MOG/CFA-Induced EAE in C57BL/6 Mice

Hooke runs most commonly-used EAE models. Click here for an overview of EAE and a list of models offered.

We usually recommend MOG/CFA-induced EAE as a first pass screen for potential MS treatments, even if your drug's exact mode of action is not understood. Its short duration (~25 to 30 days) and use of C57BL/6 mice makes it the least expensive EAE model. It has a large therapeutic window, good sensitivity, and very good predictive value for efficacy in MS. It is also very robust; 10 to 12 mice/group give good statistical results.

This model may also be used to test neuronal regeneration. FTY720 (fingolimod, Gilenya), BG-12 (dimethyl fumarate, DMF, Tecfidera), diroximel fumarate (Vumerity) and methylprednisolone are the most commonly used positive controls.

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MOG35-55 vs. MOG1-125

In this direct EAE model, disease is induced by immunization with MOG peptide or protein.

Most often MOG35-55 peptide antigen is used, but the model can also be run with whole MOG protein (MOG1-125). The disease induced by either antigen is similar, except that EAE induced by whole MOG protein is reported to be dependent on B cells; this may be of interest if your compound targets B cells.

Typical results in this model

Prophylactic treatment
Prophylactic treatment typical scores
Therapeutic treatment
Therapeutic treatment typical scores
Vehicle FTY720 BG-12
Median
day of onset
12.0 22.5 18.0
Onset score is not meaningful
with prophylactic treatment
MMS
± SD
3.67 ± 0.50 0.35 ± 0.75 2.55 ± 1.12
p value
(MMS)
<0.0001 0.0061
End score
± SD
3.22 ± 0.75 0.05 ± 0.16 1.90 ± 1.29
p value
(end score)
<0.0001 0.0375
% weight at end
± SD
86.3 ± 5.5 106.2 ± 5.6 92.1 ± 12.9
p value
(body weight)
<0.0001 0.2334
Vehicle FTY720 Methylpred-
nisolone
Mean day of onset
± SD
10.0 ± 1.56 10.2 ± 1.87 10.1 ± 1.85
Mean onset score
± SD
0.80 ± 0.42 0.80 ± 0.42 0.75 ± 0.43
MMS
± SD
3.45 ± 0.64 3.00 ± 0.33 3.00 ± 0.33
p value
(MMS)
0.0428 0.0428
End score
± SD
2.70 ± 1.09 1.00 ± 0.82 1.30 ± 1.01
p value
(end score)
0.0043 0.0215
% weight at end
± SD
92.1 ± 8.2 98.7 ± 7.6 95.0 ± 8.2
p value
(body weight)
0.0385 0.2190

Disease development

Chronic EAE develops in C57BL/6 mice after immunization with an emulsion of MOG (either MOG35-55 or MOG1-125) in CFA, followed by administration of pertussis toxin (PTX) in PBS. The emulsion provides antigen which initiates expansion and differentiation of MOG-specific autoimmune T cells. PTX enhances EAE development by providing additional adjuvant and is believed to facilitate entrance of autoimmune T cells into the CNS.

Typically, more than 90% of mice develop EAE 9-16 days after immunization. The first wave of EAE usually lasts 7 days, followed by partial recovery and continuing chronic paralysis.

Direct EAE induction in C57BL/6 mice
Direct EAE induction in C57BL/6 mice

Treatment regimens

This model can be used with any of the standard EAE treatment regimens.

Prophylactic treatment

When used with prophylactic treatment, EAE induced by MOG35-55/CFA in C57BL/6 mice has the largest therapeutic window and is sensitive to the broadest range of targets of any EAE model. We recommend it as an initial screen for compounds aimed at MS treatment.

In prophylactic studies treatment normally lasts 28 days. Median time to disease onset is usually the most sensitive measure of compound efficacy. Small changes in immune response can delay EAE - suppression of antigen presentation or of T cell activation, proliferation, or differentiation into Th1 and/or Th17 cells all delay disease onset.

In addition to FTY720, methylprednisolone, and dexamethasone, glatiramer acetate (Copaxone) and dimethyl fumarate (BG-12) are all efficacious when dosed prophylactically in this model.

Overall treatment efficacy is indicated by both delayed onset of EAE and reduced maximum severity (vs. negative controls). Of these, mean maximum score (MMS) is usually more important - reduced MMS indicates an overall reduction in EAE severity.

Semi-therapeutic treatment

Semi-therapeutic treatment starts before all mice are sick (usually 10 to 11 days after immunization). This is a compromise between prophylactic and therapeutic treatment.

Therapeutic treatment

Therapeutic treatment specifically demonstrates whether a compound will reverse the course of disease and/or improve recovery. Therapeutic treatment requires a relatively small amount of drug, because in most studies each mouse receives only 14 days of treatment. We usually recommend this stringent treatment regimen as a follow-up to prophylactic studies, to establish compound efficacy after disease onset.

Rolling enrollment is used - mice are assigned to groups one at a time as they show the first signs of EAE.

To achieve tight results (highly uniform groups), groups are balanced for similar day of EAE onset and similar EAE scores at enrollment; these correlate well with maximum EAE score. Disease is induced in ~15% more mice than will be enrolled; this provides a larger pool of mice for balancing groups.

Treatment of each mouse begins immediately at enrollment. The final day of treatment differs for individual mice, depending on their day of enrollment.

Results are usually analyzed by synchronizing scores to the day of disease onset for each mouse.

The most important result in therapeutic treatment is the average clinical EAE score at the end of the study.

Late therapeutic treatment

Late therapeutic treatment is similar to therapeutic treatment, except that treatment begins a fixed number of days after each mouse shows the first signs of disease. Most often, this treatment regimen is used to evaluate neuroregeneration effects.

In addition to day of EAE onset and onset score, groups are also balanced for maximum score before enrollment.

Tissue collection and end-of-study analysis

Hooke offers an extensive set of tissue collection and analysis options. Click here for more information.

See also