@article{BuschWesthofenKochetal.2014, author = {Busch, Martin and Westhofen, Thilo C. and Koch, Miriam and Lutz, Manfred B. and Zernecke, Alma}, title = {Dendritic Cell Subset Distributions in the Aorta in Healthy and Atherosclerotic Mice}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {2}, issn = {1932-6203}, doi = {10.1371/journal.pone.0088452}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119907}, pages = {e88452}, year = {2014}, abstract = {Dendritic cells (DCs) can be sub-divided into various subsets that play specialized roles in priming of adaptive immune responses. Atherosclerosis is regarded as a chronic inflammatory disease of the vessel wall and DCs can be found in non-inflamed and diseased arteries. We here performed a systematic analyses of DCs subsets during atherogenesis. Our data indicate that distinct DC subsets can be localized in the vessel wall. In C57BL/6 and low density lipoprotein receptor-deficient (Ldlr-/-) mice, CD11c+ MHCII+ DCs could be discriminated into CD103- CD11b+F4/80+, CD11b+F4/80- and CD11b-F4/80- DCs and CD103+ CD11b-F4/80- DCs. Except for CD103- CD11b- F4/80- DCs, these subsets expanded in high fat diet-fed Ldlr-/- mice. Signal-regulatory protein (Sirp)-α was detected on aortic macrophages, CD11b+ DCs, and partially on CD103- CD11b- F4/80- but not on CD103+ DCs. Notably, in FMS-like tyrosine kinase 3-ligand-deficient (Flt3l-/-) mice, a specific loss of CD103+ DCs but also CD103- CD11b+ F4/80- DCs was evidenced. Aortic CD103+ and CD11b+ F4/80- CD103- DCs may thus belong to conventional rather than monocyte-derived DCs, given their dependence on Flt3L-signalling. CD64, postulated to distinguish macrophages from DCs, could not be detected on DC subsets under physiological conditions, but appeared in a fraction of CD103- CD11b+ F4/80- and CD11b+ F4/80+ cells in atherosclerotic Ldlr-/- mice. The emergence of CD64 expression in atherosclerosis may indicate that CD11b+ F4/80- DCs similar to CD11b+ F4/80+ DCs are at least in part derived from immigrated monocytes during atherosclerotic lesion formation. Our data advance our knowledge about the presence of distinct DC subsets and their accumulation characteristics in atherosclerosis, and may help to assist in future studies aiming at specific DC-based therapeutic strategies for the treatment of chronic vascular inflammation.}, language = {en} } @article{TilstamGijbelsHabbeddineetal.2014, author = {Tilstam, Pathricia V. and Gijbels, Marion J. and Habbeddine, Mohamed and Cudejko, Celine and Asare, Yaw and Theelen, Wendy and Zhou, Baixue and D{\"o}ring, Yvonne and Drechsler, Maik and Pawig, Lukas and Simsekyilmaz, Sakine and Koenen, Rory R. and de Winther, Menno P. J. and Lawrence, Toby and Bernhagen, J{\"u}rgen and Zernecke, Alma and Weber, Christian and Noels, Heidi}, title = {Bone Marrow-Specific Knock-In of a Non-Activatable Ikkα Kinase Mutant Influences Haematopoiesis but Not Atherosclerosis in Apoe-Deficient Mice}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {2}, doi = {10.1371/journal.pone.0087452}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117450}, pages = {e87452}, year = {2014}, abstract = {Background: The Ikkα kinase, a subunit of the NF-kappa B-activating IKK complex, has emerged as an important regulator of inflammatory gene expression. However, the role of Ikkα-mediated phosphorylation in haematopoiesis and atherogenesis remains unexplored. In this study, we investigated the effect of a bone marrow (BM)-specific activation-resistant Ikk alpha mutant knock-in on haematopoiesis and atherosclerosis in mice. Methods and Results: Apolipoprotein E (Apoe)-deficient mice were transplanted with BM carrying an activation-resistant Ikkα gene (Ikkα(AA/AA) Apoe(-/-)) or with Ikkα(+/+) Apoe(-/-) BM as control and were fed a high-cholesterol diet for 8 or 13 weeks. Interestingly, haematopoietic profiling by flow cytometry revealed a significant decrease in B-cells, regulatory T-cells and effector memory T-cells in Ikkα(AA/AA) Apoe(-/-) BM-chimeras, whereas the naive T-cell population was increased. Surprisingly, no differences were observed in the size, stage or cellular composition of atherosclerotic lesions in the aorta and aortic root of Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) BM-transplanted mice, as shown by histological and immunofluorescent stainings. Necrotic core sizes, apoptosis, and intracellular lipid deposits in aortic root lesions were unaltered. In vitro, BM-derived macrophages from Ikkα(AA/AA) Apoe(-/-) vs Ikkα(+/+) Apoe(-/-) mice did not show significant differences in the uptake of oxidized low-density lipoproteins (oxLDL), and, with the exception of Il-12, the secretion of inflammatory proteins in conditions of Tnf-α or oxLDL stimulation was not significantly altered. Furthermore, serum levels of inflammatory proteins as measured with a cytokine bead array were comparable. Conclusion: Our data reveal an important and previously unrecognized role of haematopoietic Ikkα kinase activation in the homeostasis of B-cells and regulatory T-cells. However, transplantation of Ikkα AA mutant BM did not affect atherosclerosis in Apoe(-/-) mice. This suggests that the diverse functions of Ikkα in haematopoietic cells may counterbalance each other or may not be strong enough to influence atherogenesis, and reveals that targeting haematopoietic Ikkα kinase activity alone does not represent a therapeutic approach.}, language = {en} }