title: Human NK cell-mediated cytotoxicity triggered by CD86 and Gal alpha 1,3-Gal is inhibited in genetically modified porcine cells.
abstract: 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.
authors.affiliation: Department of Molecular Sciences, Alexion Pharmaceuticals, Cheshire, CT 06410, USA.
authors.forename: Cristina
authors.initials: C
authors.lastname: Costa
authors.forename: Domingo F
authors.initials: DF
authors.lastname: Barber
authors.forename: William L
authors.initials: WL
authors.lastname: Fodor
mesh_terms: D000069594:Abatacept; D000818:Animals; D030801:Animals, Genetically Modified / Q000276:immunology*; D015703:Antigens, CD / Q000096:biosynthesis / Q000502:physiology*; D000943:Antigens, Differentiation / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D018122:B7-1 Antigen / Q000096:biosynthesis; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000096:biosynthesis; D018957:CD59 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D060908:CTLA-4 Antigen; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic / Q000235:genetics* / Q000276:immunology; D004187:Disaccharides / Q000378:metabolism / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D005347:Fibroblasts / Q000276:immunology* / Q000378:metabolism; D005647:Fucosyltransferases / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007111:Immunity, Cellular / Q000235:genetics; D018796:Immunoconjugates; D007694:Killer Cells, Natural / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000494:pharmacology; D013552:Swine; D014161:Transduction, Genetic; D000097631:Galactoside 2-alpha-L-fucosyltransferase
chemical_list: D000069594:Abatacept; D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018106:CD28 Antigens; D018957:CD59 Antigens; D060908:CTLA-4 Antigen; D004187:Disaccharides; D005647:Fucosyltransferases; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C497964:CD86 protein, human; C556706:CTLA4 protein, human; C055075:galactosyl-(1-3)galactose