Efficient gene transfer to human peripheral blood monocyte-derived dendritic cells using human immunodeficiency virus type 1-based lentiviral vectors

Dendritic cells (DCs) are potent antigen-presenting cells and are capable o f activating naive T cells, Gene transfer of tumor antigen and cytokine gen es into DCs could be an important strategy for immunotherapeutic applicatio ns. Dendritic cells derived from peripheral blood monocytes do not divide a nd are therefore poor candidates for gene transfer by Moloney murine leukem ia virus (Mo-MuLV)-based retroviral vectors, Lentiviral vectors are emergin g as a powerful tool for gene delivery into dividing and nondividing cells, A three-plasmid expression system pseudotyped with the envelope from vesic ular stomatitis virus (VSV-G) was used to generate lentiviral vector partic les expressing enhanced green fluorescent protein (EGFP), Peripheral blood monocyte-derived DCs were cultured in the presence of GM-CSF and IL-4 and t ransduced with lentiviral or Mo-MuLV-based vectors expressing EGFP, FAGS an alysis of lentiviral vector-transduced DCs derived either from normal healt hy volunteers or from melanoma patients demonstrated transduction efficienc y ranging from 70 to 90% compared with 2-8% using Mo-MuLV-based vectors pse udotyped with VSV-G, Comparison of lentiviral vectors expressing EGFP drive n by CMV or human PGK promoters showed similar levels of transgene expressi on. Lentiviral vector preparations produced in the absence of HIV accessory proteins transduced DCs at efficiencies equal to vectors produced with acc essory proteins, Alu-HIV-1 LTR PCR demonstrated the genomic integration of the lentiviral vector in the transduced DCs, Transduced cells showed charac teristic dendritic cell phenotype and strong allostimulatory capacity and m aintained the ability to respond to activation signals such as CD40 ligand and lipopolysaccharide. These results provide evidence that lentiviral vect ors are efficient tools for gene transfer and expression in monocyte-derive d DCs that could be useful for immunotherapeutic applications.