Interferon omega

Since 1985, interferon (IFN)-ω, a type I IFN, has been detected in many animals, but not in dogs and mice. It has been shown to have antiviral, antiproliferative and antitumor effects similar to those of IFN-α. To date, IFN-ω has been explored as a treatment option for some diseases or viral infections in humans and other animals. Studies have shown that human IFN-ω exhibits antitumor activities in some experimental approaches and that it can be used to diagnose some diseases. Recombinant feline IFN-ω is approved in several countries for the treatment of canine parvovirus, feline leukemia virus and feline immunodeficiency virus infections, but also shows some efficacy in the treatment of other viral infections or diseases (Li SF et al. 2017).

Interferon-omega (IFN- ω) is a member of the type I interferon family. Interferon omega is best known for its antiviral and immunomodulatory properties. Interferons belong to a larger family of cytokines, which are signaling molecules that contribute to the regulation of immune responses.

Type I IFNs, including IFN-ω and IFN-α, share a common mechanism of action. IFNs interact with specific cell surface receptors, inducing the expression of IFN-stimulated genes (ISGs), some of which encode antiviral effectors or molecules such as signaling proteins, transcription factors and apoptotic proteins, while chemokines regulate IFN signaling and other host responses in a positive or negative manner (An D et al. 2017). IFN-ω is thought to share antiviral activities with IFN-α because it binds to the same type I IFN receptor complex. Studies have shown that IFN-ω induces transcription of the Mx1, ISG15, IFIT3 and ISG56 genes ((An D et al. 2017). However, unlike IFN-α, it shows some degree of cross-species activity; therefore, IFNs might have different physiological functions in the host. For example, bovine IFN-ω (BoIFN-ω) protects Madin-Darby bovine kidney cells, primary embryonic bovine lung cells, feline kidney cells, porcine kidney cells, rabbit kidney cells and primary bovine testicular cells from vesicular stomatitis virus infection. These results indicate that cells tend to be insensitive to IFN-ω from distantly related species. Recombinant serotin-bat IFN-ω can inhibit the replication of European bat lyssavirus type 1, European bat lyssavirus type 2 and rabies virus in a dose-dependent manner (He X et al. 2014).

For HCV, a combination of IFN-α and RBV has been the standard therapy for chronic HCV infections (El-Raziky MS et al. 2015).The therapy has significant side effects. Some studies have shown that IFN-ω is equally effective in inhibiting HCV replication compared to IFN-α and IFN-β. Interestingly, the combinations of IFN-ω and IFN-α or IFN-β primarily showed antagonistic interactions (El-Raziky MS et al. 2015). In addition, other studies showed that the activity of non-glycosylated IFN-ω was comparable to that of IFN-α, while glycosylated IFN-ω was more potent in suppressing HCV RNA replicons. Thus, IFN-ω can be used as a potential antiviral candidate for the treatment of HCV infections (Li SF et al. 2017).

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2. An D et al. (2017) Molecular characterization and biological activity of bovine interferon-omega3. Res Vet Sci 115:125-131.
3. El-Raziky MS et al. (2015) Natural history and response to treatment of HCV infection among Egyptian survivors of childhood malignancy. Pediatr Hematol Oncol 32:138-145.
4. He X et al. (2014) Anti-lyssaviral activity of Interferons kappa and omega from the serotine bat, Eptesicus serotinus. J Virol 88:5444-5454.
5. Li SF et al. (2017) Interferon-omega: Current status in clinical applications. Int Immunopharmacol 52:253-260.
6. Wolf SJ et al. (2022) IFN-κ is critical for normal wound repair and is decreased in diabetic wounds. JCI Insight 7:e152765.