BACKGROUND. In inflammatory blood vessel diseases, macrophages represent a key component of the vascular infiltrates and are responsible for tissue injury and wall remodeling. METHODS. To examine whether inflammatory macrophages in the vessel wall display a single distinctive effector program, we compared functional profiles in patients with either coronary artery disease (CAD) or giant cell arteritis (GCA). RESULTS. Unexpectedly, monocyte-derived macrophages from the 2 patient cohorts displayed disease-specific signatures and differed fundamentally in metabolic fitness. Macrophages from CAD patients were high producers for T cell chemoattractants (CXCL9, CXCL10), the cytokines IL-1β and IL-6, and the immunoinhibitory ligand PD-L1. In contrast, macrophages from GCA patients upregulated production of T cell chemoattractants (CXCL9, CXCL10) but not IL-1β and IL-6, and were distinctly low for PD-L1 expression. Notably, disease-specific effector profiles were already identifiable in circulating monocytes. The chemokinehicytokinehiPD-L1hi signature in CAD macrophages was sustained by excess uptake and breakdown of glucose, placing metabolic control upstream of inflammatory function. CONCLUSIONS. We conclude that monocytes and macrophages contribute to vascular inflammation in a disease-specific and discernible pattern, have choices to commit to different functional trajectories, are dependent on glucose availability in their immediate microenvironment, and possess memory in their lineage commitment. FUNDING. Supported by the NIH (R01 AR042527, R01 HL117913, R01 AI108906, P01 HL129941, R01 AI108891, R01 AG045779 U19 AI057266, R01 AI129191), I01 BX001669, and the Cahill Discovery Fund.
Ryu Watanabe, Marc Hilhorst, Hui Zhang, Markus Zeisbrich, Gerald J. Berry, Barbara B. Wallis, David G. Harrison, John C. Giacomini, Jörg J. Goronzy, Cornelia M. Weyand
Differential expression of the immunoinhibitory ligand PD-L1 on monocyte-derived macrophages from GCA and CAD patients.