title: Production and characterization of transgenic mice systemically expressing endo-beta-galactosidase C.
abstract: The alphaGal epitope (Galalpha1-3Gal) is a sugar structure expressed on the cell surface of almost all organisms except humans and old-world-monkeys, which express natural anti-alphaGal antibodies. The presence of these antibodies elicits a hyper acute rejection (HAR) upon xenotransplantation of cellular materials, such as from pigs to human beings. Endo-beta-galactosidase C (EndoGalC), an enzyme isolated from Clostridium perfringens, removes the alphaGal epitope by cleaving the Galbeta1-4GlcNAc linkage in the Galalpha1-3Galbeta1-4GlcNAc sequence. To explore the possibility that cells or organs from transgenic pigs systemically expressing EndoGalC might be suitable for xenotransplantation, we first introduced the EndoGalC transgene into the mouse genome via pronuclear injection. The progeny of the resulting transgenics expressed EndoGalC mRNA and protein. Flow cytometry and histochemical analyses revealed a dramatic reduction in the expression of the alphaGal epitope in these mice. They also exhibited abnormal phenotypes, such as occasional death immediately after birth, growth retardation, and transient skin lesions. Interestingly, the phenotypic abnormalities seen in these transgenics were similar to those observed in beta1,4-galactosyltransferase 1 (beta4GalT-1) knockout (KO) mice. Most probably, these phenotypes were caused by exposure of the internal N-acetylglucosamine residue at the end of the sugar chain on the cell surface. The present findings also provide some basis for evaluating possible application of the transgenic approach for xenotranplantation.
authors.affiliation: Animal Genome Research Unit, Division of Animal Science, National Institute of Agrobiological Sciences, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan. kettle@affrc.go.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Masako
authors.initials: M
authors.lastname: Misawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuzaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sakurai
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramatsu
authors.forename: Taka-Aki
authors.initials: TA
authors.lastname: Yokomine
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sato
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D018703:Founder Effect; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D014183:Transplantation, Heterologous
chemical_list: D012333:RNA, Messenger; D006026:Glycoside Hydrolases; C057030:endo-beta-D-galactosidase C