Embodiments of the present invention describe a method of changing the phenotype of monocytes and macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype. The method can comprises providing a composition comprising a recombinant adeno-associated virus (rAAV) vector comprising an exogenous gene encoding ApoA-I Milano or a fragment thereof, and administering the composition to a mammal in need thereof to change the phenotype of monocytes or macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype. By changing the phenotype of monocytes or macrophages from a proinflammatory M1 phenotype to an anti-inflammatory M2 phenotype, atherosclerosis can be treated. The present invention also describes a method of monitoring macrophage phenotypic switching and a method of assessing the efficacy of the treatment of atherosclerosis.
