Modulation of Dendritic Cell Maturation and Function by siRNA-Bearing 5ʹ-Triphosphate
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 wordsIndoleamine 2 3-dioxygenase siRNA bifunctional siRNAs dendritic cells immunosuppression
- 12.Furset Flatekval, G. and Sioud, M. (2009) Modulation of dendritic cell function and maturation with mono- and bifunctional small interfering RNAs targeting indoleamine 2,3-dioxygenase (p). Immunology DOI: 10.1111/j.1365–2567.2009.03093.x.Google Scholar
- 13.Poeck, H., Besch, R., Maihoefer, C., Renn, M., Tormo, D., Morskaya, S.S., Kirschnek, S., Gaffal, E., Landsberg, J., Hellmuth, J., Schmidt, A., Anz, D., Bscheider, M., Schwerd, T., Berking, C., Bourquin, C., Kalinke, U., Kremmer, E., Kato, H., Akira, S., Meyers, R., Häcker, G., Neuenhahn, M., Busch, D., Ruland, J., Rothenfusser, S., Prinz, M., Hornung, V., Endres, S., Tüting, T., and Hartmann, G. (2008) 5ʹ-Triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma. Nat Med, 14, 1256–1263.PubMedCrossRefGoogle Scholar