TABLE 1.

Genetically-modified pigs produced for xenotransplantation research^*

Complement regulation by human complement-regulatory gene expression:

CD46 (membrane cofactor protein)

CD55 (decay-accelerating factor)

CD59 (protectin or membrane inhibitor of reactive lysis)

Antigen ‘masking’ or deletion:

human H-transferase gene expression (expression of blood type O antigen)

endo-beta-galactosidase C (reduction of Gal antigen expression)

α1,3-galactosyltransferase gene-knockout (GTKO)

Cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) gene-knockout (NeuGc-KO)

Suppression of cellular immune response by gene expression or downregulation

CIITA-DN (MHC class II transactivator knockdown, resulting in swine leukocyte antigen class II knockdown)

HLA-E/human β2-microglobulin (inhibits human natural killer cell cytotoxicity)

human FAS ligand (CD95L)

human GnT-III (N-acetylglucosaminyltransferase III) gene

porcine CTLA4-Ig (Cytotoxic T-Lymphocyte Antigen 4 or CD152)

human TRAIL (tumor necrosis factor-alpha-related apoptosis-inducing ligand)

Anticoagulation and anti-inflammatory gene expression or deletion

von Willebrand factor (vWF)-deficient (natural mutant)

human tissue factor pathway inhibitor (TFPI)

human thrombomodulin

human CD39 (ectonucleoside triphosphate diphosphohydrolase-1)

Anticoagulation, anti-inflammatory, and anti-apoptotic gene expression

human A20 (tumor necrosis factor-alpha-induced protein 3)

human heme oxygenase-1 (HO-1)

Prevention of porcine endogenous retrovirus (PERV) activation

PERV siRNA

Combinations of GTKO and expression of transgenes are available (e.g., GTKO.hCD46.hCD55)

^*Modified from Ekser B, et al [39]