Dendritic cell marker Clec4a4 deficiency limits atherosclerosis progression

Atherogenesis results from altered lipid metabolism and impaired immune response. Emerging evidence has suggested that dendritic cells (DCs) participate to atherosclerosis-related immune response, but their impact is scarcely characterized. Clec4a4 or DCIR2 (Dendritic cell immunoreceptor 2) is a C-type lectin receptor, mainly expressed by CD8α− DCs, able to modulate T cell immunity. However, whether this DC subset could play a role in the atherogenesis is still poorly understood. Thus, the aim of this study is to investigate whether the absence of Clec4a4 could affect atherosclerosis-related immune response and atherosclerosis itself. Dcir2−/− Ldlr−/− and Ldlr−/− mice were fed a standard diet or cholesterol-enriched diet for 12 weeks. Subsequently, the profile of circulating and lymph nodes-resident immune cells was investigated together with the analysis of plasma lipid levels and atherosclerotic plaque extension in the aorta. Here, we show that Clec4a4 expression is downregulated under hypercholesterolemia and its deficiency in Ldlr−/− mice results in the reduction of atherosclerotic plaque formation, together with altered lipid metabolism and impaired myeloid immune cell distribution. Our findings suggest a pro-atherosclerotic role of Clec4a4 in experimental atherosclerosis.