend</td><td>421701</td><td>Store at 4&amp;deg;C</td></tr><tr><td>Excel software</td><td>Microsoft</td><td></td><td>Analysis spreadsheet</td></tr><tr><td>Forceps</td><td>Fine Science Tools</td><td>11152-10</td><td></td></tr><tr><td>Goat Anti-Mouse IgG, Human ads-HRP</td><td>SouthernBiotech</td><td>1030-05</td><td>Store at 4 &amp;deg;C</td></tr><tr><td>LED light source</td><td>Fisher</td><td>AMPSILED21</td><td></td></tr><tr><td>Microplate reader</td><td>Fisher</td><td>14-377-575&amp;nbsp;</td><td></td></tr><tr><td>Molecular biology grade water</td><td>Corning</td><td>46-000-Cl</td><td></td></tr><tr><td>Mouse MOG35-55 peptide</td><td>EZBiolab</td><td>cp7203</td><td>Store at -80 &amp;deg;C</td></tr><tr><td>Multichannel pipette</td><td>Axygen</td><td>AP-12-200-P</td><td></td></tr><tr><td>Noyes spring scissors</td><td>Fine Science Tools</td><td>15011-12</td><td></td></tr><tr><td>Nunc MaxiSorp 96-well plates</td><td>BioLegend</td><td>423501</td><td></td></tr><tr><td>Orbital shaker</td><td>Fisher</td><td>88-861-023</td><td></td></tr><tr><td>Oven</td><td>VWR</td><td>445-0024</td><td></td></tr><tr><td>Phosphate buffer saline (PBS)</td><td>Thermo Fisher</td><td>14190144</td><td></td></tr><tr><td>Refrigerated tabletop centrifuge</td><td>Thermo Fisher</td><td>75002441</td><td></td></tr><tr><td>Stop solution</td><td>Thermo Fisher</td><td>N600</td><td></td></tr><tr><td>Tween 20</td><td>Bio-Rad</td><td>1706531</td><td></td></tr></tbody></table>

quantification of autoreactive antibodies in mice upon experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a disease model that recapitulates the autoimmune disorder multiple sclerosis (MS) at histopathological and molecular levels. EAE is induced by immunizing experimental animals via subcutaneous injection of short myelin peptides together with specific adjuvants to boost the immune response. Like the human counterpart, EAE mice develop demyelinating lesions, immune cell infiltration into the central nervous system (CNS), glia activation and neuronal injury. A consistent body of evidence also supports a mechanistic role for B cell dysfunction in the etiology of both MS and EAE. B cells can serve as antigen-presenting cells as well as a primary source of pro-inflammatory cytokines and autoantibodies. In EAE, antibodies are generated against the myelin peptides that were employed to induce the disease. Such autoantibodies have been shown to mediate either myelin loss or pathogenic T cell reactivation into the CNS. This article describes an efficient ELISA-based protocol to quantify autoantibodies in the serum of C57BL/6J mice immunized with the myelin oligodendrocyte glycoprotein 35-55 (MOG35-55) peptide. The proposed method serves as a powerful tool to investigate the specificity and magnitude of the aberrant humoral response in the context of autoimmune demyelination.

To demonstrate the robustness of the present ELISA assay, the method was tested on serum samples isolated from a cohort of C57BL/6J female mice at 20 days post-immunization (dpi) with 100 &#956;g of MOG35-55 peptide in complete Freund&#39;s adjuvant (CFA) following a validated EAE induction protocol12,13,14. The animals also received 400 ng of pertussis toxin on day 0 and 2. Serum samples from mock immunized animals with everything but without the peptide served as negative controls. All EAE mice developed the first signs of disease between 11-14 dpi and reached by 20 dpi an average score of 2.6 &#177; 0.6 (standard error, SE) on a 0-6 scale (0, no signs; 1, decreased tail tone; 2, mild monoparesis or paraparesis; 3, severe paraparesis; 4, paraplegia; 5, quadriparesis; and 6, moribund or death)12. As expected, the EAE samples displayed significantly higher OD values compared to control samples (Figure 2). These data confirm the presence of a robust IgG immunoglobulin response against the MOG peptide at the peak of disease.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/66218/66218fig01.jpg" /> 
Figure 1: Cardiac puncture procedure. (A-E) Representative images of the thoracotomy procedure to access the heart in adult mice. (F) Representative image of the correct procedure for needle insertion into the left ventricle of the mouse heart. Relevant anatomical structures are indicated in each panel to facilitate the dissection. <a href="https://www.jove.com/files/ftp_upload/66218/66218fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/66218/66218fig02.jpg" /> 
Figure 2: MOG peptide autoantibody ELISA. Serum levels of anti-MOG35-55 IgG immunoglobulins were tested in EAE and mock immunized mice at 20 days post-immunization (dpi) using the reported ELISA protocol. Consistently higher OD values were detected in EAE samples compared to controls. Data are presented as means &#177; SE (N = 3 per group). Differences between groups were assessed by one-tailed Mann-Whitney U test, *P&#160;&#8804; 0.05. <a href="https://www.jove.com/files/ftp_upload/66218/66218fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Quantification of Autoreactive Antibodies in Mice upon Experimental Autoimmune Encephalomyelitis at JoVE.com

Author Spotlight: Novel Assay for Studying B-Cell Responses in Multiple Sclerosis Research

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS), which shares with the human disease a robust humoral autoimmune response. Here, we report a simple and flexible ELISA protocol to quantify autoantibodies in the serum of EAE immunized mice.

Quantification of Autoreactive Antibodies in Mice upon Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a disease model that recapitulates the autoimmune disorder multiple sclerosis (MS) at histopathological ...

quantification-autoreactive-antibodies-mice-upon-experimental

Nanyang Technological University

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Immunology and Infection

717 Views.  East Carolina University. Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS), which shares with the human disease a robust humoral autoimmune response. Here, we report a simple and flexible ELISA protocol to quantify autoantibodies in the serum of EAE immunized mice.

Video: Author Spotlight: Novel Assay for Studying B-Cell Responses in Multiple Sclerosis Research

Overcoming Unresponsiveness in Experimental Autoimmune Encephalomyelitis (EAE) Resistant Mouse Strains by Adoptive Transfer and Antigenic Challenge

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the central nervous system (CNS) and has been used as an animal model for study of the human demyelinating disease, multiple sclerosis (MS). EAE is characterized by pathologic infiltration of mononuclear cells into the CNS and by clinical manifestation of paralytic disease. Similar to MS, EAE is also under genetic control in that certain mouse strains are susceptible to disease induction while others are resistant. Typically, C57BL/6 (H-2b) mice immunized with myelin basic protein (MBP) fail to develop paralytic signs. This unresponsiveness is certainly not due to defects in antigen processing or antigen presentation of MBP, as an experimental protocol described here had been used to induce severe EAE in C57BL/6 mice as well as other reputed resistant mouse strains. In addition, encephalitogenic T cell clones from C57BL/6 and Balb/c mice reactive to MBP had been successfully isolated and propagated.
The experimental protocol involves using a cellular adoptive transfer system in which MBP-primed (200 &mu;g/mouse) C57BL/6 donor lymph node cells are isolated and cultured for five days with the antigen to expand the pool of MBP-specific T cells. At the end of the culture period, 50 million viable cells are transferred into naive syngeneic recipients through the tail vein. Recipient mice so treated normally do not develop EAE, thus reaffirming their resistant status, and they can remain normal indefinitely. Ten days post cell transfer, recipient mice are challenged with complete Freund adjuvant (CFA)-emulsified MBP in four sites in the flanks. Severe EAE starts to develop in these mice ten to fourteen days after challenge. Results showed that the induction of disease was antigenic specific as challenge with irrelevant antigens did not induce clinical signs of disease. Significantly, a titration of the antigen dose used to challenge the recipient mice showed that it could be as low as 5 &mu;g/mouse. In addition, a kinetic study of the timing of antigenic challenge showed that challenge to induce disease was effective as early as 5 days post antigenic challenge and as long as over 445 days post antigenic challenge. These data strongly point toward the involvement of a "long-lived" T cell population in maintaining unresponsiveness. The involvement of regulatory T cells (Tregs) in this system is not defined.

Overcoming Unresponsiveness in Experimental Autoimmune Encephalomyelitis EAE Resistant Mouse Strains by Adoptive Transfer and Antigenic Challenge

Certain mouse strains are able to resist induction of experimental autoimmune encephalomyelitis (EAE) with myelin basic protein. Described here is a simple immunization protocol that reverses the unresponsiveness and induces paralytic disease in several typical EAE resistant mouse stains.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the central nervous system (CNS) and has been used as an animal model for ...

