Regulatory T Lymphocyte Subpopulations in Early Carotid Atherosclerosis

An increasing number of studies has contributed to clarify some of the immune-inflammatory pathways underlying plaque formation. It has been demonstrated that CD4+ T lymphocyte subpopulations including T helper 1 (Th1), T helper 17 (Th17), and T CD4+CD28– cells are involved in carotid plaque growth and its complications, whereas CD4+CD25+ regulatory T lymphocytes (Tregs) exert protective actions against atherosclerosis. However, Tregs can pass the blood-brain barrier and have been directly related to the extent of brain damage after ischemic injury, suggesting that regulatory T cells can exert pleiotropic and opposite effects in the different stages of atherosclerotic diseases.