Fig. 4: Injection of ALL EVs in vivo affects maintenance of murine HSC.

A NSG mice were injected with fluorescent EVs (ATTO488 EVs) by i.v. injections at 10¹⁰ particles/mouse. Mice were sacrificed 24 h after the injection, and florescence was determined by flow cytometry on Lin⁻, LSK (c-Kit⁺ Sca1⁺) and SLAM (LSK CD150⁺ CD48⁻) cells. B Procedure followed to treat NSG mice with ALL EVs or control EVs, through three consecutive i.v. injections, at 10¹⁰ particles/mouse/every 10 days. Ten days after the third injection, mice were sacrificed to perform experiments on Sca1⁺ cells. C The absolute number of Sca1⁺ cells detected in BM. Data are shown as means ± SD; n = 4 mice. D The number of hematopoietic progenitors (CD45⁺ Sca1⁺ c-Kit⁺ cells) and HSC (SLAM; LSK CD150⁺ CD48⁻ cells) were determined by flow cytometry. Data are shown as means ± SD; n = 4 mice. E Sca1⁺ cells (10⁵ cells) isolated from mice were analyzed on semi-solid methylcellulose media for growth of murine hematopoietic CFU. Data show the percentage of total CFU and CFU-GM per Sca1⁺ cells, as well as the distribution among colonies. Data are shown as means ± SD; n = 4 mice. F Sca1⁺ cells (3 × 10⁵ cells) were injected in C57BL/6.SJL (Ly.1) mice and the hematopoietic reconstitution was examined by flow cytometry, 4 weeks after the transplantation. Absolute number of CD45.2 total and Lin⁻ BM cells. Data are shown as means ± SD; n = 3 transplanted mice. G Hematopoietic reconstitution for progenitors (LSK cells) and HSC (SLAM cells). Absolute number of CD45.2 cells in BM. Data are shown as means ± SD; n = 3 transplanted mice. On this figure, P value is measured by one-way Anova with Tukey’s multiple comparison test; **P < 0.01; ***P < 0.001; ns, non-significant.