Molecular cloning of pigGnT-I and I.2: an application to xenotransplantation.
Xenotransplantation is one of the most attractive solutions for the current worldwide shortage of organs. The knocking out of alpha1,3-galactosyltransferase in pigs resulted in a drastic reduction in xenoantigenicity. However, more recent studies indicate that other xeno-antigens, so-called non-Gal antigens, will also need to be downregulated. In this study, pig N-acetylglucosaminyltransferase I (GnT-I), a key enzyme that initiates the biosynthesis of hybrid- and complex-type N-linked sugar chains, was isolated and the pigGnT-I.2 specific for the O-linked sugar chain was also isolated. Point mutants, pigGnT-I(123) and pigGnT-I(320), were subsequently constructed. While pigGnT-I(123) shows an indistinct dominant negative effect for endogenous GnT-I in pig cells, pigGnT-I(320) had a drastic effect. In addition, in the case of pig cell transfectants with pigGnT-I(320), cell surface carbohydrate structures were significantly altered and its antigenicity to human serum was reduced. Consequently, pigGnT-I(320) appears to be potentially useful in xenotransplantation by remodeling the carbohydrate structures on pig cells.
Division of Organ Transplantation, Department of Regenerative Medicine, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Katsuyoshi
K
Matsunami
Shuji
S
Miyagawa
Kenji
K
Nakagawa
Hideaki
H
Otsuka
Otsuka
O
Hideaki
Ryota
R
Shirakura
D000595:Amino Acid Sequence; D000818:Animals; D015478:Antigens, Heterophile / Q000737:chemistry / Q000276:immunology; D001483:Base Sequence; D002241:Carbohydrates / Q000737:chemistry / Q000276:immunology; D002460:Cell Line; D003001:Cloning, Molecular; D003167:Complement Activation; D006168:Guinea Pigs; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D017354:Point Mutation; D013552:Swine / Q000235:genetics* / Q000276:immunology*; D014162:Transfection; D014183:Transplantation, Heterologous
D015478:Antigens, Heterophile; D002241:Carbohydrates; D017351:N-Acetylglucosaminyltransferases; C446926:UDP-GlcNAc alpha-D-mannoside beta-1,2-N-acetylglucosaminyltransferase; C024850:alpha-1,3-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase I