Lentiviral transduction of human dendritic cells.

Dendritic cells (DCs) are potent antigen-presenting cells (APCs) that play a pivotal role in stimulating antigen-specific T cells in vivo. The cardinal properties of DCs are: the ability to take up, process, and present antigens; (2) the ability to migrate through different tissues into lymphoid organs; and (3) the ability to interact with and stimulate T cells (3). Because of their unique capability of generating primary CD4+ and CD8+ T-cell responses, DCs are of particular interest for immunotherapeutic approaches to infectious disease and cancer. There are many ways to load DCs with antigen and to subsequently induce specific immune responses in vivo and in vitro. One strategy relies on genetically modified peripheral blood mononuclear cell (PBMC)-derived DCs to establish expression of a gene that encodes a specific antigen. In contrast to pulsing DCs with antigenic peptides or proteins, genetic engineering of DCs has the advantages of providing multiple epitopes for major histocompatibility class (MHC) class I-and MHC class II-restricted immune responses as well as a continuous supply of antigen for presentation alone or together with immunomodulatory proteins (cytokines, for example).