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.
Brockmeier
S L
SL
National Animal Disease Center, United States Department of Agriculture, Agricultural Research Service, 2300 Dayton Avenue, Ames, IA 50010, USA. Susan.Brockmeier@ars.usda.gov
Lager
K M
KM
Grubman
M J
MJ
Brough
D E
DE
Ettyreddy
D
D
Sacco
R E
RE
Gauger
P C
PC
Loving
C L
CL
Vorwald
A C
AC
Kehrli
M E
ME
Lehmkuhl
H D
HD
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