The Role of Secretory Leukocyte Proteinase Inhibitor During Transplantation

Abstract

Old and new players of the innate immune response have been studied in the context of transplantation. Nonetheless, little interest has been focused toward the immune regulatory feedback in transplantation. Here, we revised the role of secretory leukocyte proteinase inhibitor (SLPI), which limits the activity of serine proteases, in solid organ transplantation. Ischemia-reperfusion injury increases SLPI gene expression. Furthermore, post-transplant acute kidney injury increases the expression of SLPI transcript and protein. Several studies have shown that SLPI exerts direct, indirect, and locally mediated beneficial effects in multiple ischemia-reperfusion models. Moreover, the addition of SLPI in the preservation solution improved cardiac performance in a cardiac transplantation model. Diverse factors present at the time of transplantation facilitate the production and secretion of SLPI, which in turn acts as a feedback mechanism to control graft injury. The pleiotropic activity of SLPI as a tolerogenic factor, as well as microbicidal and wound healing agent, should motivate the exploration of its utility as an adjuvant therapeutic tool in transplanted patients. Further studies are also required to analyze the utility of SLPI as a biomarker of graft quality and injury.