Inhibition of retroviral pathogenesis by RNA interference.
BACKGROUND
RNA interference (RNAi) is a newly discovered cellular defense system that is known to suppress replication of genomic parasites in model organisms. It has been widely conjectured that RNAi may also serve as an antiviral system in vertebrates.


RESULTS
Retroviral infection could be initiated by electroporation of cloned Rous sarcoma virus (RSV) proviral DNA into the developing chick neural tube. Coelectroporation of proviral DNA and short double-stranded RNAs matching sequences of avain retroviruses, which were designed to induce RNAi against RSV, inhibited viral replication. Replication of RSV after electroporation resulted in disruption of embryonic development and early death, but this, too, could be suppressed by RNAi against the RSV genome. RNAi could also inhibit the growth of RSV and HIV in cell culture. Analysis of the step of the retroviral life cycle that is inhibited by RNAi revealed that it primarily prevented accumulation of the viral RNAs synthesized late during infection. RNA genomes introduced in viral particles early during infection were less sensitive.


CONCLUSIONS
RNAi can block retroviral infection in vertebrates. The tissue electroporation method described here should allow RNAi to be used widely to study gene function and control of infection in vertebrate animals.
Hu
Wen-Yuan
WY
Infectious Disease Laboratory, La Jolla, CA 92037, USA.
Myers
Christopher P
CP
Kilzer
Jennifer M
JM
Pfaff
Samuel L
SL
Bushman
Frederic D
FD
D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics / Q000472:pathogenicity; D001483:Base Sequence; D002642:Chick Embryo; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000378:metabolism; D009420:Nervous System / Q000196:embryology; D009841:Oligonucleotides / Q000737:chemistry; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D014774:Virulence / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
D008164:Luminescent Proteins; D009841:Oligonucleotides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins