RNAi in treating honey bee diseases

Authors: Chen, Yanping - Judy; Evans, Jay

Submitted to: American Bee Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2012
Publication Date: 12/1/2012
Citation: Chen, Y., Evans, J.D. 2012. RNAi in treating honey bee diseases. American Bee Journal. 140:27-29.

Interpretive Summary: RNA interference (RNAi), a naturally occurring process that living cells use to turn down or silence the activity of specific genes, has emerged as a promising tool for combating diseases. We conducted studies to explore the antiviral effect of RNAi on the infection of a honey bee virus that was linked to honey bee Colony Collapse Disorder (CCD). The results showed that the virus infection rates in bees received RNAi treatment were significantly lower than the negative controls without treatment. Quantification of virus concentration in infected bees showed that bees received RNAi treatment had significantly lower level of the virus concentration compared to bees without the treatment. Our study clearly demonstrates the potential of RNAi for treatment of honey bee diseases. The results have relevance to scientists, regulators, and beekeepers seeking to combat recent bee losses.

Technical Abstract: RNA interference (RNAi) is a sequence-specific posttranscriptional gene-silencing mechanism that the cell uses to eliminate unwanted genetic elements in organisms ranging from plants to mammals and has been a powerful tool for treating a variety of diseases. We conducted studies to elucidate the antiviral effect of RNAi on the infection and replication of Israeli acute paralysis virus (IAPV), a virus that was link to honey bee Colony Collapse Disorder (CCD). The antiviral effect of siRNA in IAPV infected bees was focused on the ribosome entry sites (IRES) of 5’ untranslated region (UTR) that mediates translation of genes encoding for non-structural and structural proteins and is required for virus replication. The results showed that the feeding of a small interfering RNA (siRNA) targeting the IRES could confer antiviral activity in bees. The IAPV infection rates in bees that were fed with siRNA were significantly lower than the negative controls without siRNA. Quantification of the IAPV titer in infected bees showed that bees received siRNA treatment had significantly lower level of IAPV titer compared to bees without siRNA treatment. Our study clearly demonstrates the feasibility of using siRNA to block or impair the translation of viral proteins to reduce virus replication, and reinforces the therapeutic potential of RNAi for treatment of honey bee diseases.