DC transfected with siRNA for downregulation of A20 or A20/IL-10

Attenuated Expression of A20 Markedly Increases the Efficacy of Double Stranded RNA-Activated Dendritic Cells as an Anti-Cancer Vaccine

A20 is a zinc finger protein with ubiquitine-modifying activity. It has been described that A20 negatively regulates signaling induced by the tumor necrosis factor receptor and toll like receptor (TLR) family in a number of cell types, including mouse bone marrow-derived dendritic cells (DCs). However, the expression and effect of A20 in activated monocyte-derived DCs have not been previously evaluated. We report that DCs activated with the TLR3 ligand poly(I:C), upregulate A20. Downregulating A20 demonstrated its role in the functional activation of DCs. A20 downregulated DCs showed higher activation of the transcription factors nuclear factor-kB (NF-kB) and activator protein-1 (AP-1), which resulted in increased and sustained production of interleukin (IL) -6, IL-10 and IL-12p70. We additionally silenced the immunosuppressive IL-10 and demonstrated that IL-10 inhibits T cell proliferation. We further demonstrated that A20 downregulated DCs skew naive CD4+ T cells towards IFN-g producing T helper 1 cells, a process which is dependent on IL-12p70 and which is unaffected by IL-10. Furthermore, A20 and/or IL-10 downregulated DCs had an enhanced capacity to prime Melan-A/MART-1 specific CD8+ T cells. Finally, we demonstrated that potent T cell stimulatory DCs are generated by the simultaneous delivery of poly(I:C12U), A20 or A20/IL-10 small interfering RNA (siRNA) and antigen-encoding mRNA, introducing a one step approach to improve DC-based vaccines. Together these findings demonstrate that A20 negatively regulates NF-kB and AP-1 in DCs and that silencing of A20 results in DCs with enhanced T cell stimulatory capacity.

The generated DC will be clinically tested.

• biomaterial type
• monocyte,
• human bone marrow,
• Mus musculus

• molecule type
• T helper cell 1,
• Interleukin-12 p70,
• poly(I:C(12)U),
• double-stranded RNA,
• Interleukin-6,
• Nuclear factor NF-kappa B,
• Interleukin-10,
• Interferon gamma,
• Melan A,
• small interfering RNA,
• Polyinosinic acid:polycytidylic acid,
• protein,
• CD4

• cell type
• T cell

created over 15 years ago (17 December 2009)    last modified over 13 years ago (28 September 2011)   [ RDF ]   [ RelFinder ]