Dendritic cells transfected with lentiviral vector-encoding hTERT peptide augment antitumor T cell response in vitro

Abstract

Abstract. HIV-1 derived lentiviral vectors (LVs) have emerged as a powerful tool for gene delivery. hTERT is an ideal tumorassociated antigen with which to develop a potential dendritic cell (DC) vaccine. The purpose of this study was to construct a recombinant lentivirus vector of the hTERT peptide and to determine the hTERT-specific cytotoxic T lymphocyte response elicited by DCs transfected with hTERT-lentivirus vectors in vitro. LVs encoding the hTERT peptide were constructed, DCs from cord blood were prepared, their morphology was observed and phenotype was analyzed by flow cytometry. Lenti-hTERT was transfected into DCs to construct the DC vaccines. T lymphocytes stimulated with DC vaccines and HepG2 cells (hTERT + ) or 293T cells (hTERT -) were co-cultured for 24 h, respectively. The ability to stimulate proliferation of allogeneic T lymphocytes and the killing activity of CTLs activated by these DCs were determined using the MTT method. According to our results, the recombinant vector lenti-hTERT and lenti-hTERT-DC vaccine were successfully constructed. The stimulatory capacity of the lenti-hTERT DCs in the allogeneic T lymphocyte reaction was markedly enhanced compared with the DC control group (P<0.01). Inhibition rates in HepG2 cells of CTLs stimulated with lenti-hTERT-DCs (CTL T ) were significantly higher than CTLs stimulated with the control DC group (CTL N ) (P<0.01). Inhibition rates in 293T cells of CTL T and CTL N were low and there was no difference between the different DC groups (P>0.05). DCs transfected with the hTERT peptide were capable of eliciting a stronger hTERT-specific CTL response in vitro. Our data indicate that lenti-hTERT-DCs may potentially be used as an effective approach for cancer immunotherapy.

SYK-targeted dendritic cell-mediated cytotoxic T lymphocytes enhance the effect of immunotherapy on retinoblastoma

“…Using this strategy, we expressed SYK to prime T lymphocytes. Importantly, the DCs transfected with lentiviral vectors can activate specific anti-tumor immune responses (Ahmed Ali et al 2014 ; Cui et al 2012 ; Lopes et al 2006 ; Wang et al 2010 ; Xiao et al 2012 ). We aimed to investigate whether: (1) SYK can be used as a specific target for RB; (2) cell immunotherapy is an effective and safe approach for RB treatment; and (3) presenting DCs with lentivirus could promote T-lymphocyte maturation and increase specific cytotoxicity against RB-Y79 cells in vitro.…”

Targeting Telomere Dynamics as an Effective Approach for the Development of Cancer Therapeutics

“…The lenti-hTERT vector-transduced DC vaccines dramatically evoked anticancer immunity in telomerase positive HepG2 cells. 109 Analogously, DC vaccines that expressed hTERT through the transduction with an hTERT recombinant adenoviral vector 110 or the transfection with lipid-mediated hTERT plasmid, 111 could arouse antitumor immune reactions by the induction of hTERT specific cytotoxic T lymphocytes and the increased production of IFN-γ in hTERT-positive cancer cells. 110 Moreover, DCs transfected with TERT mRNA could markedly restrain the TERT-positive tumor growth and improve the survival of tumor-bearing mice, through the induction of antitumor immunity.…”