BACKGROUNDObjective evaluation of the antitumor effect of interleukin-12 (IL-12) gene-transfected dendritic cell (DC) vaccine on laryngeal carcinoma requires in vivo and in vitro tests. The aim of this study was to investigate the function of IL-12 gene transfected DC at initiating specific immune response to laryngeal carcinoma in vitro.

METHODSRecombinant adenovirus with IL-12 gene was constructed. DCs were isolated from the peripheral blood of patients with laryngeal carcinoma, pulsed with tumor lysate of laryngeal carcinoma cells (DC⁺Ag), and transfected with IL-12 (DC-IL-12⁺Ag). The cells pheotypes including CD83, CD86 and HLA-DR on surface of DCs were assayed by flow cytometry (FCM). The concentration of IL-12 in culture supernatant of DCs and interferon γ (IFN-γ) in culture supernatant of T cells cocultured with DCs were quantified by ELISA. Methyl thiazolys tetrazolium (MTT) was used to evaluate proliferation of autologous T lymphocytes and activation of cytotoxic T lymphocytes (CTL) stimulated by IL-12-transfected DCs pulsed with tumor lysate against laryngeal carcinoma cells.

RESULTSThe recombinant adenovirus expressing IL-12 gene was constructed successfully. Gene-transfected DC plused with tumor lysate with IL-12 (DC-IL-12⁺Ag) expressed higher level of CD83, CD86 and produced higher level of IL-12 than untransfected DCs (DC⁺Ag) (CD83: (60.2 ± 1.8)% vs. (50.7 ± 1.2)%, P < 0.05; CD86: (88.9 ± 2.1)% vs. (78.2 ± 3.9)%, P < 0.05; IL-12: (262.5 ± 3.0) ng/L vs. (103.8 ± 5.1) ng/L, P < 0.05). The proliferation of autologous T lymphocytes and production of IFN-γ stimulated by DC transfected with IL-12 were more obviously than untransfected DCs. Cytotoxicity of CTL stimulated by IL-12-transfected DC pulsed with tumor lysate against laryngeal carcinoma cells were significantly stronger than stimulated by untransfected DC.

CONCLUSIONIt is a promising approach for IL-12-transfected DC pulsed with tumor lysate to increase the antitumoral effect.