Fig. 3: NRP1 inhibition accelerates hematopoietic regeneration following TBI.

a PB WBC, neutrophil (NEU), and lymphocyte (LYMPH) counts at days +3, +7, and +10 following 500 cGy and treatment with IgG or anti-NRP1 (n = 5–10 mice/group, mean values +/− SEM; WBC: d7: p = 0.0016, d10 p = 0.002; NEU: d7: p = 0.0089, d10: p = 0.0035, LYMPH: d10: p = 0.0482). b BM cell counts at day +10 following 500 cGy and treatment with IgG or anti-NRP1 (n = 5–10 mice/group, p = 0.0033). Dotted line represents BM cell counts in non-IRR controls. c At left, flow cytometry of BM c-kit⁺sca-1⁻lin⁻ progenitors and KSL cells at day +10 following 500 cGy; at right, numbers of BM c-kit⁺sca-1⁻lin⁻ cells and KSL at day +10 (n = 5–10 mice/group, p < 0.0001). d At left, PB donor CD45.2⁺ cell engraftment at 20 weeks in CD45.1⁺ mice transplanted with BM cells collected at day +10 from 500 cGy—irradiated CD45.2⁺ mice treated with IgG or anti-NRP1, along with CD45.1⁺ BM competitor cells. At right, % total CD45.2⁺ cells, CD45.2⁺Mac1⁺Gr1⁺ myeloid cells, CD45.2⁺B220⁺ B cells, and CD45.2⁺CD3⁺ T cells at 20 weeks (n = 12–13 mice/group, total: p = 0.0288, myeloid: p = 0.0266, B cells: p = 0.0051, T cells: p = 0.0001). e At left, histograms of donor CD45.2⁺KSL cells in the BM of transplanted CD45.1⁺ mice at 20 weeks (n = 5 mice/group, p = 0.0079). f Percent survival of C57BL/6J mice following 800 cGy TBI and treatment with anti-NRP1 or IgG for 10 days (Log-rank test, p = 0.001, n = 12 mice/group). g PB WBCs and hemoglobin (Hb) at day +7, +10 and +14 from C57BL/6J mice following 800 cGy and treatment with anti-NRP1 or IgG (n = 8–10 mice/condition; WBC d7: p = 0.4045, WBC d10: p = 0.0415, WBC d14: p = 0.8714; Hb d7: p = 0.0154, Hb d10: p = 0.2741, Hb d14: p = 0.6216). h At left, flow cytometry of BM KSL cells 10 days following 800 cGy and treatment with anti-NRP1 or IgG; at right, %KSL cells (n = 10 mice/condition; p = 0.0358). a Two-way ANOVA with Holm Sidak’s multiple comparison two-sided t-test. b, c Two-sided t-test, d, e Two-sided Mann–Whitney test, f Two-sided log-rank test, g Two-way ANOVA with Holm-Sidak’s multiple comparison two-sided t-tests, and h Student’s two-sided unpaired t-test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Source data are provided as a Source Data file.