In vivo analysis of lineage distribution of DNMT3A variants. (A) UMAP clustering of CD34-enriched samples based on their immunophenotype as defined by expression of 50 unique hematopoietic surface antigens with cell type labels transferred from Triana et al.50 (B-C) Intradonor/intrapatient, genotype-specific cellular composition of indicated donor samples. Fifteen cell clusters were defined according to the UMAP in panel A, as shown in the color-matched legend. Fisher exact test was used for analysis of statistical significance in the contribution of a mutant vs nonmutant genotype to a given cell population. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. (D) Schematic representation of the humanized mice model used to evaluate W305∗ and R882H mutant hematopoiesis after producing sustained erythropoietic stress via successive bleeding/EPO injection and phenylhydrazine treatment. (E-F) Frequency of W305∗ (E) or R882H (F) mutations represented as fold expansion from HSPC and mature cell subsets. Each dot represents an individual humanized mouse. t test was used to determine statistical significance. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. Overlaid heat map representing the fold expansion of each mutation within the different cell populations of the hematopoietic system is provided to visualize the differential lineage bias of the 2 DNMT3A mutations. CLP, common lymphoid progenitor; CMP, common myeloid progenitor; DC, dendritic cell; ERP, erythroid progenitor; FC, fold change; G, granulocyte; GMP, granulocyte-monocyte progenitor; hHSC, human HSC; M, monocyte; MEP, megakaryocyte erythroid progenitor; MPP, multipotent progenitor; NK, natural killer; n.s., non-significant; NA, not available.
