Dendritic cell marker Clec4a4 deficiency limits atherosclerosis progression

Atheroscler Plus. 2022 Dec 17:51:8-12. doi: 10.1016/j.athplu.2022.12.001. eCollection 2023 Mar.

Abstract

Background and aims: 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.

Methods: 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.

Results: 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.

Conclusions: Our findings suggest a pro-atherosclerotic role of Clec4a4 in experimental atherosclerosis.

Keywords: Atherosclerosis; C-type lectin receptors; Clec4a4; Dendritic cells; Immune response.