Adenovirus-mediated expression of interferon-alpha delays viral replication and reduces disease signs in swine challenged with porcine reproductive and respiratory syndrome virus.
In this study, pigs were injected with a nonreplicating human adenovirus type 5 vector expressing porcine interferon-alpha (Ad5-pIFN-alpha) and then challenged with porcine reproductive and respiratory syndrome virus (PRRSV) to determine whether the presence of increased levels of IFN-alpha would decrease viral replication and/or disease. Groups of 10 pigs each were inoculated with Ad5-pIFN-alpha and not challenged, Ad5-pIFN-alpha and challenged with PRRSV 1 d later, or inoculated with a control adenovirus that does not express IFN-alpha (Ad5-null) and challenged 1 d later with PRRSV. IFN-alpha levels in all pigs inoculated with the Ad5-pIFN-alpha were elevated the day of challenge (1 d after inoculation), but were undetectable by 3 d after inoculation in the pigs that were not challenged with PRRSV. Pigs inoculated with Ad5-pIFN-alpha and challenged with PRRSV had lower febrile responses, a decreased percentage of lung involvement at 10 d post-infection, delayed viremia and antibody response, and higher serum IFN-alpha levels as a result of PRRSV infection, compared to pigs inoculated with Ad5-null and challenged with PRRSV. These results indicate that IFN-alpha can have protective effects if present during the time of infection with PRRSV.
National Animal Disease Center, United States Department of Agriculture, Agricultural Research Service, 2300 Dayton Avenue, Ames, IA 50010, USA. Susan.Brockmeier@ars.usda.gov
S L
SL
Brockmeier
K M
KM
Lager
M J
MJ
Grubman
D E
DE
Brough
D
D
Ettyreddy
R E
RE
Sacco
P C
PC
Gauger
C L
CL
Loving
A C
AC
Vorwald
M E
ME
Kehrli
H D
HD
Lehmkuhl
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D016898:Interferon-alpha / Q000096:biosynthesis* / Q000097:blood / Q000276:immunology*; D007371:Interferon-gamma / Q000097:blood; D008168:Lung / Q000473:pathology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D013552:Swine; D014766:Viremia; D014779:Virus Replication
D016898:Interferon-alpha; D011994:Recombinant Proteins; D007371:Interferon-gamma