CHIP disrupts monocyte-endothelial interactions across multiple tissues to promote vascular inflammation in humans

BackgroundClonal hematopoiesis of indeterminate potential (CHIP) increases risk of cardiovascular disease yet the molecular mechanisms driving this association remain incompletely understood. We hypothesized that aberrant monocyte-endothelial interactions contribute to CHIP-mediated cardiovascular disease. MethodsWe performed single-cell RNA sequencing on blood and peripheral vascular tissue from 4 individuals with TET2 CHIP, 6 individuals with DNMT3A CHIP, and 25 controls. We predicted interactions between monocytes and endothelial cells based on expression of ligand-receptor pairs then modeled interactions between monocytes carrying CHIP mutations with endothelial cells in vitro. We performed an in silico genomewide perturbation screen to identify genetic targets capable of mediating these interactions and then experimentally evaluated the effect of inhibiting predicted targets on monocyte-endothelial interactions in vitro. ResultsExpression of ligand-receptor pairs on monocytes and endothelial cells from patients with and without CHIP highlighted differences in signaling likelihood for 6 key ligand-receptor pairs related to transendothelial migration. Co-culture of monocytes with human aortic endothelial cells demonstrated that monocytes carrying CHIP mutations have decreased velocity compared to monocytes without CHIP mutations. The perturbation screen suggested 11 druggable genetic targets capable of rescuing TET2 CHIP monocytes. Experimental inhibition of ICAM1 in endothelial cells and inhibition of CXCR2 in monocytes significantly increased the velocity of TET2-mutated monocytes over endothelial cells. ConclusionsCHIP mutations alter interactions between monocytes and endothelial cells. Therapeutics targeting CXCR2 and ICAM1 may restore normal interactions between monocytes and endothelial cells among patients with TET2 CHIP.