Lentiviral-Mediated Transcriptional Targeting of Dendritic Cells for Induction of T Cell Tolerance In Vivo

Abstract

Dendritic cells (DCs) are important APCs able to induce both tolerance and immunity. Therefore, DCs are attractive targets for immune intervention. However, the ex vivo generation and manipulation of DCs at sufficient numbers and without changing their original phenotypic and functional characteristics are major obstacles. To manipulate DCs in vivo, we developed a novel DC-specific self-inactivating lentiviral vector system using the 5′ untranslated region from the DC-STAMP gene as a putative promoter region. We show that a gene therapy approach with these DC-STAMP-lentiviral vectors yields long-term and cell-selective transgene expression in vivo. Furthermore, transcriptionally targeted DCs induced functional, Ag-specific CD4 and CD8 T cell tolerance in vivo, which could not be broken by viral immunization. Tolerized CTL were unable to induce autoimmune diabetes in a murine autoimmune model system. Therefore, delivering transgenes specifically to DCs by using viral vectors might be a promising tool in gene therapy.

Targeting dendritic cells with antigen via dendritic cell-associated promoters

“…To this end, we plan to examine the use of a prime-boost strategy, which is known to greatly increase the potency of DNA vaccinations. 38,39 Previously Dresch et al 13 have showed that lentiviral vector containing the 5 0 untranslated region of DC-STAMP yields long-term, DC-specific OVA expression in vivo. Moreover, their work confirms our data with respect to DC-STAMP promoter.…”

“…Moreover, their work confirms our data with respect to DC-STAMP promoter. 13 To transcriptionally target DCs, we have isolated several novel promoters that have a DC-specific activity and are capable of driving antigen expression. Although we have focused on the induction of immunity by permissive expression of relevant antigen in DC, the additional introduction of signal transducers or cytokines using the same techniques may favorably influence the behavior of DCs.…”

“…Recently, the 5 0 untranslated region of DC-STAMP gene was successfully used in lentiviral vectors yielding long-term and cell-selective transgene expression in vivo. 13 In order to develop additional vectors for permissive expression in DCs in vitro and in vivo with protein, the promoters of the murine genes encoding cd11c, dc-sign, 22 dc-stamp 23 and langerin 24 were cloned. We demonstrated that the DNA sequences that we cloned were primarily active in the DC cell lines, D1, and differentiated Raw 264.7 cells.…”

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

“…Many studies have been performed using hTERT mRNA or peptides transfected into DCs with different vectors, in which the adenovirus was the most popular vector employed (4-6). Until recently, HIV-1 derived lentiviral vectors (LVs) have emerged as powerful tools for gene delivery to a variety of dividing or non-dividing cells including DCs due to the high transfection rate (7)(8)(9)(10)(11)(12). To our knowledge, there are no studies available concerning DC vaccines transfected with the lentiviral vector encoding hTERT peptides.…”

Induction of antigen-specific tolerance through hematopoietic stem cell-mediated gene therapy: The future for therapy of autoimmune disease?

“…Subsequently, clinical trials have shown the effectiveness of this approach for overcoming genetic deficiencies that manifest within the hematopoietic compartment such as X-linked severe combined immunodeficiency (X-SCID) and adenosine deaminase (ADA) deficiency. The technology used for such 'restorative' gene therapy can also be harnessed to target antigen expression to APC [62][63][64].…”