Modulation of Dendritic Cell Maturation and Function by siRNA-Bearing 5ʹ-Triphosphate

  • Mouldy Sioud
Part of the Methods in Molecular Biology book series (MIMB, volume 629)


Small interfering RNAs (siRNAs) have emerged as a powerful technique for sequence-specific gene silencing in a wide variety of organisms. However, it has been shown that in vitro transcribed siRNA can activate innate immunity through RIG-1 helicase, a cytosolic sensor of viral RNA. We recently demonstrated that the activation of RIG-1 by siRNA-bearing 5ʹ-triphosphate can be used to enhance dendritic cell maturation and function. Indeed, immature DCs that had been transfected with siRNA-bearing 5ʹ-triphosphate activated T cells, indicating that, even in the absence of external stimuli such as TNF-α, those DCs were sufficiently mature to initiate T cell activation. Also, a recent study has shown that 5ʹ-bearing siRNAs targeting Bcl-2 can induce apoptosis in tumour cells, further supporting the use of this strategy to combat cancer. This chapter describes the in vitro synthesis of siRNA targeting indoleamine 2,3-dioxygenase (IDO), an enzyme that plays a critical role in hindering immunity against tumours.

Key words

Indoleamine 2 3-dioxygenase siRNA bifunctional siRNAs dendritic cells immunosuppression 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Mouldy Sioud
    • 1
  1. 1.Department of ImmunologyInstitute for Cancer Research, Rikshospitalet-Radiumhospitalet, University HospitalOsloNorway

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