Genetic Engineering of Dendritic Cells Using Retrovirus-Based Gene Transfer Techniques

Dendritic cells (DC) can be genetically engineered to constitutively express a gene of interest that could be either an immune-modulating cytokine, or an antigen (Ag) derived from a tumor/pathogen. There are numerous strategies for ex vivo transfer of genes or Ags into DCs. These include nonviral techniques (such as electroporation and liposomes) or recombinant viral-based vectors (e.g., retrovirus, adenovirus, herpes simplex virus, and avian and vaccinia viruses) (1 -4 ). The major advantages of retrovirus vectors are that they are effective in achieving stable and highly efficient transduction of genes into primary cells, such as DCs/monocytes/macrophages (see Note 1 ). The major disadvantages are that the cells to be transduced must be in mitosis (i.e., actively dividing for reverse transcription and stable viral integration), and small size genes are more efficiently transduced than larger ones.