Targeting CCR2 or CD18 Inhibits Experimental In-Stent Restenosis in Primates. Inhibitory Potential Depends on Type of Injury and Leukocytes Targeted

A central role for leukocytes in neointimal hyperplasia after arterial injury is suspected. However, the relative importance of neutrophils and monocytes in balloon or stent-induced injury are not well understood, and mechanistic targeting of leukocyte recruitment or function is crude. We determined the temporal and spatial distribution of different leukocytes after balloon and stent-induced injury in primate iliac arteries. Based on these data, we targeted neutrophil and monocyte recruitment selectively after angioplasty or stent implantation and demonstrated that monocyte-specific blockade achieved via blockade of the MCP-1 receptor CCR2, was effective at reducing neointimal hyperplasia after stenting. In contrast, combined neutrophil and monocyte blockade achieved by targeting the leukocyte β 2 -integrin β-subunit CD18 was required to reduce neointimal hyperplasia after balloon injury. Distinct patterns of leukocyte infiltration in balloon versus stent-injured arteries predict distinct mechanisms for antiinflammatory strategies targeting neutrophils or monocytes in primates and may assist design of effective clinical strategies for optimizing vascular interventions.