Induction of murine experimental autoimmune myocarditis – technical details, implementation and evaluation

Abstract Introduction Myocarditis is a complex cardiac disorder with multifactorial etiology, characterized by myocardial inflammation, cardiomyocyte damage, and fibrosis. Left untreated, myocarditis may lead to acute and chronic heart failure and life-threatening arrhythmias. Reliable experimental models of myocarditis are required to study the underlying pathological mechanisms of the disease and to develop efficient therapies. Materials and Methods Experimental autoimmune myocarditis (EAM) was induced by immunizing 9-week-old female BALB/c mice with a specific peptide derived from the cardiac α-myosin heavy chain (α-MHC) which is the major autoantigen recognized by heart-specific autoantibodies in myocarditis. The immunization activates an anti-α-MHC immune response, which triggers an inflammatory reaction leading to cardiomyocyte damage and myocardial injury. The mice received two immunizations with 100 μL of an emulsion containing α-MHC peptide emulsified 1:1 in Complete Freund’s Adjuvant (CFA) supplemented with 4 mg/mL inactivated Mycobacterium tuberculosis ( M. tuberculosis) , administered subcutaneously on Days 0 and 7. Results We highlight the essential steps for the successful preparation of the peptide-adjuvant emulsion, a key factor in the effective implementation of the model, and mouse immunization. We also demonstrate how the inflammatory, fibrotic, and functional consequences on the myocardium should be evaluated. Conclusion This efficient and reproducible murine EAM model allows experimental research on the pathophysiology and treatment of myocarditis.