Indeed, the profound effects of adjuvants such as alum [40] or Toll-like receptor ligands [41] on Th cell differentiation have been described. Thus, we favor the view that INK 128 mouse the major

effector function of IFN-γ in the pathogenesis of myocarditis is to drive the early inflammatory process, as revealed by our analysis. However, IFN-γ is not the major effector cytokine for the pathogenic remodeling of the heart muscle leading to heart failure, since it is the cooperation of IFN-γ and IL-17A that is essential for progressive disease. The early changes in the heart muscle physiology in TCR-M myocarditis could be readily detected by CMRI. We found that the initial IL-6- and IFN-γ-driven inflammation led to a significant increase in the left ventricle wall thickness at week 5. Such transient ventricular wall thickening has also been described in early stages of human myocarditis [42]. It is likely that the increased wall thickness during the early heart inflammation is the reason for the lowered end systolic and end diastolic volumes with the resulting increase in the EF. Importantly, the heart function determined as systolic volume remained stable during this phase. Our CMRI analysis in 12-week-old TCR-M mice revealed the extraordinary capacity of the mouse find more heart to fully compensate the early pathophysiological

changes and to cope with

the ongoing chronic myocarditis. Once TCR-M had overcome the first “critical” 3 months period, they survived and bred for more than 1 year (our unpublished data). We are convinced that future prospective CMRI and echocardiagraphic studies in TCR-M mice will reveal those morphological and functional parameters that are predictive for either 4��8C progression to DCM or successful compensation. Since the expression of myhca is absent in thymic epithelial cells both in humans [25] and mice ([25] and this study), central myhca-specific T-cell tolerance is not operational. Thus, in humans, it is mostly likely that the occurrence of particular MHC class II alleles critically impinges on the susceptibility to autoimmune myocarditis. Indeed, expression of the human MHC class II antigen HLA-DQ8 in autoimmune disease-prone NOD mice precipitates spontaneous autoimmune myocarditis [43, 44]. Likewise, the TCR-M transgenic mouse with spontaneously developing, Th cell driven cardiac inflammatory disease recapitulates the central processes in the transition from autoimmune myocarditis to DCM. Importantly, the TCR-M model permits the dissection of essential immune effector pathways in monoclonal heart-specific T cells, such as the contribution of Th1/Th17 cells, in a spontaneously occurring disease setting without the strong immune-biasing effects of certain adjuvants.