Interleukin-17 in atherosclerosis and cardiovascular disease: the good, the bad, and the unknown

Over the past few years our understanding of the importance of adaptive immunity in acute coronary syndromes (ACS) has considerably increased. Profound abnormalities have been observed in specific subsets of CD4+T cells, including type 1 helper T (Th1) cells, CD4+CD28nullT cells, and naturally occurring regulatory T cells (Treg cells). Recently a new lineage of CD4+T cells, type 17 helper T (Th17) cells producing the signature cytokines interleukin (IL)-17, IL-21, and IL-22, has been identified. This has fundamentally changed the Th1/Th2 dichotomy paradigm.