Cloning and characterization of a novel feline IFN-omega

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Interferons (IFNs) are crucial secreted proteins involved in antiviral defense, cell growth regulation, and immune activation.
• Human IFNs (HuIFNs) are widely utilized as antiviral drugs globally.
• Feline IFN-omega (FeIFN-omega) subtypes represent a potential area for novel antiviral therapeutic development.

Purpose of the Study:

• To identify and characterize novel feline IFN-omega (FeIFN-omega) subtypes.
• To evaluate the antiviral activity of these novel FeIFN-omega subtypes in vitro.
• To explore different expression systems for producing recombinant FeIFN-omega proteins.

Main Methods:

• Cloning and sequencing of cDNAs encoding 13 novel FeIFN-omega subtypes.
• Expression of FeIFN-omega subtypes in Escherichia coli using a periplasmic system.
• Expression of FeIFN-omega subtype 2 in E. coli cytoplasm and Pichia pastoris for secretion.
• In vitro antiviral activity assays on homologous and heterologous animal cells.

Main Results:

• 13 novel FeIFN-omega subtypes were identified with 95%-99% amino acid sequence identity among them.
• FeIFN-omega2 and FeIFN-omega4 exhibit unique insertions at position 109.
• All expressed FeIFN-omega subtypes demonstrated significant in vitro antiviral activity.
• Recombinant FeIFN-omega2 showed potent antiviral effects on various animal cells.

Conclusions:

• The identified FeIFN-omega subtypes represent a valuable resource for understanding feline interferon biology.
• The demonstrated antiviral activity suggests potential applications for FeIFN-omega in veterinary medicine.
• Successful expression in E. coli and P. pastoris facilitates further research and development of FeIFN-omega therapeutics.