Modulating endothelial cells with EGFL7 to diminish aGVHD after allogeneic bone marrow transplantation in mice.

Acute graft-versus-host disease (aGVHD) is the second most common cause of death after allogeneic hematopoietic stem cell transplantation (allo-HSCT), underscoring the need for novel therapies. Based on previous work that endothelial cell dysfunction is present in aGVHD and that epidermal growth factor-like domain 7 (EGFL7) plays a significant role in decreasing inflammation by repressing endothelial cell activation and T-cell migration, we hypothesized that increasing EGFL7 levels after allo-HSCT will diminish the severity of aGVHD. Here, we show that treatment with recombinant EGFL7 (rEGFL7) in 2 different murine models of aGVHD decreases aGVHD severity and improves survival in recipient mice after allogeneic transplantation with respect to controls without affecting graft-versus-leukemia effect. Furthermore, we showed that rEGFL7 treatment results in higher thymocytes, T, B, and dendritic cell counts in recipient mice after allo-HSCT. This study constitutes a proof of concept of the ability of rEGFL7 therapy to reduce GHVD severity and mortality after allo-HSCT.