alpha-fetoprotein and interleukin-18 gene-modified dendritic cells effectively stimulate specific type-1 CD4- and CD8-mediated T-Cell response from hepatocellular carcinoma patients in Vitro.
ABSTRACT The T-helper 1 (Th1) immune reaction is most important in dendritic cell (DC)-based immunotherapy. Interleukin (IL)-18, a Th1-biasing cytokine, plays a pivotal role in inducing cytotoxic T lymphocyte (CTL) responses. In this study, we analyzed whether dendritic cells (DCs) from patients with hepatocellular carcinoma (HCC) can be transduced with the IL-18 gene and/or alpha-fetoprotein (AFP) gene, and we examined whether vaccinations using these genetically engineered DC can induce stronger therapeutic antitumor immunity. The results showed that DC transfected with AdIL-18/AFP can expressed IL-18 and AFP by reverse transcriptase-polymerase chain reaction and enzyme-linked immunoassay. Compared with those before transfection, the expressions of membrane molecules were increased dramatically. Specific T cells generated by DC transfected with AdIL-18/AFP recognized HLA-matched HepG2 cell lines specifically. Most importantly, The cytotoxic activity of CTLs against HepG2 with DC expressing AFP(AFP-DC) was significantly augmented by co-transduction with the IL-18 gene. Administration with such vaccine also significantly increased the production of interleukin-12p70 and interferon-gamma. These results indicate that a vaccination therapy using DC co-transduced with the TAA gene and IL-18 genes is effective strategy for immunotherapy in terms of the activation of DCs, CD4+ T, cells and CD8+ T cells, and may be useful in the clinical application of a cancer vaccine therapy.
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ABSTRACT: Dendritic cells (DCs) are professional antigen presenting cells that are being considered as potential immunotherapeutic agents to promote host immune responses against tumor antigens. The use of such modified antigen-presenting cells for research or therapeutic have been limited by several factors, including maintaining DCs in a highly activated state, efficient transduction and expression, stable expression, identification of appropriate tumor-associated antigens, and absence of unintended functional changes or cytotoxicity. In this study, the feasibility of using CD34-DCs for tumor immunotherapy after transduction with a recombinant adenovirus containing HBsAg gene (AdVHBsAg), an HCC-associated antigen, was investigated. The gene transfer with recombinant adenovirus vectors (AdV) can obtained high levels of stable expression of HBsAg and its efficiency was increased in a multiplicity of infection (MOI)-dependent manner. Moreover, the AdVHBsAg infection had no appreciable effect on apoptosis of DCs compared with that of mock-infected DCs. The T cell lines, primed by the recombinant AdVHBsAg-infected DCs in vitro, recognized HBsAg-expressing tumor cell lines in a human leukocyte antigen (HLA) class I-restricted manner, and evoked a higher CTL response, which indicated that high potent and specific antitumor immune response could be induced by AdVHBsAg DC vaccine. It may be a promising the therapeutic modality for the treatment of HBsAg-expressing tumors, and will be a foundation for further study on DC vaccines and gene therapy for HCC.Cellular Immunology 04/2006; 240(1):14-21. · 1.74 Impact Factor
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ABSTRACT: alpha-Fetoprotein (AFP) may be a possible target for a hepatocellular carcinoma (HCC)-specific vaccination. But some studies have demonstrated that dendritic cells (DCs) treated with AFP become dysfunctional. So in this study, we try to transfect AFP mRNA into DCs and observe the ability of DCs to induce AFP-specific CD4(+) and CD8(+) T cells. We hope that AFP can be processed and presented by DCs directly, rather than released to the cultures. So there will be no AFP negative effect on the function of DCs. In the study, immature DCs generated from peripheral blood mononuclear cells (PBMCs) of HLA-A2(+) HCC patients were transfected with AFP mRNA. Then the transfected, matured DCs were used to stimulate autologous T cells. The results showed that the expressions of membrane molecules of DCs after transfection were increased dramatically, and interleukin-12 (IL-12) p70 release in the supernatant was elevated significantly. There was only a minority of AFP release in the supernatants of transfected DCs. CTLs induced by the transfected DCs recognized HLA-matched AFP positive HepG2 cell line specifically and the AFP-specific proliferative T-cell responses could also be induced. These findings indicate that this AFP mRNA transfection strategy could generate fully functional DCs, which could induce specific T cells to recognize AFP(+) HCC cells.Cellular Immunology 03/2006; 239(2):144-50. · 1.74 Impact Factor
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ABSTRACT: Alpha-fetoprotein (AFP) is a self protein expressed by fetal liver at high levels, but is transcriptionally repressed at birth. AFP is up-regulated in hepatocellular carcinomas, and patients with active disease could have plasma levels as high as 1 mg/mL. We previously identified four immunodominant HLA-A*0201-restricted peptides [hAFP(137-145) (PLFQVPEPV), hAFP(158-166) (FMNKFIYEI), hAFP(325-334) (GLSPNLNRFL), and hAFP(542-550) (GVALQTMKQ)] derived from human AFP that could stimulate specific T cell responses in healthy donor peripheral blood lymphocytes in vitro. We conducted a phase I/II clinical trial in which HLA-A*0201 patients with AFP-positive hepatocellular carcinoma were immunized with three biweekly intradermal vaccinations of the four AFP peptides pulsed onto autologous dendritic cells (DC). DCs were prepared from adherent peripheral blood mononuclear cells cultured with granulocyte-macrophage colony-stimulating factor and interleukin-4 for 7 days. Sixteen subjects were enrolled and 10 were treated. Peripheral blood lymphocytes were isolated from these patients before, during, and after AFP peptide/DC immunization and were tested ex vivo with MHC tetramer and IFNgamma ELISPOT analysis. Six of 10 subjects expanded statistically significant levels of AFP-specific T cells postvaccine to at least one peptide by MHC tetramer. Also, 6 of 10 subjects increased IFNgamma producing AFP-specific T cell responses to at least one of the peptides postvaccination, by ELISPOT. We conclude that the human T cell repertoire is capable of responding to the AFP self antigen after the administration of AFP peptide-pulsed DC even in an environment of high circulating levels of this oncofetal antigen.Clinical Cancer Research 06/2006; 12(9):2817-25. · 7.84 Impact Factor