Effects of human recombinant alpha-2b interferon and feline recombinant omega interferon on in vitro replication of feline herpesvirus-1.
OBJECTIVE
To evaluate the effects of recombinant human interferon alpha-2b (rHuIFN-alpha2b) and recombinant feline interferon omega (rFeIFN-omega) on in vitro replication of feline herpesvirus (FHV)-1.


METHODS
Cultures of Crandell-Rees feline kidney (CRFK) cells.


METHODS
CRFK cells were treated with rFeIFN-omega or rHuIFN-alpha2b at concentrations ranging from 100 to 500,000 U/mL. Cultures were then inoculated with FHV-1. Constant concentrations of interferon products were maintained throughout the study. Reductions in the number and size of plaques were used as indicators of antiviral activity. Six plaque reduction assays were performed in duplicate. A 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay was used to detect cytotoxic effects of interferon. A 1-way ANOVA and Dunnett test were used to determine significant differences.


RESULTS
Treatment with rFeIFN-omega at various concentrations resulted in significant reductions in the number of plaques (100,000 U/mL, 54.7%; and 500,000 U/mL, 59.8%) and in plaque size (100,000 U/mL, 47.5%; 250,000 U/mL, 81.0%; and 500,000 U/mL; 70.5%). Treatment with various concentrations of rHuIFN-alpha2b resulted in a significant reduction in plaque size (100,000 U/mL, 56.0%; 250,000 U/mL, 75.7%; and 500,000 U/mL, 69.0%). None of the tested concentrations of interferon caused significant cellular toxicosis.


CONCLUSIONS
At some of the higher concentrations, the antiviral effect of rFeIFN-omega was greater than the antiviral effect of rHuIFN-alpha2b. Reduction in plaque size appeared to be a good indicator of the antiviral activity of interferon against FHV-1.
Siebeck
Nicola
N
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, 30602, USA.
Hurley
David J
DJ
Garcia
Maricarmen
M
Greene
Craig E
CE
Köstlin
Roberto G
RG
Moore
Phillip A
PA
Dietrich
Ursula M
UM
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002415:Cats; D006564:Herpesviridae / Q000187:drug effects*; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D011994:Recombinant Proteins; D013045:Species Specificity; D010948:Viral Plaque Assay / Q000662:veterinary; D014779:Virus Replication / Q000187:drug effects*
D000998:Antiviral Agents; D007370:Interferon Type I; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; C063743:interferon omega 1