Induction of Experimental Autoimmune Encephalomyelitis in Mice and Evaluation of the Disease-dependent Distribution of Immune Cells in Various Tissues

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) resulting in cognitive and motor impairment. Experimental autoimmune encephalomyelitis (EAE) is a useful animal model of MS, because it is also characterized by lesion formation in the CNS, motor impairment and is also driven by autoimmune and inflammatory reactions. One of the EAE models is induced with a peptide derived from the myelin oligodendrocyte protein (MOG)35-55 in mice. The EAE mice develop a progressive disease course. This course is divided into three phases: the preclinical phase (day 0 - 9), the disease onset (day 10 - 11) and the acute phase (day 12 - 14). MS and EAE are induced by autoreactive T cells that infiltrate the CNS. These T cells secrete chemokines and cytokines which lead to the recruitment of further immune cells. Therefore, the immune cell distribution in the spinal cord during the three disease phases was investigated. To highlight the time point of the disease at which the activation/proliferation/accumulation of T cells, B cells and monocytes starts, the immune cell distribution in lymph nodes, spleen and blood was also assessed. Furthermore, the levels of several cytokines (IL-1&#946;, IL-6, IL-23, TNF&#945;, IFN&#947;) in the three disease phases were determined, to gain insight into the inflammatory processes of the disease. In conclusion, the data provide an overview of the functional profile of immune cells during EAE pathology.

This manuscript describes the methods for induction and scoring of the experimental autoimmune encephalomyelitis (EAE) model, together with the assessment of immune cell distribution and mRNA cytokine levels in lymph nodes, spleen, blood and spinal cord using flow cytometry and quantitative PCR, respectively, at various disease phases.

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) ...

Visualizing Impairment of the Endothelial and Glial Barriers of the Neurovascular Unit during Experimental Autoimmune Encephalomyelitis In Vivo

The neurovascular unit (NVU) is composed of microvascular endothelial cells forming the blood-brain barrier (BBB), an endothelial basement membrane with embedded pericytes, and the glia limitans composed by the parenchymal basement membrane and astrocytic end-feed embracing the abluminal aspect of central nervous system (CNS) microvessels. In addition to maintaining CNS homeostasis the NVU controls immune cell trafficking into the CNS. During immunosurveillance of the CNS low numbers of activated lymphocytes can cross the endothelial barrier without causing BBB dysfunction or clinical disease. In contrast, during neuroinflammation such as in multiple sclerosis or its animal model experimental autoimmune encephalomyelitis (EAE) a large number of immune cells can cross the BBB and subsequently the glia limitans eventually reaching the CNS parenchyma leading to clinical disease. 
Immune cell migration into the CNS parenchyma is thus a two-step process that involves a sequential migration across the endothelial and glial barrier of the NVU employing distinct molecular mechanisms. If following their passage across the endothelial barrier, T cells encounter their cognate antigen on perivascular antigen-presenting cells their local reactivation will initiate subsequent mechanisms leading to the focal activation of gelatinases, which will enable the T cells to cross the glial barrier and enter the CNS parenchyma. Thus, assessing both, BBB permeability and MMP activity in spatial correlation to immune cell accumulation in the CNS during EAE allows to specify loss of integrity of the endothelial and glial barriers of the NVU. 
We here show how to induce EAE in C57BL/6 mice by active immunization and how to subsequently analyze BBB permeability in vivo using a combination of exogenous fluorescent tracers. We further show, how to visualize and localize gelatinase activity in EAE brains by in situ zymogaphy coupled to immunofluorescent stainings of BBB basement membranes and CD45+ invading immune cells.

Here, we present protocols to investigate impairment of the neurovascular unit during experimental autoimmune encephalomyelitis in vivo. We specifically address how to determine blood-brain barrier permeability and gelatinase activity involved in leukocyte migration across the glia limitans.&#160;

The neurovascular unit (NVU) is composed of microvascular endothelial cells forming the blood-brain barrier (BBB), an endothelial basement membrane with ...

Flow Cytometric Analysis of Lymphocyte Infiltration in Central Nervous System during Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) caused by the combination of environmental factors and susceptible genetic background. Experimental autoimmune encephalomyelitis (EAE) is a typical disease model of MS widely used for investigating the pathogenesis in which T lymphocytes specific for myelin antigens initiate an inflammatory reaction in CNS. It is very important to assess how lymphocytes in the CNS regulate the development of disease. However, the approach for measuring the quantity and quality of infiltrated lymphocytes in the CNS is very limited due to the difficulties in isolating and detecting infiltrated lymphocytes from the brain. This manuscript presents a protocol for that is useful for the isolation, identification, and characterization of infiltrated lymphocytes from the CNS and will be helpful for our understanding of how lymphocytes are involved in the development of the CNS autoimmune disease.

