Distinct Tumor Necrosis Factor Alpha Receptors Dictate Stem Cell Fitness Versus Lineage Output in Dnmt3a-Mutant Clonal Hematopoiesis
Clonal hematopoiesis resulting from enhanced fitness of mutant hematopoietic stem cells (HSCs) associates with both favorable and unfavorable health outcomes related to the types of mature mutant blood cells produced, but how this lineage output is regulated is unclear. Using a mouse model of a clonal hematopoiesis-associated mutation, DNMT3AR882/+ (Dnmt3aR878H/+), we found that aging-induced TNF signaling promoted the selective advantage of mutant HSCs as well as stimulated mutant B lymphoid cell production. Genetic loss of TNF receptor TNFR1 impaired mutant HSC fitness without altering lineage output, while loss of TNFR2 reduced lymphoid cell production and favored myeloid cell production from mutant HSCs without altering overall fitness. These results support a model where clone size and mature blood lineage production can be independently controlled to harness potential beneficial aspects of clonal hematopoiesis. Statement of SignificanceThrough identification and dissection of TNF signaling as a key driver of murine Dnmt3a-mutant hematopoiesis, we report the discovery that clone size and production of specific mature blood cell types can be independently regulated.