Ex vivo lentivirus transduction and immediate transplantation of uncultured hepatocytes for treating hyperbilirubinemic Gunn rat.
BACKGROUND
Ex vivo liver gene therapy provides an attractive alternative to orthotopic liver transplantation for the treatment of liver diseases. We previously reported a protocol in which human primary hepatocytes are highly transduced in Suspension with Lentiviral vectors and Immediately Transplanted (SLIT). Here, we evaluated the SLIT approach in Gunn rats, the animal model for Crigler-Najjar syndrome type 1, a defect in bilirubin UDP-glucuronosyltransferase (BUGT).


METHODS
We constructed lentiviral vectors coding for BUGT under control of an ubiquitous promoter. Control vectors contained Green Fluorescent Protein (GFP) under control of the same promoter. Hepatocytes were isolated from jaundiced Gunn rats and transduced in suspension for four hr. After washing, 2x10 hepatocytes were immediately transplanted into syngeneic rats. Bilirubinemia and bile pigments were regularly assessed after cell transplantation. The percentage and presence of transduced hepatocytes was analyzed by immunohistochemistry in GFP-transplanted animals.


RESULTS
In rats receiving BUGT-transduced hepatocytes, bilirubinemia decreased by about 30%. The level of correction remained stable for up to 240 days. Bilirubin glucuronides were present in the bile of treated animals, indicating the metabolic activity of engrafted hepatocytes. In contrast, bilirubinemia in GFP-transplanted rats did not decline but rather increased. GFP-positive hepatocytes amounted to 0.5-1% of the liver, which is in agreement with the number of transplanted and genetically-modified hepatocytes (6x10).


CONCLUSIONS
This work reports the first demonstration of long-term metabolic benefit after rapid transplantation of ex vivo lentivirally tranduced hepatocytes. Therefore, this study demonstrates the therapeutic proof-of-principle and potential of the SLIT approach for treating inherited metabolic liver diseases.
Nguyen
Tuan Huy
TH
Department of Microbiology and Molecular Medicine, University of Geneva Medical Center, Geneva, Switzerland, and Service de biochimie, Hôpital Saint Joseph, Paris, France. Tuan.Nguyen@medecine.unige.ch
Birraux
Jacques
J
Wildhaber
Barbara
B
Myara
Anne
A
Trivin
Francois
F
Le Coultre
Claude
C
Trono
Didier
D
Chardot
Christophe
C
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004195:Disease Models, Animal; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D022781:Hepatocytes / Q000637:transplantation* / Q000821:virology; D006801:Humans; D006932:Hyperbilirubinemia / Q000601:surgery*; D007668:Kidney; D016086:Lentivirus / Q000235:genetics*; D008099:Liver / Q000821:virology; D008297:Male; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D011911:Rats, Gunn; D014185:Transplantation, Isogeneic
D012333:RNA, Messenger; D012367:RNA, Viral; D049452:Green Fluorescent Proteins