BioProject

Wilms’ tumor 1 antigen (WT1) is overexpressed in acute myeloid leukemia (AML). More...

Wilms’ tumor 1 antigen (WT1) is overexpressed in acute myeloid leukemia (AML). Unfortunately, clinical immunotherapeutic use of WT1 peptides against AML has been inconclusive. A tricistronic lentiviral vector co-expressing a truncated form of WT1 (lacking the DNA-binding domain), GM-CSF and IL-4 was used to transduce human monocytes. The overnight transduction procedure induced the self-differentiation of monocytes into highly viable and immunophenotypically stable “SmartDC/tWT1” (GM-CSF+, IL-4+, WT1+, IL-6+, IL-8+, TNF-?+, MCP-1+, HLA-DR+, CD86+, CCR2+, CCR5+). RNA expression pattern analyses revealed up-regulation of several toll-like receptors, interferons and interferon-stimulated genes in lentivirally-reprogrammed SmartDC/tWT1 in comparison with conventional DCs. Remission samples from a FLT3-ITD+ AML patient and surplus material from the donor lymphocyte infusion (DLI) obtained from the matched related donor were used to produce SmartDC/tWT1. In our donor-patient model, donor T cells expanded with SmartDC/tWT1 showed high reactivity against WT1 and against primary AML. Intracellular processing of WT1 peptides by SmartDC/tWT1 resulted in superior WT1-specific CD8+ cytotoxicity against the primary leukemia blasts than exogenous peptide pulsing. Therefore, SmartDC/tWT1 produced in a single day of ex vivo culture with broad homeostatic, innate immunity, antigenic presentation and cytotoxic T cell stimulation properties can be clinically developed in combination with DLI for boosting anti-leukemia responses. Overall design: Seeking to better characterize possible effects of truncated WT1 over-expression in the transcriptional activity of dendritic cells, we compared the gene expression pattern of SmartDC/tWT1 with those of SmartDC and Conventional DC. Less...