Mutated cells mediate distinct inflammatory responses in clonal hematopoiesis

Abstract

Clonal hematopoiesis (CH) is an age-associated phenomenon that increases risk for hematologic malignancy and cardiovascular disease. CH is thought to increase cardiovascular disease risk through inflammation in the peripheral blood¹. Here, we profile peripheral blood gene expression in 104,566 single cells from a cohort of 17 CH patients and 6 controls. We discovered that patients harboring DNMT3A and TET2 CH mutations at baseline and in response to IL-6 stimulation confer a pro-inflammatory profile to CD14+ monocytes through previously unrecognized pathways including Macrophage Inhibitory Factor (MIF). A germline genetic variant in MIF modifies TET2 CH cardiovascular disease risk. Using mitochondrial lineage tracing, we used a novel method to compare gene expression between mutated and non-mutated cells within individual CH patients. We found that the mutated CH monocytes, but not non-mutated monocytes are pro-inflammatory, explaining why patients with larger CH clones have increased cardiovascular disease risk.