Soluble NRP-1 inhibits liver, spleen, and bone infiltration of leukemic cells.
M1 cells (2 × 106 cells per mouse) were injected intravenously into SCID mice. After 7 days, adenoviral vectors encoding for Fc-sNRP-1 (Avii-ix and Biii-iv), VEGF (Aiv,vi and Bii,v), and lacZ (Ai-iii and Bi,iv) were injected intravenously, as described in “Materials and methods.” On day 28, 2 mice from each group were killed and their bones, livers, and spleens were processed for histologic examination. (A) Liver tissues were processed for LacZ staining (Ai,iv,vii), as described in “Materials and methods.” Liver and spleen tissues were also stained with H&E (ii,v,viii and iii,vi,ix, respectively). Stained sections were examined microscopically and representative images were recorded (original magnification × 200). (B) Bone sections were stained with H&E (i-iii) and with anti–mouse CD31 antibodies (iv-vi). Stained sections were examined microscopically and representative images were recorded (original magnification × 200).