This manuscript presents a protocol to induce active experimental autoimmune encephalomyelitis (EAE) in mice. A method for the isolation and characterization of the infiltrated lymphocytes in the central nervous system (CNS) is also presented to show how lymphocytes are involved in the development of CNS autoimmune disease.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) caused by the combination of environmental factors and susceptible ...

Quantitative Measurement of Intrathecally Synthesized Proteins in Mice

Cerebrospinal fluid (CSF), a fluid found in the brain and the spinal cord, is of great importance to both basic and clinical science. The analysis of the CSF protein composition delivers crucial information in basic neuroscience research as well as neurological diseases. One caveat is that proteins measured in CSF may derive from both intrathecal synthesis and transudation from serum, and protein analysis of CSF can only determine the sum of these two components. To discriminate between protein transudation from the blood and intrathecally produced proteins in animal models as well as in humans, CSF protein profiling measurements using conventional protein analysis tools must include the calculation of the albumin CSF/serum quotient (Qalbumin), a marker of the integrity of the blood-brain interface (BBI), and the protein index (Qprotein/Qalbumin), an estimate of intrathecal protein synthesis. This protocol illustrates the entire procedure, from CSF and blood collection to quotients and indices calculations, for the quantitative measurement of intrathecal protein synthesis and BBI impairment in mouse models of neurological disorders.

Elevated spinal fluid protein levels can either be the result of diffusion of plasma protein across an altered blood-brain barrier or intrathecal synthesis. An optimized testing protocol is presented in this article that helps to discriminate both cases and provides quantitative measurements of intrathecally synthesized proteins.

Cerebrospinal fluid (CSF), a fluid found in the brain and the spinal cord, is of great importance to both basic and clinical science. The analysis of the ...

Neuroscience

Histological Staining of Spinal Cord for Assessing EAE Disease Severity

Scoring Central Nervous System Inflammation, Demyelination, and Axon Injury in Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a common immune-based model of multiple sclerosis (MS). This disease can be induced in rodents by active immunization with protein components of the myelin sheath and Complete Freund&#39;s adjuvant (CFA) or by the transfer of myelin-specific T effector cells from rodents primed with myelin protein/CFA into na&#239;ve rodents. The severity of EAE is typically scored on a 5-point clinical scale that measures the degree of ascending paralysis, but this scale is not optimal for assessing the extent of recovery from EAE. For example, clinical scores remain high in some EAE models (e.g., myelin oligodendrocyte glycoprotein [MOG] peptide-induced model of EAE) despite the resolution of inflammation. Thus, it is important to complement clinical scoring with histological scoring of EAE, which also provides a means to study the underlying mechanisms of cellular injury in the central nervous system (CNS).
Here, a simple protocol is presented to prepare and stain spinal cord and brain sections from mice and to score inflammation, demyelination, and axonal injury in the spinal cord. The method for scoring leukocyte infiltration in the spinal cord can also be applied to score brain inflammation in EAE. A protocol for measuring soluble neurofilament light (sNF-L) in the serum of mice using a Small Molecule Assay (SIMOA) assay is also described, which provides&#160;feedback on the extent of overall CNS injury in live mice.

Author Spotlight: Unveiling the Pathway Linking Obesity to Autoimmune Inflammation in Multiple Sclerosis 

Experimental autoimmune encephalomyelitis (EAE) serves as an animal model of multiple sclerosis. This article describes an approach for scoring spinal cord inflammation, demyelination, and axonal injury in EAE. Additionally, a method to quantify soluble neurofilament light levels in the mice serum is presented, facilitating the assessment of axonal injury in live mice.

Experimental autoimmune encephalomyelitis (EAE) is a common immune-based model of multiple sclerosis (MS). This disease can be induced in rodents by ...

Induction and Evaluation of Experimental Autoimmune Encephalomyelitis in 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.

Author Spotlight: Creating a Versatile Experimental Autoimmune Encephalomyelitis Model Relevant for Both Male and Female Mice 

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.

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system (CNS). It is characterized by different ...

