Immune-cell population and structural reconstitution of spleen and lymph nodes in NOD/SCID mice that received human Thy/Liv/CD34⁺ FLCs. Spleens and lymph nodes were harvested from control NOD/SCID mice (n = 6) and NOD/SCID mice that received human Thy/Liv/CD34⁺ FLCs at death between 18 and 25 weeks after human tissue/cell transplantation (n = 5), and assessed by H&E and immunohistochemical staining. (A-C) H&E staining of representative spleen samples from control NOD/SCID mice (A) and NOD/SCID mice that received Thy/Liv/CD34⁺ FLCs (B, arrow indicates a central artery), and mesenteric lymph node (C) from NOD/SCID mice that received Thy/Liv/CD34⁺ FLCs (original magnification, × 200). (D-L) Immunohistochemical staining of representative spleen sections from control NOD/SCID mice (D,G,J) and NOD/SCID mice that received a graft of Thy/Liv/CD34⁺ FLCs (E,H,K), and mesenteric lymph node sections from NOD/SCID mice that received a graft of Thy/Liv/CD34⁺ FLCs (F,I,L). Shown are results of 2-color immunohistochemistry with anti–human CD20 (blue) and anti–human CD3 (brown) (D-F; original magnification, × 200), anti–HLA-DR (blue) and anti–human CD11c (brown) (G-I; original magnification, × 400), or anti–HLA-DR (blue) and anti–human CD123 (brown) (J-L; original magnification, × 400). bl indicates blue; br, brown.