Feline immunodeficiency virus lacks sensitivity to the antiviral activity of feline IFN-gamma.
The antiviral activity of recombinant feline interferon-gamma (rFeIFN-gamma) against feline immunodeficiency virus (FIV) was investigated. A persistently FIV(Bang)-infected feline T cell line (FeT-J/Bang) was treated with either rFeIFN-omega, rFeIFN-gamma, or recombinant human IFN-alpha2 (rHuIFN-alpha2), and the culture fluids were tested for antiviral activity by reverse transcriptase (RT) assay. FeT-J/Bang cell cultures treated with rFeIFN-omega showed dose-dependent inhibition of RT activity. In contrast, rFeIFN-gamma treatment had no antiviral effect on FIV replication but instead caused a statistically significant enhancement on day 9 of culture. Antiviral activity of rFeIFN-gamma was also tested on feline peripheral blood mononuclear cells (PBMC). PBMC cultures were inoculated with FIV(Bang) and simultaneously treated with either rFeIFN-omega, rFeIFN-gamma, or rHuIFN-alpha2. FeIFN-gamma had no effect on FIV replication, unlike the rFeIFN-omega and rHuIFN-alpha2, which had strong anti-FIV effects. In another study, rFeIFN-gamma treatment was initiated 3 days before FIV(Bang) infection, the day of FIV(Bang) infection, or 3 days post-FIV(Bang) infection and then tested for antiviral activity. The time of initiating rFeIFN-gamma treatment had no effect on the antiviral activity. Hence, these results suggest that unlike rHuIFN-alpha2 and rFeIFN-omega, rFeIFN-gamma has no inhibitory effect on FIV replication in PBMC but causes a slight enhancement in a feline T cell line.
Tanabe
T
T
Department of Pathobiology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
Yamamoto
J K
JK
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002415:Cats / Q000821:virology*; D002460:Cell Line; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D016089:Immunodeficiency Virus, Feline / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D007371:Interferon-gamma / Q000494:pharmacology*; D007700:Kinetics; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000821:virology; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D011994:Recombinant Proteins; D007371:Interferon-gamma; D012194:RNA-Directed DNA Polymerase