title: Emergence of dendritic cells in the myocardium after acute myocardial infarction - implications for inflammatory myocardial damage.
abstract: Dendritic cells (DC) are crucial for T cell mediated immune responses. Recently, we observed a significant decrease in circulating myeloid DC precursors in patients with acute myocardial infarction (AMI). The aim of the present study was to investigate whether myeloid DC are present in infarcted myocardium. Myocardial specimens of 10 patients with AMI and 7 accident victims (controls) were collected after autopsy. In immunostainings the presence of DC (CD209(+), fascin(+)), T cells (CD3(+)), macrophages (CD68(+)), and HLA-DR expression was analyzed. Significantly higher numbers of CD209(+)-DC (97 vs. 44 cells/0.25 mm(2), p=0.03), fascin(+)-DC (54 vs. 8 cells/0.25 mm(2), p=0.02), T cells (27 vs. 6 cells/0.25 mm(2), p=0.02), and macrophages (44 vs. 6 cells/0.25 mm(2), p=0.01) associated with high HLA-DR expression were detected in infarcted myocardium. Frequent colocalizations of DC and T cells were observed. In occluded coronary arteries numerous DC, T cells, macrophages and high HLA-DR expression were found. We show that DC are present in infarcted myocardium after AMI. High HLA-DR expression and the colocalization with T cells suggest that they might trigger an immune response leading to further myocardial damage.
authors.affiliation: Clinic of Internal Medicine I, Department of Cardiology, University Hospital Jena, Jena, Germany;
authors.forename: Atilla
authors.initials: A
authors.lastname: Yilmaz
authors.forename: Barbara
authors.initials: B
authors.lastname: Dietel
authors.forename: Iwona
authors.initials: I
authors.lastname: Cicha
authors.forename: Katja
authors.initials: K
authors.lastname: Schubert
authors.forename: Roland
authors.initials: R
authors.lastname: Hausmann
authors.forename: Werner G
authors.initials: WG
authors.lastname: Daniel
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Garlichs
authors.forename: Christian
authors.initials: C
authors.lastname: Stumpf
keywords: adaptive immunity; atherosclerosis; dendritic cells; innate immunity; leukocyte