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World J Gastroenterol. Nov 28, 2007; 13(44): 5944-5950
Published online Nov 28, 2007. doi: 10.3748/wjg.v13.i44.5944
In-vitro activation of cytotoxic T lymphocytes by fusion of mouse hepatocellular carcinoma cells and lymphotactin gene-modified dendritic cells
Xi-Ling Sheng, Hao Zhang
Xi-Ling Sheng, Department of Intensive Care Unit, the Red Cross Hospital, Hangzhou 310003, Zhejiang Province, China
Hao Zhang, Department of Hepatobiliary Surgery, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China
Author contributions: All authors contributed equally to the work.
Supported by the Science & Technology Foundation for Academicians of Zhejiang Province, China, No. 203201513
Correspondence to: Dr. Hao Zhang, Department of Hepatobiliary Surgery, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang Province, China. zhanghao111111@tom.com
Telephone: +86-571-87236570 Fax: +86-571-87236570
Received: July 30, 2007
Revised: August 31, 2007
Accepted: October 23, 2007
Published online: November 28, 2007
Abstract

AIM: To investigate the in-vitro activation of cytotoxic T lymphocytes (CTLs) by fusion of mouse hepatocellular carcinoma (HCC) cells and lymphotactin gene-modified dendritic cells (DCs).

METHODS: Lymphotactin gene modified DCs (DCLptn) were prepared by lymphotactin recombinant adenovirus transduction of mature DCs which differentiated from mouse bone marrow cells by stimulation with granulocyte/macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-α). DCLptn and H22 fusion was prepared using 50% PEG. Lymphotactin gene and protein expression levels were measured by RT-PCR and ELISA, respectively. Lymphotactin chemotactic responses were examined by in-vitro chemotaxis assay. In-vitro activation of CTLs by DCLptn/H22 fusion was measured by detecting CD25 expression and cytokine production after autologous T cell stimulation. Cytotoxic function of activated T lymphocytes stimulated with DCLptn/H22 cells was determined by LDH cytotoxicity assay.

RESULTS: Lymphotactin gene could be efficiently transduced to DCs by adenovirus vector and showed an effective biological activity. After fusion, the hybrid DCLptn/H22 cells acquired the phenotypes of both DCLptn and H22 cells. In T cell proliferation assay, flow cytometry showed a very high CD25 expression, and cytokine release assay showed a significantly higher concentration of IFN-γ and IL-2 in DCLptn/H22 group than in DCLptn, DCLptn+H22, DC/H22 or H22 groups. Cytotoxicity assay revealed that T cells derived from DCLptn/H22 group had much higher anti-tumor activity than those derived from DCLptn, H22, DCLptn+H22, DC/H22 groups.

CONCLUSION: Lymphotactin gene-modified dendritoma induces T-cell proliferation and strong CTL reaction against allogenic HCC cells. Immunization-engineered fusion hybrid vaccine is an attractive strategy in prevention and treatment of HCC metastases.

Keywords: Hepatocellular carcinoma; Dendritic cell; Cytotoxic T lymphocyte