Suppression of RNA Interference Increases Alphavirus Replication and Virus-Associated Mortality in Aedes aegypti Mosquitoes Export

@article{citeulike:4142380, abstract = {Background: Arthropod-borne viruses (arboviruses) can persistently infect and cause limited damage to mosquito vectors. RNA interference (RNAi) is a mosquito antiviral response important in restricting RNA virus replication and has been shown to be active against some arboviruses. The goal of this study was to use a recombinant Sindbis virus (SINV; family Togaviridae; genus Alphavirus) that expresses B2 protein of Flock House virus (FHV; family Nodaviridae; genus Alphanodavirus), a protein that inhibits RNAi, to determine the effects of linking arbovirus infection with RNAi inhibition. Results: B2 protein expression from SINV (TE/3'2J) inhibited the accumulation of non-specific small RNAs in Aedes aegypti mosquito cell culture and virus-specific small RNAs both in infected cell culture and Ae. aegypti mosquitoes. More viral genomic and subgenomic RNA accumulated in cells and mosquitoes infected with TE/3'2J virus expressing B2 (TE/3'2J/B2) compared to TE/3'2J and TE/3'2J virus expressing GFP. TE/3'2J/B2 exhibited increased infection rates, dissemination rates, and infectious virus titers in mosquitoes following oral bloodmeal. Following infectious oral bloodmeal, significantly more mosquitoes died when TE/3'2J/B2 was ingested. The virus was 100\% lethal following intrathoracic inoculation of multiple mosquito species and lethality was dose-dependent in Ae. aegypti. Conclusion: We show that RNAi is active in Ae. aegypti cell culture and that B2 protein inhibits RNAi in mosquito cells when expressed by a recombinant SINV. Also, SINV more efficiently replicates in mosquito cells when RNAi is inhibited. Finally, TE/3'2J/B2 kills mosquitoes in a dose-dependent manner independent of infection route and mosquito species.}, author = {Cirimotich, Christopher M. and Scott, Jaclyn C. and Phillips, Aaron T. and Geiss, Brian J. and Olson, Ken E.}, citeulike-article-id = {4142380}, citeulike-linkout-0 = {http://dx.doi.org/10.1186/1471-2180-9-49}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19265532}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19265532}, day = {05}, doi = {10.1186/1471-2180-9-49}, issn = {1471-2180}, journal = {BMC Microbiology}, keywords = {aedes, alphavirus, antiviral, arbovirus, fitness, rnai, sindbis}, month = {March}, pages = {49+}, posted-at = {2009-04-13 20:17:48}, priority = {0}, title = {Suppression of RNA Interference Increases Alphavirus Replication and Virus-Associated Mortality in Aedes aegypti Mosquitoes}, url = {http://dx.doi.org/10.1186/1471-2180-9-49}, volume = {9}, year = {2009} }

TY - JOUR ID - citeulike:4142380 L3 - citeulike-article-id:4142380 N2 - Background: Arthropod-borne viruses (arboviruses) can persistently infect and cause limited damage to mosquito vectors. RNA interference (RNAi) is a mosquito antiviral response important in restricting RNA virus replication and has been shown to be active against some arboviruses. The goal of this study was to use a recombinant Sindbis virus (SINV; family Togaviridae; genus Alphavirus) that expresses B2 protein of Flock House virus (FHV; family Nodaviridae; genus Alphanodavirus), a protein that inhibits RNAi, to determine the effects of linking arbovirus infection with RNAi inhibition. Results: B2 protein expression from SINV (TE/3'2J) inhibited the accumulation of non-specific small RNAs in Aedes aegypti mosquito cell culture and virus-specific small RNAs both in infected cell culture and Ae. aegypti mosquitoes. More viral genomic and subgenomic RNA accumulated in cells and mosquitoes infected with TE/3'2J virus expressing B2 (TE/3'2J/B2) compared to TE/3'2J and TE/3'2J virus expressing GFP. TE/3'2J/B2 exhibited increased infection rates, dissemination rates, and infectious virus titers in mosquitoes following oral bloodmeal. Following infectious oral bloodmeal, significantly more mosquitoes died when TE/3'2J/B2 was ingested. The virus was 100% lethal following intrathoracic inoculation of multiple mosquito species and lethality was dose-dependent in Ae. aegypti. Conclusion: We show that RNAi is active in Ae. aegypti cell culture and that B2 protein inhibits RNAi in mosquito cells when expressed by a recombinant SINV. Also, SINV more efficiently replicates in mosquito cells when RNAi is inhibited. Finally, TE/3'2J/B2 kills mosquitoes in a dose-dependent manner independent of infection route and mosquito species. JF - BMC Microbiology SN - 1471-2180 TI - Suppression of RNA Interference Increases Alphavirus Replication and Virus-Associated Mortality in Aedes aegypti Mosquitoes VL - 9 SP - 49 KW - aedes KW - alphavirus KW - antiviral KW - arbovirus KW - fitness KW - rnai KW - sindbis AU - Cirimotich, Christopher AU - Scott, Jaclyn AU - Phillips, Aaron AU - Geiss, Brian AU - Olson, Ken PY - 2009/03/05/ UR - http://dx.doi.org/10.1186/1471-2180-9-49 ER -