Impaired Arteriogenic Response to Acute Hindlimb Ischemia in CD4-Knockout Mice

Abstract
Background— T lymphocytes, components of the immune and inflammatory systems, are involved in such normal processes as wound healing and host defense against infection and in such pathological processes as tumor growth and atherosclerotic plaque development. Angiogenesis is a mechanism common to each. Because CD4+ T lymphocytes are active in regulating humoral and cellular responses of the immune system, we determined whether CD4+ cells contribute to collateral vessel development by using the mouse ischemic hindlimb model. Methods and Results— One week after ischemia, CD4−/− mice showed reduced collateral flow induction, macrophage number, and vascular endothelial growth factor levels in the ischemic muscle compared with wild-type mice. There was also delayed recovery of hindlimb function and increased muscle atrophy/fibrosis. Spleen-derived purified CD4+ T cells infused into CD4−/− mice selectively localized to the ischemic limb and significantly increased collateral flow as well as macrophage number and...