Treatment of AG129 mice with antisense morpholino oligomers increases survival time following challenge with dengue 2 virus.
OBJECTIVE
To determine the antiviral activity of phosphorodiamidate morpholino oligomers (PMO) and peptide-conjugated PMO (PPMO) in AG129 mice infected with dengue 2 virus (DENV-2).


METHODS
Antisense PMO and PPMO were designed against the 5' terminal region (5'SL) or the 3'-cyclization sequence region (3'CS) of DENV genomic RNA and administered to AG129 mice before and/or after infection with DENV-2. In addition, cell culture evaluations designed to determine optimum PPMO length, and pharmacokinetic and toxicity analysis of PPMO were also carried out.


RESULTS
Mock-treated AG129 mice lived for 9-17 days following intraperitoneal (ip) infection with 10(4)-10(6) pfu of DENV-2 (strain New Guinea C). Intraperitoneal administration of 5'SL or 3'CS PPMO before and after DENV infection produced an increase in the average survival time of up to 8 days. Animals receiving only post-infection PPMO treatment did not benefit significantly. Cell culture studies showed that PPMO of 22-24 bases long produced substantially higher DENV titre reductions than did PPMO that were either shorter or longer. Pharmacokinetic and toxicology analysis with non-infected animals showed that nine consecutive once-daily ip treatments of 10 mg/kg PPMO resulted in high concentrations of PPMO in the liver and caused little impact on overall health.


CONCLUSIONS
The data indicate that PPMO had considerable antiviral efficacy against DENV-2 in the AG129 mouse model and that PPMO treatment early in the course of an infection was critical to extending the survival times of DENV-2-infected mice in the AG129 model system.
Stein
David A
DA
AVI BioPharma Inc., 4575 SW Research Way, Corvallis, OR 97333, USA. dave.stein@comcast.net
Huang
Claire Y-H
CY
Silengo
Shawn
S
Amantana
Adams
A
Crumley
Stacy
S
Blouch
Robert E
RE
Iversen
Patrick L
PL
Kinney
Richard M
RM
D000818:Animals; D000998:Antiviral Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D001835:Body Weight; D003715:Dengue / Q000188:drug therapy*; D003716:Dengue Virus / Q000187:drug effects / Q000235:genetics; D007274:Injections, Intraperitoneal; D008099:Liver / Q000737:chemistry; D051379:Mice; D009025:Morpholines / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D060172:Morpholinos; D016376:Oligonucleotides, Antisense / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D010949:Plasma / Q000737:chemistry; D016019:Survival Analysis; D010948:Viral Plaque Assay
D000998:Antiviral Agents; D009025:Morpholines; D060172:Morpholinos; D016376:Oligonucleotides, Antisense