TY - JOUR

T1 - In vivo screening of modified siRNAs for non-specific antiviral effect in a small fish model: number and localization in the strands are important

A1 - Schyth,Brian Dall

A1 - Bramsen,Jesper Bertram

A1 - Pakula,Malgorzata Maria

A1 - Larashati,Sekar

A1 - Kjems,Jørgen

A1 - Wengel,Jesper

A1 - Lorenzen,Niels

AU - Schyth,Brian Dall

AU - Bramsen,Jesper Bertram

AU - Pakula,Malgorzata Maria

AU - Larashati,Sekar

AU - Kjems,Jørgen

AU - Wengel,Jesper

AU - Lorenzen,Niels

PB - Oxford University Press

PY - 2012

Y1 - 2012

N2 - Small interfering RNAs (siRNAs) are promising new active compounds in gene medicine but the induction of non-specific immune responses following their delivery continues to be a serious problem. With the purpose of avoiding such effects chemically modified siRNAs are tested in screening assay but often only examining the expression of specific immunologically relevant genes in selected cell populations typically blood cells from treated animals or humans. Assays using a relevant physiological state in biological models as read-out are not common. Here we use a fish model where the innate antiviral effect of siRNAs is functionally monitored as reduced mortality in challenge studies involving an interferon sensitive virus. Modifications with locked nucleic acid (LNA), altritol nucleic acid (ANA) and hexitol nucleic acid (HNA) reduced the antiviral protection in this model indicative of altered immunogenicity. For LNA modified siRNAs, the number and localization of modifications in the single strands was found to be important and a correlation between antiviral protection and the thermal stability of siRNAs was found. The previously published sisiRNA will in some sequences, but not all, increase the antiviral effect of siRNAs. The applied fish model represents a potent tool for conducting fast but statistically and scientifically relevant evaluations of chemically optimized siRNAs with respect to non-specific antiviral effects in vivo.

AB - Small interfering RNAs (siRNAs) are promising new active compounds in gene medicine but the induction of non-specific immune responses following their delivery continues to be a serious problem. With the purpose of avoiding such effects chemically modified siRNAs are tested in screening assay but often only examining the expression of specific immunologically relevant genes in selected cell populations typically blood cells from treated animals or humans. Assays using a relevant physiological state in biological models as read-out are not common. Here we use a fish model where the innate antiviral effect of siRNAs is functionally monitored as reduced mortality in challenge studies involving an interferon sensitive virus. Modifications with locked nucleic acid (LNA), altritol nucleic acid (ANA) and hexitol nucleic acid (HNA) reduced the antiviral protection in this model indicative of altered immunogenicity. For LNA modified siRNAs, the number and localization of modifications in the single strands was found to be important and a correlation between antiviral protection and the thermal stability of siRNAs was found. The previously published sisiRNA will in some sequences, but not all, increase the antiviral effect of siRNAs. The applied fish model represents a potent tool for conducting fast but statistically and scientifically relevant evaluations of chemically optimized siRNAs with respect to non-specific antiviral effects in vivo.

U2 - 10.1093/nar/gks033

DO - 10.1093/nar/gks033

JO - Nucleic Acids Research

JF - Nucleic Acids Research

SN - 0305-1048

IS - 10

VL - 40

SP - 4653

EP - 4665

ER -