Global gene expression profiling of cardiac dendritic cells subsets

Innate and adaptive immune cells modulate heart failure pathogenesis during viral myocarditis, yet their identity and functions remain poorly defined. In this study we characterized the phenotype, life-cycle and function of different conventional dendritic cells (cDC) populations in the heart, with focus on the 2 major subsets (CD103+ and CD11b+), which differentially rely on local proliferation and precursor recruitment to maintain tissue residency. Following viral infection of the myocardium, cDCs accumulate in the heart coincident with monocyte infiltration and loss of resident reparative embryonic-derived cardiac macrophages. cDC depletion abrogates antigen-specific CD8+ T cell proliferative expansion, transforming subclinical cardiac injury to overt heart failure. Importantly, these effects are mediated by BATF3-dependent CD103+ cDCs. Collectively, our findings definitively identify resident cardiac cDC subsets, define their origins, and implicate an essential role for CD103+ cDCs in antigen-specific T cell responses during viral myocarditis. Cardiac CD103+ and CD11b+ classical dendritic cells and MHC-II hi macrophages were sorted (n = 3 for each population). Global gene expression analysis was performed using the Affymetrix GeneChip® Mouse Gene 2.0 ST Array.