Fig 2: Deletion of IL-1ß in JAK2-V617F mutant hematopoietic cells prevented the loss of nestin+ MSCs in bone marrow.a Scheme of non-competitive (1:0) transplantation into Nestin-GFP mice. b Complete blood counts at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4) and 8-weeks (VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4) after transplantation. c Spleen weights after 8 weeks of transplantation (VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4). d Number of Ter119-CD45-CD31-GFP+ cells in BM (1 tibia and 2 hip bones) at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 5, and WT; n = 4) and 8-weeks (VF; n = 6, VF;IL-1ß-/-; n = 6, and WT; n = 4) after transplantation. e Total number of Ter119-CD45-CD31-GFP+ cells co-expressing platelet derived growth factor receptor a (PDGFR a) at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 5, and WT; n = 4) and 8-weeks (VF; n = 6, VF;IL-1ß-/-; n = 6, and WT; n = 4). f Grade of reticulin fibrosis 8-weeks after transplantation. VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4. g Representative images of glial fibrillary acidic protein (GFAP)-positive Schwann cells in skull BM and quantification of GFAP area at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 5, and WT; n = 4) and 8-weeks (VF; n = 6, VF;IL-1ß-/-; n = 6, and WT; n = 4) after transplantation (right). h Representative images of tyrosine hydroxylase (TH)-positive sympathetic nerve fibers in skull BM and quantification at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 5, and WT; n = 4) and 8-weeks (VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4) after transplantation (right). i Representative images of Nestin-GFP cells in skull BM and quantification at 4-weeks (VF; n = 7, VF;IL-1ß-/-; n = 5, and WT; n = 4) and 8-weeks (VF; n = 7, VF;IL-1ß-/-; n = 6, and WT; n = 4) (right). Similar results were obtained with other mice of each genotype in g–i (left panel). Scale bar is 100 µm in g–i (left panel). Statistical significances in all graphs were determined by multiple unpaired two-tailed t-tests. Grey area represents normal range. All data are presented as mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. See also Supplementary Fig. 12. Source data and exact p values are provided as a Source Data file.

Fig 3: Loss of the miR-15 family results in B cell progenitor expansion in vitro. (A) Schematic illustration of the sorting strategy for the B cell progenitor in vitro culture. B220+c-KIT+NK1.1-CD19- B cell progenitors were sorted from the bone marrow of miR-15a/bfl/fl Vav-Cre and miR-15a/b+/+ Vav-Cre mice and cultured in the presence of IL-7, FLT3L and SCF. A representative FACS plot depicts the percentages of pro-B (c-KIT+CD25-), intermediate B (c-KIT-CD25-) and pre-B cells (c-KIT-CD25+) under basal conditions after 1 week. (B) Statistical analysis of the distribution of pro-, intermediate and pre-B cell progenitors derived from miR-15a/bfl/fl Vav-Cre mice and miR-15a/b+/+ Vav-Cre mice under basal conditions. (C) Representative FACS blots and statistical analysis of the progenitor B cell differentiation upon IL-7 withdrawal in vitro. (D) Progenitors from miR-15a/bfl/fl Vav-Cre mice and miR-15a/b+/+ Vav-Cre mice were labeled via stable expression of either dsRed or GFP, mixed at equal ratios at a cell density of 5 x 104 cells/ml and tracked over time by flow cytometry in the presence of all growth factors. (E) The bar graph depicts the percentages of EdU+ progenitors derived from miR-15a/bfl/fl Vav-Cre mice or miR-15a/b+/+ Vav-Cre mice after labeling with 10 ug/ml EdU for 4 hrs. (F) Quantification of the percentage of apoptotic progenitors under steady state conditions as analyzed by AnnexinV staining. Error bars depict the standard deviation of the mean. Numbers indicate the percentage of cells in the respective region. MiR-15a/bfl/fl Vav-Cre progenitors were statistically compared to miR-15a/b+/+ Vav-Cre progenitors by an unpaired two-tailed Student’s t-test. *P < 0.05.

Fig 4: TNFR2 Engagement on ILC2s Induces the Non-canonical NF-?B Pathway(A) BALB/cByJ mice were challenged i.n. on days 1–3 with 0.5 µg rmIL-33. On day 4, aILC2s were FACS sorted as lineage-, CD45+ ST2+ CD127+ and cultured in vitro for 24 h with rmIL-2 (10 ng/mL) and rmIL-7 (10 ng/mL) with or without rmTNFa (40 ng/mL).(B) Volcano plot comparison of whole-transcriptome gene expression on ILC2s from PBS-versus rmTNF-a—stimulated ILC2s. Differentially downregulated or upregulated genes (p < 0.05 and 2-fold change cutoff) are presented in blue and yellow, respectively.(C) Heatmap representation of statistically differentially regulated cytokines, chemokines, and their receptors in ILC2s from PBS-versus rmTNF-a-stimulated ILC2s.(D) Upregulated (red) and downregulated (green) genes in the non-canonical NF-?B pathway and corresponding quantitation, presented as normalized counts ± SEM.(E and F) Representative flow cytometry plots of NF-?B p65 (E) and NF-?B p52 (F) and corresponding quantitation, presented as MFI ± SEM in rmTNF-a-versus PBS-treated ILC2s.Data are representative of 3 individual experiments (n = 3–5). *p < 0.05, **p < 0.01, ***p < 0.001.

Fig 5: Loss of Kat2a diversifies cell fates and promotes RT1(9a) preleukemia progression.(A and B) Pseudo-time single-cell trajectory of (A) Kat2aWT cells (B) Kat2aNULL RT1(9a) cells 2 and 4 months after transplantation. Trajectories were inferred using Monocle3 (21); compartments were labeled as per hematopoietic markers in (fig. S5, C and D). (C) Proportion of candidate progenitor cell compartments in the RT1(9a) pseudo-time trajectory contributed by individual Kat2aWT or Kat2aNULL, 2-month or 4-month samples. (D) Representative flow cytometry histograms of B220 B cell marker detection in plate 2 CFC of RT1(9a)-transduced Kat2aWT and Kat2aNULL cells during in vitro transformation. (E) Aggregate results of B220 staining as in (D). Mean ± SD, n = 3. (F) Representative flow cytometry histograms of F4/80 monocyte marker detection in plate 2 CFC of RT1(9a)-transduced Kat2aWT and Kat2aNULL cells during in vitro transformation. (G) Aggregate results of F4/80 staining as in (F). Mean ± SD, n = 3.