Engineered Mesenchymal Stromal Cell Therapy during Pig Ex Vivo Lung Perfusion and Transplant

Purpose Ex vivo lung perfusion (EVLP) enables novel therapeutic approaches to repair damaged lungs for transplantation. We investigated the concept and feasibility of elective cell therapy for donor lungs. Dosing, efficacy and transgene expression kinetics of engineered mesenchymal stromal cell therapy were examined in pig EVLP and transplantation. Methods Human umbilical cord perivascular mesenchymal stromal/stem cells were transduced with an adenoviral vector encoding human IL-10 (MSC-hIL-10 cells), cryopreserved and recovered 1h before use. Pig lungs with 4 to 24-hour cold ischemia (n=5) were connected to EVLP for 6 (n=3) or 12 hours (n=2) and MSC-hIL-10 cells (40-150 × 10 6 ) were administered through the pulmonary artery after 1h of EVLP. Left single lung transplantation was performed after EVLP and the grafts were monitored up to 4h (n=4) and 3d (n=1) after reperfusion. Human IL-10 levels were determined by ELISA and fluorescence in situ hybridization with human-specific ALU probes was used to track MSC-hIL-10 cells. Results Supra-therapeutic levels of hIL-10 were present in EVLP perfusate within minutes after MSC-hIL10 cell administration and the levels consistently increased during EVLP (Figure 1A). Recipient plasma hIL-10 levels were elevated 1h after lung transplantation, remained high for 4h and gradually decreased to low levels by 3d after transplantation (Figure 1C). Elevated tissue and bronchoalveolar lavage hIL-10 levels were observed in the transplanted lung and remained low in the recipient native lung. MSC-hIL-10 cells were detected in the donor lung during EVLP and after transplantation (Figure 1B). Conclusion Engineered mesenchymal stromal cell therapy during EVLP is a novel and practical “off-the-shelf” strategy to achieve rapid transient therapeutic levels of soluble cytokines such as IL-10 for pre-transplant lung repair and protection. Ongoing studies will determine the therapeutic effect and longer-term fate of MSC-hIL-10 cells delivered during EVLP.