Dendritic cells (DC) are the professional antigen‐presenting cells of the immune system, fully equipped to prime naive T cells and thus essential components for cancer immunotherapy.

We tested the influence of several elements (cPPT, trip, WPRE, SIN) on the transduction efficiency of human DC. Human and murine DC were transduced with tNGFR‐encoding lentiviruses to assess the effect of transduction on phenotype and function. Human DC were transduced with lentiviruses encoding huIi80MAGE‐A3 and murine DC with huIi80tOVA to test antigen presentation.

A self‐inactivating (SIN) lentiviral vector containing the trip element was most efficient in transducing human DC. The transduction of DC with trip/SIN tNGFR encoding lentiviral vectors at MOI 15 resulted in stable gene expression in up to 94.6% (murine) and 88.2% (human) of the mature DC, without perturbing viability, phenotype and function. Human huIi80MAGE‐A3‐transduced DC were able to stimulate MAGE‐A3‐specific CD4⁺ and CD8⁺ T cell clones and could prime both MAGE‐A3‐specific CD4⁺ and CD8⁺ T cells in vitro. Murine huIi80tOVA‐transduced DC were able to present OVA peptides in the context of MHC class I and class II in vitro and induced a strong OVA‐specific cytotoxic T lymphocyte response in vivo, that was protective against subsequent challenge with OVA‐expressing tumor cells.

We show that, using lentiviral vectors, efficient gene transfer in human and murine DC can be obtained and that these DC can elicit antigen‐specific immune responses in vitro and in vivo. The composition of the transfer vector has a major impact on the transduction efficiency. Copyright © 2003 John Wiley & Sons, Ltd.