The innate immune system after ischemic injury: lessons to be learned from the heart and brain.

Innate immune cells are critically involved in ischemic complications of atherosclerosis. While new insight emerged on the origin and role of leukocytes in steady state, the knowledge about myeloid cells' sources, functions, and fate after stroke is limited. In our review, we highlight open questions in this important area while examining potential parallels in the immune response after stroke and myocardial infarction. We stress the need to better understand systemic interactions between ischemic tissue, immunity, and hematopoiesis, as turnover of leukocytes in inflammatory sites can be rapid, and cell production and supply may serve as future therapeutic targets to modulate inflammation in the vessel wall, brain, and heart.