Lukas Theissen (Düsseldorf / DE), Dr. med. Christopher Nelke (Düsseldorf / DE), PD Dr. med. Amin Polzin (Düsseldorf / DE), Dr. med. Philipp Mourikis (Düsseldorf / DE), Prof. Dr. Norbert Gerdes (Düsseldorf / DE), Univ.-Prof. Dr. med. Dr. rer. nat. Sven G. Meuth (Düsseldorf / DE), PD Dr. med. Tobias Ruck (Düsseldorf / DE)
Abstract-Text (inkl. Referenzen)
Background and aim
Myasthenia gravis is an autoantibody-mediated disease of the neuromuscular synapse characterized by aberrant activation of the complement system. Current models require extensive antigen preperation. To better characterize the underlying pathophysiology, we employed an immunization model with recombinant human acetylcholine receptor subunit alpha (CHRNA1) protein.
Methods
For this project, we induced experimental autoimmune myasthenia gravis (EAMG) in a total of 10 mice at 8 weeks of life, as well as at 12 weeks of life using CHRNA1 and Complete Freund's Adjuvant (CFA). Controls received CFA and PBS only. We tested the forefoot grip strength before and after exercise with a grip-strength meter (GSM) twice a week and validated our model using triple immunofluorescence staining of the muscle sections with DAPI, C3 and α-Bungarotoxin.
Results
We detected decreased grip strength in seven out of ten EAMG mice as compared to controls starting with the second immunization in week 12. Three out of 10 mice displayed an EAMG score of at least 1. Analysis of three muscle specimens by immunofluorescence staining demonstrated accumulation of complement (C3) at the neuromuscular junction at all three as evidenced by alpha-bungaratoxin labeling. C3 deposition was not detected in controls.
Conclusion
Taken together, our protocol allows for the induction of EAMG using recombinant ACHR as a simplified and robust model of MG.