Leukocyte recruitment to atherosclerotic lesions, a complex web of dynamic cellular and molecular interactions

The accumulation of leukocytes in atherosclerotic lesions is of fundamental importance in the development of atherosclerosis. Consequently, the adhesive and signaling mechanisms responsible for leukocyte invasion in the arterial wall have been intensively studied as potential targets for therapeutic intervention. During recent years, it has become increasingly clear that leukocyte recruitment in atherosclerosis is mediated by a complex series of cellular and molecular interactions that in many ways resemble those that take place in tissue inflammation. However, certain aspects of leukocyte recruitment in atherosclerosis are specific for this disease and present themselves as interesting drug targets. This review summarizes the current knowledge about the mechanisms that guide the extravasation of leukocytes to inflamed tissues, with special focus on atherosclerotic lesions. Moreover, novel experimental techniques are described, techniques that allow for the study of dynamic events taking place in atherosclerosis and that have provided interesting insights into lesion pathology. The data reviewed contribute to the understanding of atherosclerosis, and may help in the development of treatment strategies for a disease that is a major contributor to morbidity and mortality in the western world today.