title: Induction of accommodation model by combined RNA interference targeting 1,3-galactosyltransferase gene and low-dose GS-IB4 lectin in vitro.
abstract: OBJECTIVE
  This study sought to mimic the interaction of xenograft endothelial cells and human serum in vitro after successfully silencing the expression of porcine alpha1,3-galactosyltransferase (alpha1,3GT) gene by RNA interference (RNAi), and to investigate the possibility of inducing accommodation in vitro by stimulation of alpha-Gal-specific binding lectin, Griffonia simplicifolia isolectin B4 (GS-IB4) and RNAi.
  
  
  METHODS
  Various alpha-Gal expression patterns on a pig endothelial cell immortalized line (PED) was achieved by serial doses of small interfering RNA (siRNA) targeting porcinc alpha1,3GT gene. alpha1,3GT-siRNA transfected PEDs were exposed to increasing doses of GS-IB4 lectin (0.5, 2, and 8 microg/mL) for 4 hours before incubation with normal human serum (NHS). Accommodation phenomenon of PEDs in NHS was observed by 51Cr release and antibody/complement binding assays.
  
  
  RESULTS
  With combined RNAi and low-dose GS-IB4 stimulation, PEDs remarkably inhibited complement-mediated cytotoxicity, which showed a better protective effect than using RNAi alone. At a concentration of 2 mug/mL, GS-IB4 exhibited the maximum protective effect. The expression of E-selectin on alpha1,3GT-siRNA transfected PEDs did not differ from that on parental PEDs with heat-inactivated NHS (HINHS) stimulation. Combined with GS-IB4 stimulation, however, it inhibited expression of E-selectin, which was GS-IB4 dose dependent, resulting in mean fluorescence intensity values of 98.5, 42.0, and 36.3 at 0.5, 2, and 8 microg/mL. The mRNA expression of the protective gene HO-1 was significantly up-regulated after treatment with RNAi and low-dose of GS-IB4.
  
  
  CONCLUSIONS
  Combined RNAi and low-dose GS-IB4 induced pig endothelial cell accommodation in vitro. The level of alpha-Gal expression played an important role in the induction of accommodation.
authors.affiliation: Key Laboratory of Organ Transplantation, Ministry of Education and Health, Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: M
authors.initials: M
authors.lastname: Zhu
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: D
authors.initials: D
authors.lastname: Chen
authors.forename: H G
authors.initials: HG
authors.lastname: Qi
authors.forename: Z X
authors.initials: ZX
authors.lastname: Xia
authors.forename: S S
authors.initials: SS
authors.lastname: Wang
authors.forename: Y B
authors.initials: YB
authors.lastname: Huang
authors.forename: W J
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Z K
authors.initials: ZK
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Chen
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004730:Endothelium, Vascular / Q000201:enzymology*; D005700:Galactosyltransferases / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D037102:Lectins / Q000494:pharmacology*; D034622:RNA Interference; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D037102:Lectins; D005700:Galactosyltransferases