Hypodermin C improves the survival of kidney allografts.

Although immunosuppressive therapies have made organ transplantation a common medical procedure worldwide, chronic toxicity is a major issue of long-term treatment. One method to improve such therapies is the application of immunomodulatory agents from parasites, such as Hypoderma lineatum (Diptera: Oestridae). Hypodermin C (HC) is an enzyme secreted by H. lineatum larvae, and our previous study showed that recombinant HC could degrade guinea pig C3 and inhibit the complement pathway in vitro, suggesting potential activity for inhibiting transplant rejection. However, such properties have not been fully demonstrated in vivo. In this study, we investigated the impact of HC on a fully MHC-mismatched, life-sustaining, murine model of kidney allograft rejection using B6 donors and BABL/c (HC transgenic or wild-type) recipients. Kidney grafts were analyzed by histology, immunohistochemistry and western blotting. The results suggested that HC could effectively inhibit kidney allograft rejection. These findings suggest HC is a promising strategy to improve the survival of human implants.