Carotene accelerates the resolution of atherosclerosis in mice

[beta]-Carotene oxygenase 1 (BCO1) catalyzes the cleavage of [beta]-carotene to form vitamin A. Besides its role in vision, vitamin A regulates the expression of genes involved in lipid metabolism and immune cell differentiation. BCO1 activity is associated with the reduction of plasma cholesterol in humans and mice, while dietary [beta]-carotene reduces hepatic lipid secretion and delays atherosclerosis progression in various experimental models. Here we show that [beta]-carotene also accelerates atherosclerosis resolution in two independent murine models, independently of changes in body weight gain or plasma lipid profile. Experiments in Bco1.sup.-/- mice implicate vitamin A production in the effects of [beta]-carotene on atherosclerosis resolution. To explore the direct implication of dietary [beta]-carotene on regulatory T cells (Tregs) differentiation, we utilized anti-CD25 monoclonal antibody infusions. Our data show that [beta]-carotene favors Treg expansion in the plaque, and that the partial inhibition of Tregs mitigates the effect of [beta]-carotene on atherosclerosis resolution. Our data highlight the potential of [beta]-carotene and BCO1 activity in the resolution of atherosclerotic cardiovascular disease.