Use of siRNA or lentivirus-mediated RNAi in hematopoïétic cells to control the class-I immunological pathway: implications for the inflammation and host versus graft reaction.

DANIEL COMPAGNO

Nancy, France

Conferencia; Conferencia-Internal meeting; 2004

Specific NF-kappaB/Rel proteins regulate murine dendritic cell (DC) survival, differentiation, and activation, but little is known of their role in human cells because of limited loss-of-function analyses. RNA interference (RNAi) is a mechanism to effectively silence gene expression via sequence-specific double-stranded small interfering RNAs (siRNAs). RNAi was used to assess the role of the p50(NF-kappaB1) protein in the maturation and activation of cultured human monocyte-derived DC (MoDC). Transfection of cultured MoDC with siRNAs reduced p50 mRNA and protein levels in a specific, dose-dependent, and time-dependent manner. Basal or maturation-induced expression of HLA-DR and costimulatory molecules were not affected, whereas transcription of the IL-12 p40 gene and the secretion of IL-12ab were reduced. Such MoDC induced less IFN- production by T cells in MLR. This is the first report of RNAi-induced phenotpe in human primary DC with a method that caused no measurable toxicity or type-I IFN response. siRNAs appear useful for the study of signaling pathways in immune cells, revealing a pivotal requirement for p50 in MoDC for IL-12 production and induction of optimal type-1 immune responses.B/Rel proteins regulate murine dendritic cell (DC) survival, differentiation, and activation, but little is known of their role in human cells because of limited loss-of-function analyses. RNA interference (RNAi) is a mechanism to effectively silence gene expression via sequence-specific double-stranded small interfering RNAs (siRNAs). RNAi was used to assess the role of the p50(NF-kappaB1) protein in the maturation and activation of cultured human monocyte-derived DC (MoDC). Transfection of cultured MoDC with siRNAs reduced p50 mRNA and protein levels in a specific, dose-dependent, and time-dependent manner. Basal or maturation-induced expression of HLA-DR and costimulatory molecules were not affected, whereas transcription of the IL-12 p40 gene and the secretion of IL-12ab were reduced. Such MoDC induced less IFN- production by T cells in MLR. This is the first report of RNAi-induced phenotpe in human primary DC with a method that caused no measurable toxicity or type-I IFN response. siRNAs appear useful for the study of signaling pathways in immune cells, revealing a pivotal requirement for p50 in MoDC for IL-12 production and induction of optimal type-1 immune responses.