Transgenic expression of human leukocyte antigen‐E attenuates Gal KO .h CD 46 porcine lung xenograft injury
Author(s) -
Laird Christopher T.,
Burdorf Lars,
French Beth M.,
Kubicki Natalia,
Cheng Xiangfei,
Braileanu Gheorghe,
Sun Wenji,
O'Neill Natalie A.,
Cimeno Arielle,
Parsell Dawn,
So Edward,
Bähr Andrea,
Klymiuk Nikolai,
Phelps Carol J.,
Ayares David,
Azimzadeh Agnes M.,
Pierson Richard N.
Publication year - 2017
Publication title -
xenotransplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.052
H-Index - 61
eISSN - 1399-3089
pISSN - 0908-665X
DOI - 10.1111/xen.12294
Subject(s) - xenotransplantation , transplantation , lung , immunology , antibody , in vivo , antigen , chemistry , microbiology and biotechnology , andrology , biology , medicine
Abstract Background Lung xenografts remain susceptible to loss of vascular barrier function within hours in spite of significant incremental advances based on genetic engineering to remove the Gal 1,3‐αGal antigen (Gal TKO ) and express human membrane cofactor protein ( hCD 46). Natural killer cells rapidly disappear from the blood during perfusion of Gal TKO . hCD 46 porcine lungs with human blood and presumably are sequestered within the lung vasculature. Here we asked whether porcine expression of the human NK cell inhibitory ligand HLA ‐E and β2 microglobulin inhibits Gal TKO .hCD46 pig cell injury or prolongs lung function in two preclinical perfusion models. Methods Lungs from pigs modified to express Gal TKO .h CD 46 (n=37) and Gal TKO .h CD 46. HLA ‐E (n=5) were harvested and perfused with human blood until failure or elective termination at 4 hours. Airway pressures and pulmonary artery hemodynamics were recorded in real time. Blood samples were also collected throughout the experiment for analysis. Porcine aortic endothelial cells ( PAEC s) from each genotype were cultured in monolayers in microfluidic channels and used in fluorescent cytotoxicity assays using human NK cells. Results HLA ‐E expression on Gal TKO .h CD 46 PAEC s was associated with significantly decreased antibody‐dependent and antibody‐independent NK ‐mediated cytotoxicity under in vitro conditions simulating physiologic shear stress. Relative to Gal TKO . hCD 46 pig lungs perfused with human blood on an ex vivo platform, additional expression of HLA ‐E increased median lung survival (>4 hours, vs 162 minutes, P =.012), and was associated with attenuated rise in pulmonary vascular resistance, and decreased platelet activation and histamine elaboration. As expected, HLA ‐E expression was not associated with a significant difference in NK cell adhesion to endothelial cells in vitro, or NK cell and neutrophil sequestration during organ perfusion. Conclusions We conclude human NK cell activation contributes significantly to Gal TKO .h CD 46 pig endothelial injury and lung inflammation and show that expression of HLA ‐E is associated with physiologically meaningful protection of Gal TKO .h CD 46 cells and organs exposed to human blood.