ORGAN PRESERVATION Recipient Intramuscular Administration of Naked Plasmid TGF-1 Attenuates Lung Graft Reperfusion Injury Niccolo` Daddi, MD, a Samer A. Kanaan, MD, a Takashi Suda, MD, a Tsutomu Tagawa, MD, a Franco D’Ovidio, MD, b Kathleen Grapperhaus, BSc, a Benjamin D. Kozower, MD, a Jon H. Ritter, MD, c T. Mohanakumar, PhD, a,d and G. Alexander Patterson, MD, FRCS(C) a Background: Gene therapy may be an effective strategy for modulating lung graft ischemia–reperfusion injury. We investigated whether recipient intramuscular (IM) naked plasmid gene transfer of transforming growth factor 1–active (TGF-1–active) ameliorates lung graft ischemia–reperfusion injury. Methods: Preliminary studies in F344 rats demonstrated that gastrocnemius muscle transfection of TGF-1–active produced muscle and plasma protein expression at 24 and 48 hours after transfection. Recipients (n  8) received IM injection of naked plasmid-encoding chloramphenicol acetyl transferase (CAT), TGF-1–latent or TGF- 1–active, respectively, at 24 or at 48 hours before left lung transplantation. We did not treat the control group before transplantation (18-hour cold ischemia). Donor lungs were flushed with low-potassium dextran–1% glucose and stored for 18 hours at 4°C. All groups were killed at 24 hours after transplantation. Immediately before killing the animals, we clamped the contralateral right hilum and assessed graft function. We measured wet-to-dry ratio (W/D), myeloperoxidase, pro-inflammatory cytokines (interleukin 1 [IL-1], tumor necrosis factor  [TNF-], interferon- [INF-], and IL-2) and performed immunohistochemistry. Results: Arterial oxygenation was greatest in the recipient group transfected with TGF- 1–active at 24 hours before transplantation compared with CAT, TGF-1–latent, and 18-hour cold ischemia groups (p  0.01). The W/D ratio and myeloperoxidase decreased in both 24- and 48-hour groups, with TGF-1–active compared with CAT, and 18-hour cold ischemia groups (W/D, p  0.02 and p  0.004, respectively; myeloperoxidase, p  0.05 and p  0.01, respectively). All pro-inflammatory cytokines decreased in the 24-hour TGF-1–active group compared with CAT, TGF-1–latent, From the a Division of Cardiothoracic Surgery, c Department of Pathology, and d Department of Immunology, Washington Uni- versity School of Medicine, St. Louis, Missouri; and b Universita ` degli Studi di Bologna, Bologna, Italy. This work is supported by National Institutes of Health Grants RO1 HL-41281 (G.A.P.) and R01 HL56643 (T.M.). S.A.K. is supported by individual NRSA-NIH Grant 1F32HL68401-01. Presented in the poster session of the 21st Annual Meeting and Scientific Session of the International Society for Heart and Lung Transplantation, Vancouver, Canada, April 25–28, 2001. Reprint requests: G. Alexander Patterson, MD, 3108 Queeny Tower, One Barnes-Jewish Hospital Plaza, St. Louis, Missouri 63110. Telephone: 314-362-6025. Fax: 314-362-0328. E-mail: pattersona@msnotes.wustl.edu Copyright © 2003 by the International Society for Heart and Lung Transplantation. 1053-2498/03/$–see front matter doi:10.1016/j.healun.2003.09.011 1323