Combined blockade of VEGFR-3 and Itga-9 inhibits corneal lymphangiogenesis and valvulogenesis in vivo and promotes high-risk transplant survival

Abstract

Purpose

Corneal transplantation is the last hope for vision restoration for corneal blindness. The rejection rate of high-risk grafts can be 50-90%, irrespective of current treatment modalities. As VEGFR-3 (vascular endothelial growth factor receptor-3) is a central regulator of lymphatic vessel formation (lymphangiogenesis, LG), integrin alpha9beta1 (Itga-9) is essential for lymphatic maturation by luminal valve formation (valvulogenesis, VG). This study is to investigate the combined blockade of VEGFR-3 and Itga-9 on high-risk corneal transplant rejection.

Materials and methods

High-risk corneal transplantation was performed between fully mismatched BALB/c (donor) and Prox-1-GFP (green fluorescent protein) mice in C57BL/6 background (recipient). The recipient mice were randomized to receive neutralizing antibodies of VEGFR-3 and Itga-9. Processes of corneal LG and VG were assessed in vivo by an advanced live imaging system. Corneal grafts were also evaluated by ophthalmic slit-lamp microscopy.

Results

Combined blockade of VEGFR-3 and Itga-9 significantly suppressed both LG and VG after corneal transplantation. This treatment also led to a significant promotion of graft survival in the high-risk setting.

Conclusions

This study offers new insights into corneal LG, VG and transplant rejection. It may also provide a novel approach to manage transplant rejection and other lymphatic- and immune-related diseases in the body.