Role of CD4 T Cell in Relapsing-Remitting Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease characterized by the infiltration of immune cells and demyelination in the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) serves as a prototypic animal model for studying MS. In this study, we aimed to investigate the role of CD4 T cells in the initiation and relapse of EAE, focusing on the activation phase and immune response. To create the EAE mice model, female mice were immunized with myelin oligodendrocyte glycoprotein (MOG)35-55 emulsified with complete Freund&#39;s adjuvant (CFA). Clinical scores were assessed daily, and results demonstrated that mice in the EAE group exhibited a classic relapsing-remitting pattern. Hematoxylin-eosin (H&#38;E) and luxol fast blue (LFB) staining analysis revealed significant infiltration of inflammatory cells in the CNS and demyelination in EAE mice. Regarding the activation phase, both CD4+CD69+ effector T (Teff) cells and CD4+CD44+CD62L- effector memory T (Tem) cells may contribute to the initiation&#160;of EAE, however, the relapse stage was probably dominated by CD4+CD44+CD62L- Tem cells. Additionally, in terms of immune function, helper T (Th)1 cells are primarily involved in initiating the EAE. However, both Th1 and Th17 cells contribute to the relapse stage, and the immunosuppressive function of regulatory T (Treg) cells was inhibited during the EAE pathological process.

An experimental autoimmune encephalomyelitis (EAE) model in mice was employed to investigate the role of CD4 T cells in the initial and relapse of EAE from the perspective of the activation phase and immune effect function.

Multiple sclerosis (MS) is an autoimmune disease characterized by the infiltration of immune cells and demyelination in the central nervous system (CNS). ...

Induction and Diverse Assessment Indicators of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a typical autoimmune disease of the central nervous system (CNS) characterized by inflammatory infiltration, demyelination, and axonal damage. Currently, there are no measures to cure MS completely, but multiple disease-modifying therapies (DMT) are available to control and mitigate disease progression. There are significant similarities between the CNS pathological features of experimental autoimmune encephalomyelitis (EAE) and MS patients. EAE has been widely used as a representative model to determine MS drugs' efficacy and explore the development of new therapies for MS disease. Active induction of EAE in mice has a stable and reproducible effect and is particularly suitable for studying the effects of drugs or genes on autoimmune neuroinflammation. The method of immunizing C57BL/6J mice with myelin oligodendrocyte glycoprotein (MOG35-55) and the daily assessment of disease symptoms using a clinical scoring system is mainly shared. Given the complex etiology of MS with diverse clinical manifestations, the existing clinical scoring system can't satisfy the assessment of disease treatment. To avoid the shortcomings of a single intervention, new indicators to assess EAE based on clinical manifestations of anxiety-like moods and osteoporosis in MS patients are created to provide a more comprehensive assessment of MS treatment.

The present protocol describes the induction of experimental autoimmune encephalomyelitis in a mouse model using myelin oligodendrocyte glycoprotein and monitoring the disease process using a clinical scoring system. Experimental autoimmune encephalomyelitis-related symptoms are analyzed using mouse femur micro-computed tomography analysis and open field test to assess the disease process comprehensively.

Multiple sclerosis (MS) is a typical autoimmune disease of the central nervous system (CNS) characterized by inflammatory infiltration, demyelination, and ...

Biology

Generation of Experimental Autoimmune Encephalomyelitis in a Mouse Model

Begin this procedure with anesthetization of C57BL/6 mice that have been housed in specific pathogen-free conditions as described in the text protocol. Fix the anesthetized mouse in one hand and inject 30 microliters of MOG peptide in complete fluorescent adjuvant emulsion subcutaneously into each of the hind leg flanks in close proximity to the inguinal lymph nodes.
Now, place the mouse on its belly and inject 20 microliters of the MOG peptide emulsion into the soft fatty tissue on both the left and right at the tail root. Also, inject a little droplet of the emulsion into the neck of the mouse. Inject 100 microliters of pertussis toxin solution intraperitoneally into the mouse. Hold the head of the mouse below the body center to avoid injection into the intestine.
Replace the maintenance diet to the breeding diet in order to provide the mice with food of higher energy content before enduring the expected clinical disease. Repeat the pertussis toxin injection 48 hours after the first treatment.
Check the health status of EAE mice every morning by taking a look inside the cages. Score EAE mice every afternoon. Take every individual mouse included in the EAE experiment out of the cage, and check whether the tail has tonus.
Move the tail upward with a finger. A healthy mouse will keep its tail up. If clinical EAE has started, the tail tonus will be lower visible by a gradual drop of the tail. Eventually, the mouse will not be able to lift its tail at all.