Cloning and structural analysis of four genes encoding interferon-omega in rabbit

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Interferons (IFNs) are crucial antiviral proteins.
• Interferon-tau (IFN-tau) plays a role in pregnancy.
• The genetic basis of interferon-omega (IFN-omega) in rabbits was previously unclear.

Purpose of the Study:

• To isolate and characterize rabbit interferon-omega (IFN-omega) genes.
• To determine the functional activity of the identified IFN-omega proteins.
• To investigate the expression patterns of rabbit IFN-omega genes.

Main Methods:

• Screening a rabbit genomic library using an ovine IFN-tau cDNA probe.
• Sequencing of isolated gene fragments.
• Subcloning gene regions into expression vectors for functional assays.
• Transfection of monkey COS-7 cells.
• Analysis of gene expression in induced rabbit leukocytes using Northern blot.
• Southern blot analysis of the rabbit genome.

Main Results:

• Four rabbit IFN-omega genes were isolated, sharing >98% identity in coding regions and >96% in amino acid sequences.
• Rabbit IFN-omega proteins exhibit high sequence similarity to human and porcine IFN-omega but lower similarity to ovine IFN-tau.
• Functional assays confirmed that the cloned genes encode active IFN proteins capable of protecting cells against vesicular stomatitis virus.
• IFN-omega gene expression was induced in rabbit leukocytes upon Sendai virus stimulation.
• Southern blot analysis suggests the presence of at least eight IFN-omega genes or pseudogenes in the rabbit genome.

Conclusions:

• Rabbit IFN-omega genes encode functional antiviral proteins.
• The identified genes are structurally related to the IFN-omega family.
• IFN-omega expression is inducible in rabbit immune cells.
• The rabbit genome contains a complex family of IFN-omega genes or pseudogenes.