Interaction of B7-H1 on intrahepatic cholangiocarcinoma cells with PD-1 on tumor-infiltrating T cells as a mechanism of immune evasion.
OBJECTIVE
The B7-H1/PD-1 pathway has recently been found to contribute to immune evasion of cancer cells from host immune system. This study aimed to investigate the expression of B7-H1 and its receptor PD-1 and to explore their significance in the progression of intraheptic cholangiocarcinoma (ICC).


METHODS
Thirty-one surgically resected ICC tissues and the corresponding cancer adjacent tissues were enrolled from 2006 to 2007. Immunohistochemical studies were performed with antibody of B7-H1, PD-1, CD8, and CD4. Apoptosis status of tumor-infiltrating lymphocytes (TILs) was detected by TUNEL assay.


RESULTS
Expression of B7-H1 and PD-1 was found to be up-regulated in ICC tissues compared with the cancer adjacent tissues. Tumor-related B7-H1 expression was significantly correlated with both tumor differentiation and pTNM stage and was inversely correlated with CD8+ TILs but not CD4+ TILs. TILs in primary carcinoma showed a high level of apoptosis.


CONCLUSIONS
B7-H1/PD-1 pathway may be linked to malignant potential of ICC and contribute to tumor immune evasion by promoting CD8+ TILs apoptosis. Thus, this pathway may indeed be a potential therapeutic target in the treatment of this disease.
Ye
Yufu
Y
Key Lab of Combined Multi-organ Transplantation, Ministry of Public Health, Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China.
Zhou
Lin
L
Xie
Xiaojun
X
Jiang
Guoping
G
Xie
Haiyang
H
Zheng
Shusen
S
D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D060890:B7-H1 Antigen; D001650:Bile Duct Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018281:Cholangiocarcinoma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D018655:Lymphocyte Count; D016246:Lymphocytes, Tumor-Infiltrating / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor; D019139:Tumor Escape; D015854:Up-Regulation
D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor