West Nile virus infection of Drosophila melanogaster induces a protective RNAi response.
To determine if West Nile virus (WNV) infection of insect cells induces a protective RNAi response, Drosophila melanogaster S2 and Aedes albopictus C6/36 cells were infected with WNV, and the production of WNV-homologous small RNAs was assayed as an indicator of RNAi induction. A distinct population of approximately 25 nt WNV-homologous small RNAs was detected in infected S2 cells but not C6/36 cells. RNAi knockdown of Argonaute 2 in S2 cells resulted in slightly increased susceptibility to WNV infection, suggesting that some WNV-homologous small RNAs produced in infected S2 cells are functional small interfering RNAs. WNV was shown to infect adult D. melanogaster, and adult flies containing mutations in each of four different RNAi genes (Argonaute 2, spindle-E, piwi, and Dicer-2) were significantly more susceptible to WNV infection than wildtype flies. These results combined with the analysis of WNV infection of S2 and C6/36 cells support the conclusion that WNV infection of D. melanogaster, but perhaps not Ae. albopictus, induces a protective RNAi response.
Chotkowski
Heather L
HL
Division of Genetic Disorders, Wadsworth Center, New York State Department of Health, Albany, NY 12201-2002, USA. chotkow@wadsworth.org
Ciota
Alexander T
AT
Jia
Yongqing
Y
Puig-Basagoiti
Francesc
F
Kramer
Laura D
LD
Shi
Pei-Yong
PY
Glaser
Robert L
RL
D000251:Adenosine Triphosphatases / Q000235:genetics; D000330:Aedes / Q000235:genetics / Q000821:virology; D000818:Animals; D060565:Argonaute Proteins; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D003465:Culex / Q000235:genetics / Q000821:virology; D017931:DNA Primers / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics* / Q000821:virology*; D005260:Female; D017344:Genes, Insect; D009154:Mutation; D011506:Proteins / Q000235:genetics; D020365:RNA Helicases / Q000235:genetics; D034622:RNA Interference; D034743:RNA-Induced Silencing Complex / Q000235:genetics; D043244:Ribonuclease III; D013045:Species Specificity; D014709:Vero Cells; D014902:West Nile virus / Q000472:pathogenicity*
C433807:AGO2 protein, Drosophila; D060565:Argonaute Proteins; D017931:DNA Primers; D029721:Drosophila Proteins; D011506:Proteins; D034743:RNA-Induced Silencing Complex; C116498:piwi protein, Drosophila; C478069:DCR-2 protein, Drosophila; D043244:Ribonuclease III; D000251:Adenosine Triphosphatases; C096355:spn-E protein, Drosophila; D020365:RNA Helicases