Titration of myelin oligodendrocyte glycoprotein (MOG) - Induced experimental autoimmune encephalomyelitis (EAE) model

Background: Experimental autoimmune encephalomyelitis (EAE) induced by the myelin oligodendrocyte glycoprotein (MOG) peptide 35-55, is a widely used multiple sclerosis (MS) model. Unlike the spontaneous occurrence of MS, in EAE, external immunization with the MOG peptide (200 300 mu g/mouse), emulsified in adjuvant enriched with Mycobacterium Tuberculosis (MT) H37Ra (100 500 mu g mouse), and pertussis toxin (PTx, 200 500 ng/mouse) injections, are applied, which heavily boosts the immune system. New Method: A detailed and systematic titration of the MOG 35-55 EAE induction protocol in C57BL/6 mice reveals the minimal doses of the MOG 35-55 peptide, MT H37Ra, and PTx, required for disease manifestation. Results: The amounts of MOG 35-55 peptide, MT H37Ra, and PTx can be drastically reduced from the standard protocol, to level of 5 mu g MOG, 25 mu g MT H37Ra, and 50 ng PTx, without affecting the clinical manifestations. The titrated protocols induced a high disease incidence and a consistent robust disease course, with full histopathological characteristics of the MOG model, inflammation, demyelination and axonal damage. Comparison with Existing Methods: Similar disease incidences, day of symptoms appearance, maximal clinical score, and histopathology were obtained for the standard and the titrated protocols. Conclusions: Reducing the reagent dosages used for EAE induction, without attenuating the disease, can give a truer and less artificial perspective of MS. We propose an improved protocol for this extensively used model, with high disease incidence, a consistent robust course, and characteristic histological manifestations, which may be more sensitive for testing therapeutic modalities, cost-effective, and less distressing to the animals.

Automated summary

By titrating the doses of MOG 35-55 peptide, MT H37Ra, and PTx during EAE induction, researchers were able to drastically reduce the amount of reagents used while maintaining similar disease manifestations, high disease incidence, and consistent disease course. This improved protocol may offer a more sensitive and cost-effective model for testing therapeutic modalities for MS.