Aberrant expression of α‐Gal on primary human endothelium does not confer susceptibility to NK cell cytotoxicity or increased NK cell adhesion

Publisher Website
Google Scholar
Abstract
The contribution of Galα1,3Gal (α‐Gal) to cell‐mediated organ xenograft rejection is controversial. We have used recombinant lentiviruses encoding a porcine α1,3 galactosyltransferase (α1,3GalT) to obtain α‐Gal‐expressing primary human aortic endothelial cells (HAEC) at a frequency of 70–90%. These cells were compared to non‐transduced and mock‐transduced HAEC with regard to their susceptibility to human NK cell‐mediated lysis, ability to stimulate IFN‐γ production by NK cells, and support of NK cell adhesion under static and dynamic conditions. Using green fluorescent protein (GFP) as a reporter gene, it was shown that the frequency of green fluorescent HAEC increased until day 5 post‐transduction, and at a multiplicity of infection of 2.5, it reached98%. Lentiviral transduction did not result in activation of HAEC, and transduced HAEC responded as expected to TNF‐α and IFN‐γ stimulation. No differences were detected between non‐α‐Gal‐ and α‐Gal‐expressing HAEC in terms of their susceptibility to NK cell‐mediated lysis, ability to stimulate IFN‐γ production by NK cells, or ability to support NK cell adhesion under static and dynamic conditions. In conclusion, these data argue against an important role for the α‐Gal epitope in the direct interaction between endothelium and NK cells and prove that recombinant lentiviruses are efficient gene carriers for primary human endothelial cells.