Sleeping Beauty‐based gene therapy with indoleamine 2,3‐dioxygenase inhibits lung allograft fibrosis

Abstract

Sleeping Beauty (SB) transposon is a natural nonviral gene transfer system that can mediate long-term transgene expression. Its potential utility in treating organ transplantation-associated long-term complications has not yet been explored. In the present study we generated an improved SB transposon encoding the human gene indoleamine-2,3-dioxygenase (hIDO), an enzyme that possesses both T cell-suppressive and antioxidant properties and selectively delivered the SB transposon in combination with a hyperactive transposase plasmid to donor lung using the cationic polymer polyethylenimine (PEI) as transfection reagent. This nonviral gene therapeutic approach led to persistent and uniform transgene expression in the rat lung tissue without noticeable toxicity and inflammation. Importantly, IDO activity produced by hIDO transgene showed a remarkable therapeutic response, as evident by near normal pulmonary function (peak airway pressure and oxygenation), histological appearance, and reduced collagen content in lung allografts. In addition, we established a hIDO-overexpressing type II cell line using the SB-based gene transfer system and found that hIDO-overexpressing lung cells effectively inhibited transforming growth factor-beta-stimulated fibroblast proliferation in vitro. In summary, the SB-based gene therapy with hIDO represents a new strategy for treating lung transplantation-associated chronic complications, e.g., obliterative bronchiolitis.

Reduced Cytotoxic Function of Effector CD8+ T Cells Is Responsible for Indoleamine 2,3-Dioxygenase-Dependent Immune Suppression

“…The most direct evidence supporting the view about IDO as an immune-suppressive enzyme arises from transplant-related research. These studies consistently showed that enhanced IDO activity in donor organ/cells provides an efficient immunological shield to prevent a destructive allograft-reactive response without additional immunosuppressive treatments in a variety of animal models of organ/tissue transplantation, including heart (3), lung (4,5), liver (6), kidney (7), pancreas (8), skin (9), and bone marrow (10).…”

“…The orthotopic left lung transplants were performed using Lewis donors and SpragueDawley recipient (allografts) or the same strain (isografts), as described previously (4,5,13). Some rats receiving allografts were given IDO inhibitor 1-mT in drinking water (5 mg/ml, pH 7) immediately after surgery.…”

Nonviral Gene Delivery with the Sleeping Beauty Transposon System

“…Color images available online at www.liebertonline.com/hum hypertension (L. Liu et al, 2006a). Furthermore, PEI-based systemic delivery of the SB transposon system encoding the human indoleamine-2,3-dioxygenase (hIDO) gene was evaluated in the context of lung transplantation-associated chronic complications, and found to elicit a remarkable therapeutic response, as evidenced by near normal pulmonary function in lung allografts (H. Liu et al, 2006). Last, SBmediated gene transfer significantly increased survival of mice bearing human glioblastoma xenografts by expressing antiangiogenic gene products (Ohlfest et al, 2005a), and improved the efficacy of immunotherapy by facilitating sustained cytokine expression after local, intratumoral injections of vector-PEI complexes (Wu et al, 2007).…”

Indoleamine 2,3-dioxygenase attenuates inhibitor development in gene-therapy-treated hemophilia A mice

“…Culture medium and total cell lysates from 24 independent clones were resuspended in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) lysis buffer (20 mM HEPES, 0.5 M NaCl, 1 mM EDTA, 0.25% Triton X-100, 1 mM EGTA supplemented with a protease inhibitor cocktail) and screened for expression of IDO by western blotting and IDO activity assays. 46 As a negative control, cells transfected with the transposon pMSZ-CMV-GFP were used in place of the pMSZ-CMV-IDO and an identical selection process was carried out.…”