Human NK cell-mediated cytotoxicity triggered by CD86 and Gal alpha 1,3-Gal is inhibited in genetically modified porcine cells

• Published in: The Journal of immunology (1950) Vol. 168; no. 8; pp. 3808 - 3816
• Main Authors: Costa, Cristina, Barber, Domingo F, Fodor, William L
• Format: Journal Article
• Language: English
• Published: United States 15.04.2002
• Subjects: Abatacept; Animals; Animals, Genetically Modified - immunology; Antigens, CD - biosynthesis; Antigens, CD - physiology; Antigens, Differentiation - biosynthesis; Antigens, Differentiation - genetics; Antigens, Differentiation - pharmacology; B7-1 Antigen - biosynthesis; B7-2 Antigen; CD28 Antigens - biosynthesis; CD59 Antigens - biosynthesis; CD59 Antigens - genetics; CD59 Antigens - pharmacology; Cell Line; Cell Membrane - immunology; Cell Membrane - metabolism; Cells, Cultured; CTLA-4 Antigen; Cytotoxicity Tests, Immunologic; Cytotoxicity, Immunologic - genetics; Cytotoxicity, Immunologic - immunology; Disaccharides - metabolism; Disaccharides - physiology; Endothelium, Vascular - cytology; Endothelium, Vascular - immunology; Endothelium, Vascular - metabolism; Fibroblasts - immunology; Fibroblasts - metabolism; Fucosyltransferases - biosynthesis; Fucosyltransferases - genetics; Galactoside 2-alpha-L-fucosyltransferase; Humans; Immunity, Cellular - genetics; Immunoconjugates; Killer Cells, Natural - immunology; Membrane Glycoproteins - antagonists & inhibitors; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - physiology; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - pharmacology; Swine; Transduction, Genetic
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.168.8.3808

Delayed xenograft rejection is a major hurdle that needs to be addressed to prolong graft survival in pig-to-primate xenotransplantation. NK cell activation has been implicated in delayed xenograft rejection. Both Ab-dependent and independent mechanisms are responsible for the high susceptibility of porcine cells to human NK cell-mediated cytotoxicity. Previous reports demonstrated a role of Galalpha1,3-Gal Ag in triggering the Ab-independent responses. We hypothesize that expression of CD80 and/or CD86 on porcine cells may also play a role in NK cell activation as human NK cells express a variant of CD28. Our initial analysis showed that porcine endothelial cells and fibroblasts express CD86, but not CD80. Genetic engineering of these cells to express hCD152-hCD59, a chimeric molecule designed to block CD86 in cis, was accompanied by a reduction in susceptibility to human NK cell-mediated cytotoxicity. The use of a specific anti-porcine CD86-blocking Ab and the NK92 and YTS cell lines further confirmed the involvement of CD86 in triggering NK cell-mediated lysis of porcine cells. Maximal protection was achieved when hCD152-hCD59 was expressed in H transferase-transgenic cells, which show reduced Galalpha1,3-Gal expression. In this work, we describe two mechanisms of human NK cell-mediated rejection of porcine cells and demonstrate that genetically modified cells resist Ab-independent NK cell-mediated cytotoxicity.