Cloning, Prokaryotic Soluble Expression, and Analysis of Antiviral Activity of Two Novel Feline IFN-ω Proteins

Cats are becoming more popular as household companions and pets, forming close relationships with humans. Although feline viral diseases can pose serious health hazards to pet cats, commercialized preventative vaccines are lacking. Interferons (IFNs), especially type I IFNs (IFN-&alpha
IFN-&beta
and interferon omega (IFN-&omega
)), have been explored as effective therapeutic drugs against viral diseases in cats. Nevertheless, there is limited knowledge regarding feline IFN-&omega
(feIFN-&omega
), compared to IFN-&alpha
and IFN-&beta
In this study, we cloned the genes encoding feIFN-&omega
a and feIFN-&omega
b from cat spleen lymphocytes. Homology and phylogenetic tree analysis revealed that these two genes belonged to new subtypes of feIFN-&omega
The recombinant feIFN-&omega
b proteins were expressed in their soluble forms in Escherichia coli, followed by purification. Both proteins exhibited effective anti-vesicular stomatitis virus (VSV) activity in Vero, F81 (feline kidney cell), Madin&ndash
Darby bovine kidney (MDBK), Madin&ndash
Darby canine kidney (MDCK), and porcine kidney (PK-15) cells, showing broader cross-species antiviral activity than the INTERCAT IFN antiviral drug. Furthermore, the recombinant feIFN-&omega
b proteins demonstrated antiviral activity against VSV, feline coronavirus (FCoV), canine parvovirus (CPV), bovine viral diarrhea virus (BVDV), and porcine epidemic diarrhea virus (PEDV), indicating better broad-spectrum antiviral activity than the INTERCAT IFN. The two novel feIFN-&omega
proteins (feIFN-&omega
b) described in this study show promising potential to serve as effective therapeutic agents for treating viral infections in pet cats.