Ex Vivo Delivery of Viral-Mediated Gene Therapy for the Amelioration of Post-Transplant Rejection

/Abstract This R01 application for the NOSI: Somatic Cell Gene Editing Therapies to Improve Transplantation Outcomes details a novel method of AAV vector delivery during normothermic ex vivo lung perfusion (EVLP) to genetically modify donor lung grafts. While early post-operative outcomes have marginally improved, lung transplantation continues to be limited by the lowest rates of organ utilization, the highest rates of early allograft dysfunction, and the worst long-term recipient survival due to acute cellular rejection (ACR) and resultant chronic lung allograft dysfunction (CLAD).High-dose systemically-administered immunosuppression regimens intended to mitigate ACR further contributes to poor outcomes due to complications including infection and renal toxicity. There is a clear unmet need for novel therapeutic interventions to prevent alloimmune injury and resultant CLAD, and PD-L1 overexpression may be one method of preventing rejection allowing for lower immunosuppression, and thereby extending survival and minimizing complications of immunosuppression. The long-term goal of this work is to establish a new paradigm to genetically augment all solid organ grafts for clinical transplantation and this proposal serves the long-term goal by detailing AAV based gene therapy to isolated lung grafts during ex vivo machine perfusion. Collaborative efforts by the research team have experimentally demonstrated the feasibility of this approach, and give confidence that the therapeutic transgene, PD-L1, will impart a protective effect on donor lungs. Aim 1 will test the efficacy AAV-mediated PD- L1 over-expression using two AAV serotypes, AAV9 and AAV4, delivered during EVLP that preferentially infect epithelium and endothelium respectively, on the amelioration of alloimmune injury after transplant. Aim 2 will then examine the durability of AAV transduction among cell types as well as evaluate the impact of acute lung injury on expression. Finally, Aim 3 will extend observations from Aim 1 to a clinically-relevant large animal lung transplant model and discarded human lung. Demonstrating effective gene therapy deliver to lung allografts ex situ would radically change organ preservation, while concomitantly enhancing long-term outcomes via immunomodulation. Therefore, the development of the proposed approach would be of tremendous public health importance and will leverage the team’s transdisciplinary expertise of lung transplantation, organ preservation, viral based gene therapy and pulmonary regeneration. The technology proposed herein, once developed, could be translated into clinical use by transplant programs across the globe. Importantly, principles developed herein are generalizable to other solid organs, including heart, kidney, and small bowel, to extend the longevity of transplanted solid organs. Project Number: 1R01AI197208-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Allergy and Infectious Diseases (NIAID) | Principal Investigator: Matthew Hartwig | Institution: DUKE UNIVERSITY, DURHAM, NC | Award Amount: $597,613 | Activity Code: R01 | Study Section: Surgery, Anesthesiology and Trauma Study Section[SAT] View on NIH RePORTER: https://reporter.nih.gov/project-details/1R01AI19720801A1