Extended Data Figure 3. Analysis of vascular organoids transplanted into mice.
a, Infusion of the human specific anti-CD31 antibody (i.v.) to label perfused human blood vessels (NC8) transplanted into immunodeficient NSG mice. Murine vessels are visualized by a mouse-specific anti-CD31 antibody (mCD31). b, Functional human vasculature (detected by human-specific anti-CD31 immunostaining, hCD31, red) in mice revealed by FITC-Dextran perfusion (green). a,b, Experiments were repeated independently on n = 3 biological samples, with similar results. c, Representative axial T2-weighted image, blood flow (perfusion), relative blood volume (rBV), mean transit time (MTT) and leakage (K2) measured by MRI. The axial plane was chosen so that both kidneys (outlined in white) and the implant (outlined in red) are visible. The analysed muscle tissue is outlined in green. Quantitative values (mean +/- SD) for perfusion, rBV, MTT and K2 are given in the table. n = 3 mice analysed. d, Representative low magnification image of a transplanted vascular organoid stained for E-Cadherin and human CD31. e, Arteriole (A) and venule (V) phenotypes appearing within the human vascular organoid transplants (NC8). Representative H&E stained histological sections are shown. f, Generation of human arterioles (A) shown by staining for human specific CD31 (endothelial cells), tightly covered with vascular smooth muscle cells (vSMC) detected by SMA, Calponin-1, and human-specific MYH11 immunostaining. As a control, endothelial cells of murine kidney arterioles do not cross react with the human-specific CD31 antibody (right top panel). Samples were also stained with DAPI to determine nuclei. g,h, Arterioles of human origin (hCD31+) express arterial markers EphrinB2 and Dll4. i,j, Human venous structures (hCD31+) show expression of the venous markers EphB4 and CoupTF2. k, BFP-tagged vascular organoids (H9), transplanted into mice, co-stained with human-specific CD31 (hCD31) antibody, revealing human identity. A representative image from n=5 mice is shown. d-k, Experiments were repeated independently on n = 3 biological samples, with similar results. DAPI was used to counterstain nuclei. Scale bars: a=200μm, b,k=100μm, d=500μm e,f,g,h,i,j=20μm, f,g=50μm.