Adenovirus-mediated Bcl-2 gene transfer inhibits apoptosis and promotes survival of allogeneic transplanted hepatocytes.
BACKGROUND
Donor hepatocyte apoptosis that is induced by host cytotoxic T lymphocytes (CTLs) limits the application of hepatocyte transplantation. Hepatocytes from Bcl-2 transgenic mice can resist the lethal effect of anti-Fas antibody. However, the anti-apoptotic effect of Bcl-2 expression on allogeneic transplanted hepatocytes remains elusive. This study tested the feasibility of Bcl-2 gene transfer as an approach to inhibit CTL-mediated apoptosis in allogeneic transplanted hepatocytes.


METHODS
An adenovirus vector that encoded human Bcl-2 gene (AdCMVhBcl-2) was used to transfect cultured rat hepatocytes, which were then transplanted into allogeneic spleens. DNA fragmentation and caspase-3 activation were examined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay and immunohistochemistry for active caspase-3, respectively. Cocultivation of hepatocytes and allogeneic CD8(+) T lymphocytes was performed, and cytotoxicity on hepatocytes was examined by alanine transaminase release.


RESULTS
Bcl-2 gene transfer inhibited apoptosis and increased liver-associated enzyme activities in allogeneic transplanted hepatocytes, which were associated with inhibition of caspase-3 activation. Alanine transaminase release in hBcl-2 modified hepatocytes was lower compared with controls, which could not be further decreased by inhibition of Fas ligand and granzyme B.


CONCLUSIONS
Adenovirus-mediated Bcl-2 gene transfer blocks CTL-mediated apoptosis in allogeneic hepatocytes by inhibition of caspase-3 activation. Bcl-2 gene transfer could be used to promote survival of transplanted hepatocytes.
Song
E
E
Department of Hepatobiliary Surgery, Sun-Yat-Sen Memorial Hospital, Sun-Yat-Sen University of Medical Science, Guangzhou, People's Republic of China.
Chen
J
J
Antus
B
B
Su
F
F
Wang
M
M
Exton
M S
MS
D000256:Adenoviridae; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D018920:Coculture Techniques; D004789:Enzyme Activation / Q000502:physiology; D015870:Gene Expression; D018014:Gene Transfer Techniques; D019254:Genes, bcl-2; D005822:Genetic Vectors; D022781:Hepatocytes / Q000637:transplantation*; D008099:Liver / Q000201:enzymology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013154:Spleen / Q000201:enzymology / Q000601:surgery; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology; D014019:Tissue Donors; D014162:Transfection; D014184:Transplantation, Homologous
C505407:CASP3 protein, human; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases