Regulatory Role of CD4⁺ T Cells in Myocarditis

Figure 1

Role of CD4⁺ T cells in myocarditis. Break of central tolerance: CD4⁺ T cells undergo maturation and selection in the thymus. Due to a defect in negative selection, α-MyHC-specific CD4⁺ T cells do not undergo anergy or apoptosis and are released to the periphery. Break of peripheral tolerance: Inflammation results in activation of α-MyHC-loaded DCs which upregulate MHC II-peptide complexes as well as costimulatory molecules on the surface and migrate to the draining lymph nodes, where they interact with circulating T cells. Activated through the TCR meeting cognate peptide and upon costimulation with CD28, naive heart-specific T cells differentiate to effector T cells entering the heart.