Immunoprotective role of indoleamine 2,3-dioxygenase in engraftment of allogenic skin substitute in wound healing

Delayed wound healing can significantly impact survival of patients who suffer from severe thermal injury. In general, the use of a wound coverage, particularly with those of bilayer skin substitute, would be ideal to promote healing and prevent infection and fluid loss. Although the use of an autologous skin substitute is desirable, its preparation is time consuming and its immediate availability is impossible. To overcome this difficulty, the authors have previously demonstrated that the expression of indoleamine 2,3 dioxygenase (IDO) could function as a local immune suppressive factor in protecting allogenic fibroblasts and keratinocytes without using any immunosuppressive medication in a wound healing animal model. IDO, which is naturally expressed in the placenta by trophoblast cells during pregnancy, plays an essential role in maternal tolerance toward the fetus. The potent and selective local immunosuppressive function of IDO makes this enzyme a very promising tool for engineering a nonrejectable skin allograft. Here, the authors reviewed and discussed how the expression of IDO by the primary cells of our skin substitute can serve as a source of IDO enzyme activity and generate a tryptophan-deficient environment. Under this condition, only skin cells but not immune cells (CD4+ and CD8+ cells) would survive and protect engraftment of this engineered and shelf-ready skin substitute to be used not only as wound coverage but also as a rich source of wound healing promoting factors. Therefore, this review summarizes the body of work on immunoprotective role of IDO in engraftment of allogenic skin substitute in wound healing, which has recently been reported by the authors' research group and others. Copyright © 2012 by the American Burn Association

A comparative study of inhibitory effect of human calprotectin on the growth of Human Gingival Fibroblast and Foreskin Fibroblast

In the present study, cytotoxicity effects of calprotectin on Human Gingival Fibroblast (HGF) and Human Foreskin Fibroblast (HFFF) were compared. For these evaluations, both cells were exposed to the different concentrations of calprotectin, for 24, 48 and 72 h. Cell proliferation was assessed using MTT assay. Our results revealed that growth inhibition of calprotectin on HGF and HFFF occur in a dose- and time-dependent manner. Results of this investigation showed that sensitivity of HGF cells to cytotoxic effect of human calprotectin was more than HFFF. The results indicate that drug resistance process is different for the two kinds of fibroblast cells. © 2008 Asian Network for Scientific Information