Anti-VEGFR-3 treatment results in inhibition of GVHD-associated lymphangiogenesis. Allo-HSCT recipients received intraperitoneal injections of 1 mg anti-VEGFR-3 antibody (mF4-31c1) or control antibody every second day from day 0 to day +10 or day +14: LP/J or 129/SV → C57BL/6, conditioning with Bu/Cy, allo-HSCT with 1.5 × 107 BM cells, 2 × 106 T cells. (A) Visualization of the reduction of lymphangiogenesis after anti-VEGFR-3 treatment in the colon on day +15 after allo-HSCT. Colon sections of mice treated with control antibody or anti-VEGFR-3 antibody (mF4-31c1) were stained with Lyve1 antibody (green) and counterstained with DAPI. (B) Quantification of Lyve1 positive area in the colon after control antibody or mF4-31c1 treatment (n = 4 per group). (C) Representative images of lymph vessels in the mesenteric window of mF4-31c1 antibody versus control antibody-treated allo-HSCT recipients. Mesenteric windows were taken on day +11 after HSCT and stained against Lyve1 (green) and counterstained with DAPI. (D) Quantitative analysis of Lyve1 positive area of mesenteric windows from control antibody and mF4-31c1– treated allo-HSCT recipients on day +11 post–allo-HSCT (n = 4 per group). (E-F) Quantification of lymphatic endothelial cells (gp38+ ECs) in mesenteric (E) and peripheral (F) lymph nodes via FACS. Endothelial cells were isolated from mesenteric and peripheral lymph nodes of the control antibody and mF4-31c1–treated allo-HSCT recipients on day +11 (n = 5 per group). Error bars indicate mean ± SEM; significance was tested with an unpaired Student t test. contr. Ab, control antibody.
