Apoptosis in acute rejection of hamster-to-rat liver transplantation.
OBJECTIVE
To investigate whether apoptotic cell death is involved in liver xenograft rejection and the molecular mechanism of apoptosis.


METHODS
After hamster-to-rat orthotopic liver transplantation, apoptosis in the xenograft was observed histologically and by in situ end-labelling of fragmented DNA. CD8 antigen, perforin, Fas-L and TGF-beta1 were observed immunohistochemically in the graft.


RESULTS
In xenogenic rejection, OX8 (CD8) positive T lymphocyte was observed on day 2 post-transplantation, evidently on day 5. The expression of perforin and Fas-L in grafts occurred on day 4 post-transplantation, and it was more evident in the rejection. In control group,the lymphocyte was rarely seen, and the expression of Fas-L and perforin was not found. Both xenogeneic and syngeneic grafts showed the expression of TGF-beta1 on the first day after transplantation. The expression of TGF-beta1, however, increased subsequently in the xenogeneic graft in contrast to its normalization in the syngeneic graft. In the xenogeneic graft, apoptosis occurred on day 1 after transplantation, decreased on day 2, increased on day 3, and peaked on day 5. Apoptosis was similar in the syngeneic and xenogeneic grafts on day 1 after transplantation, but decreased to normal one day later. The more severe apoptosis, the more severe acute rejection, and the more evident expression of perforin, Fas-L and TGF-beta1.


CONCLUSIONS
Apoptosis as a mechanism of cell death exists in the acute rejection of liver xenograft, and it is related closely to the expression of perforin, TGF-beta1 and Fas-L.
Tan
Jing-Wang
JW
Department of Hepatobiliary Surgery, Fuzhou General Hospital PLA, Fuzhou 350025, China. tanjingwang8@hotmail.com
Zhang
Shao-Geng
SG
Jiang
Yi
Y
Yang
Jia-Mei
JM
Qian
Guang-Xiang
GX
Wu
Meng-Chao
MC
D000208:Acute Disease; D000818:Animals; D017209:Apoptosis; D006224:Cricetinae; D005260:Female; D006084:Graft Rejection / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D007150:Immunohistochemistry; D008099:Liver / Q000378:metabolism; D016031:Liver Transplantation; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014183:Transplantation, Heterologous