Role of T Cells in Viral and Immune-mediated Myocarditis

Myocarditis is characterized by inflammatory cell infiltration into the myocardium and a high risk of deteriorating cardiac function with a heterogeneous etiology. Both viral- and myosin-induced myocarditis experimental models are used to mimic myocarditis in humans. Here, coxsackie virus B3-induced and non-virus-induced myocarditis models and data obtained in clinical studies were reviewed. Experimental murine myocarditis following immunization with α-myosin together with complete Freund adjuvant represents the classical immune-mediated model. T helper 1 (Th1) and Th2 pathways and important cytokines are involved in the autoimmunity of myocarditis, and the dynamic balance between Th17 and regulatory T cell seems to have an important role in the process of myocarditis. The purpose of this review is to summarize the existing understanding of the immunological mechanisms underlying myocarditis and exploring gaps in knowledge in both animal and human studies, since these mechanistic insights are a critical requirement for the development of novel therapeutic and vaccination strategies.