Modulation of dendritic cell maturation and function by siRNA-bearing 5'-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 5'-triphosphate can be used to enhance dendritic cell maturation and function. Indeed, immature DCs that had been transfected with siRNA-bearing 5'-triphosphate activated T cells, indicating that, even in the absence of external stimuli such as TNF-alpha, those DCs were sufficiently mature to initiate T cell activation. Also, a recent study has shown that 5'-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.
Sioud
Mouldy
M
Department of Immunology, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet, University Hospital, Oslo, Norway.
D000328:Adult; D002454:Cell Differentiation / Q000187:drug effects*; D002469:Cell Separation; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D005821:Genetic Techniques; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000494:pharmacology*; D013698:Templates, Genetic; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014764:Viral Proteins / Q000378:metabolism
D010710:Phosphates; D034741:RNA, Small Interfering; D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases