Lentivirus-Induced Dendritic Cells for Immunization Against High-Risk WT1+ Acute Myeloid Leukemia

Abstract Wilms' tumor 1 antigen (WT1) is overexpressed in acute myeloid leukemia (AML), a high-risk neoplasm warranting development of novel immunotherapeutic approaches. Unfortunately, clinical immunotherapeutic use of WT1 peptides against AML has been inconclusive. With the rationale of stimulating multiantigenic responses against WT1, we genetically programmed long-lasting dendritic cells capable of producing and processing endogenous WT1 epitopes. A tricistronic lentiviral vector co-expressing a truncated form of WT1 (lacking the DNA-binding domain), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-4 (IL-4) was used to transduce human monocytes ex vivo. Overnight transduction induced self-differentiation of monocytes into immunophenotypically stable “SmartDC/tWT1” (GM-CSF+, IL-4+, tWT1+, IL-6+, IL-8+, TNF-α+, MCP-1+, HLA-DR+, CD86+, CCR2+, CCR5+) that were viable for 3 weeks in vitro. SmartDC/tWT1 were produced with peripheral blood mononuclear cells (PBMC) obtained from an F...