Purpose

Porcine organs are a potential source for clinical xenotransplantation. Pig lungs perfused with human blood exhibit inflammation and loss of vascular barrier function within hours. Here we report transfection of swine lungs with human IL-10, an anti-inflammatory cytokine, using an adenoviral vector and evaluate its effects in a hyperacute lung rejection model.

Methods

Lungs from five pigs expressing human CD46 and knockout of galactosyl transferase were placed onto an ex vivo lung perfusion (EVLP) system with STEEN solution. After stabilization of perfusion, 1E10 pfu of adenovirus containing cDNA coding for human IL-10 (ad5CMVhIL-10) was delivered bronchoscopically into each terminal bronchiole of one lung, and empty vector (ad5CMVempty) was given to the contralateral lung. Following 9-12 hour EVLP, lung blocks were divided and each lung individually perfused with fresh heparinized human blood for up to 6 hours. Pulmonary vascular resistance (PVR), airway pressures, IL-10 concentrations, blood cell counts, and inflammatory markers were compared between ad5CMVhIL-10-treated and empty vector-treated lungs.

Results

Bronchoscopically delivered ad5CMVhIL-10 was associated with increasing amount of IL-10 detected in EVLP perfusate and BAL samples. At conclusion of the subsequent human blood perfusion, there was almost tenfold more circulating IL-10 in plasma from the ad5CMVhIL-10 -treated group vs ad5CMVempty (15,576±527 vs 1,731±884 pg/mL, p <0.01). Graft survival during perfusion with human blood was similar between the two groups (298±62min ad5CMVhIL-10 v 290±45min ad5CMVempty), although there was a trend towards lower final PVR (283±169mmHg ad5CMVhIL-10 vs. 515±233mmHg ad5CMVempty) and wet-to-dry ratio (6.0±0.7 ad5CMVhIL-10 vs 7.1±0.7 ad5CMVempty).

Conclusions

Bronchoscopic delivery of ad5CMVhIL-10 into porcine lungs significantly increased expression of hIL-10. Although increased IL-10 failed to prolong lung xenograft survival in this stringent hyperacute rejection model, the trend toward reduced vascular injury (blunted PVR rise) and attenuated loss of vascular barrier function suggest that local expression of this anti-inflammatory cytokine may be useful as part of a strategy to enable successful lung xenotransplantation.

CITATION INFORMATION: Laird C, Burdorf L, Cheng X, O'Neill N, Sendil S, Parsell D, Cypel M, Phelps C, Ayares D, Azimzadeh A, Pierson R. Human IL-10 Transfection of Porcine Lungs Significantly Increases IL-10 Levels in Vascular Perfusate During Human Blood Perfusion. Am J Transplant. 2017;17 (suppl 3).

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