Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.

Highly pathogenic avian influenza (HPAI) H5N1 virus is endemic in many regions around the world and remains a significant pandemic threat. To date H5N1 has claimed almost 300 human lives worldwide, with a mortality rate of 60% and has caused the death or culling of hundreds of millions of poultry si...

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Main Authors: Cameron R Stewart, Adam J Karpala, Sue Lowther, John W Lowenthal, Andrew G Bean
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3128588?pdf=render
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author Cameron R Stewart
Adam J Karpala
Sue Lowther
John W Lowenthal
Andrew G Bean
author_facet Cameron R Stewart
Adam J Karpala
Sue Lowther
John W Lowenthal
Andrew G Bean
author_sort Cameron R Stewart
collection DOAJ
description Highly pathogenic avian influenza (HPAI) H5N1 virus is endemic in many regions around the world and remains a significant pandemic threat. To date H5N1 has claimed almost 300 human lives worldwide, with a mortality rate of 60% and has caused the death or culling of hundreds of millions of poultry since its initial outbreak in 1997. We have designed multi-functional RNA interference (RNAi)-based therapeutics targeting H5N1 that degrade viral mRNA via the RNAi pathway while at the same time augmenting the host antiviral response by inducing host type I interferon (IFN) production. Moreover, we have identified two factors critical for maximising the immunostimulatory properties of short interfering (si)RNAs in chicken cells (i) mode of synthesis and (ii) nucleoside sequence to augment the response to virus. The 5-bp nucleoside sequence 5'-UGUGU-3' is a key determinant in inducing high levels of expression of IFN-α, -β, -λ and interleukin 1-β in chicken cells. Positioning of this 5'-UGUGU-3' motif at the 5'-end of the sense strand of siRNAs, but not the 3'-end, resulted in a rapid and enhanced induction of type I IFN. An anti-H5N1 avian influenza siRNA directed against the PB1 gene (PB1-2257) tagged with 5'-UGUGU-3' induced type I IFN earlier and to a greater extent compared to a non-tagged PB1-2257. Tested against H5N1 in vitro, the tagged PB1-2257 was more effective than non-tagged PB1-2257. These data demonstrate the ability of an immunostimulatory motif to improve the performance of an RNAi-based antiviral, a finding that may influence the design of future RNAi-based anti-influenza therapeutics.
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spelling doaj.art-39f9c8940e2042e392765dfbfb2b4fe32022-12-22T00:51:55ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0167e2155210.1371/journal.pone.0021552Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.Cameron R StewartAdam J KarpalaSue LowtherJohn W LowenthalAndrew G BeanHighly pathogenic avian influenza (HPAI) H5N1 virus is endemic in many regions around the world and remains a significant pandemic threat. To date H5N1 has claimed almost 300 human lives worldwide, with a mortality rate of 60% and has caused the death or culling of hundreds of millions of poultry since its initial outbreak in 1997. We have designed multi-functional RNA interference (RNAi)-based therapeutics targeting H5N1 that degrade viral mRNA via the RNAi pathway while at the same time augmenting the host antiviral response by inducing host type I interferon (IFN) production. Moreover, we have identified two factors critical for maximising the immunostimulatory properties of short interfering (si)RNAs in chicken cells (i) mode of synthesis and (ii) nucleoside sequence to augment the response to virus. The 5-bp nucleoside sequence 5'-UGUGU-3' is a key determinant in inducing high levels of expression of IFN-α, -β, -λ and interleukin 1-β in chicken cells. Positioning of this 5'-UGUGU-3' motif at the 5'-end of the sense strand of siRNAs, but not the 3'-end, resulted in a rapid and enhanced induction of type I IFN. An anti-H5N1 avian influenza siRNA directed against the PB1 gene (PB1-2257) tagged with 5'-UGUGU-3' induced type I IFN earlier and to a greater extent compared to a non-tagged PB1-2257. Tested against H5N1 in vitro, the tagged PB1-2257 was more effective than non-tagged PB1-2257. These data demonstrate the ability of an immunostimulatory motif to improve the performance of an RNAi-based antiviral, a finding that may influence the design of future RNAi-based anti-influenza therapeutics.http://europepmc.org/articles/PMC3128588?pdf=render
spellingShingle Cameron R Stewart
Adam J Karpala
Sue Lowther
John W Lowenthal
Andrew G Bean
Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
PLoS ONE
title Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
title_full Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
title_fullStr Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
title_full_unstemmed Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
title_short Immunostimulatory motifs enhance antiviral siRNAs targeting highly pathogenic avian influenza H5N1.
title_sort immunostimulatory motifs enhance antiviral sirnas targeting highly pathogenic avian influenza h5n1
url http://europepmc.org/articles/PMC3128588?pdf=render
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