Potentiation of the immunotherapeutic effect of autologous dendritic cells by pretreating hepatocellular carcinoma with low-dose radiation.
OBJECTIVE
To determine whether exposing hepatocellular carcinoma (HCC) to low dose radiation increases the efficacy of dendritic cell-mediated immunotherapy for HCC.


METHODS
Tumour specimens collected from 20 recruited patients with HCC were cultured in primary culture (half successfully) and then exposed to low-dose radiation (0.5 Gy). Immature DCs derived from peripheral blood monocytes of patients were pulsed with autologous HCC cell lysates and matured with a cytokine cocktail. Autologous tumour lysate-pulsed DCs (TLP-DCs) were used to stimulate mixed lymphocytes, which were then tested for inhibitory effect on the growth of HCC cells. Surface markers of immunogenicity on primary HCC cells, MHC, and Fas were investigated before and after low-dose irradiation.


RESULTS
Exposing HCC cells to low-dose (0.5 Gy) radiation enhanced the immunotherapeutic effect of TLP-DC-stimulated lymphocytes. Growth inhibition increased from 50.6+/-7.5% without irradiation to 74.3+/-4.3% with radiation. The expression of MHC class ll and Fas was upregulated after irradiating HCC cells.


CONCLUSIONS
Exposing tumour cells to a low dose of radiation can enhance the immunotherapeutic effect of the autologous tumor lysate-pulsed DC vaccine.
Division of Gastroenterology, Mackay Memorial Hospital, Mackay Medicine, Nursing and Management College, Taipei, Taiwan.
Ching-Chung
CC
Lin
Tsang-En
TE
Wang
Chia-Yuan
CY
Liu
Chin-Ping
CP
Lin
Tsang-Pai
TP
Liu
Ming-Jen
MJ
Chen
Wen-Hsiung
WH
Chang
Jiunn-Chang
JC
Lin
Kuo-Ming
KM
Chang
Cheng-Hsin
CH
Chu
Shou-Chuan
SC
Shih
K S Clifford
KS
Chao
Yu-Jen
YJ
Chen
D006528:Carcinoma, Hepatocellular / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*; D002455:Cell Division / Q000528:radiation effects; D003713:Dendritic Cells / Q000276:immunology* / Q000528:radiation effects; D006801:Humans; D007167:Immunotherapy; D008113:Liver Neoplasms / Q000276:immunology / Q000473:pathology / Q000532:radiotherapy*; D008214:Lymphocytes / Q000276:immunology / Q000528:radiation effects; D011879:Radiotherapy Dosage; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000528:radiation effects*