The Expression and Function of CCL5 in Early Atherosclerosis

Atherosclerosis is a chronic cardiovascular disease initiated by the accumulation of lipid-loaded macrophages within the artery wall. Chemokines can have several potential functions in atherosclerosis. CCL5, an inflammatory chemokine, is considered proatherogenic. Since CCL5 expression is dramatically increased in early mouse atherosclerotic lesions, the goals were to identify which cells express CCL5 and the functions of CCL5 in early lesion development. CCL5 mRNA and protein were up-regulated both by myeloid and endothelial cells in lesions. Bone marrow transplantation studies demonstrated that CCL5 deficiency in bone marrow-derived cells transiently affected lesion myeloid cell content but did not significantly affect macrophage proliferation or monocyte recruitment. Additionally, CCL5 deficiency in non-hematopoietic cells had no effect on lesion parameters. These studies suggest that although CCL5 is expressed abundantly within lesions, the effects of CCL5 deficiency in early lesion development is minimal and this may be due to compensatory functions of related chemokines.M.Sc