[Antitumor immune responses induced by gene transfer of 4-1BBL into hepatocellular carcinoma Hepa1-6 in vitro].
OBJECTIVE
To study the cytotoxic activity against tumor cells and cytokines production of spleen cells induced in vitro by murine 4-1BBL gene transfected Hepa1-6.


METHODS
The eukaryotic expression vector pCDNA3.1(+)-m4-1BBL was transfected into murine hepatocellular carcinoma cell line Hepa1-6 by Liposomes. Then the transfected cells were selected in medium containing G418 (400 - 800 micro g/ml) and termed as Hepa1-6-m4-1BBL. The TCV-m4-1BBL was obtained by treating them with mitomycin (MMC). Cocultivation TCV with syngeneic murine spleen cells, then the lymphocytes were tested for cytotoxic activity against Hepa1-6-wt cells and the supernatants were harvested for detecting the cytokines (IL-2, TNF-alpha and GM-CSF).


RESULTS
Hepa1-6-m4-1BBL cells expressed 4-1BBL protein with highest cell surface level. The 4-1BBL mRNA could still be detected in the cells when cultured 48 h after treated with MMC (80 mg/L). Comparing with TCV-Hepa1-6, the tumor cell vaccine derived from Hepa1-6-m4-1BBL (TCV-m4-1BBL) could induce a more efficient cytotoxic activity of syngeneic murine lymphocyte against its parental tumor cell Hepa1-6 (P < 0.05), but not against non-parental tumor cell H22 and NIH3T3. Higher levels of IL-2, TNF-alpha and GM-CSF were released by the splencytes after stimulated by TCV-m4-1BBL.


CONCLUSIONS
These results suggest the expression of m4-1BBL by tumor cells is effective in inducing antitumor immune responses.
Liu
Cheng-li
CL
Department of Hepatobiliary Surgery, Fourth Military Medical University, Xi'an 710032, China.
Dou
Ke-feng
KF
Zang
Xiao-xia
XX
Zhu
Bang-fu
BF
Chen
Su-min
SM
D053330:4-1BB Ligand; D000818:Animals; D019496:Cancer Vaccines / Q000276:immunology*; D005260:Female; D066298:In Vitro Techniques; D008114:Liver Neoplasms, Experimental / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D048069:Tumor Necrosis Factors / Q000235:genetics / Q000502:physiology*
D053330:4-1BB Ligand; D019496:Cancer Vaccines; C505975:Tnfsf9 protein, mouse; D048069:Tumor Necrosis Factors